Breeding bird communities and environmental variable correlates of Scottish peatland wetlands - Fox, A. D.; Bell, M. C. (Hydrobiologia, 1994)
The majority of lochs and water courses in an area of northern Scotland were visited during July 1988. Breeding waterfowl and details of environmental variables were recorded for each site and subjected to multivariate classification techniques. Non-hierarchical classification identified seven habitat types on the basis of environmental parameters. These corresponded well with, and further sub-divided, categorisation using conventional trophic-level habitat type classifications. A hierarchical approach, using TWIN-SPAN, classified twelve waterfowl groupings based on the presence of indicator species. This approach identified characteristic community types and groupings with high diversity and hence conservation importance. Correspondence between habitat classifications and waterfowl communities was reasonable, but failure to identify key features of wetland complexity was probably the reason for the inability to identify clear relationships. Induction analysis was used to show that waterfowl species with the most restricted distributions characterised the main groupings. with Black-throated Diver and Common Scoter showing preferences for mesotrophic/eutrophic waters with islands, where peaty waters drain onto base-rich sandy substrates. Greylag Geese occurred on large acidic oligotrophic lochs and Wigeon on base-rich streams. The need for catchment-wide site-safeguard and management programmes to safeguard the wetlands of greatest significance is discussed.
Keywords: Breeding Season; Habitat; Black Scoter; Melanitta nigra

Changes in body mass and organ size during remigial moult in common scoter Melanitta nigra - Fox, Anthony D.; Hartmann, Poul; Petersen, Ib K. (Journal of Avian Biology, 2008)
The "cost-benefit" hypothesis states that avian body organs show mass changes consistent with the trade-off between their functional importance and maintenance cost, which may vary throughout the annual cycle. Flightless moulting common scoter Melanitta nigra in Danish marine waters select rich undisturbed offshore feeding areas lacking predators, suggesting active feeding during moult. We tested four predictions relating to organ size during flightlessness in moulting male common scoter under this hypothesis. Namely that (i) pectoral muscles would show atrophy followed by hypertrophy, but that there would be no change in (ii) leg muscles and heart (the locomotory architecture required to sustain diving for food), (iii) digestive organs and liver (required to process food), or (iv) fat deposits (because birds could fulfil daily energy requirements from locally abundant food resources). Dissection of scoters collected at different stages during wing moult south of the Danish island of L ae so provided data on organ size that were consistent with these predictions. Pectoral muscle mass showed a c.23% atrophy during the middle of the flightless period relative to that at the end of moult. There was no significant loss in leg muscle, heart, digestive organs (except gizzard mass), liver, fat reserves or body mass with remigial growth. These findings are consistent with the hypothesis that common scoter moult in a rich feeding area, and rely on their diet to meet the nutritional requirements of remigial moult. These results differ in detail from those of a similar study of terrestrial feeding moulting greylag geese Anser anser, but because of the widely differing ecology of the species concerned, both sets of findings provide strong support for the hypothesis that variations in phenotypic plasticity in size of fat stores, locomotor and digestive organs can be interpreted as evolutionary adaptations to meet the conflicting needs (feather growth, nutritional challenges and predator avoidance) of the flightless moult period in different Anatidae species.
Keywords: Nonbreeding Seasons; Molt; Physiology; Energetics and Nutrition; Black Scoter; Melanitta nigra

Late Summer Habitat Selection by Breeding Waterfowl in Northern Scotland Uk - Fox, A. D.; Jarrett, N.; Gitay, H.; Paynter, D. (Wildfowl, 1989)
The majority of lochs and water courses were visited in an area of northern Scotland during July 1988. The breeding waterfowl of these waters were recorded along with details of environmental parameters at each site, including water quality. In a correspondence analysis, three axes accounted for 72% of the variance, with conductivity, pH and other measures of habitat type all highly represented. Site analysis showed that different species had distinct habitat preferences. Waterfowl of most restricted distribution on the peatlands (namely Black-throated Diver and Common Scoter) showed strong preferences for lochs with islands and with high pH/conductivity, Red-throated Divers tended to occur on midrange water quality lochs, Teal selected acidic, base-poor waters and Mallard showed little selectivity in their use of peatland waters. Some implications of peatland afforestation are discussed with respect to breeding waterfowl communities.
Keywords: Breeding Season; Habitat; Black Scoter; Melanitta nigra

Current and potential threats to Nordic duck populations - a horizon scanning exercise - Fox, A. D.; Jonsson, J. E.; Aarvak, T.; Bregnballe, T.; Christensen, T. K.; Clausen, K. K.; Clausen, P.; Dalby, L.; Holm, T. E.; Pavon-Jordan, D.; Laursen, K.; Lehikoinen, A.; et al. (Annales Zoologici Fennici, 2015)
We review the current and future threats to duck populations that breed, stage, moult and/or winter in the Nordic countries. Migratory duck species are sensitive indicators of their changing environment, and their societal value confirms the need to translate signals from changes in their distribution, status and abundance into a better understanding of changes occurring in their wetland environments. We used expert opinion to highlight 25 major areas of anthropogenic change (and touch briefly on potential mitigation measures through nature restoration and reserve management projects) that we consider key issues likely to influence Nordic duck populations now and in the near future to stimulate debate, discussion and further research. We believe such reviews are essential in contributing to development of successful management policy as well as stimulating specific research to support the maintenance of duck species in favourable future conservation status in the face of multiple population pressures and drivers.
Fox, Anthony D. Jonsson, Jon Einar Aarvak, Tomas Bregnballe, Thomas Christensen, Thomas Kjaer Clausen, Kevin Kuhlmann Clausen, Preben Dalby, Lars Holm, Thomas Eske Pavon-Jordan, Diego Laursen, Karsten Lehikoinen, Aleksi Lorentsen, Svein-Hakon Moller, Anders Pape Nordstrom, Mikael Ost, Markus Soderquist, Par Therkildsen, Ole Roland
Keywords: Conservation; Common Eider; Bucephala clangula; Somateria mollissima; Common goldeneye

Rafting behaviour and predator disturbance to Steller Eiders Polysticta stelleri in northern Norway - Fox, Anthony D.; Mitchell, Carl (Journal fuer Ornithologie, 1997)
Steller's Eiders responded to overlying Great Blackbacked Gulls Larus marinus by "spooking" - flushing from feeding and aggregating on open water. Birds did not react at high tide when aggregated into dense roosting flocks. The significant reduction in inter-bird distance associated with this escape behaviour suggests that rafting in this way (and at rest) serves an anti-predator function. In 32% of spooks, up to 56% of the flocks were displaced from feeding sites; even when all birds remained, they took an average of 3.5 minutes for half of the flock to resume feeding, representing a minimum total of 17% loss of feeding time throughout the 24 hour period. At observed rates, the cost of flight behaviour in response to guns was estimated to equate to a minimum of 7.8% of daily existence energy. Hence such predator responses can cost Steller's Eiders loss of access to favoured feeding area, loss of feeding time (already restricted by tidal exposure) and additional energy costs.
Keywords: Behavior; Nonbreeding Seasons; Polysticta stelleri; Steller's eider

The conservation of Steller's Eider Polysticta stelleri in Varangerfjord, Finnmark, Norway - Fox, A. D.; Mitchell, Carl; Henriksen, Gunnar; Lund, Erick; Frantzen, Bjorn (Wildfowl, 1997)
Declines in the North American segment of the circumpolar Steller's Eider population has emphasised the conservation importance of the 30,000-45,000 birds wintering in the western Palearctic. Analysis of distribution data from the most important wintering area, Varangerfjord in Northern Norway, showed that during early May, Steller's Eiders occurred in larger flocks and a greater proportion occurred within 1 km of harbours than King Eiders or Common Eiders. This close proximity to human activity places them at risk from oil and other pollution, but tighter pollution control in recent years has reduced the likelihood of major incidents. Elders drown in lumpsucker fishing nets, although the numbers involved are unknown. Modification of nets used and regulation of the season could reduce this source of mortality. illegal hunting is thought to have very little impact on the population now, but the apparent low levels of recruitment in the population means that it may be sensitive to small scale changes in adult survival rate. During early May, Steller's Eiders foraged on different food resources at different states of the tide cycle, and foraged for extended periods throughout the 24 hour period. This feeding specificity and duration make them especially sensitive to habitat loss and human disturbance, the long feeding duration allowing little flexibility within the tidal cycle to compensate for lost feeding time. Extension of existing reserves to include inshore areas used by Steller's Eiders would seem to be an important conservation objective. More research is required to understand factors affecting the population outside of the wintering period, and this is being facilitated through newly established collaborative projects with Russian scientists.
Keywords: Conservation; Nonbreeding Seasons; Polysticta stelleri; Steller's eider

Lead Fragments in Tissues from Wild Birds a Cause of Misleading Analytical Results - Frank, A. (Science of the Total Environment, 1986)
Seriously damaged eider ducks (Somateria mollissima) and long-tailed ducks (Clangula hyemalis) were shot in connection with an oil spill in 1974. Liver and kidney tissues were analyzed for environmental pollutants and lead analysis gave irreproducible results. By means of X-ray photographs, X-ray-dense particles could be observed in the tissues. The foreign particles were extracted by dissolution of the organ tissues in Soluene-350 (Packard Instruments Co. Inc) and then washed with toluene. The insoluble particles consisted of lead and bone splinters of varying size. The form of the former ranged from irregular fragments to dust, and arose by disruption of lead pellets upon collision with bone tissue. Birds shot with lead pellets should not be used for lead determination unless careful X-ray investigations are made prior to the chemical analysis. Determinations should be made on at least two different samples of the tissue examined.
Keywords: Clangula hyemalis; Long-tailed Duck; Contaminants; Techniques

In Search of Biomonitors for Cadmium Cadmium Content of Wild Swedish Fauna During 1973-1976 - Frank, A. (Science of the Total Environment, 1986)
Forty-five species of birds and 22 species of mammals of the terrestrial and aquatic fauna, herbivores as ell as carnivores, were investigated during the period 1973-1976 for cadmium-accumulating properties in order to find biomonitors for cadmium in the Swedish environment. The herbivores of the terrestrial fauna, birds as well as mammals, are preferred to carnivores, since they demonstrate generally higher renal Cd levels. The moose (Alces alces), roe deer (Capreolus capreolus) and hare (Lepus europaeus and Lepus timidus) were found to be suitable as biomonitors because of their common occurrence and uniform geographical distribution. The eider duck (Somateria mollissima), although a short-distance migrating bird whose diet is composed mainly of mussels and crustaceans, and which lives along a great part of the Swedish coastline, is suggested as a biomonitor of cadmium for the aquatic environment. The accumulation rate of cadmium in the kidneys is rapid. Renal levels of cadmium in the parts per million range are reached 10 weeks after hatching. Juvenile birds should be collected for monitoring purposes before leaving their feeding domains in the end of the summer.
Keywords: Breeding Season; Common Eider; Contaminants; Somateria mollissima

Contaminants in Sea Ducks: Metals, Trace Elements, Petroleum, Organic Pollutants, and Radiation - Franson, J. C. (Studies in Avian Biology, 2015)
Exposure to lead and petroleum has caused deaths of sea ducks, but relatively few contaminants have been shown to cause mortality or be associated with population level effects. This chapter focuses primarily on field reports of contaminant concentrations in tissues of sea ducks in North America and Europe and results of some pertinent experimental studies. Much of the available interpretive data for contaminants in waterfowl come from studies of freshwater species. Limits of available data present a challenge for managers interested in sea ducks because field reports have shown that marine birds may carry greater burdens of some pollutants than freshwater species, particularly metals. It is important, then, to distinguish poisoning due to a particular contaminant as a cause of death in sea ducks versus simple exposure based solely on tissue residues. A comprehensive approach that incorporates information on field circumstances, any observed clinical signs and lesions, and tissue residues is recommended when evaluating contaminant concentrations in sea ducks.
Keywords: Contaminants

Renal Coccidiosis in Oldsquaws Clangula-Hyemalis from Alaska USA - Franson, J. C.; Derksen, D. V. (Journal of Wildlife Diseases, 1981)
Renal coccidiosis was found in 4 of 12 oldsquaw ducks (C. hyemalis) collected from the north slope of Alaska and Prince William Sound. Numerous 1-2 mm white foci were observed on the kidney surface of 1 bird. Microscopically, there was distention of renal tubules with oocysts, flattening of tubular epithelium and interstitial accumulation of mononuclear cells. Kidneys from several other species of sea ducks from Prince William Sound were not infected.
Keywords: Breeding Season; Nonbreeding Seasons; Clangula hyemalis; Long-tailed Duck; Disease

Selenium Concentrations and Enzyme Activities of Glutathione Metabolism in Wild Long-Tailed Ducks and Common Eiders - Franson, J. Christian; Hoffman, David J.; Flint, Paul L. (Environmental Toxicology and Chemistry, 2011)
The relationships of selenium (Se) concentrations in whole blood with plasma activities of total glutathione peroxidase, Se-dependent glutathione peroxidase, and glutathione reductase were studied in long-tailed ducks (Clangula hyemalis) and common eiders (Somateria mollissima) sampled along the Beaufort Sea coast of Alaska, USA. Blood Se concentrations were >8 mu g/g wet weight in both species. Linear regression revealed that the activities of total and Se-dependent glutathione peroxidase were significantly related to Se concentrations only in long-tailed ducks, raising the possibility that these birds were experiencing early oxidative stress. Environ. Toxicol. Chem. 2011;30:1479-1481. (C) 2011 SETAC
Keywords: Breeding Season; Common Eider; Clangula hyemalis; Long-tailed Duck; Contaminants; Somateria mollissima; Physiology

Effects of dietary selenium on tissue concentrations, pathology, oxidative stress, and immune function in common eiders (Somateria mollissima) - Franson, J. Christian; Hoffman, David J.; Wells-Berlin, Alicia; Perry, Matthew C.; Shearn-Bochsler, Valerie; Finley, Daniel L.; Flint, Paul L.; Hollmen, Tuula (Journal of Toxicology and Environmental Health Part A, 2007)
Common eiders (Somateria mollissima) were fed added Se (as L-selenomethionine) in concentrations increasing from 10 to 80 ppm in a pilot study (Study 1) or 20 (low exposure) and up to 60 (high exposure) ppm Se in Study 2. Body weights of Study I ducks and high-exposure ducks in Study 2 declined rapidly. Mean concentrations of Se in blood reached 32.4 ppm wet weight in Study 1 and 17.5 ppm wet weight in high-exposure birds in Study 2. Mean Se concentrations in liver ranged from 351 (low exposure, Study 2) to 1252 ppm dry weight (Study 1). Oxidative stress was evidenced by Se-associated effects on glutathione metabolism. As Se concentrations in liver increased, Se-dependent glutathione peroxidase activity, glutathione reductase activity, oxidized glutathione levels, and the ratio of hepatic oxidized to reduced glutathione increased. In Study 2, the T-cell-mediated immune response was adversely affected in high-exposure eiders, but ducks in the low-exposure group exhibited evidence of an enhanced antibody-mediated immune response. Gross lesions in high-exposure ducks included emaciation, absence of thymus, and loss of nails from digits. Histologic lesions included severe depletion of lymphoid organs, hepatopathy, and necrosis of feather pulp and feather epithelium. Field studies showed that apparently healthy sea ducks generally have higher levels of Se in liver than healthy fresh-water birds, but lower than concentrations found in our study. Data indicate that common ciders and probably other sea ducks possess a higher threshold, or adverse effect level, for Se in tissues than fresh-water species. However, common eiders developed signs of Se toxicity similar to those seen in fresh-water birds.
Keywords: Common Eider; Contaminants; Somateria mollissima; Physiology; SDJV funded

Lead and delta-aminolevulinic acid dehydratase in blood of Common Eiders (Somateria mollissima) from the Finnish archipelago - Franson, J. Christian; Hollmen, Tuula; Hario, Martti; Kilpi, Mikael; Finley, Daniel L. (Ornis Fennica, 2002)
Keywords: Common Eider; Contaminants; Somateria mollissima

Metals and trace elements in tissues of Common Eiders (Somateria mollissima) from the Finnish archipelago - Franson, J. Christian; Hollmen, Tuula; Poppenga, Robert H.; Hario, Martti; Kilpi, Mikael (Ornis Fennica, 2000)
We sampled Common Eiders (Somateria mollissima) at five locations near coastal Finland in 1997 and 1998 for evidence of exposure to arsenic, cadmium, chromium, copper, iron, mercury, magnesium, manganese, molybdenum, lead, selenium, and zinc. Livers and kidneys were collected from adult males and females found dead and hunter-killed males, and livers were collected from ducklings. Two adult females, one of which had an ingested lead shot in its gizzard, were poisoned by lead. The concentrations of metals and trace elements that we found in tissues of eiders, other than the two lead poisoned birds, were not high enough to have independently caused mortality.
Keywords: Breeding Season; Common Eider; Nonbreeding Seasons; Contaminants; Somateria mollissima

Selected trace elements and organochlorines: Some findings in blood and eggs of nesting common eiders (Somateria mollissima) from Finland - Franson, J. Christian; Hollmen, Tuula; Poppenga, Robert H.; Hario, Martti; Kilpi, Mikael; Smith, Milton R. (Environmental Toxicology and Chemistry, 2000)
In 1997 and 1998, we collected blood samples from nesting adult female common eiders (Somateria mollissima) at five locations in the Baltic Sea near coastal Finland and analyzed them for lead, selenium, mercury, and arsenic. Eggs were collected from three locations in 1997 for analysis of selenium, mercury, arsenic, and 17 organochlorines (OCs). Mean blood lead concentrations varied by location and year and ranged from 0.02 ppm (residues in blood on wet weight basis) to 0.12 ppm, although one bird had 14.2 ppm lead in its blood. Lead residues in the blood of eiders were positively correlated with the stage of incubation, and lead inhibited the activity of the enzyme delta-aminolevulinic acid dehydratase (ALAD) in the blood. Selenium concentrations in eider blood varied by location, with means of 1.26 to 2.86 ppm. Median residues of selenium and mercury in eider eggs were 0.55 and 0.10 ppm (residues in eggs on fresh weight basis), respectively, and concentrations of both selenium and mercury in eggs were correlated with those in blood. Median concentrations of p,p'-dichlorodiphenyldichloroethylene in eggs ranged from 13.1 to 29.6 ppb, but all other OCs were below detection limits. The residues of contaminants that we found in eggs were below concentrations generally considered to affect avian reproduction. The negative correlation of ALAD activity with blood lead concentrations is evidence of an adverse physiological effect of lead exposure in this population.
Keywords: Breeding Season; Common Eider; Contaminants; Somateria mollissima

Contaminants in molting long-tailed ducks and nesting common eiders in the Beaufort Sea - Franson, J. C.; Hollmen, T. E.; Flint, P. L.; Grand, J. B.; Lanctot, R. B. (Marine Pollution Bulletin, 2004)
In 2000, we collected blood from long-tailed ducks (Clangula hyemalis) and blood and eggs from common eiders (Somateria mollissima) at near-shore islands in the vicinity of Prudhoe Bay, Alaska, and at a reference area east of Prudhoe Bay. Blood was analyzed for trace elements and egg contents were analyzed for trace elements, organochlorine pesticides, polychlorinated biphenyls, and polycyclic aromatic hydrocarbons. Except for Se (mean=36.1 mug/g dry weight (dw) in common eiders and 48.8 mug/g dw in long-tailed ducks), concentrations of trace elements in blood were low and, although several trace elements differed between areas, they were not consistently higher at one location. In long-tailed ducks, Se in blood was positively correlated with activities of two serum enzymes, suggestive of an adverse effect of increasing Se levels on the liver. Although common eiders had high Se concentrations in their blood, Se residues in eggs were low (mean=2.28 mug/g dw). Strontium and Ni were higher in eggs near Prudhoe Bay than at the reference area, but none of the other trace elements or organic contaminants in eggs differed between locations. Concentrations of Ca, Sr, Mg, and Ni differed among eggs having no visible development, early-stage embryos, or late-stage embryos. Residues of 4,4'-DDE, cis-nonachlor, dieldrin, hexachlorobenzene, oxychlordane, and trans-nonachlor were found in 100% of the common eider eggs, but at low concentrations (means of 2.35-7.45 mug/kg wet weight (ww)). The mean total PCB concentration in eggs was 15.12 mug/kg ww. Of PAHs tested for, residues of 1- and 2-methylnaphthalene and naphthalene were found in 100% of the eggs, at mean concentrations of 0.36-0.89 mug/kg ww.
Keywords: Breeding Season; Common Eider; Nonbreeding Seasons; Molt; Clangula hyemalis; Long-tailed Duck; Contaminants; Somateria mollissima

Heavy metals in seaducks and mussels from Misty Fjords National Monument in southeast Alaska - Franson, J. Christian; Koehl, Philip S.; Derksen, Dirk V.; Rothe, Thomas C.; Bunck, Christine M.; Moore, John F. (Environmental Monitoring and Assessment, 1995)
Quartz Hill, in Misty Fjords National Monument near Ketchikan, Alaska, is the site of a proposed molybdenum-producing mine. To provide baseline data for use in post-development comparisons, we analyzed tissues of Barrow's goldeneyes (Bucephala islandica), common mergansers (Mergus merganser), and blue mussels (Mytilus edulis) for seven heavy metals that could potentially be released into the environment as a result of mining operations. Specimens were collected in 1980, 1981, and 1982 from two fjords likely to be used for discharge of tailings from the proposed mine and from two control fjords. Concentrations of arsenic, cadmium, copper, chromium, molybdenum, lead, and zinc were measured in soft tissues of mussels and in kidney, liver, and muscle of birds. The highest mean concentrations of metals found in bird tissues were 55.7 ppm dry weight cadmium in kidneys and 154 ppm dry weight zinc in livers of Barrow's goldeneyes. Concentrations of several metals in blue mussels differed among seasons and locations, but the most significant finding in mussels was a maximum mean cadmium concentration of 9.6 ppm dry weight, a level higher than normally found in undisturbed areas. With the exception of 104 ppm dry weight cadmium in the kidney of one common merganser and 12.7 ppm dry weight lead in the kidney of another, concentrations of other metals in seaduck and mussel tissues were low, consistent with what would be expected for a pre-development environment. Molybdenum was found in low concentrations ( lt 10 ppm dry weight) in all avian kidney samples and most liver samples, but was not detected in blue mussels.
Keywords: Nonbreeding Seasons; Contaminants; Common merganser; Mergus merganser; Barrow's Goldeneye; Bucephala islandica

Blood lead concentrations of spectacled eiders near the Kashunuk River, Yukon Delta National Wildlife Refuge, Alaska - Franson, J. Christian; Petersen, Margaret R.; Creekmore, Lynn H.; Flint, Paul L.; Smith, Milton R. (Ecotoxicology, 1998)
We collected 342 blood samples from spectacled spiders (Somateria fischeri) on their breeding grounds in western Alaska from late May through to early August 1993-1995. Lead concentrations of ltoreq 0.50 p.p.m. wet weight were found in the blood of 20% of the adult female eiders, 2% of the adult males and 6% of the ducklings. Lead was detected 0.02 p.p.m.) more frequently in the blood of adult females than in adult males or ducklings and the maximum concentrations were 14.37, 0.50 and 4.28 p.p.m. wet weight, respectively. In adult females, there was a significant difference in the proportion of detectable blood lead concentrations between three collection times (arrival/nesting, hatch and brood rearing), with the highest proportion (92%) occurring at hatch. Nine hens with blood lead concentrations of ltoreq 0.50 p.p.m. were captured a second time several weeks to 1 year later. In the hens sampled twice at intervals of several weeks, the blood lead concentrations increased and declined at mean daily rates of 1.10 and 0.94, respectively. The lead concentrations in the blood of adults were not correlated with body weights. Radiographs were taken of 119 eiders and corresponding blood samples from 98 of these birds were analysed for lead. Ingested shot was seen in X-rays of 12 adults and three ducklings and, of the 13 blood samples tested, all had detectable lead concentrations. Of the birds without radiographic evidence of ingested shot, 84% of the adult females. 19% of the adult males and 17% of the ducklings had detectable lead concentrations in their blood. Breeding ground exposure of waterfowl to lead shot is unusual and is of particular concern in spectacled eiders because of their threatened status and declining numbers in western Alaska.
Keywords: Breeding Season; Somateria fischeri; Spectacled Eider; Contaminants

Lead poisoning of spectacled Eiders (Somateria fischeri) and of a common Eider (Somateria mollissima) in Alaska - Franson, J. Christian; Petersen, Margaret R.; Meteyer, Carol U.; Smith, Milton R. (Journal of Wildlife Diseases, 1995)
Lead poisoning was diagnosed in four spectacled eiders (Somateria fischeri) and one common eider (Somateria mollissima) found dead or moribund at the Yukon Delta National Wildlife Refuge, Alaska (USA) in 1992, 1993, and 1994. Ingested lead shot was found in the lower esophagus of one spectacled eider and in the gizzard of the common eider. Lead concentrations in the livers of the spectacled eiders were 26 to 38 ppm wet weight, and 52 ppm wet weight in the liver of the common eider. A blood sample collected from one of the spectacled eiders before it was euthanized had a lead concentration of 8.5 ppm wet weight. This is the first known report of lead poisoning in the spectacled eider, recently listed as a threatened species by the U.S. Fish and Wildlife Service.
Keywords: Breeding Season; Somateria fischeri; Spectacled Eider; Common Eider; Contaminants; Somateria mollissima

The Steller's Eider Polysticta-Stelleri in Finnmark 1985-1992 - Frantzen, B.; Henriksen, G. (Fauna (Oslo), 1992)
From 1985 to 1992, Steller's eiders in the Varangerfjord in Finnmark county have been counted. The counts indicate a minimum winter population of Steller's eiders between 5,400 and 12,500 individuals, but most likely the total population holds some 10,000-20.000 birds. The Norwegian winter population of this species seems to be stable. The birds do migrate or move within the fjord. The main threats to the Steller's eiders are oil spills and fishing nets, in which the birds fasten and drown. As the total world population of this duck species has decreased dramatically, the management of the Varangerfjord and its winter population of Steller's eiders will have increased imporance in the future. Norwegian authorities thus holds a growing responsibility for the Steller's eider, and should act accordingly.
Keywords: Abundance, Distribution, and Trends; Nonbreeding Seasons; Polysticta stelleri; Steller's eider

A Bioenergetics Approach to Assessing Potential Impacts of Avian Predation on Juvenile Steelhead during Freshwater Rearing - Frechette, D.; Collins, A. L.; Harvey, J. T.; Hayes, S. A.; Huff, D. D.; Jones, A. W.; Retford, N. A.; Langford, A. E.; Moore, J. W.; Osterback, A. M. K.; Satterthwaite, W. H.; Shaffer, S. A. (North American Journal of Fisheries Management, 2013)
Times Cited: 0 Frechette, Danielle Collins, Alison L. Harvey, James T. Hayes, Sean A. Huff, David D. Jones, Andrew W. Retford, Nicolas A. Langford, Alina E. Moore, Jonathan W. Osterback, Ann-Marie K. Satterthwaite, William H. Shaffer, Scott A. 0
Keywords: Breeding Season; Trophic Interactions; Common merganser; Mergus merganser

Steller's Eider (Polysticta stelleri) - Fredrickson, Leigh H. (The Birds of North America, 2001)
Keywords: Polysticta stelleri; Steller’s Eider

Fish Attack on Black Guillemot Cepphus-Grylle and Common Eider Somateria-Mollissima in Maine USA - French, T. W. (Wilson Bulletin, 1981)
Keywords: Common Eider; Somateria mollissima; Trophic Interactions

Mass occurrences of Sandeels (Ammodytes spp.) causing aggregations of diving ducks - Frengen, Otto; Thingstad, Per Gustav (Fauna Norvegica, 2002)
In autumn 1999, large, compact flocks of foraging diving ducks, particularly Common Eiders Somateria mollissima, were observed within and at the mouth of Trondheimsfjord in Central Norway. Some of these aggregations were at places previously not known as particularly rich feeding grounds. This situation continued through the winter, and still existed in March 2000. Investigations on these feeding grounds showed that the only possible prey species occurring in significant quantities was Sandeel (only Ammodytes tobianus was verified). Although most of the fish were swallowed before the birds reached the surface, some ducks (including Velvet Scoter Melanitta fusca and Goldeneye Bucephala clangula) were observed eating Sandeels. Sandeel populations fluctuate in size annually and shoals are very patchily distributed. Consequently, the very variable occurrence in time and space of this food resource may occasionally bring about unusually dense and patchy aggregations of various species of diving ducks. Due to the specific habitat requirements of the Sandeel, these aggregations may also occur at localities that are not generally preferred feeding grounds for diving ducks, as was the case here. These findings may be relevant for some monitoring projects involving populations of diving ducks in marine environments.
Keywords: Common Eider; Melanitta fusca; Nonbreeding Seasons; White-winged Scoter; Somateria mollissima; Trophic Interactions

The introduced clam Ensis americanus in the Wadden Sea: field experiment on impact of bird predation and tidal level on survival and growth - Freudendahl, Anna Sowe L.; Nielsen, Mette M.; Jensen, Tomas; Jensen, Kurt Thomas (Helgoland Marine Research, 2010)
In the Danish Wadden Sea the intertidal distribution of the introduced bivalve Ensis americanus (syn. E. directus) is restricted to a narrow zone around the mean low water level. To test the possible impact of birds and submersion time on dynamics and distribution of the clams, adult specimens of E. americanus collected near the low water line were transplanted to two intertidal sites and established in open and net-covered experimental plots for 9 weeks (autumn 2001). The lowest survival of clams was registered at the low-shore-site (LSS) in plots open to bird predators, suggesting that birds such as Common Eider (Somateria mollissima) or Oystercatcher (Haematopus ostralegus) may control the abundance of E. americanus at the lower tidal levels. For clams showing increment in shell length during the study period, the shell growth rates were highest at the LSS and lowest in the open plots at the high-shore-site (HSS). Differences in immersion time and thus food supply may explain this pattern. Body mass index (BMI) of the clams showed basically the same pattern as the survivorship: lowest BMI in open plots at the LSS and highest in the covered plots at this site. Clams from the HSS were intermediate in their BMI. Disturbance by birds in the open plots at the LSS may explain the low BMI. In conclusion birds may be an important factor controlling abundance of E. americanus in the lower intertidal zone.
Keywords: Common Eider; Somateria mollissima; Trophic Interactions

Occurrence and distribution of king eiders Somateria spectabilis and common eiders S. mollissima at Disko, West Greenland - Frimer, Ole (Polar Research, 1993)
King eiders and common eiders were recorded at Disko Island, West Greenland, in the period 1989-1993. Both species occur year-round in the area, although in low numbers during the period of extensive ice-cover January-April. In May and the first half of June, large numbers of king and common eiders on spring migration stage along the western coast of Disko. In the autumn (August-October) an estimated 15,400-20,100 king eiders undergo prebasic moult in the area, with the highest concentrations in the fjords and bays of western Disko and along the coast of southeast Disko. This estimate indicates that a recent population decline may have taken place. Only two female common eiders with ducklings were recorded during the study period. In the period July-September an estimated 3,200-4,800 male common eiders undergo prebasic moult in the area, mainly at the archipelago of Kitsissut and in the outer fjords and bays of western Disko Island.
Keywords: Abundance, Distribution, and Trends; Common Eider; Nonbreeding Seasons; Molt; Migration; Somateria mollissima; King Eider; Somateria spectabilis

Autumn arrival and moult in King Eiders (Somateria spectabilis) at Disko, West Greenland - Frimer, Ole (Arctic, 1994)
Observations of King Eiders and their moult carried out at western Disko Island, West Greenland, July-October 1991 and 1992 showed two waves of immigration. The post-breeding males arrived mainly in early August in advanced body moult and undertook wing moult between mid-August and late September. Females arrived from mid-August and peaked in the second half of August. Females undertook body and wing moult from late August into October. A significant part of the females as well as males from the eastern Canadian Arctic appear to perform a moult migration to central West Greenland.
Keywords: Nonbreeding Seasons; Molt; King Eider; Somateria spectabilis

The behaviour of moulting King Eiders Somateria spectabilis - Frimer, Ole (Wildfowl, 1994)
Activity budgets and distribution patterns of King Elders were studied at Disko Island, West Greenland during the moulting season of July to September, and compared with the activity budgets of non-moulting King Eiders. King Elders were generally active in the daylight hours, and spent most of the night and a period at mid-day resting. The feeding intensity peaked early and late in the day, with no marked tidal influence on the feeding pattern. The amount of time devoted to diurnal feeding increased during the moulting period, and was negatively correlated with daylength. There was no evidence of increased feeding intensity by moulting birds compared to non-moulting birds. Moulting King Eiders devoted more time to comfort movements than non-moulting birds. Ice conditions and daylength are suggested to be ultimate factors affecting the timing of moult.
Keywords: Behavior; Nonbreeding Seasons; Molt; King Eider; Somateria spectabilis

Comparative behaviour of sympatric moulting populations of Common Eider Somateria mollissima and King Eider S. spectabilis in central West Greenland - Frimer, Ole (Wildfowl, 1995)
Activity budgets and distribution patterns of Common Eider moulting at Disko Island, West Greenland, were studied and compared to the behaviour of King Eider moulting in the same general area (Frimer 1994b). Both species are diurnal feeders who spend most of the night resting. The daily foraging pattern was essentially similar in the two species, with peak intensity early and late in the day, and there was no significant difference in the amount of time spent foraging. However, while Common Eiders foraged near the rocky shoreline at depths of less than 15 m, King Eiders foraged mainly on silt bottom at depths of 15-25 m. Dabbling comprised between 10.7% and 45.6% of the foraging time in Common Eiders, and less than 1% in King Eiders. The total food niche overlap between the two eider species is estimated to be less than 16%. A low interspecific food competition may be crucial to the survival of the species in the late autumn and winter, when days are short and the birds spend most of the day foraging. Some adaptations of the species to their feeding habitats are discussed.
Keywords: Behavior; Abundance, Distribution, and Trends; Common Eider; Nonbreeding Seasons; Molt; Somateria mollissima; King Eider; Somateria spectabilis; Habitat

Adaptations by the King Eider Somateria spectabilis to its moulting habitat: Review of a study at Disko, West Greenland - Frimer, Ole (Dansk Ornitologisk Forenings Tidsskrift, 1995)
Keywords: Nonbreeding Seasons; Molt; King Eider; Somateria spectabilis

Diet of moulting King Eiders Somateria spectabilis at Disko Island, West Greenland - Frimer, Ole (Ornis Fennica, 1997)
During the autumns of 1990-1992, 109 moulting King Eiders Somateria spectabilis were collected at Disko Island, West Greenland, for analysis of stomach contents. All collected birds had food in their stomachs. The mean number of prey items per stomach was 11.1. Moulting King Eiders had a varied diet (minimum 41 prey species), with mollusks comprising the bulk of the food. Bivalves of 21-40 mm length occurred more frequently in the stomachs than did other size categories of bivalves. There was no marked difference in food composition between sex and age classes of eiders, and the diet varied only slightly between the study years. Female eiders depend strongly on a high prey density owing to their late arrival in the area and shorter day lengths.
Keywords: Nonbreeding Seasons; Molt; King Eider; Somateria spectabilis; Trophic Interactions

Effects of oil and oil burn residues on seabird feathers - Fritt-Rasmussen, J.; Linnebjerg, J. F.; Sorensen, M. X.; Brogaard, N. L.; Riget, F. F.; Kristensen, P.; Jomaas, G.; Boertmann, D. M.; Wegeberg, S.; Gustavson, K. (Marine Pollution Bulletin, 2016)
It is well known, that in case of oil spill, seabirds are among the groups of animals most vulnerable. Even small amounts of oil can have lethal effects by destroying the waterproofing of their plumage, leading to loss of insulation and buoyancy. In the Arctic these impacts are intensified. To protect seabirds, a rapid removal of oil is crucial and in situ burning could be an efficient method. In the present work exposure effects of oil and burn residue in different doses was studied on seabird feathers from legally hunted Common eider (Somateria mollissima) by examining changes in total weight of the feather and damages on the microstructure (Amalgamation Index) of the feathers before and after exposure. The results of the experiments indicate that burn residues from in situ burning of an oil spill have similar or larger fouling and damaging effects on seabird feathers, as compared to fresh oil. (C) 2016 Elsevier Ltd. All rights reserved.
Fritt-Rasmussen, Janne Linnebjerg, Jannie Fries Sorensen, Martin X. Brogaard, Nicholas L. Riget, Frank F. Kristensen, Paneeraq Jomaas, Grunde Boertmann, David M. Wegeberg, Susse Gustavson, Kim
Keywords: Common Eider; Contaminants; Somateria mollissima

Trends in Annual Survival of Steller's Eiders Molting at Izembek Lagoon on the Alaska Peninsula, 1993-2006 - Frost, C. J.; Hollmen, T. E.; Reynolds, J. H. (Arctic, 2013)
Times Cited: 0 Frost, Charles J. Hollmen, Tuula E. Reynolds, Joel H. 0
Keywords: Nonbreeding Seasons; Molt; Survival; Polysticta stelleri; Steller's eider

Genomic characterization of multidrug-resistant ESBL-producing Escherichia coli ST58 causing fatal colibacillosis in critically endangered Brazilian merganser (Mergus octosetaceus) - Fuentes-Castillo, D.; Navas-Suarez, P. E.; Gondim, M. F.; Esposito, F.; Sacristan, C.; Fontana, H.; Fuga, B.; Piovani, C.; Kooij, R.; Lincopan, N.; Catao-Dias, J. L. (TRANSBOUNDARY AND EMERGING DISEASES, 2021)
Even though antimicrobial-resistant bacteria have begun to be detected in wildlife, raising important issues related to their transmission and persistence of clinically important pathogens in the environment, little is known about the role of these bacteria on wildlife health, especially on endangered species. The Brazilian merganser (Mergus octosetaceus) is one of the most threatened waterfowl in the world, classified as Critically Endangered by the International Union for Conservation of Nature. In 2019, a fatal case of sepsis was diagnosed in an 8-day-old Brazilian merganser inhabiting a zoological park. At necropsy, major gross lesions were pulmonary and hepatic congestion. Using microbiologic and genomic methods, we identified a multidrug-resistant (MDR) extended-spectrum beta-lactamase (ESBL) CTX-M-8-producing Escherichia coli (designed as PMPU strain) belonging to the international clone ST58, in coelomic cavity, oesophagus, lungs, small intestine and cloaca samples. PMPU strain harboured a broad resistome against antibiotics (cephalosporins, tetracyclines, aminoglycosides, sulphonamides, trimethoprim and quinolones), domestic/hospital disinfectants and heavy metals (arsenic, mercury, lead, copper and silver). Additionally, the virulence ofE. coliPMPU strain was confirmed using a wax moth (Galleria mellonella) infection model, and it was supported by the presence of virulence genes encoding toxins, adherence factors, invasins and iron acquisition systems. Broad resistome and virulome of PMPU contributed to therapeutic failure and death of the animal. In brief, we report for the first time a fatal colibacillosis by MDR ESBL-producing E. coli in critically endangered Brazilian merganser, highlighting that besides colonization, critical priority pathogens are threatening wildlife.E. coliST58 clone has been previously reported in humans, food-producing animals, wildlife and environment, supporting broad adaptation and persistence at human-animal-environment interface.
Times Cited in Web of Science Core Collection: 12 Total Times Cited: 12 Cited Reference Count: 61
Keywords: waterfowl; HEALTH; ANTIMICROBIAL RESISTANCE; bacterial infection; DIVERSITY; enterobacterales; ENTEROBACTERIACEAE; ESBL; EXPRESSION; HLYE; PREVALENCE; PROTEIN; virulence; VIRULENCE FACTORS; wildlife

Characterization of an avian rotavirus A strain isolated from a velvet scoter (Melanitta fusca): implication for the role of migratory birds in global spread of avian rotaviruses - Fujii, Y.; Hirayama, M.; Nishiyama, S.; Takahashi, T.; Okajima, M.; Izumi, F.; Takehara, K.; Masatani, T.; Sugiyama, M.; Ito, N. (JOURNAL OF GENERAL VIROLOGY, 2022)
Avian G18P[17] rotaviruses with similar complete genome constellation, including strains that showed pathogenicity in mammals, have been detected worldwide. However, it remains unclear how these strains spread geographically. In this study, to investigate the role of migratory birds in the dispersion of avian rotaviruses, we analysed whole genetic characters of the rotavirus strain RK1 that was isolated from a migratory species of birds [velvet scoter (Melanitta fusca)] in Japan in 1989. Genetic analyses revealed that the genotype constellation of the RK1 strain, G18-P[17]-14-R4-C4-M4-A21-N4-T4-E4-H4, was highly consistent with those of other G18P[17] strains detected in various parts of the world, supporting the possibility that the G18P[17] strains spread via migratory birds that move over a wide area. Furthermore, the RK1 strain induced diarrhoea in suckling mice after oral gastric inoculation, indicating that at least some of the rotaviruses that originated from migratory birds are infectious to and pathogenic in mammals. In conclusion, it was demonstrated that migratory birds may contribute to the global spread of avian rotaviruses that are pathogenic in mammalian species.
Times Cited in Web of Science Core Collection: 2 Total Times Cited: 2 Cited Reference Count: 53
Keywords: BOVINE; CALF FECES; CLASSIFICATION; diarrhoea; genotype; global spread; GROUP-A ROTAVIRUS; IDENTIFICATION; interspecies transmission; migratory bird; NSP1; PATHOGENICITY; Rotavirus A; SEQUENCE-ANALYSIS; TRANSMISSION; VP4 GENE

Incorporating uncertainty about species' potential distributions under climate change into the selection of conservation areas with a case study from the Arctic Coastal Plain of Alaska - Fuller, Treuon; Morton, Dauid P.; Sarkar, Sahotra (Biological Conservation, 2008)
This analysis presents a conservation planning framework for decisions under uncertainty and applies it to the Arctic Coastal Plain of Alaska. Uncertainty arises from variable distributional shifts of species' ranges due to climate change. The planning framework consists of a two-stage optimization model that selects a nominal conservation area network in the first stage and evaluates its performance under the climate scenarios in the second stage. The model is applied to eleven at-risk species in Alaska including the threatened Spectacled Eider and Steller's Eider sea ducks and the polar bear. The 109th United States Congress and 2008 federal budget proposed opening for oil and gas development the "1002 Area" of the Arctic National Wildlife Refuge, which intersects the Plain. This analysis finds that, if Arctic Alaska experiences 1.5 degrees C of warming by 2040 (as predicted by the Intergovernmental Panel on Climate Change's A2 scenario), then potential habitat will decrease significantly for eight of these at-risk species, including the polar bear. This analysis also shows that there is synergism between oil and gas development and climate change. For instance, climate change accompanied by no development of the 1002 Area results in an increase of potential habitat for Steller's Eider. However, if development accompanies climate change, then there is a 20% decrease in that area. Further, this analysis quantifies the tradeoff between development and maintenance of suitable habitat for at-risk species. (c) 2008 Elsevier Ltd. All rights reserved.
Keywords: Conservation; Breeding Season; Somateria fischeri; Spectacled Eider; Habitat; Polysticta stelleri; Steller's eider

Assessing vulnerability of marine bird populations to offshore wind farms - Furness, R. W.; Wade, H. M.; Masden, E. A. (Journal of Environmental Management, 2013)
Times Cited: 1 Furness, Robert W. Wade, Helen M. Masden, Elizabeth A. 1
Keywords: Conservation; Nonbreeding Seasons; Sea ducks

Energy Cost During Incubation and Thermoregulation in the Female Common Eider Somateria-Mollissima - Gabrielsen, G. W.; Mehlum, F.; Karlsen, H. E.; Andresen, O.; Parker, H. (Norsk Polarinstitutt Skrifter, 1991)
Metabolic rate during incubation (IMR) was measured in two wild incubating Eiders at Ny-Alesund, Svalbard (79.degree. N). IMR, measured toward the end of incubation (day 15-20), averaged 0.80 ml O2/g .cntdot. h. The respiratory quotient (RQ) was 0.70, indiating that fat was the major metabolic fuel during this long period of fast. Both birds showed a decrease in mean daily energy expenditure with decreasing body mass but no significant decrease in specific resting metabolic rate. Thermoregulation was studied in 12 non-incubating Eiders in the laboratory. Resting metabolic rate (RMR) averaged 0.86 ml O2/g .cntdot. h, thermal conductance (TC) 0.0240 ml O2/g .cntdot. h .cntdot. .degree. C and deep body temperature 40.1.degree. C. The RMR value of non-incubating Eiders tended to be 7.5% higher than the IMR value of incubating birds (0.05 > p > 0.10, t-test). Both IMR and RMR values were above predicted values based on equations by Lasiewski and Dawson (1967) and Aschoff and Pohl (1970). TC was lower than values predicted from equations of Herreid and Kessel (1967) and higher than those predicted by Aschoff (1981). Calculation of daily energy expenditure (DEE) during incubation (day 20) based on weight loss was 24% and 29% less, respectively, than DEE measurements derived from indirect calorimetry of incubating and non-incubating eiders. Measurements of water influx rate close to hatching suggested that Eiders increased their water consumption then.
Keywords: Breeding Season; Common Eider; Somateria mollissima; Energetics and Nutrition

Winter Diet of the Harlequin Duck at Sequim Bay Puget Sound Washington USA - Gaines, W. L.; Fitzner, R. E. (Northwest Science, 1987)
Little information is available concerning the diet of harlequin ducks (Histrionicus histrionicus), therefore we examined their diet in Sequim Bay, Puget Sound, WA. We analyzed esophagi and gizzard contents of 21 harlequin ducks collected during the winter at the mouth of Sequim Bay. Principal food items were found to be snails, limpets, crabs, and chitons. Most of the prey of the harlequin duck was associated with rocky areas. Results of this study indicate that rocky shoreline areas are very important to harlequin ducks and should be protected.
Keywords: Nonbreeding Seasons; Harlequin duck; Histrionicus histrionicus; Trophic Interactions

Long-term increase in female body condition and its effect on reproduction in two European red-listed species, Common Pochard (Aythya ferina) and Tufted Duck (Aythya fuligula) - Gajdosova, D.; Musil, P.; Zouhar, J.; Musilova, Z.; Neuzilova, S.; Pavon-Jordan, D. (IBIS, 2023)
Body condition of breeding females is an important driver of an individual's fitness and the consequent dynamics of populations. Long-term changes in female body condition are likely to be affected by recent shifts in climatic and environmental conditions that can result in changes to population demography. To help explain the drivers shaping body condition during the incubation period and its consequences for reproductive success, we examined the long-term pattern in the body condition of breeding females of two declining sympatric diving duck species: Common Pochard Aythya ferina and Tufted Duck Aythya fuligula. We analysed the data obtained from 139 females of Common Pochard and 251 females of Tufted Duck breeding on fishponds in South Bohemia, Czechia, between 2004 and 2020. We calculated the body condition index of females during late incubation based on the residuals from the relationship between body mass and tarsus length and used the incubation stage as an additional predictor of body mass. Body condition of both species did not decline over the 17 years of the study. The effect of winter weather conditions (winter temperature), water transparency (a proxy for food availability) and reproductive investment on body condition was not confirmed. Female body condition positively affected mean egg mass and hatchability in both studied species, i.e. females in better body condition laid larger eggs and hatched eggs with a higher hatching probability. We conclude that the population declines of the studied species are probably not connected to decreasing body condition of breeding females, but other reasons such as change in breeding propensity or offspring survival and recruitment should be considered in future studies.
Times Cited in Web of Science Core Collection: 0 Total Times Cited: 0 Cited Reference Count: 139
Keywords: climate change; CLIMATE-CHANGE; CLUTCH-SIZE; SPRING MIGRATION; LESSER SCAUP; BREEDING SUCCESS; EGG SIZE; body condition index; CONDITION-DEPENDENT MODEL; CONSPECIFIC BROOD PARASITISM; diving ducks; egg mass; GOLDENEYE BUCEPHALA-CLANGULA; hatchability; NUTRIENT RESERVES

Species composition and prevalence of seabird trematode larvae periwinkles at two littoral sites in North-Norway - Galaktionov, Kirill; Bustnes, Jan Ove (Sarsia, 1995)
We investigated the species composition and prevalence of seabird (final hosts) trematodes in periwinkles (mainly Littorina saxatilis and L. obtusata; first intermediate hosts) in two different areas near Tromso, North-Norway. The environmental conditions at the two sites were different. The first area was a large sheltered mudflat with high density of common eider Somateria mollissima broods, while the other consisted of exposed rocky shores, with a high density of breeding gulls Larus sp. We found a total of eight species of trematodes. At the first site, the prevalence of trematodes with autonomic life-cycles (microphallids of the pygmaeus group), and with the common eider as the most frequent final host, was significantly higher than in the other study area. There were no significant differences between the areas for most trematodes with two intermediate hosts and one or two free living larval stages, most of which have gulls as final hosts. We argue that for eider trematodes the density of final hosts is probably of importance for the infestation in intermediate hosts, while for species with more complex life-cycles, environmental exposure is probably of more importance for the transmission success.
Keywords: Breeding Season; Common Eider; Somateria mollissima; Parasites

Microphallus Kurilensis Sp Nov., a New Species of Microphallids from the Pygmaeus Species Group (Trematoda, Microphallidae) from the Coastal Areas of Okhotsk and Bering Seas - Galaktionov, K. V.; Regel, K. V.; Atrashkevich, G. I. (Parazitologiya (St. Petersburg), 2010)
The pygmaeus-species group is composed of close related species from the genus Microphallus in which metacercariae develop inside daughter sporocysts without encystment. Infection of periwinkles Littorina (Neritrema) spp. with intramolluscan stages of a new species of this group (Microphallus kurilensis sp. nov.) was recorded on the coasts of Sakhalin and Kuril islands, north of the Sea of Okhotsk and Chukchi Peninsula (the Bering Sea). Application of molecular methods allowed us to establish that M. kurilensis metacercariae are conspecific with one of the morphotypes of microphallid adults obtained from the intestine of the Pacific common eider (Somateria mollissima v-nigrum), which was shot in the north of the Sea of Okhotsk (Galaktionov, Olson, and Blasco-Costa, in press). The adults of the same morphotype were recorded in the Pacific common eider from the northwestern part of the Bering Sea (Chukchi Peninsula). In the course of experimental infection of the slaty-backed gull Larus schistisagus chicks with metacercariae of M kurilensis, few microphallid adults were obtained. These adults were identical in their morphology with specimens of the microphallid morphotype from the Pacific common eider, which had been identified as M. kurilensis based on molecular data. Morphological description of metacercaria and adult of M. kurilensis and list of their differences from the same developmental stages of other species from pygmaeus-group are provided. It is concluded that M. kurilensis is transmitted in the host system including periwinkle Littorina (Neritrema) and seaducks (predominately, Pacific common eider). Most probably, distribution of M. kurilensis is not limited by the north Asiatic coast but expanded to the North American coast of the Pacific Ocean.
Keywords: Common Eider; Somateria mollissima; Parasites

Food chain, parasites and climate changes in the high Arctic: a case study on trophically transmitted parasites of common eider Somateria mollissima at Franz Josef Land - Galaktionov, K. V.; Weslawski, J. M.; Stempniewicz, L. (POLAR BIOLOGY, 2021)
Assessment of the impact of climate change on the Arctic nearshore ecosystems requires knowledge of the "reference points", that is, the state of things before the effects of the warming become pronounced. For parasites, which play an essential role in the nearshore ecosystems, this knowledge is scarce and fragmentary. This study, based on the materials collected at Franz Josef Land (FJL) in 1990-1993, partly fills this gap. We present the first data on the diet of the common eider Somateria mollissima at FJL, the transmission of helminths in its population and the infection of nearshore invertebrates with helminth larvae. We found that gastrointestinal helminth communities were impoverished (only ten species) and dominated by cestodes and acanthocephalans. This is associated with the prevalence of nearshore crustaceans, the intermediate hosts of these helminths, in the diet of the eiders. The absence of the vulnerable free-living larvae also facilitates transmission of helminths parasitizing eiders at FJL. Infection with helminths and the diet were different in ducklings and in adult birds as well as in eiders from different parts of the archipelago. The infection distribution of molluscs and crustaceans with helminth larvae was patchy and higher in the vicinity of the eider colonies. A high-infection intensity of FJL eiders with cestodes and acanthocephalans recorded in our study seems to have a certain negative effect on the bird population. Its significance is likely to grow considering that the transmission of helminths is promoted by the climate warming in the Arctic.
Times Cited in Web of Science Core Collection: 1 Total Times Cited: 1 Cited Reference Count: 181
Keywords: Climate change; GENETIC-STRUCTURE; 1913 CESTODA; ANTIPARASITE TREATMENT; Benthic invertebrates; Bird; DIGENEA NOTOCOTYLIDAE; Feeding behaviour; HELMINTH-PARASITES; High Arctic; HISTORICAL BIOGEOGRAPHY; LIFE-CYCLES; Parasite; PECHORA SEA; SPATIAL HETEROGENEITY; TREMATODE INFECTIONS

Reidentification of "Hymenolepis setigera" from eider ducks of the Murman coast - Galkin, A. K. (Parazitologiya (St. Petersburg), 1997)
Bielopolskaya (1952) mentions eider duck Somateria mollissima of the Murman Coast as a new host for Hymenolepis setigera (Froelich, 1789) (= Tschertkovilepis setigera). This tapeworm is known as a common parasite of geese. In the Zoological Institute one of Bielopolskaya's slides (N 1631) is presented. It is interesting to compare the morphology of eider duck's parasite with the same of Tsch. setigera from Anser anser. The investigation revealed that it is quite different. The scolex of Tsch. setigera resembles that of Diorchis, with short rostellum and oval suckers. The length of the rostellar hooks is 0.038-0.042 mm. They are of "rostelloid" type as the guard is well-developed but much shorter than the blade. The topography of gonads is rather peculiar. The middle testis is situated antiporally to the median line of the proglottis, the female gonads lie just near the antiporal testis. The similar topography of gonads is in Wardoides nyrocae. Testes are present even in pregravid proglottids. Cirrus is very expressive, 0.3 X 0.045-0.05 in dimensions. The spines in its middle part attain 0.015 in length. The ovarium consists of 5-7 lobes. Uterus is sac-form, with numerous eggs in it. The length of the gravid strobile is more than 200 mm, it consists of several thousands of proglottids. Worms on the slide N 1631 undoubtedly belong to the genus Microsomacanthus as their scoleces have a rostrum. The length of rostellar hooks is 0.045 mm, their guard is rudimental. Gonads are slightly displaced to the antiporal side. Cirrus is 0.12 X 0.012-0.018 in dimensions, the longest spines attaining 0.006 mm are in its middle part. The ovary is small, 3-lobed; two lateral lobes are much more voluminous than the middle one. Testes are resorbed rapidly, so they are absent in the female zone of the strobile. The young uterus is tube-form, curved like a yoke, with its lateral ends turned onward. The number of eggs in it is restricted to about 40. Pregravid strobile consists of 300 proglottids. Material of Bielopolskaya is identical to Microsomacanthus heterospinus Spassky et Jurpalova, 1964. This species described from eider duck of the Bering Sea in morphologically very close to the type species of the genus Microsomacanthus, M. microsoma (Creplin, 1829). However, the precise characteristic of M. microsoma is lacking. So we preliminary redetermine the material from the Barents Sea eider ducks as M. heterospinus. Deep distinctions observed between Tsch. setigera and M. heterospinus do not permit to consider them in the limits of one genus. The diagnosis of the genus Microsomacanthus given by Chaplinski, Vaucher (1994) is too vague. To our opinion, the validity of the genus Tschertkovilepis Spassky et Spasskaja, 1954 with the type species Tsch. setigera is out of question.
Keywords: Common Eider; Somateria mollissima; Parasites

Redescription and new data on Microsomacanthus diorchis (Fuhrmann, 1913) (Cestoda : Hymenolepididae) - Galkin, Alexander K.; Mariaux, Jean; Regel, Kira V.; Skirnisson, Karl (Systematic Parasitology, 2008)
Microsomacanthus diorchis (Fuhrmann, 1913) is redescribed and illustrated on the basis of the type-material and new findings from common eider Somateria mollissima captured in Iceland and specimens from the same host species from the Barents, White and Bering Seas. A lectotype is designated and an amended diagnosis is provided. The main differentiating features of M. diorchis are the size and shape of rostellar hooks and the cirrus, the well-marked delay in the antiporal testis development and the bow-shaped uterus. This parasite is shown to be specific to S. mollissima for both Atlantic and Pacific populations of the host. Hymenolepis (Microsomacanthus) somateriae of Bishop & Threlfall (1974) [nec M. somateriae Ryzhikov, 1965] is recognised as a synonym of M. diorchis (Fuhrmann, 1913). The taxonomic position of the species described as Aploparaksis murmanica Baylis, 1919 from common eider is discussed.
Keywords: Common Eider; Somateria mollissima; Parasites

Spatial and temporal trends of contaminants in terrestrial biota from the Canadian Arctic - Gamberg, Mary; Braune, Birgit; Davey, Eric; Elkin, Brett; Hoekstra, Paul F.; Kennedy, David; Macdonald, Colin; Muir, Derek; Nirwal, Amar; Wayland, Mark; Zeeb, Barbara (Science of the Total Environment, 2005)
Contaminants in the Canadian Arctic have been studied over the last twelve years under the guidance of the Northern Contaminants Program. This paper summarizes results from that program from 1998 to 2003 with respect to terrestrial animals in the Canadian Arctic. The arctic terrestrial environment has few significant contaminant issues, particularly when compared with freshwater and marine environments. Both current and historical industrial activities in the north may have a continuing effect on biota in the immediate area, but effects tend to be localized. An investigation of arctic ground squirrels at a site in the Northwest Territories that had historically received applications of DDT concluded that DDT in arctic ground squirrels livers was the result of contamination and that this is an indication of the continuing effect of a local point source of DDT. Arsenic concentrations were higher in berries collected from areas around gold mines in the Northwest Territories than from control sites, suggesting that gold mining may significantly affect arsenic levels in berries in the Yellowknives Dene traditional territory. Although moose and caribou from the Canadian Arctic generally carry relatively low contaminant burdens, Yukon moose had high renal selenium concentrations, and moose and some woodland caribou from the same area had high renal cadmium levels, which may put some animals at risk of toxicological effects. Low hepatic copper levels in some caribou herds may indicate a shortage of copper for metabolic demands, particularly for females. Similarities in patterns of temporal fluctuations in renal element concentrations for moose and caribou suggest that environmental factors may be a major cause of fluctuations in renal concentrations of some elements. Concentrations of persistent organochlorines and metals in beaver and muskrat from the Northwest Territories, and carnivores from across the Canadian Arctic were very low and considered normal for terrestrial wildlife. Two new classes of persistent fluorinated contaminants, perfluorooctane sulfonate (PFOS) and perfluoroalkyl carboxylates (PFCAs) were found in arctic carnivores and were most abundant in arctic fox and least abundant in mink. Although trace element concentrations in king and common eider ducks were low and not of toxicological concern, the number of nematode parasites in common eiders was positively correlated with total and organic mercury concentrations. Future research should focus on cadmium in moose and caribou, mercury in caribou, and emerging contaminants, with an effort to sample moose and caribou annually where possible to explore the role of naturally occurring cycles in apparent temporal trends. (c) 2005 Elsevier B.V. All rights reserved.
Keywords: Breeding Season; Common Eider; Contaminants; Somateria mollissima; King Eider; Somateria spectabilis

Behavior Body Condition and Foods of Buffleheads and Lesser Scaups During Spring Migration through the Klamath Basin California USA - Gammonley, J. H.; Heitmeyer, M. E. (Wilson Bulletin, 1990)
Behavior, body condition, and food habits of Buffleheads (Bucephala albeola) and Lesser Scaups (Aythya affinis) were studied in the Klamath Basin in northern California in spring 1986 and 1987. Peak Lesser Scaup and Bufflehead numbers were present in early February and and mid-March, respectively. The first spring migrants of both species were mostly paired or courting adults. Buffleheads and Lesser Scaups spent 63-82% and 23-50% of their diurnal activities feeding, respectively. Both species consumed primarily (66-77% volume, 58-72% dry weight) invertebrates. Chironomidae larvae were the most important food consumed by both species. Body and carcass masses of both species were near mid-winter levels but below masses observed upon their arrival at northern breeding areas. Our data indicate that wetland habitats in the Klamath Basin provide important food and resting resources for migrating Buffleheads and Lesser Scaups.
Keywords: Behavior; Nonbreeding Seasons; Energetics and Nutrition; Trophic Interactions; Bucephala albeola; Bufflehead

Haematology, blood biochemistry, parasites and pathology of common eider (Somateria mollisima) males during a mortality event in the Baltic - Garbus, S. E.; Christensen, J. P.; Buchmann, K.; Jessen, T. B.; Lyngs, P.; Jacobsen, M. L.; Garbus, G.; Lund, E.; Garbus, P. G.; Madsen, J. J.; Thorup, K.; Sonne, C. (SCIENCE OF THE TOTAL ENVIRONMENT, 2019)
A mortality event at the Christianso colony in the Baltic proper killed 115 common eiders (Somateria mollissima) in mid-May 2016. To complement previous studies of incubating females, 39 males were necropsied and from a subsample of these a biochemical and haematological profile was obtained. The birds were emaciated and cachexic having a 50% reduction in body mass. Twenty-nine eiders were diagnosed with hydropericardium, 15 had hunger edema, three birds had enteritis and a single air sac infection. All birds were infested with intestinal Polymorphus minutus and 32 of these with the intestinal Trematoda spp. Microscopic parasitic investigations identified endoparasitic trematodes of the families Bucephhalidae, Echinostomidae, Notocotyluridae and Levinsiniella. White blood cell count showed slight heterophilia and lymphopenia while the albumin: globulin ratio (0.28) indicated stress, immune supression and inflammatory reactions supported by a high heterophil: lymphocyte index (13). Declined plasma concentration of glucose, fructosamine, amylase, albumin and protein likewise indicated long-term starvation prior to mortality indicating phase III starvation (catabolism of protein). The dramatic increase in aspartate transaminase, glutamate-dehydrogenase, lactate-dehydrogenase and bile acids indicate liver disorders while dehydration, renal, heart and bone disorders was reflected in the increased uric acid, urea, phosphor and potassium values. These findings show that male eiders undergo long-term starvation and multi organ failure similar to that of incubating females previously reported from the same colony. It increases our knowledge of the physiology of starving eiders and add to our understanding of the recurrent mortality events in the colony that seems to be linked to changes in food availability being an important factor together with a warmer climate in a declining Baltic eider population. We recommend future studies to focus on food composition, migration patterns and environmental changes including parasitic infections and global warming. (C) 2019 Elsevier B.V. All rights reserved.
Times Cited in Web of Science Core Collection: 10 Total Times Cited: 11 Cited Reference Count: 48
Keywords: MOLLISSIMA; BODY-MASS; PROTEIN; Biochemistristry; CHEMISTRY; Endoparasites; Haematology; Multi-organ failure; STARVATION; UREA; URIC-ACID; WADDEN SEA

Changes in blood biochemistry of incubating Baltic Common Eiders (Somateria mollisima) - Garbus, S. E.; Christensen, J. P.; Lyngs, P.; Eulaers, I.; Mosbech, A.; Dietz, R.; Garbus, P.; Huusmann, R.; Sonne, C. (JOURNAL OF ORNITHOLOGY, 2020)
In this study, we analyzed biochemical parameters and the body masses of 14 incubating Common Eiders (Somateria mollissima) breeding on Christianso in the Baltic Sea from April to May 2015. The eiders were examined and sampled on days 4 and 24, corresponding to early and late incubation. In comparison to reference values, concentrations of alkaline phosphatase (161%), phosphorus (33%), and calcium (44%) were all significantly increased on day 4 by 33-161% due to egg production (p < 0.05). On day 24, we observed a significant loss of body mass (28%) compared to day 4 (p < 0.05). The average plasma concentrations of fructosamine (1-amino-1-deoxy-d-fructose, 21%), amylase (54%), albumin (30%), and total protein declined significantly (all p < 0.05). These declines resemble those seen for other avian species in which the female is the sole incubator, suggesting reduced food intake during the incubation period. A decline in total protein and albumin from day 4 to day 24 (18-30%) is indicative of stage III protein metabolism. Nonetheless, stable concentrations of urea, sodium, and potassium suggest that the incubating females were significantly hydrated. The change in the plasma albumin:globulin ratio from day 4 (0.82) to day 24 (0.57) may imply slight immune suppression, which is supported by the observation of a mass mortality incident shortly after the studied incubation period. These biochemical observations may add to our understanding of the recurrent mortality events that strike without warning in the declining Baltic eider population.
Times Cited in Web of Science Core Collection: 4 Total Times Cited: 4 Cited Reference Count: 54
Keywords: BODY CONDITION; MASS; MOLLISSIMA; URIC-ACID; Blood biochemistry; Body weight; CLINICAL-CHEMICAL PARAMETERS; ENERGY-EXPENDITURE; Health; HEMATOLOGY; MORTALITY EVENT; PATHOLOGY; Plasma; PLASMA BIOCHEMISTRY; Starvation; Stress

Pathology and Plasma Biochemistry of Common Eider (Somateria mollissima) Males Wintering in the Danish Part of the Western Baltic - Garbus, S. E.; Krogh, A. K. H.; Jacobsen, M. L.; Sonne, C. (JOURNAL OF AVIAN MEDICINE AND SURGERY, 2019)
Blood biochemistry, body mass, and gross pathology of male eiders (Somateria mollissima) wintering in the Inner Danish Waters of the western Baltic Sea (the Great Belt Strait) were assessed in this study. In November 2015, 14 specimens were obtained from the area defined for examination. Of the subject animals captured, 1 had dilated intestines and 2 had granulomas with encapsulated shotgun pellets considered to be chronic in nature. All 14 males were determined to have enteritis along with acanthocephalan and trematode endoparasites. Compared with reference values for captive eiders, plasma values of alanine aminotransferase (93%), total bilirubin (45%), gamma-glutamyl transferase (41%), and alkaline phosphatase (92%) showed significant increases in all 14 male birds. Altogether, the plasma biochemistry and gross pathology findings suggest that up to as many as 20% of the eider males in the Inner Danish Waters of the western Baltic Sea may suffer from liver and bile duct lesions and enteritis. The overall effect on the bird's survival from the results of this investigation is unknown. Therefore, the authors emphasize that more research is required on wintering eiders in the western Baltic to obtain a better understanding of their overall health status during winter, as well as their responses to wound-related lesions associated with gunshot pellets.
Times Cited in Web of Science Core Collection: 3 Total Times Cited: 3 Cited Reference Count: 37
Keywords: Somateria mollissima; waterfowl; WADDEN SEA; CLINICAL-CHEMICAL PARAMETERS; Alanine aminotransferase; alkaline phosphatase; ALP; ALT; Avian; Common Eiders; ducks; gamma-glutamyl transferase; GGT; hunting; MORTALITY; pathology; SERUM; total bilirubin; western Baltic

Common Eider (Somateria mollissima) body condition and parasitic load during a mortality event in the Baltic Proper - Garbus, S. E.; Lyngs, P.; Christensen, J. P.; Buchmann, K.; Eulaers, I.; Mosbech, A.; Dietz, R.; Gilchrist, H. G.; Sonne, C. (AVIAN BIOLOGY RESEARCH, 2018)
During late spring of 2007 and 2015, we observed unusually high mortality of Common Eiders (Somateria mollissima) on Christianso in the Baltic Proper. The number of dead birds (2007: 125; 2015: 110) composed 5-10% of the total colony. In 2015, we collected 15 (12 adult females, three subadult males) of the 110 recently deceased Common Eiders for detailed autopsy. The average body mass of the females was 1,040 g (920-1,160 g) which is ca 60% lower than what can be expected of healthy females during wintertime. Similarly, for the subadult males the average body mass of 1,203 g (1,070-1,300 g) comprised only 45% of what can be expected for healthy subadult males during winter. All 15 birds were thus severely emaciated and cachexic with general atrophy of muscles and internal organs. Hunger oedema, distended gall bladder, empty stomach, empty and dilated intestines and dilated cardiomyopathy were observed as well. In addition, all 15 Common Eiders were infected with high loads of the acanthocephalan parasite Polymorphus minutes. No gross morphological changes suggested toxicological, bacteriological or viral causes to the mortality. Taken together, our autopsy suggested starvation leading to secondary metabolic catabolism and eventually congestive heart failure. Five birds that were examined in 2007 showed the same symptoms. We suspect that the introduction of suboptimal feeding conditions in combination with a high parasite load over the last decade synergistically caused high physiological stress leading to population level effects manifested as high mortality.
Times Cited in Web of Science Core Collection: 17 Total Times Cited: 21 Cited Reference Count: 27
Keywords: waterfowl; avian; WADDEN SEA; ATROPHY; emaciation; food depletion; MUSCLE; parasite infection; starvation

Distribution and Numbers of the Barrows Goldeneye Bucephala-Islandica in Iceland - Gardarsson, A. (Natturufraedingurinn, 1978)
Distribution and numbers were studied during 1975-78. During censuses each bird was sexed and aged with the maximum possible accuracy. A brief review is given of the general distribution of the species with emphasis on the eastern part of the distribution. The breeding range is centered on Lake Myvatn and the uppermost Laxa river which together account for at least 95% of the breeding population. Prior estimates of the Barrow's goldeneye population of the Myvatn region are briefly reviewed. Better estimates are needed of the number of females, the number of breeders and the number of fledged young. Further studies are required to show conclusively whether censuses in Iceland account for the entire Icelandic population or whether there is a non-breeding segment in eastern North America.
Keywords: Breeding Season; Abundance, Distribution, and Trends; Barrow's Goldeneye; Bucephala islandica

Temporal processes and duck populations: examples from Myvatn - Gardarsson, Arnthor (Hydrobiologia, 2006)
Studies of temporal processes at Lake Myvatn, Iceland, on three scales, millennial, centennial and decadal, are reviewed and a summary is presented of the main results of waterfowl population monitoring studies conducted during the past three decades. The characteristics of shallow, subarctic Lake Myvatn and its volcanic environment, are outlined, as well as recent conflicts between development and conservation. Mining of the bottom sediment of Lake Myvatn has been a major agent causing habitat destruction and damage to the food web. Population limitation of waterbirds at Myvatn is discussed, as three research questions and emerging answers: (1) How is reproductive output determined? All species studied showed positive correlations of production of young with levels of aquatic insects, catastrophic weather was rarely important; (2) How is the dispersion of breeding ducks determined? Densities of migratory species are determined mainly by resource levels on the breeding ground in the year before they return to the breeding area; a year-round resident species, Bucephala islandica, adjusts its density to the current availability of insect food in each of two main habitats used; (3) How are flyway populations of ducks determined? For most species, there is not enough information on total numbers and the state of the habitat on a flyway scale. In B. islandica, there are indications that the total population is limited by resources in winter. The Myvatn study area is dominated by a single, shallow and eutrophic lake and for many waterbird species the area seems to form a single functional unit. This leads to significant correlations when comparing demography with environmental conditions, such as food resources.
Keywords: Breeding Season; Sea Ducks - General; Population Dynamics; Trophic Interactions; Barrow's Goldeneye; Bucephala islandica

Harlequin Ducks in Iceland - Gardarsson, Arnthor (Waterbirds, 2008)
In Iceland, the Harlequin Duck (Histrionicus histrionicus) is generally distributed as a breeder oil rapA clear-water streams, from sea level to about 700 in. Densities are generally low, except at the headwaters of streams draining productive lakes where blackflies (Simulium vittalum) are abundant. In northwest, north and cast Iceland, molting Harlequin Ducks are found in similar localities as the wintering birds, but molting birds are largely absent front the southwest coast. During the molt, the birds often stay close to cliffs or rocks and are hard to find. Harlequin Ducks winter oil exposed rocky coasts and densities are correlated with substrate as indicated by shore exposure. In 1998-2001, the total wintering population of Harlequin Ducks in Iceland was estimated at 14,000, with 95% confidence limits of 12,000 to 16,000. Assuming that migration in and out. Of Iceland is insignificant, the total Icelandic breeding Population is 3,000-5,000 females, or three to five females (pairs) 100 km(-2). A decline in wintering numbers was found in southwest Iceland in 1961-2002, but. numbers in the northeast have increased. This may be related to increased temperatures, but changes in exploitation may also have affected the population. The conservation of the Icelandic population of the Harlequin Duck is largely a matter of wise use of the coast and streams Which Should include preemptive measures, such as minimizing pollution and development. Small-scale river-development for power production and salmon fishing pose potential threats to Harlequin Ducks, but direct exploitation Of this population is not likely.
Keywords: Breeding Season; Abundance, Distribution, and Trends; Nonbreeding Seasons; Harlequin duck; Histrionicus histrionicus

Responses of breeding duck populations to changes in food supply - Gardarsson, Arnthor; Einarsson, Arni (Hydrobiologia, 1994)
We describe the main results of a monitoring study at Lake Myvatn, northern Iceland, begun in 1975. The aims were to find factors that limit production of young and cause changes in density of breeding ducks of several species. We estimated numbers of ducks in spring, before nesting, numbers of ducklings produced, and numbers moulting. Chironomid and simuliid dipterans were monitored with window traps. In all duck species studied, production of young was correlated with food abundance. Reproductive performance determined subsequent changes in spring population density of Eurasian Wigeon, Tufted Duck, Greater Scaup, Common Scoter and Harlequin Duck. The spring population of Barrow's Goldeneve apparently did not respond to variation in reproductive success. Moulting numbers of male Tufted Duck were related to chironomid abundance, but not those of Scaup and Barrow's Goldeneye. Moulting numbers were not associated with previous reproductive output.
Keywords: Breeding Season; Abundance, Distribution, and Trends; Harlequin duck; Histrionicus histrionicus; Productivity; Trophic Interactions; Black Scoter; Melanitta nigra; Barrow's Goldeneye; Bucephala islandica

Relationships among Food, Reproductive Success and Density of Harlequin Ducks on the River Laxa at Myvatn, Iceland (1975-2002) - Gardarsson, Arnthor; Einarsson, Arni (Waterbirds, 2008)
Harlequin Ducks (Histrionicus histrionicus) and aquatic insects have been monitored oil the River Laxa at Myvatn, from 1975 and 1977, respectively, tip to the present. The area holds the densest breeding population of this species in Iceland. The relationship between food abundance, reproductive success and density of breeding Harlequin Ducks were examined oil three sections (outlet, upper and lowland) of the Laxa. Spring density was highest Oil the lake Outlet (2.1 ha(-1)) and much lower oil the upper (0.3 ha(-1)) and lowland (0.4 ha(-1)) sections. Numbers of Harlequin Ducks on the Laxa increased significantly during the study period, 1975-2002. The trend of increasing numbers could be attributed to either a general, as yet unexplained, increase of Harlequin Ducks in northern and northeastern Iceland, or perhaps to the successful eradication of American Mink (Mustela. vison) breeding at the lake outlet (the main production centre of young Harlequin Ducks). Sex ratio in spring was 41% females at the outlet and oil the upper Laxa but 36% on tire lowland part. Yearling males were about 1% of all males oil the upper river but 6-19% on the lowland part. Most young were produced at the outlet, while few females or broods were found further down the liver. The mean total number of young produced annually at the Outlet was 74 +/- 11 (range = 9,235). Young per female present in spring at the Outlet and upper part was 0.49 +/- 0.09, or if only females at the Outlet in spring are considered, 0.82 +/- 0.17. Annual production of young was positively correlated with total yearly black (IN, abundance. We conclude that food limits the production of young in the Harlequin Duck. Changes in the densities of adults Oil the breeding grounds showed density dependence but were not significantly associated with food resources or previous production Of Voting.
Keywords: Breeding Season; Harlequin duck; Histrionicus histrionicus; Productivity; Population Dynamics; Trophic Interactions

Exploratory Surveys of Migratory Birds Breeding in the Western and Central Canadian Arctic 2005-2011 - Garrettson, P. R.; Kruse, K. L.; Moser, T. J.; Groves, D. J. (JOURNAL OF FISH AND WILDLIFE MANAGEMENT, 2020)
The Canadian Arctic and subarctic are the primary breeding areas of many species of North American water and land birds. Because of the remote location and the logistical difficulties of working there, wildlife biologists have not systematically surveyed most important areas for wildlife, nor have they surveyed these areas very frequently. During the summers of 2005-2011, various Joint Ventures, and U.S., Canadian, and state wildlife agencies and other partners funded exploratory fixed-wing aircraft surveys of migratory birds (excluding passerines and shorebirds) in important habitats in Canada's western and central Arctic. Our objectives were to provide access to the complete survey dataset (all bird and mammal observations and associated location data) and summarize information on several species. Thus, we produced maps of average relative density and estimates of abundance in the survey area for cackling geese Branta hutchinsii, greater white-fronted geese Anser albifrons, tundra swans Cygnus columbianus, king eiders Somateria spectabilis, long-tailed ducks Clangula hyemalis, white-winged Melanitta fusca and surf Melanitta perspicillatas scoters, and yellow-billed Gavia adamsii, red-throated Gavia stellata, and Pacific Gavia pacifica loons. We reviewed previous survey efforts in the area and, where possible, compared them with our results.
Times Cited in Web of Science Core Collection: 0 Total Times Cited: 0 Cited Reference Count: 51
Keywords: Arctic; ABUNDANCE; ducks; aerial surveys; geese; loons; migratory birds; swans

Identification of areas of seabird concentrations in the German North Sea and Baltic Sea using aerial and ship-based surveys - Garthe, Stefan (Progress in Marine Conservation in Europe:NATURA 2000 SITES IN GERMAN OFFSHORE WATERS, 2006)
Keywords: Abundance, Distribution, and Trends; Sea Ducks - General

Scaling possible adverse effects of marine wind farms on seabirds: developing and applying a vulnerability index - Garthe, Stefan; Huppop, Ommo (Journal of Applied Ecology, 2004)
1. Marine wind farms have attracted substantial public interest. The construction of wind facilities offshore may become Europe's most extensive technical development in marine habitats. Due to political pressure to complete construction soon, assessments of possible wind farm locations, for example in the German sectors of the North Sea and Baltic Sea, have to be based on existing knowledge. 2. In this study, we developed a wind farm sensitivity index (WSI) for seabirds. We applied this index to the Exclusive Economic Zone and the national waters of Germany in the North Sea. We chose nine factors, derived from species' attributes, to be included in the WSI: flight manoeuvrability; flight altitude; percentage of time flying; nocturnal flight activity; sensitivity towards disturbance by ship and helicopter traffic; flexibility in habitat use; biogeographical population size; adult survival rate; and European threat and conservation status. Each factor was scored on a 5-point scale from 1 (low vulnerability of seabirds) to 5 (high vulnerability of seabirds). Five of these factors could be dealt with by real data but four could only be assessed by subjective considerations based on at-sea experience; in the latter cases, suggestions of the first author were independently modulated by experts. 3. Species differed greatly in their sensitivity index (SSI). Black-throated diver Gavia arctica and red-throated diver Gavia stellata ranked highest (= most sensitive), followed by velvet scoter Melanitta fusca, sandwich tern Sterna sandvicensis and great cormorant Phalacrocorax carbo. The lowest values were recorded for black-legged kittiwake Rissa tridactyla, black-headed gull Larus ridibundus and northern fulmar Fulmarus glacialis. 4. A WSI score for areas of the North Sea and Baltic Sea was calculated from the species-specific sensitivity index values. Coastal waters in the south-eastern North Sea had values indicating greater vulnerability than waters further offshore throughout the whole year. 5. Derived from the frequency distribution of the WSI, we suggest a 'level of concern' and a 'level of major concern' that are visualized spatially and could act as a basis for the selection of marine wind farm locations. 6. Synthesis and applications. The wind farm sensitivity index might be useful in strategic environmental impact assessments (EIA). Results of small-scale EIA from wind installations should be considered within a more global perspective, provided, for example, by large mapping projects and detailed behavioural studies. This is difficult in normal EIA, particularly in highly dynamic coastal/marine habitats, and the results of this study fill an important gap by providing information on the potential sensitivity of seabirds and the importance of locations of wind installations.
Keywords: Conservation; Sea Ducks - General

Estimation of seabird numbers in the German North Sea throughout the annual cycle and their biogeographic importance - Garthe, Stefan; Sonntag, Nicole; Schwemmer, Philipp; Dierschke, Volker (Vogelwelt, 2007)
Increasing plans for economic activities at sea have recently led to intensive studies of seabird IV distribution and seabird numbers. However, there are still some temporal gaps concerning seabird numbers, and important up-to-date information is still missing. Thus, the aim of this study is to provide most recent seabird numbers for all seasons and all species that are regularly resting and/or foraging in German waters of the North Sea, split into the politically relevant areas EEZ as well as the 12 nautical miles zones of Niedersachsen and Schleswig-Holstein, respectively.For our analyses at sea, we investigated seabird numbers from the outer Wadden Sea islands to the outer boarders of German waters, using standardised ship-based (years: 1993-2003) and aerial (2002-2006) transect methods. We calculated and applied species-specific correction factors for birds presumably overlooked in the outer transect area. Using grid maps of seabird distribution, geographic units of sinnilar bird densities were designed for each bird species and each season, covering the entire study area. Then, numbers within each unit were calculated by firstly dividing the total number of birds by the total area surveyed and by secondly multiplying this value by the size of the unit. Finally, the total was derived as the sum across all of these units. In addition to the numbers at sea, we included (1) data from regular counts on Helgoland, (2) data from counts along the German Wadden Sea coast and (3) from aerial censuses for sea ducks as well as (4) colony census data.When only considering numbers at sea, between 183,000 (autumn) and 265,000 (winter) birds occur in the German part of the North Sea. The most numerous species are Common I Scoter Melanitta nigra (130,000 ind.; winter), Lesser Black-backed Gull Larus fuscus (45,000 ind.; summer) and Northern Fulmar Fulmarus glacialis (40,000 ind.; summer). Including coastal areas, total numbers range from 463,000 ind. (autumn) to 693,000 ind. (summer). Common Eiders Somateria mollissima are most numerous (180,000 ind.; autumn), followed by Black-headed Gulls Larus ridibundus (170,000 ind.; autumn) and Common Scoters (135,000 ind.; winter). In relation to their biogegographic populations, Common Eiders (23.7%; autumn), Lesser Black- backed Gulls (19.9%; summer) and Sandwich Terns Sterna sandvicensis (12.5%; summer) are most important. From a conservation point of view, summer is the most important time of the year. overall, our results show that 13 species occur in internationally important concentrations in the German North Sea area.
Keywords: Abundance, Distribution, and Trends; Sea Ducks - General; Nonbreeding Seasons

The effect of spring muskrat trapping on waterfowl in Maine - Gashwiler, Jay S. (Jour Wildlife Management, 1949)
A total of 127 ducks caught in spring set muskrat traps was received at the Maine Cooperative Wildlife Research Unit from 1938 to 1947. These consisted of 43% black ducks, 27% wood ducks, 12% green-winged teal, 9% ring-necked ducks, and 8% hooded mergansers; other spp. were of little significance. Quantitative data were obtained on 6 study areas in central and eastern Maine in the spring of 1946 and 1947. In 1946 a ratio of 14.7 muskrats was trapped to each duck[long dash]in 1947 it was 17.7 muskrats per duck. The total kill of ducks in muskrat traps in 1946 for Maine was conservatively estimated as 1945 birds with an additional estimated 2220 ducks trapped and released alive, suffering various degrees of injury. These figures assume greater importance when it is considered that they were birds already in, or approaching, the breeding cycle. As a rule, the surface feeding ducks were most susceptible to muskrat trapping. Spring muskrat trapping seasons are in effect in at least 15 of the 22 states and provinces that constitute the major part of the known black duck breeding range. Waterfowl mortality resulting from spring trapping over this vast area may be of serious concern. ABSTRACT AUTHORS: J. S. Gashwiler
Keywords: Conservation; Breeding Season; Hooded Merganser; Lophodytes cucullatus

Observations of Common Eiders in Hudson Strait Canada Aerial Surveys in 1980-83 - Gaston, A. J.; Cooch, F. G. (Reed, A. (Ed.). Canadian Wildlife Service Report Series, No. 47. Eider Ducks in Canada. V+177p. Canadian Wildlife Service: Ste-Foy, Quebec, Canada. Illus. Maps. Paper, 1987)
Keywords: Abundance, Distribution, and Trends; Common Eider; Somateria mollissima

Experimentally-Induced Polygyny in Buffleheads Evidence for a Mixed Reproductive Strategy - Gauthier, G. (Animal Behaviour, 1986)
Keywords: Behavior; Breeding Season; Bucephala albeola; Bufflehead

Brood Territories in Buffleheads Determinants and Correlates of Territory Size - Gauthier, G. (Canadian Journal of Zoology, 1987)
In most species of ducks, only females tend the brood, and they do not defend brood territories. However, in buffleheads (Bucephala albeola), females strongly defend brood territories. I examined factors affecting territory size of broods, and their consequences for growth rate and survival of ducklings. Brood density tended to be higher on ponds with higher food density. Territory size was inversely correlated with both food abundance in the territory and brood density on the pond. The slope of the relationship between territory size and food did not differ significantly from -1, the slope expected if females adjust territory size to maintain a constant food supply. Partial correlation analysis, however, revealed that brood density may be a more important proximate determinant of territory size than food. Growth rates of ducklings were not affected by food density but were depressed at high brood density in one year. Duckling survival increased with food density in the first year but was depressed at high brood density in the next. I suggest that females select a brood territory and that the size of that territory varies according to both food and brood density. This apparently buffers the effects of variation in food and brood density on growth and survival of ducklings.
Keywords: Breeding Season; Productivity; Survival; Habitat; Bucephala albeola; Bufflehead

The Adaptive Significance of Territorial Behavior in Breeding Buffleheads a Test of Three Hypotheses - Gauthier, G. (Animal Behaviour, 1987)
Waterfowl show considerable variability in their degree of territoriality. In this study, the adaptive significance of territorial behaviour in buffleheads, Bucephala albeola, a highly territorial species, was investigated. The following hypotheses were tested: (1) the territory secures food resources for the laying female (food hypothesis), (2) the territory provides undisturbed feeding time for the female and ensures paternity (mate-guarding hypothesis), (3) the territory protects the nest site (nest site hypothesis). Contrary to predictions of the food hypothesis, territory size was not inversely related to food abundance in the territory, and food was correlated to only two of five measures of reproductive success: females started laying earlier and clutch weight was slightly higher (but only in one year) on territories with more food. When males were removed during the egg-laying period, neighbouring males behaved aggressively toward widowed females and they usually evicted these females from their territory. Widowed females spent less time feeding and more time alert. Females tended to use a territory adjacent to the nest, and those that did not do so suffered a higher rate of nest parasitism. Thus mate guarding may be a major function of territorial behaviour in buffleheads. Protection of the nest site may further explain why bufflehead territories are more site-specific than those of other territorial ducks.
Keywords: Behavior; Breeding Season; Bucephala albeola; Bufflehead

Factors Affecting Nest-Box Use by Buffleheads and Other Cavity-Nesting Birds - Gauthier, G. (Wildlife Society Bulletin, 1988)
Keywords: Breeding Season; Bucephala albeola; Bufflehead

The Effect of Experience and Timing on Reproductive Performance in Buffleheads - Gauthier, G. (Auk, 1989)
I investigated the relationship among breeding experience, timing of reproduction, and reproductive performance in female Buffleheads (Bucephala albeola) over a 5-yr period. There were significant yearly fluctuations in date of nest initiation and in clutch size. On average, first-time breeders began nesting later, had a lower nesting success, fledged less young, and tended to have smaller clutches (although not significantly so) than experienced breeders. Birds that used nest boxes also began to lay later, had lower nesting success, and fledged fewer young than those that used natural cavities. This could not be explained solely by the higher use of nest boxes by first-time breeders. Repeatability was moderate for date of nest initiation and clutch size, but low for the number of young fledged. There was a seasonal decline in clutch size for both first-time and experienced breeders, although the relationship was much stronger for the latter group. Nesting success also decreased throughout the season, but the number of young fledged did not decrease. More early-hatched than late-hatched females were recruited into the breeding population. Early nesting was advantageous for experienced breeders.
Keywords: Breeding Season; Productivity; Bucephala albeola; Bufflehead

Philopatry Nest-Site Fidelity and Reproductive Performance in Buffleheads - Gauthier, G. (Auk, 1990)
I examined the consequences of breeding-site fidelity and natal philopatry on reproductive performance in Buffleheads (Bucephala albeola). Return rates of breeding females averaged 44% over 4 years. Females were twice as likely to return after their second breeding year than after their first. This difference was not associated with a poor reproductive performance in the previous year because birds that failed to return to the study area had a reproductive performance similar to those that returned, irrespective of breeding experience. Probability of return for successful breeders (45%) did not differ significantly (P > 0.1) from failed nesters (29%). However, nest-site fidelity was high (68%) and was associated with nesting success because successful breeders (83%) were much more likely to reuse the same nest site than were failed breeders (29%). Nest-site fidelity provided some benefits to females. Birds who used the same site laid earlier and laid more eggs. The return rate of females banded as ducklings was 13% in the first two years after banding. Natal philopatry was strongly female-biased and no male ducklings were known to have returned to the study area. The average distance of natal dispersal for returning females was 0.99 km. My results supported Rohwer and Anderson's (1988) prediction that female ducks should gain in terms of reproductive success by returning to a familiar area.
Keywords: Breeding Season; Productivity; Dispersal; Bucephala albeola; Bufflehead

Bufflehead (Bucephala albeola) - Gauthier, Gilles (Birds of North America, 1993)
Keywords: Breeding Season; Nonbreeding Seasons; Bucephala albeola; Bufflehead

Bufflehead (Bucephala albeola) - Gauthier, Gilles (The Birds of North America, 2014)
Keywords: Bucephala albeola; Bufflehead

Territorial Behavior Nest-Site Availability and Breeding Density in Buffleheads - Gauthier, G.; Smith, J. N. M. (Journal of Animal Ecology, 1987)
(1) Buffleheads (Bucephala albeola) are cavity-nesting ducks that are highly territorial during the nesting period. We tested whether nest-site availability or territorial behaviour limits breeding density. (2) The number of suitable cavities was two to three times higher than the number of breeding pairs during all 4 years. (3) Added next boxes, used increasingly by buffleheads as the study progressed, were compensated for by a concomitant decline in the number of natural cavities used. (4) The number of breeding pairs remained stable throughout the study. There was, however, a surplus of adult males in the population, and possibly also a surplus of adult females. (5) We removed seven territorial males during the nesting season. There were four replacements, three by previously unmated males and one by a new pair. (6) We conclude the nest sites are not limiting for buffheads in the Cariboo Parkland, BC [Canada], but the territorial behaviour may limit breeding density in this population.
Keywords: Behavior; Breeding Season; Habitat; Bucephala albeola; Bufflehead

Dispersal of the Common Eider Somateria-Mollissima in the St-Lawrence Estuary Quebec Canada - Gauthier, J.; Bedard, J. (Naturaliste Canadien (Quebec), 1976)
Common Eiders (20,000 pairs) nest on 10 islands scattered amid the 5000 km2 St. Lawrence estuary [Quebec, Canada]. The post-breeding dispersal of 1300 individually tagged females was followed in 1972 and 1973. From 12-15% of these take an active part in the rearing of ducklings. Their dispersal among the islands and along the shores of the estuary is influenced mainly by distance and physical conditions encountered during crossings (surface currents and waves) as well as by duckling vigor and the attraction of species coastal stations upon certain females. Females not accompanying ducklings scatter along the same coastal stretches visited by females accompanying ducklings, but their dispersal to such sites is less strongly affected by factors of distance and weather. By late July, birds which had completed brood-rearing joined non-breeding females and moved eastward for the duration of the molt. About 4000 males had already reached these molting grounds by late June while the remainder of the population, about 16,000, had probably left the estuary prematurely. Males and females were capable of flight (following molt) in mid and late-Sept., respectively. At this time, fall migration really began along 2 major axes. One towards the NE was coastal, bringing the birds around Gaspe Peninsula. The other, towards the SW leading the eiders upriver, around Montmagny at which point they undertook an overland journey towards the coast of Maine [USA]. By late-Nov., the estuary had been practically deserted by the eider. The spring migration occurred during the first weeks of May. About 20% of the marked birds displayed philopatry to either nest sites or rearing sites.
Keywords: Breeding Season; Common Eider; Nonbreeding Seasons; Molt; Migration; Somateria mollissima; Dispersal

Overland Migration by Common Eiders of the St-Lawrence Estuary Canada - Gauthier, J.; Bedard, J.; Reed, A. (Wilson Bulletin, 1976)
Evidence indicating the presence of an overland route, the numbers and status of eiders [Somateria mollissima] undertaking the overland trip, their behavior preparatory to the overland flight and the possible significance of the alternative migration routes were analyzed and discussed.
Keywords: Common Eider; Nonbreeding Seasons; Migration; Somateria mollissima

Polymorphic microsatellite markers for the goosander (Mergus merganser) - Gautschi, B.; Koller, B. (Molecular Ecology Notes, 2005)
To investigate the population genetic structure of the goosander (Mergus merganser) in Europe and to identify populations with a significant conservation value, we isolated nine microsatellite loci, and screened them in the subspecies Mergus merganser merganser and Mergus merganser americanus. All markers were polymorphic with two to 15 alleles per locus. Average observed and expected heterozygosity values were 0.422 and 0.624, respectively, for the European and 0.497 and 0.667, respectively, for the North American subspecies. Only one marker departed significantly from Hardy-Weinberg expectations in both subspecies. This marker was highly variable but homozygous in all females, suggesting a sex-linked inheritance.
Keywords: Techniques; Common merganser; Mergus merganser

Waterbird surveys at Hamilton Harbour, Lake Ontario, 1985-1988 - Gebauer, Martin B.; Dobos, Rob Z.; Weseloh, D. Vaughn (Journal of Great Lakes Research, 1992)
Waterbird surveys were conducted at Hamilton Harbour and Windermere Basin from 1985-88 to help assess current wildlife usage of Burlington Bay vis-a-vis the Remedial Action Plan (RAP) for Hamilton Harbour. A total of 43 and 32 waterbird species (not including shorebirds) was recorded at Hamilton Harbour and Windermere Basin, respectively. Generally, more species of loons and grebes and aquatic raptors such as osprey and bald eagle were found at Hamilton Harbour than at Windermere Basin. Species such as mallard and Canada goose which key into unnatural food sources at marinas and golf courses, and double-crested cormorants, associated with a growing colony, were present in large numbers at Hamilton Harbour. Large numbers of common mergansers congregated on the harbour in early winter before freeze-up. On average, waterbirds were found in greater numbers at Windermere Basin. The large numbers of scaup and dabbling ducks, such as black duck and mallard, present at Windermere Basin were attracted by the warm water, low disturbance, and abundant available food source. The ice-free conditions at Windermere Basin also attracted regionally rare wintering species such as northern pintail, northern shoveler, ruddy duck, and green-winged teal. Survey results were compared to unpublished survey data from Cootes Paradise and published results of the annual mid-winter waterfowl survey of western Lake Ontario. The importance of Hamilton Harbour and Windermere Basin to migratory waterbirds should be considered regarding future clean-up of Burlington Bay.
Keywords: Abundance, Distribution, and Trends; Sea Ducks - General; Nonbreeding Seasons; Common merganser

Mycobacterial conjunctival granuloma in a Scaly-sided merganser (Mergus squamatus) - Geboers, B.; Garmyn, A.; Hellebuyck, T.; Haesendonck, R.; Bosseler, L.; Ducatelle, R.; Antonissen, G. (VLAAMS DIERGENEESKUNDIG TIJDSCHRIFT, 2018)
A five-year-old, female scaly-sided merganser was presented with a chronic recurrent conjunctivitis of the left eye. Physical examination showed a caseous nodular lesion at the palpebral conjunctiva associated with excessive tearing. Necropsy revealed caseous necrotic debris at the left conjunctiva and infra-orbital sinus, but also multiple granuloma in several internal organs. Histological examination showed granulomatous splenitis, hepatitis, arteritis, fibrinonecrotic enteritis and conjunctivitis, and also amyloidosis of liver and spleen. Bacterial and molecular tests of a conjunctival swab in the live animal showed the presence of a multiresistant Escherichia coli strain and Chlamydia psittaci, respectively. These bacteria had only a secondary pathogenic role. No premortem cytological examination or Ziehl-Neelsen (ZN) staining of the histological section of the conjunctiva biopt or additional tests, such as blood test and radiographs, were performed. Finally, a Mycobacterium avium infection of the conjunctiva and internal organs was confirmed following necropsy by ZN staining and PCR analysis. Local and systemic antimicrobial treatments with fluoroquinolones, tetracyclines and aminoglycosides were unsuccessful.
Times Cited in Web of Science Core Collection: 0 Total Times Cited: 0 Cited Reference Count: 30
Keywords: HEALTH; CHLAMYDIA-SUIS; INFECTION; MANIFESTATIONS; OUTBREAK; RESPIRATORY-DISEASE; TUBERCULOSIS

K-ATP-CHANNELS PLAY A MINOR ROLE IN THE PROTECTIVE HYPOXIC SHUT-DOWN OF CEREBELLAR ACTIVITY IN EIDER DUCKS (SOMATERIA MOLLISSIMA) - Geiseler, S. J.; Ludvigsen, S.; Folkow, L. P. (Neuroscience, 2015)
Eider duck (Somateria mollissima) cerebellar neurons are highly tolerant toward hypoxia in vitro, which in part is due to a hypoxia-induced depression of their spontaneous activity. We have studied whether this response involves ATP-sensitive potassium (K-ATP) channels, which are known to be involved in the hypoxic/ischemic defense of mammalian neural and muscular tissues, by causing hyperpolarization and reduced ATP demand. Extracellular recordings in the Purkinje layer of isolated normoxic eider duck cerebellar slices showed that their spontaneous neuronal activity decreased significantly compared to in control slices when the K-ATP channel opener diazoxide (600 mu M) was added (F-1,F-70 = 92.781, p < 0.001). Adding the K-ATP channel blocker tolbutamide (400 mu M) 5 min prior to diazoxide completely abolished its effect (F-1,F-55= 39.639, p < 0.001), strongly suggesting that these drugs have a similar mode of action in this avian species as in mammals. The spontaneous activity of slices treated with tolbutamide in combined hypoxia/chemical anoxia (95% N-2-5% CO2 and 2 mu M NaCN) was not significantly different from that of control slices (F-1,F-203 = 0.071, p = 0.791). Recovery from hypoxia/anoxia was, however, slightly but significantly weaker in tolbutamide-treated slices than in control slices (F-1,F-137 = 15.539, p < 0.001). We conclude that K-ATP channels are present in eider duck cerebellar neurons and are activated in hypoxia/anoxia, but that they do not play a key role in the protective shut-down response to hypoxia/anoxia. (C) 2014 IBRO. Published by Elsevier Ltd. All rights reserved.
Geiseler, S. J. Ludvigsen, S. Folkow, L. P.
Keywords: Common Eider; Somateria mollissima; Physiology

Habitat Selection and Nest Predation in a Common Eider Somateria-Mollissima Population in Southern Sweden - Gerell, R. (Ornis Scandinavica, 1985)
The breeding ecology of the Common Eider was studied in an archipelago off S. Sweden in 1972-74. Females showed two different strategies when selecting nest sites. Those who started breeding earliest (mainly experienced females) selected islands containing colonies of Herring Gulls, while later breeding females mainly selected islands with colonies of Common Gulls. Both strategies are assumed to be adaptations to the nest predation pattern that characterizes the area at the onset of the breeding period. Eider nests located within a colony of Herring Gulls survived better than those in the outskirts of the colony. Since the Herring Gull prefers open breeding habitats, less concealed Eider nests were most successful. On islands with colonies of Common Gulls and on those with few or no breeding gulls, nests with a great amount of shelter survived best. The Eiders, especially those with larger clutches, were able to breed successfully in the presence of a stationary mink, whereas nest survival was very low on islands, visited by mink only occasionally. The yearly number of young hatched was about the same during the three years despite varying nest predation rates. This suggests that compensating mechanisms act to regulate the production of young. The greater vulnerability of young females' nests may serve as a buffer which mitigates the predation pressure on the nests of old females.
Keywords: Breeding Season; Common Eider; Somateria mollissima; Productivity; Habitat

Water-bird population changes in 1976-1990 on Besnard Lake, Saskatchewan: Increases in loons, gulls, and pelicans - Gerrard, Jon M.; Dzus, Elston; Bortolotti, Gary R.; Gerrard, P. Naomi (Canadian Journal of Zoology, 1993)
Declines in Common Loon (Gavia immer) populations associated with increasing human use of lakes have been reported from many areas of North America. In the present report we describe a lake in northern Saskatchewan, Besnard Lake, where there has been a substantial increase in the number of loons, from about 85 in 1976-1979 to about 165 in 1990. A comparison was made with numbers of other birds associated with water. Increases were also seen in American White Pelicans (Pelecanus erythrorhynchos), Osprey (Pandion haliaetus), Great blue Herons (Ardea herodias), Herring Gulls (Larus argentatus), Ring-billed Gulls (L. delawarensis), and Bonaparte's gulls (L. philadelphia). No change was seen in mergansers (Mergus merganser and M. serrator), Bald Eagles (Haliaeetus leucocephalus), or Common Terns (Sterna hirundo). The period 19760-1990 has also seen increased human use on Besnard Lake. The reason for increased loon numbers is uncertain, but could possibly be related to an increase in the numbers of small fish in Besnard Lake as a result of increased fishing pressure disproportionately removing the larger, predatory fish.
Keywords: Breeding Season; Abundance, Distribution, and Trends; Sea Ducks - General

Case report: Epizootic of fowl cholera in the common eider duck - Gershman, M.; Witter, J. F.; Spencer, H. E.; Kalvaitis, A. (J Wildl Mgmt, 1964)
An epizootic was observed in eider ducks (Somateria mollissima) which were nesting on islands off the Maine coast. On the three islands where losses were observed, over 200 birds died and more than 100 nests were lost. Losses were attributed to infection with Pasteurella multocida, the cause of fowl cholera. An attempt was made to eradicate the disease by removing residual populations; burning carcasses, eggs, and nests; and spraying existing water puddles with a cresylic compound. Inspections 2 weeks later revealed no further mortality. No new outbreaks have been reported to date. || ABSTRACT AUTHORS: Authors
Keywords: Breeding Season; Common Eider; Somateria mollissima; Survival; Disease

Mercury concentrations in migratory waterfowl harvested from Southern Nevada Wildlife Management areas, USA - Gerstenberger, Shawn L. (Environmental Toxicology, 2004)
Mercury concentrations were determined in 14 species of migratory waterfowl harvested from Southern Nevada Wildlife Management areas during the 2001-2002 hunting season. Common mergansers (2.61 +- 0.87 ppm liver; 0.22 +- 0.04 ppm muscle), northern shovelers (3.51 +- 3.8 ppm liver; 0.16 +- 0.03 ppm muscle), and bufflehead (2.63 +- 0.24 ppm liver; 0.91 ppm muscle) had the highest concentrations of mercury in the liver and muscle of the species harvested. The relationships between muscle and liver concentrations were also examined. These data indicate that liver tissue can be used with reasonable confidence (r > .80 for most species) to predict mercury concentrations in muscle, the most commonly consumed portion of waterfowl. The mercury concentrations reported here are some of the highest reported in the scientific literature, and they identify certain species, such as the northern shoveler and common merganser, that have accumulated unusually high concentrations of mercury. Evidence for the use of these three species as possible bioindicators for mercury is also presented.
Keywords: Sea Ducks - General; Nonbreeding Seasons; Contaminants; Common merganser; Bufflehead

Domoic acid and saxitoxin in seabirds in the United States between 2007 and 2018 - Gibble, C. M.; Kudela, R. M.; Knowles, S.; Bodenstein, B.; Lefebvre, K. A. (HARMFUL ALGAE, 2021)
As harmful algal blooms (HABs) increase in magnitude and duration worldwide, they are becoming an expanding threat to marine wildlife. Over the past decade, blooms of algae that produce the neurotoxins domoic acid (DA) and saxitoxin (STX) and documented concurrent seabird mortality events have increased bicoastally in the United States. We conducted a retrospective analysis of HAB related mortality events in California, Washington, and Rhode Island between 2007 and 2018 involving 12 species of seabirds, to document the levels, ranges, and patterns of DA and STX in eight sample types (kidney, liver, stomach, intestinal, cloacal, cecal contents, bile, blood) collected from birds during these events. Samples (n = 182) from 83 birds were examined for DA (n = 135) or STX (n = 17) or both toxins simultaneously (n = 30), using ELISA or LCMS at the National Oceanographic and Atmospheric Administration, National Marine Fisheries Service (NOAA-NMFS) Wildlife Algal-toxin Research and Response Network (WARRN-West) or the University of California, Santa Cruz (UCSC). DA or STX was detected in seven of the sample types with STX below the minimum detection limit in blood for the three samples tested. DA was found in 70% and STX was found in 23% of all tested samples. The ranges of detectable levels of DA and STX in all samples were 0.65-681,190.00 ng g(-1) and 2.00-20.95 ng g(-1), respectively. Cloacal contents from a Pacific loon (Gavia pacifica) collected in 2017 from Ventura County, California, had the highest maximum level of DA for all samples and species tested in this study. The highest level of STX for all samples and species was detected in the bile of a northern fulmar (Fulmarus glacialis) collected in 2018 from San Luis Obispo County, California. DA detections were consistently found in gastrointestinal samples, liver, bile, and kidney, whereas STX detections were most frequently seen in liver and bile samples. Co-occurring HAB toxins (DA and STX) were detected in white-winged scoters (Melanitta deglandi) in 2009, a Brandt's cormorant (Phalacrocorax penicillatus) in 2015, and a northern fulmar and common murre (Uria aalge) in 2018. This article provides DA and STX tissue concentrations and patterns in avian samples and shows the utility of various sample types for the detection of HAB toxins. Future research to understand the pharmacodynamics of these toxins in avian species and to establish lethal doses in various bird species would be beneficial.
Times Cited in Web of Science Core Collection: 11 Total Times Cited: 12 Cited Reference Count: 78
Keywords: CLIMATE-CHANGE; TOXICITY; COAST; Seabirds; MARINE BIRDS; DA; Domoic Acid; Harmful Algal Blooms; LIONS ZALOPHUS-CALIFORNIANUS; MASS MORTALITY; MONTEREY BAY; PHYTOPLANKTON; Saxitoxin; SEA LIONS

Habitat preferences of surface-diving waterbirds and American white pelicans wintering in Redfish Bay, Texas - Gibbons, Richard E.; Withers, Kim (Southwestern Naturalist, 2006)
Habitat preferences were determined for a guild of surface-diving waterbirds wintering in Redfish Bay, Texas: common loon (Gavia immer), eared grebe (Podiceps nigricollis), pied-billed grebe (Podilymbus podiceps), double-crested cormorant (Phalacrocorax auritus), red-breasted merganser (Merges serrator), and American coot (Fulica americana). American white pelican (Pelecanus erythrorlaynchos) also was included because it occupies habitats similar to those of the surface divers. Between November 2001 and April 2002, the locations of 4,232 surface divers and American white pelicans using aquatic habitats in Redfish Bay were recorded and entered into a GIS that included a National Wetlands Inventory layer. Bird habitat preferences-avoidances were determined using a test based on Bonferroni's inequality. American coots, American white pelicans, and pied-billed grebes preferred shallower estuarine subtidal seagrass beds, whereas common loons, double-crested cormorants, and eared grebes preferred deeper estuarine subtidal unconsolidated bay bottom. Red-breasted mergansers showed no habitat preferences.
Keywords: Nonbreeding Seasons; Habitat; Mergus serrator; Red-breasted merganser

Can local ecological knowledge contribute to wildlife management? Case studies of migratory birds - Gilchrist, Grant; Mallory, Mark; Merkel, Flemming (Ecology and Society, 2005)
Sound management of wildlife species, particularly those that are harvested, requires extensive information on their natural history and demography. For many global wildlife populations, however, insufficient scientific information exists, and alternative data sources may need to be considered in management decisions. In some circumstances, local ecological knowledge (LEK) can serve as a useful, complementary data source, and may be particularly valuable when managing wildlife populations that occur in remote locations inhabited by indigenous peoples. Although several published papers discuss the general benefits of LEK, few attempt to examine the reliability of information generated through this approach. We review four case studies of marine birds in which we gathered LEK for each species and then compared this information to empirical data derived from independent scientific studies of the same populations. We then discuss how we attempted to integrate LEK into our own conservation and management efforts of these bird species with variable success. Although LEK proved to be a useful source of information for three of four species, we conclude that management decisions based primarily on LEK, in the absence of scientific scrutiny, should be treated with caution.
Keywords: Conservation; Common Eider; Sea Ducks - General; Somateria mollissima

Observations of marine birds and mammals wintering at polynyas and ice edges in the Belcher Islands, Nunavut, Canada - Gilchrist, H. Grant; Robertson, Gregory J. (Arctic, 2000)
In the Belcher Islands, southeast Hudson Bay, Canada, two types of open water exist during winter: 1) large, wind-driven expanses of water along landfast ice edges and 2) recurring polynyas located between small islands (most < 10 ha and < 15 m deep). In severe winters, only polynyas persist. In March 1998 and 1999, we recorded the species and numbers of birds and marine mammals present at ten polynyas and along four landfast ice edges around the Belcher Islands. To help interpret our observations, we also collected traditional ecological knowledge from local Inuit. Large flocks of common eiders Somateria mollissima (200-12 500 birds) were seen along floe edges, and small groups occurred in some polynyas. King eiders S. spectabilis were also observed at several locations, always associated with common eiders. Oldsquaw ducks Clangula hyemalis were common (flocks of 100-500 birds) and occurred primarily at polynyas. Our observations of king eiders represent a significant northern range expansion for this species in Canada during winter. Ravens Corvus corax and snowy owls Nyctea scandiaca were observed along landfast ice edges. Ravens were feeding on the remains of seals killed by Inuit hunters and polar bears Ursus maritimus, and owls apparently hunted sea ducks that were loitering on ice edges at night. We regularly observed bearded seals Erignathus barbatus and ringed seals Phoca hispida at polynyas and floe edges. One beluga whale Delphinapterus leucas was observed by our Inuit guides along a western landfast ice edge, and three walrus Odobenus rosmarus were observed at a floe edge along the southern margin of the Belcher Islands. Clearly, the small recurring polynyas and ice floe edges around the Belcher Islands are important wintering habitat for oldsquaw and common and king eider ducks.
Keywords: Abundance, Distribution, and Trends; Common Eider; Nonbreeding Seasons; Clangula hyemalis; Long-tailed Duck; Somateria mollissima; King Eider; Somateria spectabilis

Birds and mammals of the Lena Delta nature reserve, Siberia - Gilg, Olivier; Sane, Raphael; Solovieva, Diana V.; Pozdnyakov, Vladimir I.; Sabard, Brigitte; Tsanos, Dimitri; Zockler, Christoph; Lappo, Elena G.; Syroechkovski, Evgeny E., Jr.; Eichhorn, Goetz (Arctic, 2000)
The Lena Delta is the largest arctic delta covered entirely by tundra. Protected since 1986, it is one of the richest areas in the Arctic north of 71degree N for both species diversity and breeding densities. Between 6 June and 17 August 1997, 16 mammal species and 76 bird species were recorded in the Lena Delta Nature Reserve and the surrounding buffer zone. Several species are new to the region: far-eastern curlew, fieldfare, redwing, arctic warbler, red-breasted flycatcher, and common rat. New breeders are merlin and arctic warbler. These 1997 records, combined with those from earlier studies, give a total of 122 bird species for the region. Of these, 67 have been found breeding at least once. Densities ranging from 245 to 641 birds per km2 were recorded in two restricted study areas. Such densities are unusually high north of 70degree N for non-colonial breeding birds. Lapland longspur (100-300 individuals/km2), red phalarope (up to 200 ind./km2), and several Calidris species were the most common. Ruddy turnstone and dunlin had densities higher than those previously reported from the Lena Delta and other Siberian sites. Among the shorebirds, spotted redshank, pintail snipe, grey plover, dunlin, and curlew sandpiper may have extended their breeding range or increased in population during the last 15 years. But further evidence is still needed to confirm the westward extension of spectacled eider, long-billed dowitcher, and sharp-tailed sandpiper.
Keywords: Breeding Season; Spectacled Eider; Abundance, Distribution, and Trends; Common Eider; Sea Ducks - General

Foraging ecology of Great Black-backed Gulls during brood-rearing in the Bay of Fundy, New Brunswick - Gilliland, S. G.; Ankney, C. D.; Hicklin, P. W. (Canadian Journal of Zoology, 2004)
We studied nesting ecology of Great Black-backed Gulls (Larus marinus L., 1758) in the Bay of Fundy, New Brunswick, in 1988 and 1989. We documented diet, feeding rate, and meal size for chicks from hatching to fledging. In 1989, colonies consisted of about 350 nests on five islands. Brood size declined with chick age, and by the end of the first week of the nestling period, 11%, 22%, 31%, and 36% of nests consisted of broods of 0, 1, 2, and 3 chicks, respectively. Average meals size increased and feeding frequency declined slightly with chick age. We estimated that 619.6 kg (dry mass) of food was fed to chicks during the nestling period in 1989. The composition of the chicks' diet changed with age and was most varied early in the nestling period, when they were fed relatively equal proportions of major food types. Overall, Atlantic herring (Clupea harengus L., 1758) was the most important prey item and contributed 63% of the energy consumed by chicks during the nestling period. Northern krill (Meganyctiphanes norvegica (M. Sars, 1857); 11.9%), lumpfish (Cyclopterus lumpus L., 1758; 10.4%), and waste (fisheries and domestic; 4.7%) were also important foods. Gull chicks and Common Eider (Somateria mollissima (L., 1758)) ducklings made up 1.9% and 0.8%, respectively, of the chicks' energy budget. We conclude that the primary factor effecting productivity of the Great Black-backed Gull was food availability, and the amount of food available varied little over the nesting period in 1989.
Keywords: Breeding Season; Common Eider; Somateria mollissima; Trophic Interactions

Evaluating the sustainability of harvest among northern common eiders Somateria mollissima borealis in Greenland and Canada - Gilliland, Scott G.; Gilchrist, H. Grant; Rockwell, Robert F.; Robertson, Gregory J.; Savard, Jean-Pierre L.; Merkel, Flemming; Mosbech, Anders (Wildlife Biology, 2009)
Sustainable harvest, the extraction of game without affecting population viability, is a desirable approach to the use of wildlife. However, overharvest has been responsible for the decline of many wildlife populations globally, so there is an urgent need to balance human requirements while avoiding the severe depletion of wild populations. Northern common eiders Somateria mollissima borealis are heavily hunted in Canada and Greenland, but the effect of this intensive harvest has not been examined. We developed a population model to investigate the sustainability of the reported harvest, which consisted of two wintering areas in Greenland and Atlantic Canada and three breeding populations. The model indicated that harvest in Atlantic Canada was sustainable, but a number of conditions could lead to slow declines. In contrast, the annual winter harvest of 55,000-70,000 ciders reported during 1993-2000 in Greenland was not sustainable, and this conclusion held under a wide range of alternate conditions. The model indicated that harvest during late winter may have a greater effect on populations than harvest in early winter. We further refined the model to assume that at some low population level the success of hunters would decline and that harvest became a function of population size (a rate). This scenario had the expected and undesirable result of stabilizing populations at very low levels. Overall, our model suggests that the high harvest reported in Greenland during 1993-2000 endangers the sustainable use of the northern common eider population and that management actions Lire required. Common eider harvest levels in Greenland should be reduced by at least 40% of the 1993-2000 levels to stop projected declines, and allow for recovery of the decimated Greenland breeding population. Encouragingly, new hunting regulations were introduced in Greenland in 2002-2004, and harvest levels appear to be decreasing. If these harvest reductions continue, Our population model Could be used to re-evaluate the status of Populations in the two countries.
Keywords: Conservation; Common Eider; Nonbreeding Seasons; Somateria mollissima; SDJV funded

Composition of Eiders Harvested in Newfoundland - Gilliland, Scott G.; Robertson, Gregory J. (Northeastern Naturalist, 2009)
Somateria mollissima (Common Eider) is an important game species throughout its circumpolar range, including eastern Canada and northeastern United States. In eastern Canada, the largest harvest of Common Eiders occurs in Newfoundland; however, the age, sex, and subspecific composition (S. m. borealis and dresseri are both present) of this hunted population is not well quantified. The species, subspecies, age, and sex composition of the harvest was determined by examining heads collected from 1672 ciders (including Somateria spectabilis [King Eider]), taken mostly by hunters, from 1980-1996. Band-recovery information for Common Eiders banded in Newfoundland and Labrador were also summarized, including data from a release program of hand-reared ducklings in northern Newfoundland from 1988-1996. The composition of the eider harvest varied across the province. In northern and eastern areas, borealis Common Eiders made up the bulk of the harvest. King Eiders were also taken in these areas. In southern areas, most Common Eiders taken were dresseri. Sex ratios tend to be near 1: 1, and immature birds comprised most of the harvest. Recovery distributions showed that Common Eiders breeding in Newfoundland and Labrador were mainly taken within the province, but also contributed to harvests in Quebec and Nova Scotia, and to a lesser extent, Maine. Hand-reared ducklings had direct recovery rates of 0.047 and were most likely to be recovered within the province in the year of banding, but contributed to harvests in Atlantic Canada and New England as they aged. The harvest of ciders in Newfoundland varies regionally and seasonally; therefore specific harvest regulations could be implemented to manage the variety of populations present in the province throughout the year.
Keywords: Conservation; Common Eider; Nonbreeding Seasons; Somateria mollissima; King Eider; Somateria spectabilis

Distribution and Abundance of Harlequin Ducks Breeding in Northern Newfoundland - Gilliland, Scott G.; Robertson, Gregory J.; Goodyear, Geoff S. (Waterbirds, 2008)
The number of Harlequin Ducks (Histrionicus histrionicus) wintering in eastern North American is small, and little was known about these birds, especially their breeding distribution. During the breeding period, 990 km of river and streams oil Newfoundland's North Peninsula was surveyed where 69 Harlequin Ducks were sighted. Breeding densities varied among watersheds (range 0-0.090 males/km), were slightly lower than elsewhere in eastern North America, and lower than in western North America and Iceland. A total of 128 +/- 45 males (indicated pairs) or 284 +/- 89 birds (+/-95% CI) was estimated to occur on the North Peninsula during the breeding season. This may represent 20% of Harlequin Ducks wintering in eastern North America and highlights the importance of the Northern Peninsula as a breeding area for this rare duck.
Keywords: Breeding Season; Abundance, Distribution, and Trends; Harlequin duck; Histrionicus histrionicus

Abundance and distribution of Harlequin Ducks molting in eastern Canada - Gilliland, Scott G.; Robertson, Gregory J.; Robert, Michel; Savard, Jean-Pierre L.; Amirault, Diane; Laporte, Pierre; Lamothe, Pierre (Waterbirds, 2002)
Until recently, very little was known about the basic ecology of the Harlequin Duck (Histrionicus histrionicus) in eastern North America, including molting locations. A combination of aerial, ground and boat surveys were initiated in 1989 (Quebec) and 1994 (Newfoundland and Labrador), and continued through 1999, to locate their molting areas. Molting Harlequin Ducks were found in Labrador, Newfoundland and the Gaspe Peninsula and Anticosti Island, Quebec. Coastal areas of southern Labrador, Grey Islands, northern Newfoundland, and Bonaventure and Anticosti Islands, southern Quebec, were the most important sites. The tip of northern Labrador and possibly sites along the Quebec North Shore and Greenland are the most likely sites where the rest of the eastern population molts. Molting chronology for the ducks in Quebec is similar to those on the east and west coast of North America. Now that these sites are known, monitoring and, if necessary, protection of these sites can be considered.
Keywords: Abundance, Distribution, and Trends; Nonbreeding Seasons; Harlequin duck; Histrionicus histrionicus; Molt

Variability in remigial moult chronology and nutrient dynamics of Surf Scoters Melanita perspicillata - Gilliland, S. G.; Savard, J. P. L. (WILDFOWL, 2021)
Little is known of the moulting ecology of the Surf Scoter Melanita perspicillata. In this study, we quantify the age and sex composition of moulting flocks, determine moulting chronology and consistency between years, and assess the body condition of scoters moulting along the coast of Labrador, Canada, during 2004-2007. Flocks of moulting scoters were comprised mainly of adult male Surf Scoters and the proportion of adults and sub-adults varied among years. Adult and sub-adult males had similar structural size and body mass but differed in bill morphology. The forecrown patch was a good indicator of age in males during moult, being fully developed in adult males and partially developed in sub-adults. Female Surf Scoters moulted later than males and adult males moulted slightly earlier than sub-adult males. We estimated that Surf Scoters were able to fly when their primaries reached 80% of their full growth, which yielded a flightless period of at least 35 days. We did not find any changes in leg, breast and liver lipid and proteins, but did observe a slight increase in total lipid levels as moult progressed.
Times Cited in Web of Science Core Collection: 0 Total Times Cited: 0 Cited Reference Count: 92
Keywords: Surf Scoter; DUCKS; KING EIDERS; WING MOLT; ECOLOGY; BODY-MASS; AGE RATIOS; Labrador; Melanita perspicillata; moult chronology; nutrient dynamics; ORGAN SIZE; PACIFIC COAST; POPULATIONS; SEX-RATIOS

Estimating Population Growth and Recruitment Rates Across the Range of American Common Eiders - Giroux, J. F.; Patenaude-Monette, M.; Gilliland, S. G.; Milton, G. R.; Parsons, G. J.; Gloutney, M. L.; Mehl, K. R.; Allen, R. B.; McAuley, D. G.; Reed, E. T.; McLellan, N. R. (JOURNAL OF WILDLIFE MANAGEMENT, 2021)
Sound management of bird populations rests upon an adequate understanding of their population dynamics. Our study evaluated recruitment and population growth rates of 14 American common eider (Somateria mollissima dresseri) colonies from Labrador, Nova Scotia, Quebec, Canada, and Maine, USA, during various periods between 1970 and 2019. We used Pradel mark-recapture models to estimate colony-specific growth rates and the relative contributions of survival and recruitment on growth. We also validated this approach using annual nest counts (similar to 8,000 pairs) conducted between 2003 and 2019 during down harvest operations in 3 colonies located in the Saint Lawrence estuary in Quebec. There was generally a good agreement between estimates derived using the 2 approaches. We considered that capture-recapture data were suitable to estimate population trends of common eiders in other colonies, especially for colonies where accurate nest monitoring is impaired by dense vegetation. The breeding abundance declined at major colonies in Maine and Nova Scotia and increased or was stable in Quebec and Labrador. Female survival contributed the most to population growth, but variation in recruitment among colonies was more important than variation in survival to explain population growth. Management measures should thus strive to maximize local recruitment in colonies with declining populations. The assumption that apparent survival probabilities were homogeneous throughout an individual capture history was violated at several colonies in Quebec and Labrador. Using recaptures and band recoveries, we showed that the lower apparent survival for newly marked individuals compared to females that had been recaptured at least once was caused by a difference in site fidelity rather than true survival. But <1% of recaptured females dispersed to another colony for breeding, indicating that the lower site fidelity could be related to heterogeneity in capture probability among individuals. (c) 2021 The Wildlife Society.
Times Cited in Web of Science Core Collection: 0 Total Times Cited: 0 Cited Reference Count: 37
Keywords: survival; common eider; SOMATERIA-MOLLISSIMA; Somateria mollissima dresseri; DYNAMICS; Atlantic Flyway; capture marking recapture; GULL PREDATION; LONG-TERM; MARK; Pradel models; RECAPTURE; recruitment

The Biology of the Blackfly Simulium-Vittatum Diptera Simuliidae in the River Laxa Northern Iceland - Gislason, G. M.; Johannsson, V. (Natturufraedingurinn, 1985)
The study focused on the population dynamics of the blackfly S. vittatum, and which factors controlled its density and production. The study area was the upper part of the river, above the Laxarvirkjun hydroelectric power station. Three sampling sites were chosen as representative for the river, Midkvisl, in the outlet, Helluvad, 4 km from the lake, and Thvera, 22 km downstream. S. vittatum dominates the fauns of the Laxa River (Gislason 1985). It belongs to 2 sibling species, IIIL-1 and IS-7 (Klaus Rothfels in lit.). It is about 70-85% of the secondary production in the river. It is partly a univoltine species. In the upper reaches of the river (close to the outlet) each generation was clearly divided into 2 cohorts. One cohort grew very rapidly over the summer, with a life span of about 1-2 months. The other cohort grew more slowly, with a life span of one year. In the lower reaches of the upper part of the river, only the slow-growing cohort existed. The larvae fed on fine particulate organic matter (POM) drifting from Lake Myvatn. There was no difference in the composition of their gut contents and the seston of the river. Usually detritus was not less than 50% of the gut contents. Diatoms accounted for 10-70% of the gut contents in 1977 and 25-45% in 1978. The most frequently ingested species was Fragilaria spp. (mainly F. construens), which is abundant in the bottom sediment of L. Myvatn. Other frequently ingested diatoms were Stephanodiscus hantzschii, Nitzschia spp., Synedra spp. and Rhoicosphenia curvata. In August 1977 the blue-green alga Anabaena flos-aquae was the most frequently ingested alga and it was abundant in the gut contents in July. In 1978 this alga was rarely found. The larvae of S. vittatum is the main food of trout (Salmo trutta L.), harlequin ducks (Histrionicus histrionicus (L.)) and Barrow's goldeneye (Bucephala islandica (Gmelin)) in Laxa. The changes in the population of S. vittatum affected the population of these predators. The annual catch of trout fell from about 3000 to 1000-1500, and other studies have shown that the numbers of harlequin ducklings produced on the first 10 km of the river in the autumn fell from about 120 to 10-60 and the Barrow's goldeneye changed its feeding habits, moving from the river to L. Myvatn. With increasing production of S. vittatum, the number of harlequin ducklings produced on the upper part of the river started to increase, and was 231 in 1984.
Keywords: Breeding Season; Harlequin duck; Histrionicus histrionicus; Productivity; Trophic Interactions; Barrow's Goldeneye; Bucephala islandica

Molecular characterisation of Sarcocystis rileyi from a common eider (Somateria mollissima) in Norway - Gjerde, B. (Parasitology Research, 2014)
The breast and leg muscles of a common eider (Somateria mollissima; Anatidae: Anseriformes) from northern Norway contained numerous grossly visible cigar-shaped sarcocysts measuring about 5 x 1 mm. Light microscopic examination of isolated sarcocysts revealed that they were encapsulated by a thin fibrous layer, underneath which there was a thin and fairly smooth cyst wall with no visible protrusions. The cystozoites were straight, spindle-shaped and about 13 mu m long. Genomic DNA was extracted from 12 excised sarcocysts and each DNA isolate was subjected to PCR amplification of one to four loci: the 18S and 28S ribosomal RNA genes (four isolates), the internal transcribed spacer 1 (ITS1) region (six isolates) and the mitochondrial cytochrome c oxidase subunit 1 gene (cox1) (12 isolates). At the three nuclear loci, the new sequences showed 99.9-100 % sequence identity with previous sequences of Sarcocystis rileyi from the mallard duck in Lithuania and USA, and they could therefore be assigned to this species. At cox1, the new sequences of S. rileyi were most similar to Sarcocystis arctica and Sarcocystis neurona, but the most closely related Sarcocystis spp. in birds have not been sequenced at this locus. There was no sequence variation at any locus between the 4-12 examined isolates of S. rileyi. This is the first genetically verified record of S. rileyi in the common eider, as well as in any bird species in Norway. The phylogenetic placement of S. rileyi was inferred separately from 28S rRNA gene and cox1 sequences, and similar results were obtained in both analyses.
Gjerde, Bjorn
Keywords: Common Eider; Somateria mollissima; Parasites

Helminth Parasites of the Bufflehead Duck, Bucephala Albeola, Wintering in the Chihuahua Desert with a Checklist of Helminth Parasites Reported from This Host - Gladden, Beverly W.; Canaris, A. G. (Journal of Parasitology, 2009)
The bufflehead duck (Bucephala albeola) (Mergini) ranges from Alaska and Canada to the United States and Mexico. Buffleheads ingest invertebrates as a major component of their food throughout life. Puddle ducks (Anatinae) change mainly to vegetable foods at all early age. Loss of helminth parasite species and abundance in the fall migration has been reported for puddle ducks. This change in food has been hypothesized to cause some of the parasite loss. Nothing was known about helminth community dynamics in wintering buffleheads, including possible loss of helminths evident in puddle ducks. Helminth communities of the buffleheads were compared between wintering localities in the Chihuahua Desert of Texas and Mexico and to results from a nesting locality in Manitoba, Canada. There were no significant differences for average helminth species richness, prevalence, or abundance between the nesting and wintering grounds. Replenishment of helminths occurred in wintering buffleheads, and abundance of some helminth species increased significantly over time. The majority of helminth life cycles were indirect. These results were mostly related to the bufflehead's continued ingestion of invertebrate foods. Seven of the 41 helminth species present in buffleheads were in common to the 3 localities. Helminth community similarities between Manitoba and Texas and Manitoba and Mexico were much lower than similarity between Texas and Mexico. The dissimilarities were mostly attributable to differences in habitats but may also indicate loss of helminth species with subsequent infections with other species. The component community of the bufflehead from the Chihuahua Desert in Texas (n = 41) consisted of 23 species of helminths (10 species of cestodes, 7 trematodes, 4 nematodes, and 2 acanthocephalans) for a total of 4,008 individual specimens. Cestodes accounted for 69% of the total abundance. The component community of B. albeola from the Chihuahua Desert in Mexico (n = 26) consisted of 18 species of helminths (7 species of cestodes, 5 trematodes, 4 nematodes, and 2 acanthocephalans) for a total of 4,345 individual specimens. Cestodes accounted for 83% of the total abundance. The bufflehead shared 10 helminth species with other species of waterfowl utilizing habitats in the Chihuahua Desert. A checklist of all helminth parasites reported for buffleheads includes 27 identified to genera, 40 to species, and 12 species from buffleheads from the Chihuahua Desert in common with buffleheads from other localities.
Keywords: Nonbreeding Seasons; Bucephala albeola; Bufflehead; Parasites

Impact of predation by greater flamingos Phoenicopterus ruber on the macrofauna of two southern African lagoons - Glassom, D.; Branch, G. M. (Marine Ecology Progress Series, 1997)
Glassom, D Branch, GM

Changes in the Size of Seabird Populations in Utvaer Norway - Godo, G. (Fauna (Oslo), 1985)
Utvaer (60.degree.2'N and 4.degree.32'E) consists of about 50 islands, islets and skerries. The locality is isolated at the westernmost part of Norway, and is one of the most interesting localities for seabirds in Sogn and Fjordane County. Utvaer was investigated at the end of the last century by Grieg (1889), after the second world war by Willgohs (1951, 1952, 1954, 1955), and during the last few years (1978-1984) by the author. Shag Phalacrocorax aristotelis has increased from 40 pairs in 1949 to 281 nests in 1984. Common eider Somateria mollissima was and still is the most numerous duck in Utvaer. The most numerous of the gulls is the Herring gull Larus argentatus (90 pairs in 1984). The Kittiwake Rissa tridactyla established in Utvaer in 1964. Ten years later 56 nests were recorded, but in 1984 only 25 non-breeding birds were observed. Guillemot Uria aalge and Razorbill Alca torda were more numerous earlier, and after the second world war only a few breeding pairs have been recorded. Puffin Fratercula arctica and Black guillemots Cepphus grylle were the most numerous auks in 1984.
Keywords: Breeding Season; Abundance, Distribution, and Trends; Common Eider; Sea Ducks - General

Post-Release Behavior of Surf Scoters (Melanitta perspicillata) Following an Oil Spill: an Experimental Approach to Evaluating Rehabilitation Success - Golightly, R. T.; Gabriel, P. O.; Lockerby, C. L.; De La Cruz, S. E. W.; Takekawa, J. Y.; Henkel, L. A.; Maassey, J. G.; Ziccardi, M. H. (WATERBIRDS, 2019)
Effectiveness of rehabilitating wildlife following oil spills has been controversial. Impacts include mortality or changes in behavior affecting health or reproduction. Immediately following a bunker fuel oil spill on San Francisco Bay, California, USA, a unique experiment was conducted to examine the movement and foraging behavior of Surf Scoters (Melanitta perspicillata) that had been oiled, captured, cleaned, rehabilitated, and radiomarked. Unoiled Surf Scoters were similarly cleaned, rehabilitated, and radio-marked while other unoiled Surf Scoters were radio-marked as controls. Surf Scoters in the control group had larger home-ranges (46.29 +/- 3.23 km(2)) than either the oiled/rehabilitated (32.58 +/- 5.48 km(2)) or rehabilitated only groups (31.06 +/- 3.05 km(2)); the control group also was more likely to use unsheltered, shallow areas of the bay (66.9 +/- 4.3% of locations) than either the oiled/rehabilitated (50.3 +/- 5.2%) or rehabilitated only groups (58.2 +/- 6.5%). The oiled/rehabilitated group was closer to shore (986 +/- 149 m) than rehabilitated (1,894 +/- 295 m) or control groups (2,113 +/- 227 m). Differences in habitat use, movement patterns, and home range sizes indicated that Surf Scoters held in captivity were more restricted in their movements; therefore, captivity and rehabilitation practices may also influence success of the rehabilitation.
Times Cited in Web of Science Core Collection: 1 Total Times Cited: 1 Cited Reference Count: 49
Keywords: Melanitta perspicillata; Surf Scoter; SURVIVAL; WHITE-WINGED SCOTERS; MORTALITY; California; CLAM DENSITY; COOTS FULICA-AMERICANA; DIVING BEHAVIOR; EXPERIMENTAL SOFT-RELEASE; FORAGING BEHAVIOR; oil exposure; radio telemetry; RADIO TRANSMITTERS; RADIOTRANSMITTERS; San Francisco Bay; wildlife rehabilitation

EXPERIMENTAL ASSESSMENT OF GULL PREDATION ON THE JONAH CRAB CANCER-BOREALIS (STIMPSON) IN NEW-ENGLAND ROCKY INTERTIDAL AND SHALLOW SUBTIDAL ZONES - Good, T. P. (Journal of Experimental Marine Biology and Ecology, 1992)
GOOD, TP

Marine Foraging Birds As Bioindicators of Mercury in the Gulf of Maine - Goodale, M. Wing; Evers, David C.; Mierzykowski, Steven E.; Bond, Alexander L.; Burgess, Neil M.; Otorowski, Catherine I.; Welch, Linda J.; Hall, C. Scott; Ellis, Julie C.; Allen, R. Bradford; Diamond, Anthony W.; Kress, Stephen W.; et al. (EcoHealth, 2008)
From existing databases, we compiled and evaluated 604 total mercury (Hg) levels in the eggs and blood of 17 species of marine foraging birds from 35 Gulf of Maine islands to provide baseline data and to determine the best tissue, age class, and species for future biomonitoring. While mean Hg levels in most species did not exceed adverse effects thresholds, levels in some individual eggs did; for all species arithmetic mean egg Hg levels ranged from 0.04 to 0.62 (mu g/g, wet weight). Piscivorous birds had higher Hg levels than invertivores. Leach's storm-petrel (Oceanodroma leucorhoa), razorbill (Alca torda), and black guillemot (Cepphus grylle) adult blood and egg Hg levels were higher than other species. Our results indicate that adult blood is preferable to chick blood for detecting long-term temporal trends because adult levels are higher and not confounded by metabolic effects. However, since we found that eggs and adult blood are comparable indicators of methylmercury bioavailability, we determined that eggs are the preferred tissue for long-term Hg monitoring because the relative ease in collecting eggs ensures consistent and robust datasets. We suggest specific sampling methods, and based on our results demonstrate that common eider (Somateria mollissima), Leach's storm-petrel, double-crested cormorant, and black guillemot are the most effective bioindicators of Hg of the Gulf of Maine.
Keywords: Breeding Season; Common Eider; Contaminants; Somateria mollissima

Some breeding-habits of the Goosander - Gordon, Audrey Seton (British Birds, 1930)
Observation on a nest in a hollow alder tree in Scotland indicates that the eggs were incubated for at least 31 days before hatching about May 15. The young jumped out of the nest without assistance when about 2 days old, and probably would have remained longer if not disturbed.
Keywords: Breeding Season; Common merganser; Mergus merganser

Pituitary Prolactin Levels in the Common Eider Somateria Mollissima-Mollissima - Gorman, M. L. (Ornis Scandinavica, 1973)
Keywords: Common Eider; Somateria mollissima; Physiology

Seasonal Changes in the Adrenal Steroid Tissue of the Common Eider Somateria-Mollissima and Its Relation to Organic Metabolism in Normal and Oil Polluted Birds - Gorman, M. L.; Milne, H. (Ibis, 1971)
Keywords: Common Eider; Contaminants; Somateria mollissima; Physiology

Creche Behavior in the Common Eider Somateria-Mollissima-Mollissima - Gorman, M. L.; Milne, H. (Ornis Scandinavica, 1972)
Keywords: Behavior; Breeding Season; Common Eider; Somateria mollissima

Do Field Observers Attract Nest Predators and Influence Nesting Success of Common Eiders Somateria-Mollissima - Gotmark, F.; Ahlund, M. (Journal of Wildlife Management, 1984)
Incubating common eiders (S. mollissima) were flushed to test whether avian predators are attracted to islands in southern Sweden. The abundance of hooded crows (Corvus cornix) was slightly lower after disturbance than before, although many eider nests were exposed after disturbance. Crows did not increase their foraging effort or success in finding nests on the islands following disturbance. Gulls (Larus argentatus, L. marinus) were slightly attracted to the disturbed islands and tended to increase their foraging effort and success. Although more depredations were observed after disturbance than before, clutch size and frequency of robbed nests did not differ (P > 0.10) on disturbed and undisturbed islands. All nests were covered by the observers; this probably protected the nests. Simulated nests with exposed eggs experienced much higher predation than those covered with down.
Keywords: Conservation; Breeding Season; Common Eider; Somateria mollissima; Productivity

Historical Status of Harlequin Ducks Wintering in Eastern North America a Reappraisal - Goudie, R. I. (Wilson Bulletin, 1989)
Keywords: Breeding Season; Abundance, Distribution, and Trends; Nonbreeding Seasons; Harlequin duck; Histrionicus histrionicus

Common Eider (Somateria mollissima) - Goudie, R. Ian, Gregory J. Robertson and Austin Reed (The Birds of North America, 2000)
Keywords: Common Eider; Somateria mollissima

Multivariate behavioural response of harlequin ducks to aircraft disturbance in Labrador - Goudie, R. Ian (Environmental Conservation, 2006)
The effects of low-level aircraft over-flights on behaviour of harlequin ducks (Histrionicus histrionicus) breeding in central Labrador were quantified during 2000-2002. The Canadian Department of National Defence supports a low-level training programme in the 130 000 km(2) Military Training Area of Labrador involving military jets. The Institute for Environmental Monitoring and Research (IEMR) undertakes scientific research into environmental impacts of low-level military jet over-flights. A suite of 17 behavioural categories of paired male and female harlequin ducks was modelled, and a canonical variable representing alert behaviour, inactivity on the water and decreased inactivity out of water in response to over-flights represented 73.1% of the variance in the data cluster and provided marked separation of disturbed and undisturbed groups. Behavioural responses of harlequin ducks to military jets were 23 times stronger than their responses to floatplanes, helicopters and military cargo planes, and the significant interaction of aircraft type and noise indicated that noise may be the primary stressor affecting behaviour. A quadratic response of the canonical variable to noise generated from aircraft during standardized 30-minute observation periods was defined. The multivariate analyses were more robust because they indicated covariance in behavioural categories associated with disturbance that was not originally detected in univariate analyses, suggesting the importance of integrating behaviours other than overt responses. The significant effects of military jet over-flights on harlequin duck behaviour emphasize the need to evaluate potential population consequences of aircraft disturbance.
Keywords: Conservation; Behavior; Breeding Season; Harlequin duck; Histrionicus histrionicus

Body Size Activity Budgets and Diets of Sea Ducks Wintering in Newfoundland Canada - Goudie, R. I.; Ankney, C. D. (Ecology (Washington D C), 1986)
Morphology, diets, and activity budgets of four co-existing sea ducks, Harlequin Ducks, (Histrionicus histrionicus), Oldsquaws (Clangula hyemalis), Black Scoters (Melanitta nigra), and Common Eiders (Somateria mollissima), were studied during the fall and winter of 1983-1984 at Cape St. Mary's, Newfoundland. The diets and behavior of these species were related to body size. The smaller species, H. histrionicus and C. hyemalis, had diets with higher energy densities and spent more time feeding than did the larger M. nigra and S. mollissima. Multiple regression models were used to determine how the proportion of time spent feeding varied with five environmental and two temporal variables; we found that the two smaller species showed little flexibility in adjusting their activity budgets. This could become critical to survival of these diurnal feeders during periods of severe winter weather or ice conditions. As suggested by Bergmann in 1847, closely related species, such as these syntopic sea ducks in a harsh marine environment, adjust their behavior and diets to compensate for the thermodynamic differences associated with body size.
Keywords: Behavior; Common Eider; Nonbreeding Seasons; Harlequin duck; Histrionicus histrionicus; Clangula hyemalis; Long-tailed Duck; Somateria mollissima; Physiology; Trophic Interactions; Black Scoter; Melanitta nigra

Patterns of Habitat Use by Sea Ducks Wintering in Southeastern Newfoundland Canada - Goudie, R. I.; Ankney, C. D. (Ornis Scandinavica, 1988)
Sea duck use of coastal habitats in southeastern Newfoundland varied by shoreline type and distance from shore. Harlequin Ducks exploited areas relatively close to shore and adjacent to sunkers (skerries) when foraging. Oldsquaws, Black Scoters, and Common Eiders foraged at similar distances from shore, on average, however epiders primarily used areas adjacent to bedrock slabs where water was deeper (> 3 m) than areas off bedrock ledges and cobble beaches where oldsquaws and scoters fed. Substrate studies adjacent to seven defined shoreline classes confirmed that there were regular differences in microhabitat features. We were unable to reject a hypothesis that the sea ducks species similar in morphology would demonstrate greater separation in habitat space than dissimilar species for Harlequin Ducks verus Oldsquaws, whereas, for Common Eiders versus Black Scoters, there was least separation in these species of similar morphology. Food use by eiders and Oldsquaws at Cape Race, where Harlequin Ducks and scoters were virtually absent, suggested that competitive niche shift may be occurring at Cape St. Mary's where all species are syntopic. Habitat use by wintering sea ducks at Cape St. Mary's is in partial agreement with current concepts of interspecific competition although our evidence did not constitute proof that competition was occurring.
Keywords: Common Eider; Nonbreeding Seasons; Harlequin duck; Histrionicus histrionicus; Clangula hyemalis; Long-tailed Duck; Somateria mollissima; Habitat; Black Scoter; Melanitta nigra

The status of sea duck in the North Pacific rim: Toward their conservation and management - Goudie, R. Ian; Brault, Solange; Conant, Bruce; Kondratyev, Alexander V.; Petersen, Margaret R.; Vermeer, Kees (Transactions of the North American Wildlife and Natural Resources Conference, 1994)
Transactions of the North American Wildlife and Natural Resources Conference
Keywords: Conservation; Abundance, Distribution, and Trends; Sea Ducks - General

Aspects of Distribution and Ecology of Harlequin Ducks on the Torrent River, Newfoundland - Goudie, R. Ian; Gilliland, Scott G. (Waterbirds, 2008)
Harlequin Ducks (Histrionicus histrionicus) breeding on the upper Torrent River of the northern peninsula of Newfoundland Were Studied from 1993 to 2002. This reach of the watershed was proposed for hydro-electrical development in the 1990s. Harlequin Ducks arrive oil the Torrent River as soon as ice-out permits in early to late May. Pairs concentrate in the upper watershed that drains the Long Range Barrens ecoregion. Nesting and,, although movements of more than brood rearing appear to take place primarily in proximity to spring-pair activity tell kill were observed. Young remain if] the Upper watershed until fledging in late August to mid-September. Counts of Harlequin Ducks breeding oil the Upper Torrent River increased throughout the 1990s, and the estimated population growth rate for the Torrent River birds was very similar to the growth rate for birds wintering at Cape St. Mary's, Newfoundland (1.14 vs. 1.13) (hiring the same period. Paired females spent similar to 40% of the day in feeding activities whereas paired males allocated less time to feeding (similar to 19%) and more little to alert or vigilant behaviors while females fed. Birds rested for 35-40% of the day. Harlequin Ducks exploited rapids, riffles and runs, and were especially associated with the boulder-strewn inlets; and outlets of ponds. The large quantities Of submerged and semi-submerged angular boulders provide increased surface area for attachments of larval insects, and movement of water through boulders assures high rates of oxygenation important to filter-feeding insects. Broods selected areas with flow rates of 1.27 +/- 0.24 m/s. The family Chironomidae contained the most taxa and was the most numerous invertebrate group found in the Torrent River. Chironomidae may comprise the most important food items for pre-nesting Harlequin Ducks when considering volume of prey types consumed. A high rate of brood production in 1997 and 1998, compared to adjacent watersheds, Suggests the possibility that the Torrent River system may behave as a source population for the general region of northern Newfoundland.
Keywords: Breeding Season; Harlequin duck; Histrionicus histrionicus; Habitat

Dose-response relationships of harlequin duck behaviour to noise from low-level military jet over-flights in central Labrador - Goudie, R. Ian; Jones, Ian L. (Environmental Conservation, 2004)
Concern for the lack of field studies on the effects of low-level military jet over-flights on wildlife resulted in directed research in the Military Training Area of Labrador, 1999-2002. At Fig River, a tributary of the Lower Churchill River, a before-after-control-impact (BACI) study design quantified effects of aircraft over-flights on behaviour of individual harlequin ducks (Histrionicus histrionicus) in the 130000 km 2 Military Training Area of central Labrador. Noise generated from low-level passes (30-100 m above ground level) by military jets was sudden in onset and high in amplitude (> 100 dBA), substantially above background sound levels both at Fig Lake outlet (40-50 dBA) and rapid sections of Fig River (60-70dBA). Harlequin ducks reacted to noise from military jets with alert behaviour, showing a positive dose-response that especially intensified when noise exceeded 80dBA. Residual effects, in other words, deviations from normal behaviour patterns after initial responses, were decreased courtship behaviour for up to 1.5 h after, and increased agonistic behaviour for up to 2 h after military jet over-flights. Direct behavioural responses to military jet over-flights were of short duration (generally < 1 min), and were unlikely to affect critical behaviours such as feeding and resting in the overall time-activity budgets of breeding pairs. However, the presence of residual effects on behaviour implied whole-body stress responses that were potentially more serious; these require further study because they are potentially more detrimental than immediate responses, and may not be detected in studies that focus on readily observed overt responses. A dose-response curve relating particular behaviours of harlequin ducks to associated noise of over-flights could be a valuable conservation tool for the research and mitigation of environmental impacts of aircraft and other noise.
Keywords: Conservation; Behavior; Breeding Season; Harlequin duck; Histrionicus histrionicus

Feeding behavior of harlequin ducks (Histrionicus histrionicus) breeding in Newfoundland and Labrador: A test of the food limitation hypothesis - Goudie, R. Ian; Jones, Ian L. (Bird Behavior, 2005)
We compared foraging behavior and productivity of harlequin ducks (Histrionicus histrionicus) in Newfoundland in 1997 and 1998, and central Labrador in 1997 to 2002, and tested predictions that productivity of this species is limited by available food. Females without broods were observed early in the nesting cycle (>70% of the local population), and were ascertained to be failed nesters. These adult females without broods were indicative of what previous researchers had defined as "nonbreeders." Productivity of harlequin ducks breeding in central Labrador ranged from 10.0% to 88.9% of females producing broods with 1.00 to 3.38 young per female present, annually. Females spent relatively low proportions of time feeding (mean +/- SD: 0.385 +/- 0.014 of similar to 17 h of daylight), and there was low variability across time and space. Therefore we inferred that foraging behavior was not tracking a variable food resource, and birds could have budgeted considerably more time to feeding if this had been necessary to meet their nutritional requirements. Physical evidence of nesting, including anatomical and radiotelemetry data, indicated that all adult female harlequin ducks in our study area attempted breeding each year. We found no support for the paradigm that females were constrained by lack of sufficient food on their breeding habitat and deferred breeding. We suggest that hypotheses such as food limiting breeding productivity can be tested using behavior that can be readily quantified, and with greater rigor than attempting to measure aquatic epibenthos in fast moving rivers.
Keywords: Behavior; Breeding Season; Harlequin duck; Histrionicus histrionicus; Productivity

Behaviour and ecology of sea ducks - Goudie, R. Ian; Petersen, Margaret R.; Robertson, Gregory J. (Occasional paper - Canadian Wildlife Service, 1999)

Common eider: Somateria mollissima - Goudie, R. Ian; Robertson, Gregory J.; Reed, Austin (Birds of North America, 2000)
Keywords: Breeding Season; Common Eider; Nonbreeding Seasons; Somateria mollissima

Diets and Morphology of Digestive Organs of Five Species of Sea Ducks Wintering in Newfoundland - Goudie, R. I.; Ryan, P. C. (Journal of the Yamashina Institute for Ornithology, 1991)
Gizzard weight, small intestine length, and caeca length were measured from specimens of sea ducks collected in coastal Newfoundland during the November to March winter seasons of 1982-88. The diets of Common Eiders (Somateria mollissima) (n = 24), King Eiders (S. spectabilis) (n = 25), Black Scoters (Melanitta nigra) (n = 17), Old-squaws (Clangula hyemalis) (n = 20), and Harlequin Ducks (Histrionicus histrionicus) (n = 27) were entirely animal matter but differed in diversity and shell component. Common Eiders, Kin Eiders, and Black Scoters consumed a high proportion of mollusks and sea urchins, whereas, Oldsquaws and Harlequin Ducks consumed relatively high proportions of isopods and amphipods, respectively. Hinterspecific differences in morphology of digestive organs, not explained by body size, were accounted for by these general differences in diet. The largest gizzards were found in scoters and Common Eiders that had the highest shell component in their diets. The shortest digestive tracts were found in Black Scoters which had the most 'specialized' diet, although there was no significant difference between Black Scoters and Harlequin Ducks. Caeca length was similar between species, except they were exceptionally short in the Black Scoter. We were unable to speculate a functional relationship of the caeca although it may be correlated to the diversity of the diet. These results confirm other findings that morphological differences in digestive organs in waterfowl reflect dietary differences.
Keywords: Common Eider; Nonbreeding Seasons; Harlequin duck; Histrionicus histrionicus; Clangula hyemalis; Long-tailed Duck; Somateria mollissima; Physiology; King Eider; Somateria spectabilis; Trophic Interactions; Black Scoter; Melanitta nigra

Aquatic burst locomotion by hydroplaning and paddling in common eiders (Somateria mollissima) - Gough, W. T.; Farina, S. C.; Fish, F. E. (Journal of Experimental Biology, 2015)
Common eiders (Somateria mollissima) are heavy sea-ducks that spend a large portion of their time swimming at the water surface. Surface swimming generates a bow and hull wave that can constructively interfere and produce wave drag. The speed at which the wavelengths of these waves equal the waterline length of the swimming animal is the hull speed. To increase surface swimming speed beyond the hull speed, an animal must overtake the bow wave. This study found two distinct behaviors that eider ducks used to exceed the hull speed: (1) 'steaming', which involved rapid oaring with the wings to propel the duck along the surface of the water, and (2) 'paddle-assisted flying', during which the ducks lifted their bodies out of the water and used their feet to paddle against the surface while flapping their wings in the air. An average hull speed (0.732 +/- 0.046 m s(-1)) was calculated for S. mollissima by measuring maximum waterline length from museum specimens. On average, steaming ducks swam 5.5 times faster and paddle-assisted flying ducks moved 6.8 times faster than the hull speed. During steaming, ducks exceeded the hull speed by increasing their body angle and generating dynamic lift to overcome wave drag and hydroplane along the water surface. During paddle-assisted flying, ducks kept their bodies out of the water, thereby avoiding the limitations of wave drag altogether. Both behaviors provided alternatives to flight for these ducks by allowing them to exceed the hull speed while staying at or near the water surface.
Gough, William T. Farina, Stacy C. Fish, Frank E.
Keywords: Behavior; Common Eider; Somateria mollissima

Behaviour and chronology of pair formation by Harlequin Ducks Histrionicus histrionicus - Gowans, Billie; Robertson, Gregory J.; Cooke, Fred (Wildfowl, 1997)
The chronology of pairing and behaviours associated with pairing were studied on a small population of wintering Harlequin Ducks. Research was carried out on 17 days between 19 September and 21 November 1995 on a 2 km rocky coastline in south-western British Columbia. The behaviours rushing, agonistic pursuits and head-nodding were found to be specific to courtship. Males performed more courtship behaviour than females. Males which had completed their prealternate moult exhibited courtship behaviours more often than moulting males. Pairing began in mid-September and continued to increase steadily to between 44% and 70% of females paired by 21 November Three pairs identified during the 1994-1995 non-breeding season, re-united in the fall of 1995. Harlequin Ducks pair relatively early, probably because many pairs are re-uniting in the fall. The courtship behaviour shown by males is probably mate guarding by paired males and active courtship by bachelor males.
Keywords: Behavior; Nonbreeding Seasons; Harlequin duck; Histrionicus histrionicus

Do Arctic-nesting birds respond to earlier snowmelt? A multi-species study in north Yukon, Canada - Grabowski, M. M.; Doyle, F. I.; Reid, D. G.; Mossop, D.; Talarico, D. (Polar Biology, 2013)
Times Cited: 0 Grabowski, Meagan M. Doyle, Frank I. Reid, Donald G. Mossop, Dave Talarico, Darielle 0
Keywords: Breeding Season; Sea Ducks

Productivity of nesting spectacled eiders on the lower Kashunuk River, Alaska - Grand, James B.; Flint, Paul L. (Condor, 1997)
We studied the chronology and success of nesting Spectacled Eiders (Somateria fischeri) along the lower Kashunuk River on the Yukon-Kuskokwim Delta from 1991-1995. Nest initiation dates ranged from 16 May-22 June. Median nest initiation dates were correlated with the break-up of ice on the Kashunuk River. Clutch sizes declined seasonally, and mean clutch size varied among years ranging from 4.8-5.6 eggs. The frequency of nests containing inviable eggs (24% of successful nests, x = 0.6 unhatched eggs per successful nest) did not differ among years or nest initiation dates, and may be related to exposure to contaminants. The rate of partial depredation also did not vary among years or initiation dates (23% of nests, x = 0.5 eggs taken/successful nest). We detected no effect of marking or visitation on daily survival rate of nests. Nests initiated early in the year were more successful than late nests; thus, early nesting females laid larger clutches and were more likely to nest successfully than late nesters. Nest success varied among years and declined from 73% in 1991 to 18% in 1994. Nest success increased to 76% in 1995 when we reduced the Mew Gull (Larus canus) population on the study area. While inviability and partial depredation averaged over 1 egg per successful nest, the production lost in nests that were abandoned or completely destroyed by predators was much greater. Our data indicate that Spectacled Eiders nesting on our study area experience relatively high production; however, without information regarding annual survival and recruitment. it is not possible to draw conclusions about population growth rates.
Keywords: Breeding Season; Somateria fischeri; Spectacled Eider; Productivity

Effect of lead poisoning on spectacled eider survival rates - Grand, James B.; Flint, Paul L.; Petersen, Margaret R.; Moran, Christine L. (Journal of Wildlife Management, 1998)
Spectacled eider (Somateria fischeri) populations on the Yukon-Kuskokwim Delta (Y-K Delta), Alaska, declined rapidly through the 1980s, and low adult female survival was suggested as the likely cause of the decline. We used mark-resighting techniques to study annual survival rates of adult female spectacled eiders at 2 sites on the Y-K Delta during 1993-96. Our data suggest survival rates may differ among sites. However, a model fit to a subset of data on females for which we knew lead levels in blood suggests lead exposure influences survival. Adult females exposed to lead prior to hatching their eggs survived at a much lower rate (0.44 +- 0.10) each year than females not exposed to lead before hatch (0.78 +- 0.05). We suggest most mortality from lead exposure occurs over winter, and the related reduction in adult survival may be impeding recovery of local populations. We encourage managers to curtail input of lead shot into the environment.
Keywords: Breeding Season; Somateria fischeri; Spectacled Eider; Contaminants; Survival

Concentrations of trace elements in eggs and blood of spectacled and common eiders on the Yukon-Kuskokwim Delta, Alaska, USA - Grand, James B.; Franson, J. Christian; Flint, Paul L.; Petersen, Margaret R. (Environmental Toxicology and Chemistry, 2002)
We examined the relations among nesting success, egg viability, and blood and egg concentrations of As, Cd, Pb, Hg, and Se in a threatened population of spectacled eiders (Somateria fischeri) and a sympatric population of common eiders (S. mollissima) on the Yukon-Kuskokwim Delta, Alaska, USA, during 1995 and 1996. During the early breeding season, males and females had mean Se concentrations in their blood of 19.2 mug/g and 12.8 mug/g wet weight, respectively. Blood Se concentrations of females were correlated with egg concentrations. During brood rearing, blood Se levels were higher in adult females than in ducklings. Blood concentrations of Pb in spectacled eider females were higher than in common eider females captured at hatching, but blood concentrations of Se were similar. Trace element concentrations were not related to nest success or egg viability. We submit that nest success and egg viability of spectacled eiders are not related to concentrations of the trace elements we measured. Because blood Se concentrations declined rapidly through the breeding season and were not related to nest success or egg viability, we suggest that spectacled eiders are exposed to high concentrations of Se during winter that pose little threat to this population.
Keywords: Breeding Season; Somateria fischeri; Spectacled Eider; Common Eider; Contaminants; Somateria mollissima; Productivity

Changes in shorebird and eider abundance in the Rasmussen Lowlands, NWT - Gratto-Trevor, Cheri L.; Johnston, Victoria H.; Pepper, Stephen T. (Wilson Bulletin, 1998)
Historical records of population numbers are almost entirely lacking for shorebirds and some species of waterfowl breeding in the Nearctic. In 1975 and 1976, ground surveys of breeding birds were undertaken in the Rasmussen Lowlands, Northwest Territories. We carried out similar censuses in the same area during the summers of 1994 and 1995. Weather conditions and methods were very similar during the two sets of surveys. For all years, we compared densities in different habitat types, as well as estimates for the entire region of total numbers of breeding Red Phalaropes (Phalaropus fulicaria), Pectoral Sandpipers, (Calidris melanotos), White-rumped Sandpipers (C. fuscicollis), Semipalmated Sandpipers (C. pusilla), Black-bellied Plovers (Pluvialis squatarola), American Golden-Plovers (Pluvialis dominica), Dunlin (C. alpina), Baird's Sandpipers (C. bairdii), and King Eiders (Somateria spectabilis). We found that breeding populations of Red Phalaropes, Black-bellied Plovers, American Golden-Plovers, and King Eiders in the 1990s had decreased substantially (76-87%) from their numbers in the 1970s. Numbers of other shorebird species did not decrease significantly (17-48%). Numbers of Black-bellied Plovers have apparently decreased at staging sites on the east coast of the United States and Canada. However, for American Golden-Plovers, there is no evidence of a decline on the east coast or in at least one other area in the eastern Nearctic. No other population information exists for Red Phalaropes breeding in the eastern Nearctic. Eider numbers appear to be decreasing throughout the Arctic. Possible reasons for declines are habitat changes in migratory staging sites and southern wintering areas. We need more consistent monitoring of arctic shorebirds in order to identify species with continual population declines. Further studies should emphasize Nearctic populations of species showing substantial declines in this study, examining consistency of decreases throughout the Nearctic, and reasons for such changes.
Keywords: Breeding Season; Abundance, Distribution, and Trends; Sea Ducks - General; King Eider

Oxidative Capacity of Tissues Contributing to Thermogenesis in Eider Somateria-Mollissima Ducklings Changes Associated with Hatching - Grav, H. J.; Borch-Iohnsen, B.; Dahl, H. A.; Gabrielsen, G. W.; Steen, J. B. (Journal of Comparative Physiology B Biochemical Systemic and Environmental Physiology, 1988)
1. The development of liver and skeletal muscle oxidative capacities during hatching of the common eider (Somateria mollissima) in the Arctic has been investigated by monitoring tissue cytochrome c oxidase activity. 2. The specific activity of the liver enzyme did not change as the embryo underwent hatching, nor during subsequent growth of the duckling into adulthood. 3. Thigh muscle enzyme specific activity increased by a factor of 3.4 during the 24 h prehatching period, remained elevated for at least 48 h after hatching, and then returned to the embryonic (.sbd. 24 h) level in adults. 4. Histochemically visualized NADH-tetrzolium reductase of a typical red thigh muscle, M. vastus lateralis, showed a distinct increase in activtiy as the hatching process progressed to completion. 5. Electron microscopy of sectioned M. vastus lateralis revealed a dramatic increase in the density of the myofibrillar structure (number of mitochondrial profiles per unit area), and in the surface area of mitochondrial crista membranes in the course of the 48 h interval from 1 day prehatching to 1 day after hatching. 6. The significance of these changes for the scaling of thermoregulatory heat generation in the newly hatched eider duckling is discussed.
Keywords: Breeding Season; Common Eider; Somateria mollissima; Physiology

Ecosystem characteristics and processes facilitating persistent macrobenthic biomass hotspots and associated benthivory in the Pacific Arctic - Grebmeier, J. M.; Bluhm, B. A.; Cooper, L. W.; Danielson, S. L.; Arrigo, K. R.; Blanchard, A. L.; Clarke, J. T.; Day, R. H.; Frey, K. E.; Gradinger, R. R.; Kedra, M.; Konar, B.; et al. (Progress in Oceanography, 2015)
The northern Bering and Chukchi Seas are areas in the Pacific Arctic characterized by high northward advection of Pacific Ocean water, with seasonal variability in sea ice cover, water mass characteristics, and benthic processes. In this review, we evaluate the biological and environmental factors that support communities of benthic prey on the continental shelves, with a focus on four macrofaunal biomass "hotspots." For the purpose of this study, we define hotspots as macrofaunal benthic communities with high biomass that support a corresponding ecological guild of benthivorous seabird and marine mammal populations. These four benthic hotspots are regions within the influence of the St. Lawrence Island Polynya (SLIP), the Chirikov Basin between St. Lawrence Island and Bering Strait (Chirikov), north of Bering Strait in the southeast Chukchi Sea (SECS), and in the northeast Chukchi Sea (NECS). Detailed benthic macrofaunal sampling indicates that these hotspot regions have been persistent over four decades of sampling due to annual reoccurrence of seasonally consistent, moderate-to-high water column production with significant export of carbon to the underlying sediments. We also evaluate the usage of the four benthic hotspot regions by benthic prey consumers to illuminate predator-prey connectivity. In the SLIP hotspot, spectacled eiders and walruses are important winter consumers of infaunal bivalves and polychaetes, along with epibenthic gastropods and crabs. In the Chirikov hotspot, gray whales have historically been the largest summer consumers of benthic macrofauna, primarily feeding on ampeliscid amphipods in the summer, but they are also foraging further northward in the SECS and NECS hotspots. Areas of concentrated walrus foraging occur in the SLIP hotspot in winter and early spring, the NECS hotspot in summer, and the SECS hotspot in fall. Bottom up forcing by hydrography and food supply to the benthos influences persistence and composition of benthic prey that then influences the distributions of benthivorous upper trophic level populations. (C) 2015 Elsevier Ltd. All rights reserved.
Grebmeier, Jacqueline M. Bluhm, Bodil A. Cooper, Lee W. Danielson, Seth L. Arrigo, Kevin R. Blanchard, Arny L. Clarke, Janet T. Day, Robert H. Frey, Karen E. Gradinger, Rolf R. Kedra, Monika Konar, Brenda Kuletz, Kathy J. Lee, Sang H. Lovvorn, James R. Norcross, Brenda L. Okkonen, Stephen R. Si
Keywords: Somateria fischeri; Spectacled Eider; Common Eider; White-winged Scoter; Surf Scoter; Clangula hyemalis; Long-tailed Duck; Somateria mollissima; King Eider; Somateria spectabilis; Trophic Interactions; Habitat; Polysticta stelleri; Steller’s Eider

Abundance, distribution and habitat use of breeding goosanders Mergus merganser and red-breasted mergansers Mergus serrator on British rivers - Gregory, Richard D.; Carter, Steven P.; Baillie, Stephen R. (Bird Study, 1997)
The abundance and distribution of breeding Goosanders and Red-breasted Mergansers were surveyed along river habitats throughout Britain in the spring and summer of 1987. Broad-scale habitat information was recorded and a total of around 9300 km of rivers was surveyed. The densities of Goosanders were highest in the Borders and northwest England, and those of Red-breasted Mergansers in the Highlands and western Scotland. The influence of river characteristics, including width, flow type, extent of bankside cover, elevation and gradient on the choice of habitats by sawbills was assessed using logistic regression models. River width had a significant influence on the presence of Goosanders and Mergansers, with wider river sections more likely to hold birds. The probability of recording Goosanders decreased with increasing river gradient while Mergansers preferred slower, smoother river sections. Taking these results into account, regional and national populations of both species were estimated by extrapolation from river sections surveyed to the total extent of river habitat available, as estimated by map measurements. Standing waters, by which both species nest, were not included in this survey. The limitations of this approach are discussed. National populations on river habitats were estimated to be 2600 (95% confidence limits CLs at 2333 and 2890) adult male and 3700 (95% CLs at 3272 and 4072) redhead Goosanders, and 800 (95% CLs at 562 and 1051) adult male and 750 (95% CLs at 562 and 964) redhead Mergansers.
Keywords: Breeding Season; Abundance, Distribution, and Trends; Common merganser; Mergus merganser; Habitat; Mergus serrator; Red-breasted merganser

Recent changes in the populations of the eider, Somateria m. mollisima, and the velvet scoter, Melanitta f. fusca, in the Finnish Archipelago - Grenquist, P. (Riistatieteellisia Julkaisuja, 1952)
Reports from the network of Institute observers show an increase in eider ducks since 1947. Velvet scoters have also shown an increase since 1947. Counts of breeding stocks show that waterfowl were most abundant in the 1930s, and that the very severe winters of 1939-42 were disastrous to wintering populations. The recent incr. is attributed to mild winters, an incr. in salinity of the Baltic Sea, which promotes marine fauna, and an incr. in waterfowl preserves. || ABSTRACT AUTHORS: W. Swank
Keywords: Breeding Season; Abundance, Distribution, and Trends; Common Eider; Melanitta fusca; Nonbreeding Seasons; White-winged Scoter; Somateria mollissima; Black Scoter; Melanitta nigra

Hatching losses of common goldeneyes, in the Finnish archipelago - Grenquist, Pekka (Proc Internatl Ornithol Congr, 1963)
In 1954-61, 53 clutches of Bucephala clangula averaged 10.3 eggs (CV =8.6%) where brooding was concluded, and the mean size of broods hatched was 9.6 (CV =9.3%). For 1,554 eggs 50.6% hatched, 6.2% had incubation interrupted, 1.9% were not fertilized and 40.4% were unincubated. In this rapidly increasing population of goldeneyes nesting in boxes peaks of hatching success (80 and 75%) in a given year were twice followed by low hatching success 2 years later (33 and 33%). The disturbance caused by several young females laying eggs in the same boxes as older females of their own spp., goosanders and stock doves is thought to be an explanation of the low hatching success in overcrowded nesting areas in the archipelago. || ABSTRACT AUTHORS: P. Grenquist
Keywords: Breeding Season; Bucephala clangula; Common Goldeneye; Productivity

Cormorant and goosander in Northern Tyrol. Distribution, habitat selection, behaviour and diet during winter. Results of a survey 1999/2000 - Grimm, Ursula; Lentner, Reinhard (Berichte des Naturwissenschaftlich-Medizinischen Vereins in Innsbruck, 2007)
Synopsis: The study shows a general view of the number, habitat selection, behaviour and the diet of cormorants (Phalacrocorax carbo sinensis) and goosanders (Mergus merganser) during winter 1999/2000 in Northern Tyrol. Cormorants were present only in small numbers with a maximum in January. The maximum number at one count of the 71,6 km of flowing waters was 18 cormorants, countings at the roosts showed a maximum of 25 birds. Cormorants could be observed regularly near the roost at Erl. The maximum number of goosanders at one count of the 71,6 km was 29. The sites preferred by goosanders were at the river Inn (especially the section Kufstein to Erl) and showed large river width and good sight into the water. Analysis of pellets confirm the cormorant as a nutrition generalist.
Keywords: Abundance, Distribution, and Trends; Nonbreeding Seasons; Common merganser; Mergus merganser; Habitat

The distribution of the breeding population of Mergus merganser in southern Bavaria and Austria in relation to the water-transparency of representative rivers in the breeding area - Gross, Aurelia (Ornithologischer Anzeiger, 2000)
The abundance and distibution of breeding Mergus merganser in southern Bavaria and Austria was analysed. Over the last seven decades the development was correlated with the annual mud content of six representative rivers in the breeding area. It could be shown that the water-transparency has an influence on the breeding population. The number of breeding goosanders increased on four of the analysed rivers in response to an increasing water-transparency after several water-economical impacts. The muddy glacier waters of Inn and Salzach showed almost no changes in their low water-transparency in the last centuries and in fact there was no increase in the anyway very small number of breeding goosanders. The results also showed that a mud content above 180 mg/l seems to be not tolerable for Mergus merganser in the breeding season.
Keywords: Breeding Season; Common merganser; Mergus merganser; Habitat

Food Habits of the White-Winged Scoter in Northwestern California - Grosz, T.; Yocom, C. F. (Journal of Wildlife Management, 1972)
Keywords: Melanitta fusca; White-winged Scoter; Trophic Interactions

Bald Eagles Stealing Fish from Common Mergansers - Grubb, T. C. Jr (Auk, 1971)
Keywords: Trophic Interactions; Common merganser; Mergus merganser

A Shift in Nesting Habitat by a Population of Common Eiders - Grubb, T. C. Jr (Wilson Bulletin, 1975)
Keywords: Breeding Season; Common Eider; Somateria mollissima; Habitat

Tetratrichomonas and Trichomonas spp.-Associated Disease in Free-Ranging Common Eiders (Somateria mollissima) from Wellfleet Bay, MA and Description of ITS1 Region Genotypes - Grunenwald, C.; Sidor, I.; Mickley, R.; Dwyer, C.; Gerhold, R. (AVIAN DISEASES, 2018)
During an outbreak of Wellfleet Bay virus (WFBV) in common eiders (Somateria mollissima) from the Cape Cod region of Massachusetts, several birds were diagnosed with trichomonosis consisting of multiple trichomonad species. Six birds were examined, with trichomonads found in ceca in four birds and associated typhlitis in three of these four birds. PCR and DNA sequencing utilizing trichomonad-specific primers targeting the ITS1 region of the ribosomal DNA (rDNA) revealed the presence of Tetratrichomonas gallinarum in the gastrointestinal tracts of five birds and Trichomonas spp. in the livers of two birds, one of which had a dual Te. gallinarum-Trichomonas gallinae infection. Sequence analysis revealed no variation between Te. gallinarum sequences whereas the ITS1 sequences obtained from the other Trichomonas spp. demonstrated the presence of multiple genotypes. One sequence had 100% identity to a Trichomonas sp. previously isolated from a Cooper's hawk (Accipiter cooperii) and the other sequence was 100% identical to a previously described Tr. gallinae isolate obtained from a Pacific Coast band-tailed pigeon (Patagioenas fasciata monilis). These findings suggest Te. gallinarum and other Trichomonas spp. possibly contributed to morbidity and mortality in this species. Furthermore, to the authors' knowledge, this is the first report of trichomonad-associated disease in a free-ranging sea duck.
Times Cited in Web of Science Core Collection: 7 Total Times Cited: 7 Cited Reference Count: 41
Keywords: 1ST REPORT; common eiders; COMPLEX; CULTURES; DOVES; GALLINAE; MIMUS-POLYGLOTTOS; PIGEONS; Protozoa; Tetratrichomonas gallinarum; Trichomonas gallinae; trichomonosis; typhlitis; UNITED-STATES; WILD FINCHES

The Past Status and Exploitation of the Myvatn Iceland Waterfowl Populations - Gudmundsson, F. (Oikos, 1979)
The exceptionally rich waterfowl populations of Myvatn [Iceland] have no doubt been exploited for a very long time although sources of information about the waterfowl of the lake and its exploitation are not available for the time prior to 1712. [The waterfowl species which at present nest or have nested in the Myvatn area are: whooper swan Cygnus cygnus, grey lag goose Anser anser, mallard Anas platyrhynchos, teal A. crecca, gadwall A. strepera, wigeon A. penelope, pintail A. acuta, shoveler A. clypeata, pochard Aythya ferina, tufted duck A. fuligula, scaup A. marila, harlequin duck Histrionicus histrionicus, long-tailed duck Clangula hyemalis, common scoter Melanitta nigra, Barrow's goldeneye Bucephala islandica, red-breasted merganser Mergus serrator, and goosander M. merganser.] At least from then on and up to the present day the exploitation has entirely consisted in the exploitation of eggs while the birds have been protected. A source from the early 19th century indicates that egg harvesting was not carried out indiscriminately as it was subject to certain restrictions. Written records of the annual egg yield since the turn of the present century have been kept on some of the famrs bordering the lake. But annual egg harvest records by species from about 1900-1957 on 1 of the farms (Grimsstadir) have been particularly valuable as with their help it has been possible to reconstruct important population parameters of the various waterfowl species.
Keywords: Conservation; Breeding Season; Abundance, Distribution, and Trends; Sea Ducks - General

Radar observations of Arctic bird migration at the Northwest Passage, Canada - Gudmundsson, Gudmundur A.; Alerstam, Thomas; Green, Martin; Hedenstrom, Anders (Arctic, 2002)
Bird migration was recorded by tracking radar and visual observation at 23 sites in the region of the Northwest Passage, between Baffin Island and Herschel Island in the Beaufort Sea. The studies took place during a ship-based expedition from 29 June to 3 September 1999. A total of 692 tracks (average duration 160 s) of bird flocks on postbreeding migration were recorded. Eastward migration was widespread, with the highest intensities at three sites in the southeastern Beaufort Sea. Mainly shorebirds were responsible for these movements, migrating along routes similar to great circles towards Nova Scotia and other parts of the Atlantic coast of North America (whence they depart on transoceanic flights towards South America). Some of the birds in this migration system probably originated from Siberia, as indicated by high-altitude eastward migration at a site 100 km north of the coast in the Beaufort Sea. Another category of eastward migrants consisted of jaegers, terns, and red phalaropes traveling towards the Davis Strait region and into the Atlantic Ocean. Southward migration was recorded at Baffin Island. A westward migration was pronounced at King William Island (with simultaneous eastward migration) and Amundsen Gulf, while northward movements were important at Banks Island and Melville Island. Apart from westward molt migration of common eiders at Amundsen Gulf, the westward and northward tracks reflected mainly jaegers, terns, gulls, and red phalaropes. These birds were probably making northward flights to exploit pelagic food resources in waters where the ice had recently broken up before their westward migratory exodus from the Arctic region towards the Pacific Ocean. The mean altitude of migration was 793 m, with 27% of all tracks above 1000 m and a maximum height of 3.95 km. The altitude distribution was clearly lower than those of the corresponding migration in Siberia and the shorebird migration at Nova Scotia. The average ground speed (14.9 m/s) was only slightly faster than the mean air speed (13.8 m/s), and migrants gained in speed from the winds (ground speed exceeding air speed) in only 55% of all cases. This means that wind assistance in the study area was much less pronounced than that documented for the migrants in Siberia and Nova Scotia. Bird migration at the Northwest Passage may be characterized by, on average, lower altitudes, less favorable winds, shorter flight steps, and a more widespread accessibility to stopover sites than migration at the Northeast Passage.
Keywords: Common Eider; Sea Ducks - General; Nonbreeding Seasons; Migration

Winter extratropical cyclone influence on seabird survival: variation between and within common eider Somateria mollissima populations - Guery, L.; Descamps, S.; Hodges, K. I.; Pradel, R.; Moe, B.; Hanssen, S. A.; Erikstad, K. E.; Gabrielsen, G.; Gilchrist, H. G.; Jenouvrier, S.; Bety, J. (MARINE ECOLOGY PROGRESS SERIES, 2019)
Extratropical cyclones (ETCs) play a primary role in determining the variation in local weather and marine conditions in the mid-latitudes. ETCs have a broad range of intensities, from benign to extreme, and their paths, frequency, and intensity may change with global warming. However, how ETCs, and cyclones in general, currently affect marine wildlife is poorly studied and remains substantially unexplored. To understand how winter ETCs affect the inter-annual variability of adult seabird survival, we used capture-mark-recapture datasets collected in 2 arctic (northern Canada and Svalbard) and 1 subarctic (northern Norway) breeding populations of common eider Somateria mollissima over periods of 19, 16 and 30 yr, respectively. We found significant negative correlations between winter ETC activity and female eider survival, but different mechanisms appear to be involved in the different studied populations. The number of winter ETCs, extreme or not, was linked to survival without lags in the Canadian population, whereas amplitude and duration of extreme winter ETCs (with time lags) impacted female adult survival in the Svalbard and northern Norway eider breeding populations. We hypothesise that fjords in the wintering grounds of some populations act as climatic shelters and provide natural protection, and hence could partly explain inter-population heterogeneity in the response to ETCs. We suggest that ETCs represent a likely mechanism behind the frequently reported relationship between North Atlantic Oscillation and seabird survival in the North Atlantic.
Times Cited in Web of Science Core Collection: 8 Total Times Cited: 8 Cited Reference Count: 99
Keywords: CLUTCH SIZE; Arctic; TEMPERATURE; LIFE-HISTORY; ADULT SURVIVAL; ATLANTIC; CLIMATE VARIATION; Extreme weather and climatic events; HEART-RATE; HETEROGENEITY; Hidden states and mixture models; Inter and intra-population heterogeneity; Migratory tactics; Multi-event models; MUSSELS MYTILUS-EDULIS; NAO; WEATHER

Hidden survival heterogeneity of three Common eider populations in response to climate fluctuations - Guery, L.; Descamps, S.; Pradel, R.; Hanssen, S. A.; Erikstad, K. E.; Gabrielsen, G. W.; Gilchrist, H. G.; Bety, J. (JOURNAL OF ANIMAL ECOLOGY, 2017)
Understanding how individuals and populations respond to fluctuations in climatic conditions is critical to explain and anticipate changes in ecological systems. Most such studies focus on climate impacts on single populations without considering inter- and intra-population heterogeneity. However, comparing geographically dispersed populations limits the risk of faulty generalizations and helps to improve ecological and demographic models. We aimed to determine whether differences in migration tactics among and within populations would induce inter- or intra-population heterogeneity in survival in relation to winter climate fluctuations. Our study species was the Common eider (Somateria mollissima), a marine duck with a circumpolar distribution, which is strongly affected by climatic conditions during several phases of its annual cycle. Capture-mark-recapture data were collected in two arctic (northern Canada and Svalbard) and one subarctic (northern Norway) population over a period of 18, 15, and 29years respectively. These three populations have different migration tactics and experience different winter climatic conditions. Using multi-event and mixture modelling, we assessed the association between adult female eider survival and winter conditions as measured by the North Atlantic Oscillation (NAO) index. We found that winter weather conditions affected the survival of female eiders from each of these three populations. However, different mechanisms seemed to be involved. Survival of the two migrating arctic populations was impacted directly by changes in the NAO, whereas the subarctic resident population was affected by the NAO with time lags of 2-3years. Moreover, we found evidence for intra-population heterogeneity in the survival response to the winter NAO in the Canadian eider population, where individuals migrate to distinct wintering areas. Our results illustrate how individuals and populations of the same species can vary in their responses to climate variation. We suspect that the found variation in the survival response of birds to winter conditions is partly explained by differences in migration tactic. Detecting and accounting for inter- and intra-population heterogeneity will improve our predictions concerning the response of wildlife to global changes.
Times Cited in Web of Science Core Collection: 18 Total Times Cited: 18 Cited Reference Count: 70
Keywords: Arctic; SOMATERIA-MOLLISSIMA-BOREALIS; NORTH-ATLANTIC OSCILLATION; VARIABILITY; TIME-SERIES; BREEDING SUCCESS; COSTS; seabirds; NAO; WEATHER; CAPTURE-RECAPTURE MODELS; DEMOGRAPHY; GREENLAND; hidden states; life-history strategy; mixture models; multi-event

Digestive-rate constraint in wintering common eiders (Somateria mollissima): Implications for flying capabilities - Guillemette, Magella (Auk, 1994)
Rates of ingestion and digestion for wintering Common Elders (Somateria mollissima) feeding on blue mussels (Mytilus edulis) were estimated using information on average meal size, feeding- and resting-bout durations, and transit time. Rate of ingestion of mussel shells is two times higher than defecation rate; as a consequence, shells accumulate in the gut as ingestion progresses. On average, eiders shot when flying (n = 92) had 1.1% of their body mass as prey compared with 3.7 and 6.4% for eiders foraging in small and large Rocks (n = 77), respectively, suggesting that eiders tend to minimize the transportation of surplus mass when flying. Wing loading of the Common Eider averages 2.0 g cntdot cm-2, which is among the highest values determined for a bird species capable of flight. Maximum gut contents were between 8 and 11% of body mass for eiders foraging in large rafts; such mass of food significantly increases wing loading and is associated with a reluctance or a possible inability to take flight. I hypothesize that meal size in Common Eiders is regulated in response to flight limitations that result from the added mass of a meal.
Keywords: Common Eider; Nonbreeding Seasons; Somateria mollissima; Physiology; Trophic Interactions

The effect of time and digestion constraints in Common Eiders while feeding and diving over Blue Mussel beds - Guillemette, M. (Functional Ecology, 1998)
1. To maintain energy intake Common Eiders (Somateria mollissima) in winter should compensate for reduced day-length by increasing both the proportion of time spent feeding and diving efficiency, defined as the proportional duration of a dive bout within a dive cycle. Common Eiders swallowed Blue Mussel (Mytilus edulis) whole with their shells where any behavioural compensation in relation to short days may be limited by digestive processes. 2. Based on time budget studies conducted from mid-December to the end of April in the Gulf of St. Lawrence, Quebec, Canada, diving and feeding efficiency were compared for three seasonal periods varying in day-length (from 557 to 890 min). 3. Results showed that eiders were compensating for short days by feeding 56% of the time in mid-winter compared with 33% in spring. However, diving efficiency remained constant through the season and apparently no compensation occurred at this level of their foraging behaviour. Despite this, the daily rate of prey ingestion was much higher in mid-winter than in spring. 4. Ingestion rate values for mid-winter individuals approached or even exceeded the rate at which prey items are defecated and it was concluded that shell crushing performed by the muscular gizzard is physiologically more demanding during that period. On this basis, gizzard mass should be larger in winter when ingestion rates are higher. Data presented support that hypothesis and suggest that compensation in relation to short days can be both behavioural and physiological.
Keywords: Behavior; Common Eider; Nonbreeding Seasons; Somateria mollissima; Physiology

Foraging before spring migration and before breeding in Common Eiders: Does hyperphagia occur? - Guillemette, Magella (Condor, 2001)
Foraging performance of Common Eider (Somateria mollissima) was studied to find out if hyperphagia occurs before migration and breeding in this species. Diving efficiency and time spent feeding were quantified concomitantly for two subspecies that differ in the timing of their reproduction and migration. The foraging performance of female S. m. dresseri preparing for breeding and female S. m. borealis preparing for migration were compared with their male counterparts, which are known to achieve energy balance during these periods. Female dresseri spent 41% of their time feeding and made 404 dives daily, for a total of 169 min spent underwater each day. Female dresseri spent more time diving than did males by about one hour each day. There were no detectable differences in the foraging performances of male and female borealis, probably because the body mass of migrating females increased only slightly prior to migration. Hyperphagia in breeding female dresseri appears to be the main cause of increased body mass, although other mechanisms may play a role.
Keywords: Behavior; Common Eider; Nonbreeding Seasons; Somateria mollissima; Energetics and Nutrition

Stomach contents of diving and dabbling ducks during fall migration in the St. Lawrence River, Quebec, Canada - Guillemette, Magella; Bolduc, Francois; Desgranges, Jean-Luc (Wildfowl, 1994)
Stomach contents of ten duck species feeding on benthos were analysed in the context of new prey species invading the St. Lawrence river, eastern Canada. One hundred and twenty-three stomachs (12.3) belonging to eight species of diving ducks and two species of dabbling ducks were analysed. The amount of food found in the stomachs was low and seems to be related to the fact that the great majority of ducks were collected while flying. A bias in food composition was associated with duck species characterized by residual contents in their gizzard, which were discarded from our analysis. In general, the diet of diving ducks was mainly animal while plant material dominated the diet of dabbling ducks. The most important group of animal prey was the gastropods, two species from Which dominated the diet of diving ducks, namely Bythinya tentaculata and Viviparus sp. These two prey species are European in origin and were apparently introduced in the St. Lawrence several decades ago. This leads as to suggest that the recent introduction of the Zebra Mussel Dreissena polymorpha in the St. Lawrence could significantly alter the diet of diving ducks in the future. Incidently, one specimen of Surf Scoter Melanitto perspicillata had its gizzard filled with this species.
Keywords: Nonbreeding Seasons; Melanitta perspicillata; Surf Scoter; Trophic Interactions

Seasonal variation in energy expenditure is not related to activity level or water temperature in a large diving bird - Guillemette, M.; Butler, P. J. (Journal of Experimental Biology, 2012)
Times Cited: 1 Guillemette, Magella Butler, Patrick J. 1
Keywords: Breeding Season; Nonbreeding Seasons; Somateria mollissima; Common eider; energetics and Nutrition

Distribution of wintering common eiders over mussel beds: Does the ideal free distribution apply? - Guillemette, Magella; Himmelman, John H. (Oikos, 1996)
The preferred habitat of common eiders (Somateria mollissima) wintering in the Gulf of St. Lawrence, eastern Canada consists of submerged reefs distributed in patches of different sizes which are composed of kelp beds and urchin barrens. In this habitat, the blue mussel (Mytilus edulis), a preferred prey, is found only inside kelp beds and is considered to have a high carrying capacity to be depleted slowly over the course of the winter. We examined the effect of population density on the number of mussel patches simultaneously used by eiders. Our rationale was that if interference competition was occurring, we should observe a "spacing" of eiders and the number of patches used should increase with an increase in population density. We used the number of eiders counted in these patches as an index of density. The data show that the eiders crowd into one or two patches as population density increased. We thus discarded the possibility that interference competition was driving the distribution of wintering eiders. We also hypothesized that prey depletion could influence eider distribution over the winter and we predicted that patch use was correlated with food availability through time and follows a simple ideal free distribution. Our data supported this hypothesis. Although population density and prey depletion act at two different time scales and result in two contrasting distributions, we show that these two factors can play a role in determining eider distribution.
Keywords: Abundance, Distribution, and Trends; Common Eider; Nonbreeding Seasons; Somateria mollissima; Trophic Interactions; Habitat

Habitat selection by common eiders in winter and its interaction with flock size - Guillemette, Magella; Himmelman, John H.; Barette, Cyrille; Reed, Austin (Canadian Journal of Zoology, 1993)
We studied habitat selection in relation to prey density and water depth in the common eider, Somateria mollissima L., wintering in the Gulf of St. Lawrence, eastern Canada. In this region, eiders are confronted with low temperatures, ice cover, and reduced day length. We predicted that they should select feeding habitats characterized by high prey density and shallow water to minimize the time and energy spent while diving. About 1000 flocks were localized by triangulation on our study site (20.5 km-2). We inferred the diving depth and the habitat being used from the position of eiders on bathymetric and community maps. The highest density of prey occurred in shallow water reefs where there were patches of blue mussels, Mytilus edulis L., and green sea urchins, Strongylocentrotus droebachienensis (Muller). Despite the fact that eiders can dive to depths as great as 42 m to feed, they strongly aggregate in shallow water, and their distribution closely coincides with the highest density of prey. The degree of selection for the reef habitat varies with seasonal variations in the size of flocks and in the total number of eiders present. Although flocking as an antipredator behaviour cannot be rejected, we interpret the high degree of flocking by eiders in our study area as a strategy to facilitate feeding in winter.
Keywords: Common Eider; Nonbreeding Seasons; Somateria mollissima; Habitat

Postdevelopment experiments to detect anthropogenic disturbances: The case of sea ducks and wind parks - Guillemette, Magella; Larsen, Jesper K. (Ecological Applications, 2002)
Typically, ecological impact assessments (EIA) are conducted under time constraints, making the collection of baseline data and application of Before-After-Control-Impact (BACI) designs difficult. Here we report the results of three "postdevelopment" experiments testing the effects of a small wind park on the abundance, distribution, and behavior of wintering Common Eiders (Somateria mollissima), a large sea duck. Our approach was based on the rationale that the probability of detecting an impact should increase with decreasing distances from the wind park. Because prey abundance is likely to drive the distribution of wintering eiders, we removed that confounding variable by (1) randomizing its effect over the study area, and (2) incorporating the variable into the analysis. In the first experiment, we compared the abundance and distribution of eiders when wind turbines were switched on and off. This was complemented by investigating the escape behavior of flocks when wind turbines were switched on after they had been off for one full day. In a second experiment, we tested for any departure from the habitat-matching rule, which states that the proportion of eiders and the proportion of food should be equal at different distances from the park. In a third experiment, the flying behavior of eiders in relation to the wind park was analyzed by measuring the landing and flying rates for patches of decoys located at 100, 300, and 500 m from the wind park. We found little evidence for negative impacts, because we could not detect any effect in three tests out of four. Only in the decoy experiment did we observe eiders reducing their landing and flying near (100 m from) the wind park. We conclude, for the conditions under which our experiments were performed, that the wind park did not substantially affect wintering Common Eiders. However, many aspects of the potential impacts of offshore wind parks on sea ducks have not been covered by our study and, therefore, cannot be generalized to other species or other phases of the annual cycle. Nevertheless, we argue that the use of multiple postdevelopment experiments based on a gradient approach is a helpful complement to BACI studies.
Keywords: Conservation; Behavior; Abundance, Distribution, and Trends; Common Eider; Nonbreeding Seasons; Somateria mollissima

Temporary flightlessness in pre-laying Common Eiders Somateria mollissima: are females constrained by excessive wing-loading or by minimal flight muscle ratio? - Guillemette, Magella; Ouellet, Jean-Francois (Ibis, 2005)
Large body size, small wings and relatively low flight muscle mass are general attributes of flightlessness in birds, but a general analysis is lacking when considering these factors simultaneously. Common Eiders Somateria mollissima are large sea ducks characterized by short, pointed wings of low surface area. Because females fast throughout incubation, they need to accumulate large body reserves prior to laying. During this pre-laying period, many females cannot take off, and dive when approached under still-air conditions, whereas males take off readily when disturbed. In this paper, we examine how pre-laying female Common Eiders fit the maximum wing-loading ratio of Meunier, the marginal flight muscle ratio (FMR) of Marden and predictions of a general model of take-off performance (also by Marden). Wing morphology was recorded and flight muscles were dissected from specimens collected during the pre-laying period near one breeding colony. In addition, take-off ability, as observed during collection, was compared with the proposed thresholds for flightlessness and outputs from the general model of take-off performance. The results indicated that half of the pre-laying females exceeded the wing-loading ratio of Meunier, although all females had values above 0.160, the flight muscle ratio below which take-off would be impossible. We suggest that wing-loading and flight muscle ratio interact in Eiders, with higher FMR compensating for excessive wing-loading. Nevertheless, the model of take-off performance predicted, with reasonable accuracy, the behavioural observations under still-air conditions. Indeed, females that were predicted to be temporarily flightless could produce a specific lift of 8.8 N/kg on average (less than the 9.8 N/kg required to overcome gravity). In contrast, the average specific lift predicted for males capable of flight was estimated to be 11.4 N/kg. These results agree with our observations that female Common Eiders are at the limit of flight capability in vertebrates.
Keywords: Common Eider; Nonbreeding Seasons; Somateria mollissima; Physiology; Energetics and Nutrition

Temporary flightlessness as a potential cost of reproduction in pre-laying Common Eiders Somateria mollissima - Guillemette, Magella; Ouellet, Jean-Francois (Ibis, 2005)
The rapid growth and reabsorption of the avian ovary is thought to be adaptive, as it reduces predation risk and the metabolic cost of flight. In this paper, we use an extreme case of parental investment to show how the survival of gravid birds may be impaired by reduced take-off ability. In still air, temporary flightlessness is regularly observed in female Common Eiders Somateria mollissima preparing for breeding. From a sample of pre-laying females collected in the Baltic Sea, we quantified the relationships among body reserves, organ mass and take-off ability using a general model of take-off performance. Average body mass at the beginning and end of follicular growth was, respectively, 32% and 43% higher than winter body mass. Wing-loading increased significantly during ovary development whereas the relative mass of flight muscles decreased. In contrast, organ mass and somatic body mass were constant from early follicular growth until laying, indicating that the observed increase in body mass was caused by ovary growth. The average specific lift production of individuals collected at the beginning of follicular growth was 9.7 N/kg, which is similar to the lift required to become airborne (9.8 N/kg). As ovary mass increased, lift production decreased to 9.2 N/kg at the onset of laying. These results indicate that temporary flightlessness results from the accumulation of large body reserves and subsequent ovarian growth. Predators of Common Eiders are diverse and may come from air, water and land. We suggest that temporary flightlessness may decrease adult survival through predation, and may represent an important cost of reproduction.
Keywords: Breeding Season; Common Eider; Somateria mollissima; Physiology; Survival; Energetics and Nutrition

Egg-laying increases body temperature to an annual maximum in a wild bird - Guillemette, M.; Pelletier, D. (SCIENTIFIC REPORTS, 2022)
Most birds, unlike reptiles, lay eggs successively to form a full clutch. During egg-laying, birds are highly secretive and prone to disturbance and predation. Using multisensor data loggers, we show that average daily body temperature during egg-laying is significantly increased (1 degrees C) in wild eider ducks (Somateria mollissima). Strikingly, this increase corresponds to the annual maximum body temperature (40.7 degrees C), representing a severe annual thermogenic challenge. This egg-laying-induced rise in body temperature may prove to be a common feature of wild birds and could be caused by habitat-related thermoregulatory adjustments and hormonal modulation of reproduction. We conclude our findings with new perspectives of the benefits of high body temperature associated with egg-laying of birds and the potential effect of heat stress that may occur with the future advent of heatwaves.
Times Cited in Web of Science Core Collection: 1 Total Times Cited: 1 Cited Reference Count: 99
Keywords: COMMON EIDERS; EIDERS SOMATERIA-MOLLISSIMA; ENERGY-EXPENDITURE; ESTROUS-CYCLE; LOCOMOTOR-ACTIVITY; LUTEINIZING-HORMONE; MENSTRUAL-CYCLE; PLASMA PROGESTERONE; TEMPORARY FLIGHTLESSNESS; THYROID-HORMONES

Flightlessness and the energetic cost of wing molt in a large sea duck - Guillemette, Magella; Pelletier, David; Grandbois, Jean-Marc; Butler, Patrick J. (Ecology (Washington D C), 2007)
Although the replacement of feathers apparently represents the major event of somatic production in the annual cycle of wild birds, knowledge about the energetics of molt has always been hampered by logistical and technical difficulties, which are exacerbated by the fact that birds are able to compensate behaviorally to buffer any variation in energy demand. During wing molt, sea ducks (Mergini) and other diving birds lose all of their wing feathers at once, leading to a period of temporary flightlessness of variable duration, a condition that considerably restricts their movements and increases the probability of predation. In the present study, we present the first results aimed at quantifying the duration of flightlessness, energy expenditure, and foraging effort during molt of a wing-propelled diving bird, the Common Eider (Somateria mollissima). Data loggers were implanted in the body cavity of 13 females to record heart rate and hydrostatic pressure (depth) every two seconds for a period of 220 days. Flight frequency and duration were assessed from elevated and constant heart rate, and the absence of. light was used to quantify the duration of flightlessness, which lasted, on average, 36 +/- 8 days ( mean +/- SD). Using a period of four weeks before and four weeks after the flightless period, we found that dive depth (ranging from 1 to 2 m, on average) and daily diving time did not vary during the course of the study. Daily metabolic rate increased by 9%, and resting metabolic rate by 12% from the pre-molt period to the flightless period and remained high during the post-molt period. This study indicates that the energetic costs of replacing flight remiges in female eiders are substantial, although this is not associated with any change in foraging effort, which suggests that female Common Eiders lose mass during wing molt. Finally, estimates of energy savings associated with the total absence of. flights during wing molt represent 6% of daily metabolic rate or 14% of resting metabolic rate. This. finding contrasts with the classical view that little or no benefit is associated with a flightless condition. We suggest that such energy savings may have favored the evolution of temporary flightlessness in diving birds.
Keywords: Common Eider; Nonbreeding Seasons; Molt; Somateria mollissima; Energetics and Nutrition

It Takes Time to Be Cool: On the Relationship between Hyperthermia and Body Cooling in a Migrating Seaduck - Guillemette, M.; Polymeropoulos, E. T.; Portugal, S. J.; Pelletier, D. (FRONTIERS IN PHYSIOLOGY, 2017)
The large amount of energy expended during flapping flight is associated with heat generated through the increased work of the flight muscles. This increased muscle work rate can manifest itself in core body temperature (T-b) increase of 1-2 degrees C in birds during flight. Therefore, episodic body coolingmay bemandatory inmigratory birds. To elucidate the thermoregulatory strategy of a short-distance migrant, common eiders (Somateria mollissima), we implanted data loggers in the body cavity of wild birds for 1 year, and report information on Tb during their entire migration for 19 individuals. We show that the mean body temperature during flight (T-bMean) in the eiders was associated with rises in Tb ranging from 0.2 to 1.5 degrees C, largely depending on flight duration. To understand how eiders are dealing with hyperthermia during migration, we first compare, at a daily scale, how Tb differs during migration using a before-after approach. Only a slight difference was found (0.05 degrees C) between the after (40.30 degrees C), the before (40.41 degrees C) and the migration (40.36 degrees C) periods, indicating that hyperthermia during flight had minimal impact at this time scale. Analyses at the scale of a flight cycle (flight plus stops on the water), however, clearly shows that eiders were closely regulating Tb during migration, as the relationship between the storage of heat during flight was highly correlated (slope = 1) with the level of heat dumping during stops, at both inter-individual and intra-individual levels. Because Tb at the start of a flight (T-bStart) was significantly and positively related to T-b at the end of a flight (T-bEnd), and the maximal attained T-b during a flight (T-bMax), we conclude that in absence of sufficient body cooling during stopovers, eiders are likely to become increasingly hyperthermic during migration. Finally, we quantified the time spent cooling down during migration to be 36% of their daily (24 h) time budget, and conclude that behavioral body cooling in relation to hyperthermia represents an important time cost.
Times Cited in Web of Science Core Collection: 6 Total Times Cited: 6 Cited Reference Count: 46
Keywords: migration; RESPONSES; SPRING MIGRATION; TEMPERATURE; common eiders; body cooling; endothermy; FEET; FLIGHT; FLIGHTLESSNESS; HEAT LOSS; hyperthermia; thermoregulation; WATER

Availability and consumption of food by common eiders wintering in the Gulf of St. Lawrence: Evidence of prey depletion - Guillemette, Magella; Reed, Austin; Himmelman, John H. (Canadian Journal of Zoology, 1996)
To quantify the influence of common ciders (Somateria mollissima) on their food supply in the Gulf of St. Lawrence, eastern Canada, we measured prey availability and patch utilization during two consecutive winters. In this region, ciders fed predominantly near submerged reefs where large populations of blue mussels (Mytilus edulis) and green sea urchins (Strongylocentrotus droebachienensis) were present. Density and biomass of mussels and urchins were estimated for two reefs at the beginning of the winter of 1985-1986 using SCUBA and quadrat sampling. Prey selection was assessed by comparing the size of prey from stomach contents of shot eiders with that of prey found in the habitat. Patch use was quantified from elevated blinds by regularly counting eiders from December to April. Mussels in the habitat were small (mean length 6.5 mm) and formed dense beds (mean density 25398 individuals/m-2), whereas urchins were large (mean diameter 35 mm) and occurred at lower densities (114 individuals/m-2). However, the average biomass for these two prey species was similar, 2.8 and 3.1 kg wet mass/m-2 for mussels and urchins, respectively. The mussels eaten by common eiders tended to be larger than the average size of those available. In contrast, urchins eaten were smaller than the average size present in the habitat. Depending on the reef, consumption of food by eiders ranged from 48 to 69% of the biomass for eiders feeding on mussels and from 3 to 6% of the biomass for urchins. We compared these estimates with those from similar studies and concluded that eiders substantially deplete mussel beds in winter, which in turn seems to affect their distribution.
Keywords: Abundance, Distribution, and Trends; Common Eider; Nonbreeding Seasons; Somateria mollissima; Trophic Interactions; Habitat

Behavioural compensation reduces energy expenditure during migration hyperphagia in a large bird - Guillemette, M.; Richman, S. E.; Portugal, S. J.; Butler, P. J. (Functional Ecology, 2012)
Times Cited: 2 Guillemette, Magella Richman, Samantha E. Portugal, Steven J. Butler, Patrick J. 2
Keywords: Behavior; Nonbreeding Seasons; Migration; Common eider; somateria mollissima; energetics and Nutrition

Effects of data-loggers implanted for a full year in female Common Eiders - Guillemette, Magella; Woakes, Anthony J.; Flagstad, Annette; Butler, Patrick J. (Condor, 2002)
Data-loggers can be implanted into the body cavities of birds to monitor their physiology and behavior. This technology opens the potential for year-round monitoring, as long as data-loggers can be retrieved one year later and the implantation does not alter the bird's health or behavior. We tested the impact of carrying data-loggers on reproductive parameters of nine female Common Eiders breeding in the Baltic Sea. We minimized disturbance and maximized return rates of experimental females by implanting data-loggers during the second half of the incubation period and by choosing early breeders, which were presumably high quality individuals. All experimental females came back to the study plot the year following implantation. Using a before-after approach applied to an experimental and a control group, we found no evidence that carrying data-loggers had any harmful effect on laying dates, clutch sizes, or hatching success of experimental females. It appears that data-loggers implanted in the body cavities of female Common Eiders do not interfere with their reproductive activities. Explanations for this result are that data-loggers are small compared to body mass (<1%), and their implantation into the body cavity does not alter the hydrodynamic or aerodynamic properties of these diving birds.
Keywords: Breeding Season; Common Eider; Somateria mollissima; Techniques

The effect of depth on the diving behaviour of common eiders - Guillemette, Magella; Woakes, Anthony J.; Henaux, Viviane; Grandbois, Jean-Marc; Butler, Patrick J. (Canadian Journal of Zoology, 2004)
Diving in endotherms is largely constrained by the depth of the foraging area, as they withstand long periods without breathing. Foraging theory predicts that all phases of a dive cycle, including travel, bottom, and surface durations, are positively correlated with depth. With continued increase in depth, bottom duration should level off and then decline. We tested these qualitative predictions with common eiders (Somateria mollissima (L., 1758)), a sea duck foraging routinely on the bottom. Using data loggers implanted in the body cavity of four females for I year, we showed that average diving depth over the summer and winter was distinct for each female. When averaged for each female, the data were qualitatively similar to theoretical predictions since travel, bottom, and surface durations all increased with depth. However, within individual females, the data only supported the theory partially because some relationships between depth and phases of a dive cycle were not significant. In particular, bottom duration failed to increase with depth for two individual females during the summer. In addition, significant relationships differed substantially among individual females and even within individual females when summer and winter seasons were compared. We suggest that the large variation observed in the diving behaviour of female ciders reflects individual female diving capability, which is probably related to their physiological states.
Keywords: Behavior; Breeding Season; Common Eider; Nonbreeding Seasons; Somateria mollissima

Does hyperthermia constrain flight duration in a short-distance migrant? - Guillemette, M.; Woakes, A. J.; Larochelle, J.; Polymeropoulos, E. T.; Granbois, J. M.; Butler, P. J.; Pelletier, D.; Frappell, P. B.; Portugal, S. J. (Philosophical Transactions of the Royal Society B-Biological Sciences, 2016)
While some migratory birds perform non-stop flights of over 11 000 km, many species only spend around 15% of the day in flight during migration, posing a question as to why flight times for many species are so short. Here, we test the idea that hyperthermia might constrain flight duration (FD) in a short-distance migrant using remote biologging technology to measure heart rate, hydrostatic pressure and body temperature in 19 migrating eider ducks (Somateria mollissima), a short-distance migrant. Our results reveal a stop-and-go migration strategy where migratory flights were frequent (14 flights day(-1)) and short (15.7 min), together with the fact that body temperature increases by 1 degrees C, on average, during such flights, which equates to a rate of heat storage index (HSI) of 4 degrees C h(-1). Furthermore, we could not find any evidence that short flights were limited by heart rate, together with the fact that the numerous stops could not be explained by the need to feed, as the frequency of dives and the time spent feeding were comparatively small during the migratory period. We thus conclude that hyperthermia appears to be the predominant determinant of the observed migration strategy, and suggest that such a physiological limitation to FD may also occur in other species. This article is part of the themed issue 'Moving in a moving medium: new perspectives on flight'.
Guillennette, Magella Woakes, Anthony J. Larochelle, Jacques Polymeropoulos, Elias T. Granbois, Jean-Marc Butler, Patrick J. Pelletier, David Frappell, Peter B. Portugal, Steven J.
Keywords: Common Eider; Migration; Somateria mollissima; Physiology; Nonbreeding season

The role of energy intake rate in prey and habitat selection of common eiders Somateria mollissima in winter: A risk-sensitive interpretation - Guillemette, Magella; Ydenberg, Ronald C.; Himmelman, John H. (Journal of Animal Ecology, 1992)
1. We measured prey selection and habitat profitability of common eiders Somateria mollissima L. wintering in the Gulf of St. Lawerence, Quebec, Canada. Prey selection was evaluated by comparing the frequency of prey in stomachs of shot eiders with their frequency in the sublittoral zone. Habitat profitability was estimated using information on time spent feeding, foraging success, diving durations and energy content of the prey. 2. In this region, eiders forage on a variety of prey types from several distinct habitats, kelp beds, urchin barrens and beds of the phaeophyte Agarum cribrosum (Mert.). In kelp beds eiders feed mostly on small blue mussels Mytilus edulis L. Over barrens they capture green sea urchins Strongylocentrotus droebachiensis (Muller), and over Agarum beds they feed on both spider crabs Hyas araneus (L.) and urchins. 3. Flock size also varies with habitat type: all sizes of flocks feed in the kelp beds, whereas mostly small flocks feed in the barrens and Agarum beds. Small-flock individuals strongly select mussels and crabs whereas urchins are non-preferred prey. 4. Dive and foraging cycles differ significantly according to the above three habitats. Although, the size, density and energy content of prey differ markedly between kelp and Agarum beds, these two habitats offer an even energy return. However, the variance in energy return in these two habitats differs strikingly, being greater in the latter. We hypothesized, in the context of risk foraging theory, that this was related to flock sizes and body condition. As predicted, individuals feeding in small flocks were in bad condition compared to individuals feeding in large flocks. This suggests that small-flock individuals are seeking the habitat offering a variable intake to improve their survival probability.
Keywords: Behavior; Common Eider; Nonbreeding Seasons; Somateria mollissima; Energetics and Nutrition; Trophic Interactions; Habitat

Does hyperthermia constrain flight duration in a short-distance migrant? - Guillennette, M.; Woakes, A. J.; Larochelle, J.; Polymeropoulos, E. T.; Granbois, J. M.; Butler, P. J.; Pelletier, D.; Frappell, P. B.; Portugal, S. J. (Philosophical Transactions of the Royal Society B-Biological Sciences, 2016)
While some migratory birds perform non-stop flights of over 11 000 km, many species only spend around 15% of the day in flight during migration, posing a question as to why flight times for many species are so short. Here, we test the idea that hyperthermia might constrain flight duration (FD) in a short-distance migrant using remote biologging technology to measure heart rate, hydrostatic pressure and body temperature in 19 migrating eider ducks (Somateria mollissima), a short-distance migrant. Our results reveal a stop-and-go migration strategy where migratory flights were frequent (14 flights day(-1)) and short (15.7 min), together with the fact that body temperature increases by 1 degrees C, on average, during such flights, which equates to a rate of heat storage index (HSI) of 4 degrees C h(-1). Furthermore, we could not find any evidence that short flights were limited by heart rate, together with the fact that the numerous stops could not be explained by the need to feed, as the frequency of dives and the time spent feeding were comparatively small during the migratory period. We thus conclude that hyperthermia appears to be the predominant determinant of the observed migration strategy, and suggest that such a physiological limitation to FD may also occur in other species. This article is part of the themed issue 'Moving in a moving medium: new perspectives on flight'.
Guillennette, Magella Woakes, Anthony J. Larochelle, Jacques Polymeropoulos, Elias T. Granbois, Jean-Marc Butler, Patrick J. Pelletier, David Frappell, Peter B. Portugal, Steven J.
Keywords: Migration; Somateria mollissima; Physiology; Common eider

Multiple achromatic plumage ornaments signal to multiple receivers - Guindre-Parker, S.; Gilchrist, H. G.; Baldo, S.; Doucet, S. M.; Love, O. P. (Behavioral Ecology, 2013)
Times Cited: 0 Guindre-Parker, Sarah Gilchrist, H. Grant Baldo, Sarah Doucet, Stephanie M. Love, Oliver P. 0
Keywords: Breeding Season; Somateria mollissima; Common eider; behavior

Assessing individual movement, habitat use, and behavior of non-breeding marine birds in relation to prey availability in the US Atlantic - Gulka, J.; Berlin, A. M.; Friedland, K. D.; Gilbert, A. T.; Goetsch, C.; Montevecchi, W. A.; Perry, M.; Stenhouse, I. J.; Williams, K. A.; Adams, E. M. (MARINE ECOLOGY PROGRESS SERIES, 2023)
Resource availability is a key factor driving marine bird movements and distributions, but direct information on prey availability is difficult to obtain at relevant scales. We present novel methods for describing multi-scale trophic associations, combining movement analyses of marine birds with estimates of forage fish surface aggregations from digital aerial survey data and species occupancy from bottom trawl survey data. We analyzed satellite telemetry data from northern gannets Morus bassanus, red-throated loons Gavia stellata, and long-tailed ducks Clangula hyemalis in the US Atlantic during the non-breeding period. Using discrete-time hidden Markov models to distinguish area-restricted (i.e. putative foraging) from transit movements, we examined how environmental factors influence movement, and how forage fish species distributions and surface aggregations influence habitat use by gannets and loons that have greater dietary reliance. Our results suggest that chlorophyll a concentration significantly affected movement behavior across species, highlighting the importance of higher-productivity areas around estuaries during colder months when regional productivity is low. Though variable across species and seasons, spatial cross-correlation analysis revealed that herring species (Family Clupeidae), including Atlantic menhaden Brevoortia tyrannus, may be important resources; it also showed positive spatial correlations with forage fish aggregations. This suggests that prey patch dynamics and factors driving aggregation formation may be as important as species composition. However, spatial patterns were generally low (<0.3), suggesting a mismatch in spatiotemporal resolution, exemplifying the challenges in quantifying trophic relationships in marine systems. Disentangling predator-prey relationships is critical to understanding the mechanisms driving marine bird behavior in rapidly changing marine systems.
Times Cited in Web of Science Core Collection: 0 Total Times Cited: 0 Cited Reference Count: 140
Keywords: Behavior; TRACKING; Marine birds; SEABIRDS; FISH; DISTRIBUTIONS; Forage fish; FORAGING TACTICS; Hidden Markov model; HMM; METABOLIC-RATES; MIGRATION; Movement; NORTHERN GANNETS; PREDATOR; Predator-prey dynamics; SULA-BASSANA; Trophic links

The courtship of the common scoter - Gunn, Donald (British Birds, 1927)
[long dash]Apparently the first account of the various phases in the courtship display of Oidemia n. nigra*.
Keywords: Behavior; Black Scoter; Melanitta nigra

Density dependence in ducks: a review of the evidence - Gunnarsson, G.; Elmberg, J.; Poysa, H.; Nummi, P.; Sjoberg, K.; Dessborn, L.; Arzel, C. (European Journal of Wildlife Research, 2013)
Times Cited: 0 Gunnarsson, Gunnar Elmberg, Johan Poysa, Hannu Nummi, Petri Sjoberg, Kjell Dessborn, Lisa Arzel, Celine 0
Keywords: Population Dynamics; Sea ducks

Trends in Body Mass of Ducks over Time: The Hypotheses in Guillemain et al. Revisited - Gunnarsson, Gunnar; Elmberg, Johan; Waldenstrom, Jonas (Ambio, 2011)
Keywords: Sea Ducks - General; Energetics and Nutrition

Identifying carry-over effects of wintering area on reproductive parameters in White-winged Scoters: An isotopic approach - Gurney, K. E. B.; Wood, C. J.; Alisauskas, R. T.; Wayland, M.; DeVink, J. M. A.; Slattery, S. M. (Condor, 2014)
Events during one stage of the annual life cycle of migratory birds can have lasting (i.e. carry-over) effects that influence demographic parameters in subsequent seasons. We studied migratory connectivity and potential carry-over effects in a declining population of sea ducks. We measured stable isotope values of carbon (delta C-13) and nitrogen (delta N-15) in head feathers to assign breeding White-winged Scoters (Melanitta fusca; hereafter scoters) to either Atlantic or Pacific winter populations. The discriminant function for delta C-13 and delta N-15 correctly classified 93% of scoters sampled from these 2 winter areas. We then applied this classification scheme to head feathers of females breeding at Redberry Lake, Saskatchewan, and Cardinal Lake, Northwest Territories, to stratify each breeding population by winter provenance. We evaluated carry-over effects associated with winter location of females breeding in Saskatchewan by testing for differences in (1) nesting phenology, (2) clutch size, (3) mid-incubation body mass, (4) nest success, and (5) concentrations of trace elements contaminants of cadmium (Cd), mercury (Hg), selenium (Se), and lead (Pb) in blood, between strata of putative winter origin. Breeding females from the Atlantic coast had later dates of nest initiation, greater mid-incubation body mass, and also had higher concentrations of Cd (one year only), Pb, and Se, relative to birds from the Pacific. Neither nest initiation date nor mid-incubation body mass, however, were related to contaminant concentrations in blood. We found no differences in clutch size or nest success between putative winter strata. Our study detected carry-over effects in the Saskatchewan population that merit further attention.
Gurney, Kirsty E. B. Wood, Cindy J. Alisauskas, Ray T. Wayland, Mark DeVink, Jean-Michel A. Slattery, Stuart M.
Keywords: Breeding Season; Melanitta fusca; White-winged Scoter; Migration; Contaminants; Productivity; SDJV funded

Increased abundance and range expansion of harlequin ducks Histrionicus histrionicus wintering in Eastern Canada - Gutowsky, S. E.; Robertson, G. J.; Mallory, M. L.; McLellan, N. R.; Gilliland, S. G.; Paquet, J.; d'Entremont, A. A.; Ronconi, R. A. (ENDANGERED SPECIES RESEARCH, 2022)
The eastern population of harlequin duck Histrionicus histrionicus in Canada has been designated a species of special concern since 2001 and as endangered from 1991 to 2001, largely due to low and declining wintering numbers detected in the 1980s. Our objectives were to summarize the current state of knowledge of harlequin duck abundance and distribution in Eastern Canada, and assess trends in wintering abundance across regions over the past 30+ years. Abundance estimates were generated from targeted surveys with thorough spatial coverage of major wintering areas on insular Newfoundland (NL), Nova Scotia (NS), and New Brunswick (NB) between 2015 and 2018, complemented by regional trends estimated from Christmas Bird Count (CBC) data collected at 12 sites across the same wintering range between 1988 and 2021. Overall, targeted surveys indicated that numbers have increased and distributions have expanded beyond historically surveyed regions, particularly in NS. This was supported by trends from CBC data, with steep average increases (mean lambda > 1.05) on most CBC circles in Eastern Canada since 1988 or later. Using localized annual rates of mean population change from CBC data to project counts from dedicated surveys, we suggest wintering areas in the provinces of NL, NS, and NB may currently be supporting a combined total of 5682 birds (95% CI 5065-6354) in 2022, well exceeding the recovery target of 3000 individuals listed in the 2007 management plan. Our findings indicate that the eastern population is in recovery, but also emphasize that a consistent, dedicated monitoring program would enable managers to confidently evaluate management actions, and to respond most effectively should regional trends slow or reverse.
Times Cited in Web of Science Core Collection: 0 Total Times Cited: 0 Cited Reference Count: 30
Keywords: Histrionicus histrionicus; Abundance; Distribution; PHILOPATRY; Range expansion; Recovery; Species status assessment

Winter habitat associations of Purple Sandpiper (Calidris maritima) and Harlequin Duck (Histrionicus histrionicus) in Atlantic Canada - Gutowsky, S. E.; Ronconi, R. A.; Gutowsky, L. F. G.; Elderkin, M. F.; Paquet, J.; Mills, P. M.; Mallory, M. L. (ESTUARINE COASTAL AND SHELF SCIENCE, 2019)
Canada's coasts provide vital habitat for congregations of birds throughout the year, including during the nonbreeding period. On the Atlantic coast, the Purple Sandpiper (Calidris maritima) and Harlequin Duck (Histrionicus histrionicus) are both known for their hardiness through the winter, electing to rest and forage along some of the most turbulent, rocky coastlines and nearshore waters. Despite their resilient nature, both species also face threats on the overwintering grounds from human activities and associated habitat degradation. The aim of this study was to identify overwinter habitat characteristics for Purple Sandpiper and Harlequin Duck in Atlantic Canada, with the ultimate objective of improving survey designs whereby both species can be efficiently targeted within their overlapping winter range. Using helicopter-based survey data covering > 13,000 km of coastline between 2011 and 2016, winter habitat was characterized based on both traditional (i.e. publicly available science-quality products) and non-traditional (i.e. Atlantic Canada Shore Zone Character dataset) data sources. In the southerly extent of the Canadian winter range, densities of Purple Sandpiper were 0.045 and 0.2 groups.km(-1) surveyed, respectively. Similarly, for Harlequin Duck, densities were 0.11 and 0.06 groups.km(-1) surveyed, respectively. Both species were found there primarily in areas with lower intertidal zones classified as bedrock platforms (89% and 88% of observed locations, respectively) with the remainder as beach or tidal flats, while the backshore was mostly classified as cliff (67% and 83%, respectively). In the northern extent, Harlequin Duck were generally uncommon, while Purple Sandpipers were detected at densities of 0.05 groups.km(-1), using a greater diversity of lower intertidal zone forms (46% platform/ledge, 22% anthropogenic structure, 19% cliff, 7% low islets). Probability of Purple Sandpiper presence was highest when natural barriers (e.g. headlands) and human activity were both present, increasing with higher mean tide height and higher coastline ruggedness. For Harlequin Duck, probability of presence was most strongly influenced by oceanography, increasing with greater maximum water depth within 1.5 km of shore and lower mean monthly sea surface temperature. Notwithstanding the coarse spatial scale of the data and in turn our analyses, these results confirm the importance of winter onshore habitat associations shared between the Purple Sandpiper and Harlequin Duck in Atlantic Canada, as well as revealing differences related to their foraging ecology. Continued and improved collection of baseline survey information on habitat associations for both species will be crucial to managing population health, habitat needs, and range shifts in the face of future habitat and climate uncertainty.
Times Cited in Web of Science Core Collection: 3 Total Times Cited: 3 Cited Reference Count: 34
Keywords: Birds; Conservation; NORTH; BAY; Coastline; Maritimes; Nonbreeding; Overwinter; SHOREBIRDS; Survey

DNA Damage in Arctic Seabirds: Baseline, Sensitivity to a Genotoxic Stressor, and Association with Organohalogen Contaminants - Haarr, A.; Hylland, K.; Eckbo, N.; Gabrielsen, G. W.; Herzke, D.; Bustnes, J. O.; Blevin, P.; Chastel, O.; Moe, B.; Hanssen, S. A.; Sagerup, K.; Borga, K. (ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY, 2018)
Environmental contaminants are found throughout Arctic marine ecosystems, and their presence in seabirds has been associated with toxicological responses. However, there are few studies of genotoxicity in Arctic avian wildlife. The purpose of the present study was to quantify deoxyribonucleic acid (DNA) damage in lymphocytes of selected seabird species and to examine whether accumulation of organohalogen contaminants (SOHCs) affects DNA damage. Blood was sampled from common eider (Somateria mollissima), black guillemot (Cepphus grylle), black-legged kittiwake (Rissa tridactyla), glaucous gull (Larus hyperboreus), arctic skua (Stercorarius parasiticus), and great skua (Stercorarius skua) in Kongsfjorden, Svalbard (Norway). Contaminant concentrations found in the 6 species differed, presumably because of foraging ecology and biomagnification. Despite large differences in contaminant concentrations, ranging from SOHCs 3.3 ng/g wet weight in the common eider to SOHCs 895 ng/g wet weight in the great skua, there was no strong difference among the species in baseline DNA damage or sensitivity to a genotoxic stressor (hydrogen peroxide). Baseline levels of DNA damage were low, with median values ranging from 1.7% in the common eider to 8.6% in the great skua. There were no associations between DNA damage and contaminants in the investigated species, suggesting that contaminant concentrations in Kongsfjorden are too low to evoke genotoxic effects, or possibly that lymphocytes are resistant to strand breakage. Clearly, genotoxicity is a topic for future studies of Arctic seabirds. (C) 2017 SETAC
Times Cited in Web of Science Core Collection: 14 Total Times Cited: 14 Cited Reference Count: 49
Keywords: Arctic; ORGANOCHLORINE CONTAMINANTS; EXPOSURE; Genotoxicity; LARUS-HYPERBOREUS; Seabirds; BLOOD-CELLS; BREEDING KITTIWAKES; Comet Assay; DOUBLE-STRAND BREAKS; GLAUCOUS GULLS; Perfluoroalkyl substances; Persistent organic pollutants; REPAIR

Population trends of coastal breeding birds of the German North and Baltic Sea coasts - Haelterlein, Bernd; Suedbeck, Peter; Knief, Wilfried; Koeppen, Ulrich (Vogelwelt, 2000)
The German coasts of the North and the Baltic Sea represent important breeding grounds for several bird species with high proportions of the NW European populations. For at least 12 species Germany has a special conservation responsibility on the European level due to large fractions of the total biogeographic populations breeding here (e.g. Avocet, Kentish Plover, Gull-billed Tern, Little Tern). This paper describes the population sizes and trends for typical coastal birds in the 1990s. Coastal birds are defined as species which are closely related to coastal habitats and/or have a substantial proportion of their German populations in coastal regions. Standardised breeding bird surveys have been conducted annually since 1990 and allow reliable trend estimates, except for ducks in which estimates are less reliable due to methodological problems. In 1997, a total of 271.000 pairs of coastal birds were counted along the North and Baltic Sea coasts, most of them at the Wadden Sea (southern North Sea, 87%). Gulls represented about two third of the total on both coasts, terns and waders were significantly scarcer (9 % North Sea / 6 % Baltic Sea, resp. 24 / 5 %). The commonest species was Black-headed Gull (about 87.000 breeding pairs), followed by Herring Gull and Oystercatcher. On the Baltic Sea, Cormorant was the second most numerous species. In the 1990s, coastal birds overall and the majority of species showed increasing trends on the North Sea and decreasing trends on the Baltic Sea in Germany. The populations of meadow birds (waders) and terns declined on both coasts, coastal waders and gulls are still increasing at the North Sea. Cormorant, Red-breasted Merganser, Hen Harrier, Lesser Black-backed Gull and Common Gull strongly increased at the North Sea, whereas the Herring Gull remained stable overall, but in recent years decreased in the big colonies on the East Frisian islands. This may be related to competition with Lesser Black-backed Galls. The small populations of Mediterranean and Great Black-backed Gull are also increasing at the North Sea. Since 1995 the Spoonbill has established itself as a new breeding species in the German Wadden Sea. Ringed Plover, Lapwing, Ruff, Snipe and Common Tern showed significant negative trends. Populations of Kentish Plover and Gull-billed Tern have decreased drastically in recent years and have now reached critical levels. At the Baltic Sea coast only Cormorant and Herring Gull have definitely increased, while most species are in decline, some at an alarming rate. Especially the Dunlin as a typical breeding bird of saltmarshes is threatened by extinction. Conditions at the Baltic Sea are quite different from those at the North Sea coast: there is much less coastal habitat area, and disturbance by human activities (tourism, agriculture) and predation, particularly during the last ten years, have led to a strong concentration of coastal birds in a few small reserves.
Keywords: Breeding Season; Abundance, Distribution, and Trends; Sea Ducks - General

Ornithological importance of Belgian marine areas: Identification of areas qualifying as Special Protection Areas under the European Birds Directive - Haelters, Jan; Vigin, Laurence; Stienen, Eric W. M.; Scory, Serge; Kuijken, Eckhart; Jacques, Thierry G. (Bulletin de l'Institut Royal des Sciences Naturelles de Belgique Biologie)
Under the 1979 European Birds Directive, Member States of the European Union have to strictly protect certain bird species (those from Annex I). For those species, and for other, migrating species, the areas most suitable for their protection have to be classified as Special Protection Areas (SPA's). For the classification of areas as SPAs, only scientific criteria can be applied.In 2001, a Royal Decree was issued in Belgium, which legally protects all birds in Belgian marine waters. Thus far however, the articles in the Birds Directive concerning the classification of areas as SPA's have not been implemented in these areas, although they are considered internationally important for some bird species for foraging, migration or breeding, during certain periods of the year.This study investigates for which bird species it would be appropriate to select important areas as SPA's in Belgian marine waters. In first instance, these are birds listed in Annex I of the Birds Directive that occur in this area regularly and in sufficient numbers: the sandwich tern Sterna sandvicensis, the common tern Sterna hirundo and the little tern Sterna albifrons. A further selection was made of migrating species, not listed in Annex I, for which it would also be appropriate to investigate if certain areas classify as SPA's. In order to qualify, these species need to occur regularly and need to have a certain protection status under other international Conventions or Agreements. Their numbers in Belgian marine waters need to have attained or exceeded 1.0% of the biogeographic population within the considered period (1992-2002). These species are the great crested grebe Podiceps cristatus, the common scoter Melanitta nigra, the little gull Larus minutus and the great skua Stercorarius skua.For these seven species the study examines the extent to which a protection of their habitats in Belgian marine waters is meaningful. Their sensitivity for human activities and their distribution was investigated. For determining the distribution, a large number of seabird counts, performed by the Institute of Nature Conservation between 1992 and 2002, were processed in a geographical information system (GIS). It was investigated whether the selected species concentrated in certain areas. With this analysis, it was not possible to identify most suitable territories for the great skua and the little tern. For the remaining five species however, areas could be identified which are relatively important during certain periods of the year.For the conservation of each of these five species, the most suitable territories in number and size were selected. In bringing together these territories, three areas are identified. The first area is situated off the coastal towns of Koksijde and De Panne. It is the most important area for the sandwich tern, and it has some importance for the great crested grebe. The second area, off the constal towns from Middelkerke to Bredene, is the most important area for the great crested grebe and the common scoter, and it has some importance for the common tern and the sandwich tern. Both areas extend from the low water mark up to 6 miles offshore. The third area is situated around the harbour of Zeebrugge, and is the most important area for the common tern. Within the last two areas, two small areas with the highest densities of the little gull are also located. Within the last area, the most important foraging area for the little tern is situated, as identified during land-based research.The study concludes that the three areas thus identified classify as most suitable territories for the conservation of bird species foreseen in the Birds Directive. It is recommended to proceed to a practical delimitation of these areas, and to classify them as SPA's. In this manner the specific requirements in the Birds Directive can be met. Given the fact that the selected areas can be practically delimited in a large number of different ways, a more definite proposal does not belong to this study.
Keywords: Abundance, Distribution, and Trends; Sea Ducks - General; Black Scoter

Wintering Red-breasted Merganser Mergus serrator preying on pipefish in coastal Western Norway - Haland, Arnold (Ornis Norvegica, 2008)
Keywords: Nonbreeding Seasons; Trophic Interactions; Mergus serrator; Red-breasted merganser

Mercury Concentrations in Surface Water and Harvested Waterfowl from the Prairie Pothole Region of Saskatchewan - Hall, Britt D.; Baron, Lauren A.; Somers, Christopher M. (Environmental Science & Technology, 2009)
Mercury cycling in prairie ecosystems is poorly understood. We examined methylmercury (MeHg) concentrations in whole water from 49 diverse prairie wetlands and lakes in Saskatchewan. We also determined total Hg (THg) concentrations in waterfowl harvested by hunters for consumption. Average whole water MeHg concentrations ranged from 0.02 to over 4 ng L-1 and were higher in water from wetland ponds compared to those in lakes. High MeHg concentrations in prairie wetlands present the possibility of increased Hg concentrations in biota inhabiting these and other similar systems. We therefore measured THg in 72 birds representing 13 species of waterfowl that commonly use prairie aquatic habitats. A large range in THg concentrations was observed among individual birds, with values ranging from below the detection limit to over 435 ng g(-1). When waterfowl were classified according to diet we observed clear evidence of THg biomagnification with increasing proportion of animal prey consumed. THg concentrations in waterfowl collected by hunters did not exceed consumption guidelines of 0.5 mg kg(-1) developed for fish. This is the first study that has reported MeHg concentrations in water from the prairie pothole region of southern Saskatchewan.
Keywords: Sea Ducks - General; Contaminants

Avian Influenza Ecology in North Atlantic Sea Ducks: Not All Ducks Are Created Equal - Hall, J. S.; Russell, R. E.; Franson, J. C.; Soos, C.; Dusek, R. J.; Allen, R. B.; Nashold, S. W.; TeSlaa, J. L.; Jonsson, J. E.; Ballard, J. R.; Harms, N. J.; Brown, J. D. (Plos One, 2015)
Wild waterfowl are primary reservoirs of avian influenza viruses (AIV). However the role of sea ducks in the ecology of avian influenza, and how that role differs from freshwater ducks, has not been examined. We obtained and analyzed sera from North Atlantic sea ducks and determined the seroprevalence in those populations. We also tested swab samples from North Atlantic sea ducks for the presence of AIV. We found relatively high serological prevalence (61%) in these sea duck populations but low virus prevalence (0.3%). Using these data we estimated that an antibody half-life of 141 weeks (3.2 years) would be required to attain these prevalences. These findings are much different than what is known in freshwater waterfowl and have implications for surveillance efforts, AIV in marine environments, and the roles of sea ducks and other long-lived waterfowl in avian influenza ecology.
Hall, Jeffrey S. Russell, Robin E. Franson, J. Christian Soos, Catherine Dusek, Robert J. Allen, R. Bradford Nashold, Sean W. TeSlaa, Joshua L. Jonsson, Jon Einar Ballard, Jennifer R. Harms, Naomi Jane Brown, Justin D.
Keywords: Common Eider; Melanitta fusca; White-winged Scoter; Melanitta perspicillata; Surf Scoter; Clangula hyemalis; Long-tailed Duck; Somateria mollissima; King Eider; Somateria spectabilis; Disease; Black Scoter; Melanitta americana

Direct and indirect effects of predation by Common Eiders and abiotic disturbance in an intertidal community - Hamilton, Diana J. (Ecological Monographs, 2000)
Predation and disturbance have been well studied in intertidal communities. However, the impact of vertebrate predators, particularly waterfowl, has been only infrequently determined in long-term intertidal studies. Using predator exclusion cages and simulated abiotic disturbance, I studied the direct and indirect effects of predation by Common Eiders (Somateria mollissima) on an intertidal mussel bed community in Passamaquoddy Bay, New Brunswick, Canada. Eiders fed heavily on blue mussels (Mytilus edulis), the dominant invertebrate present, reducing their abundance in "+duck" (exposed to predation) relative to "-duck" (exclosure) plots by nearly 50% within eight months of initiation of the experiment. Based on counts and estimated consumption rates, eiders appeared to be responsible for most predation observed in this system. Although ducks fed heavily on the dominant intertidal invertebrate, they had little effect on species diversity or richness in the community. However, relative abundance of the most common invertebrates did vary. In particular, exclusion of eiders led to an increase in abundance of dogwhelks (Nucella lapillus) one year into the experiment. Whelks, in turn, fed heavily on mussels under cages and obscured the longer-term effect of ducks in the system. This indirect effect appears to be an example of asymmetric exploitation competition, with ducks influencing the food supply of whelks, but whelks having little effect on ducks. When ducks were excluded, whelks were released from this competition and acted as compensating predators. No other indirect effects developed following duck exclusion, presumably due to the increased whelk effect. Disturbance, in contrast, did lead to an increase in species diversity, which later returned to predisturbance levels as the community recovered. Predation delayed the recovery of disturbed sites, because ducks began feeding in these plots before mussel abundance had completely rebounded. Disturbance, while initially deterring predation somewhat, ultimately allowed the effects of predators to persist longer. This interaction of predation and disturbance resulted from compensatory growth of mussels under exclosures in disturbed sites. Mussels protected from eider predation grew quickly after disturbance and rapidly became larger than the preferred prey for whelks. As a consequence, whelks did not feed as heavily on mussels in disturbed sites as in undisturbed sites, where more mussels were of the preferred size, and the observed effect of ducks on mussel biomass persisted. This experiment demonstrates that eiders were significant, and, probably, keystone predators in this system. Eiders directly reduced abundance of mussels, thereby indirectly increasing whelk density in plots where ducks were excluded. Compensatory predation by whelks following duck exclusion blocked other potential indirect effects, thus preventing eiders from having more widespread effects in the system. Such compensatory predation may act to stabilize communities and evidently can occur in relatively simple systems as well as the more species-rich communities with which it is usually associated.
Keywords: Common Eider; Somateria mollissima; Trophic Interactions

Feeding behavior of Common Eider ducklings in relation to availability of rockweed habitat and duckling age - Hamilton, Diana J. (Waterbirds, 2001)
Common Eider (Somateria mollissima) ducklings and associated females in the Bay of Fundy feed extensively on invertebrates found in association with Knotted Wrack (Ascophyllum nodosum), commonly referred to as rockweed. To assess whether commercial harvest of rockweed, which is occurring in New Brunswick, might adversely affect ducklings, I examined their feeding behavior in relation to rockweed availability and duckling age. Ducklings fed in rockweed whenever it was available. Young ducklings (less than 3 weeks old) spent more time dabbling for invertebrates in the floating rockweed canopy and less time diving than did older birds. Young ducklings fed when rockweed was most available at the surface, whereas rockweed availability had no effect on the feeding rate of older ducklings. When rockweed was unavailable, older ducklings dove for food, while younger birds still attempted some dabbling. These results suggest that if rockweed harvest lowers the canopy height and reduces the time during each tidal cycle that algae floats at the surface, it might adversely affect Common Eider ducklings during the first weeks of life, when they are less able to dive for food. Consequently, in areas where ducklings feed regularly, care should be taken during harvesting to avoid changing the height and structure of the rockweed canopy. Similarly, harvesters should avoid disturbing foraging ducklings, because it could increase the already high predation risk that these birds face in their first few weeks of life.
Keywords: Conservation; Behavior; Breeding Season; Common Eider; Somateria mollissima; Trophic Interactions

PREDATION OF ZEBRA MUSSELS BY DIVING DUCKS - AN EXCLOSURE STUDY - Hamilton, D. J.; Ankney, C. D.; Bailey, R. C. (Ecology, 1994)
HAMILTON, DJ ANKNEY, CD BAILEY, RC

Shorebirds, snails, and the amphipod (Corophium volutator) in the upper Bay of Fundy: top-down vs. bottom-up factors, and the influence of compensatory interactions on mudflat ecology - Hamilton, D. J.; Diamond, A. W.; Wells, P. G. (Hydrobiologia, 2006)
Hamilton, Diana J. Diamond, Antony W. Wells, Peter G.

Predation by Common Elders on intertidal invertebrates: Community consequences - Hamilton, Diana J.; Nudds, T. D. (Bulletin of the Ecological Society of America, 1996)
Keywords: Common Eider; Somateria mollissima; Trophic Interactions

Effects of predation by common eiders (Somateria mollissima) in an intertidal rockweed bed relative to an adjacent mussel bed - Hamilton, D. J.; Nudds, T. D. (Marine Biology (Berlin), 2003)
Little is known about the effect of commercial rockweed (Ascophyllum nodosum) harvest on intertidal community structure, and on interactions among species. Using predator-exclusion cages and by simulating rockweed harvest, we studied the combined effects of predation by common eiders (Somateria mollissima) and harvest on an intertidal invertebrate community associated with rockweed. Predation had no effect on invertebrate species richness, and only a short-term (< 1 year) negative effect on total invertebrate biomass. Most of this was due to a decline in common periwinkle abundance in controls relative to exclosures. Eiders had no clear effect on blue mussels (Mytilus edulis), their preferred prey, probably because predation by dogwhelks (Nucella lapillus), which were likely the more important predator in this system, more than compensated for the absence of duck predation. Rockweed harvest had no overall effect on the invertebrate community, but did reduce the effectiveness of ducks as predators during summer, when ducklings and associated females fed on invertebrates at the top of the rockweed canopy. We conclude, by comparing results with a similar experiment conducted in the adjacent mussel bed, that both ducks and whelks are major predators of blue mussels, but that their relative importance differs in the two areas, probably as a result of differences in habitat dimensionality and heterogeneity.
Keywords: Common Eider; Somateria mollissima; Trophic Interactions

Size-selective predation of blue mussels (Mytilus edulis) by Common Eiders (Somateria mollissima) under controlled field conditions - Hamilton, Diana J.; Nudds, Thomas D.; Neate, Jennifer (Auk, 1999)
We studied size-selective predation by Common Eiders (Somateria mollissima) feeding on blue mussels (Mytilus edulis). Selection varied with location, season, and prey availability, and for the most part ducks preferred smaller mussels than those that would have been the most energetically profitable on a per prey basis. We tested predictions from two related hypotheses concerning optimal prey selection: (1) the shell-mass minimization hypothesis, which states that predators select food that minimizes shell ingestion, as opposed to maximizing energy intake per prey item; and (2) the risk-averse foraging hypothesis, which, assuming large prey are not preferred (because of high shell content, low energy value, or some other reason), states that predators feed on smaller prey when the risk of mistakenly taking large prey increases. We found support for both hypotheses, although the risk-averse foraging hypothesis should be tested further due to conflicting results and small sample sizes. During most of the year, Common Eiders selected relatively small mussels that minimized shell ingestion, even though larger available prey would have provided higher net energy gain per prey item. In winter, differences among length classes in shell ingestion became small, and birds switched to feeding on larger prey that provided more energy per unit work and probably were more profitable. During times when small and mid-sized prey were preferred, ducks foraging where large mussels were abundant usually selected smaller length classes of prey than did those feeding where large mussels were less common. Birds avoided the risk of inadvertently ingesting large prey by selecting smaller mussels. Our results provide insight into the mechanisms of prey selection by Common Eiders and may also help explain some of the discrepancies reported in previous studies of prey-size selection in this species.
Keywords: Common Eider; Somateria mollissima; Trophic Interactions

Consumption of Zebra Mussels Dreissena polymorpha by diving ducks in Lakes Erie and St. Clair - Hamilton, Diana L.; Ankney, Davison (Wildfowl, 1994)
Zebra Mussels are a novel and abundant prey item for diving ducks in the Laurentian Great Lakes region. We investigated use of Zebra Mussels as food by several species of diving ducks (Greater and Lesser Scaup, Common Goldeneye, Bufflehead, White-winged Scoter and Old-squaw) in Lakes Erie and St. Clair in 1990 and 1991. We examined 135 gizzards from ducks shot by hunters (tall) and ducks drowned in fishing nets (spring). We noted presence or absence of Zebra Mussels, and estimated lengths of mussels consumed. Mussels were eaten by all species examined and were consumed by ducks at each location. Overall, 52% of gizzards contained Zebra Mussels, including oil those from Point Pelee, Ontario Larger duck species tended to consume larger mussels, but prey sizes taken varied widely among locations. Although diving ducks probably were size-selective predators, they ate mussels from a wide size range. This suggests that at Most locations where Zebra Mussels occur, some mussels of (in acceptable size will always be present for ducks.
Keywords: Melanitta fusca; Nonbreeding Seasons; White-winged Scoter; Clangula hyemalis; Long-tailed Duck; Bucephala clangula; Common Goldeneye; Trophic Interactions; Bucephala albeola; Bufflehead

Surf Scoters use deeper offshore waters during nocturnal resting periods in the Salish Sea of Washington and British Columbia - Hamilton, L. J.; Michel, N. L.; Evenson, J. R.; Roberts, D. L. (ORNITHOLOGICAL APPLICATIONS, 2022)
Lay Summary Seabirds are vulnerable to human disturbance, particularly during nocturnal resting periods. Surf Scoters (Melanitta perspicillata) have been anecdotally observed to move offshore into deeper waters at night, where they may encounter more vessel traffic. Yet little is known about their nocturnal habitat use. We evaluated the daily movement ecology and nocturnal habitat selection of Surf Scoters to identify likely nighttime resting areas. Scoters moved into deeper offshore waters at night. They preferred to use offshore coastal areas with moderately deep water and avoided strong tidal currents and heavy vessel traffic lanes. Understanding Surf Scoter nocturnal habitat use can improve oil spill response plans by prioritizing efforts in offshore resting areas to more effectively limit the mortality of scoters and other seabirds. Diurnally biased monitoring and research dominate our ecological understanding and guide conservation and management decisions regarding important indicator sea duck species, such as Surf Scoters (Melanitta perspicillata). Advances in telemetry technology are improving our ability to track wildlife across the entire 24-hr day. Using location data derived from birds with surgically implanted satellite transmitters and habitat layers within a GIS (geographic information system), we analyzed Surf Scoter location data to (1) estimate movement distances between diurnal and nocturnal sites, (2) assess differences in environmental conditions at diurnal and nocturnal use locations, (3) evaluate the environmental conditions influencing nocturnal habitat selection, and (4) develop a predictive model to estimate likely nocturnal resting areas across the Salish Sea, which is composed of the inland marine waters of British Columbia, Canada, and Washington State. Surf Scoters in the Salish Sea traveled an average of 4,287 m between diurnal and nocturnal habitats, but distances varied regionally. We found that distance to shore, water depth, tidal current, and vessel traffic influenced nocturnal habitat use. Surf Scoter nocturnal use sites were characterized by greater distances from shore and deeper water than diurnal locations, although scoters avoided areas with strong tidal currents and heavy shipping traffic at night. The Salish Sea is experiencing increased ship traffic from multiple U.S. and Canadian ports. Oil tanker and shipping container vessel traffic pose a potential threat to nocturnal scoter flocks aggregating in deeper water adjacent to and sometimes overlapping with shipping lanes in narrow, glacial-carved channels of the Salish Sea. Current oil spill response plans in Washington State waters utilize diurnal distribution data, lacking important nocturnal use data. Our findings provide critical nocturnal habitat use information that can improve oil spill response policy and highlight the importance of elucidating nocturnal ecology for marine vertebrate species.
Times Cited in Web of Science Core Collection: 1 Total Times Cited: 1 Cited Reference Count: 47
Keywords: Melanitta perspicillata; Surf Scoter; BIRDS; DUCKS; CONSERVATION; HABITAT USE; MELANITTA-PERSPICILLATA; WHITE-WINGED SCOTERS; marine bird ecology; movement ecology; nocturnal habitat use; oil spill response; Puget Sound; RESOURCE SELECTION; Salish Sea; SPACE; WINTERING SURF

Testing whether reducing brown trout biomass in peatland lakes increases macro-invertebrate biomass and invertivorous waterbird occurrence - Hancock, M. H.; Klein, D.; Hughes, R.; Stagg, P.; Byrne, P.; Smith, T. D.; MacLennan, A.; Gaffney, P. P. J.; Bean, C. W. (AQUATIC ECOLOGY, 2023)
Waterbirds and fish sometimes compete for macro-invertebrate prey. In Scotland, the invertivorous waterbird, the common scoter Melanitta nigra, breeds at oligotrophic lakes with few brown trout Salmo trutta. This study tested whether reducing trout biomass favours this and other invertivorous waterbirds. The study took place in Scotland's Flow Country, where brown trout occur widely, attracting recreational anglers, though angling has declined. At four small lakes, over 7 years, trout were reduced using 25 m(2) exclosures, and re-introducing traditional angling (including fish removal). Trout, macro-invertebrates and waterbirds were monitored. After angling re-introduction, trout biomass density declined by 56% (95% CLs 13-78%), but there was little lake-level change in combined macro-invertebrate biomass. However, within exclosures, macro-invertebrate biomass increased 4.7-fold (CLs 1.6-14). Analysing invertebrates in eight different groups showed lake-level increases, following angling re-introduction, for two groups (freshwater shrimps Gammarus; water-surface invertebrates). Gammarus showed the strongest response, increasing sixfold (CLs 2.2-11.6). A combined analysis was performed for the commonest invertivorous waterbirds: common scoter, mallard Anas platyrhynchos, teal A. crecca, greenshank Tringa nebularia and dunlin Calidris alpina. After angling effort increased, occurrence of these species changed little initially, but rose later: 4 years after angling began, odds of occurrence had increased 4.9-fold (CLs 2.2-11). This study supports reducing trout biomass in peatland lakes by encouraging traditional angling, to increase some macro-invertebrate groups and usage by invertivorous waterbirds. Further work should test this across more lakes alongside work investigating the origins (native or stocked) of brown trout populations in the Flow Country.
Times Cited in Web of Science Core Collection: 0 Total Times Cited: 0 Cited Reference Count: 95
Keywords: CONSERVATION; RESPONSES; LONG-TERM; Angling; Bird-fish competition; BREEDING COMMON SCOTERS; Exclosures; FISH POPULATIONS; Fish removal; FRESH-WATER; LOUGH-NEAGH; Macro-invertebrates; Mesocosms; NORTHERN SCOTLAND; SALMO-TRUTTA; Trophic cascades; WHOLE-LAKE

Spatial and temporal patterns of foraging activity by breeding Common Scoters (Melanitta nigra) in Scotland - Hancock, M. H.; Robson, H. J.; Smith, T. D.; Douse, A. (ORNIS FENNICA, 2019)
Many populations of sea ducks have declined; poor foraging conditions in freshwater breeding habitats could be a contributory factor. The UK breeding population of Common Scoters (Melanitta nigra) declined by 63% between 1995 and 2007, prompting research which showed that lake use by breeding scoters was correlated with food abundance (large invertebrates) and accessibility (shallow water). Building on this earlier work, here we investigate scoter foraging activity at Scottish breeding lakes, in order to better understand declines and inform conservation measures. We hypothesised that foraging effort would (i) be concentrated in shallow water holding large invertebrates, (ii) differ between sexes, and (iii) vary through the season. We recorded scoter foraging activity during 208 c. one-hour watches, at 13 lakes over three years. Water depth and food abundance (invertebrates) were measured. Foraging was significantly associated with shallow water: areas within 10 m of lake shores, typically less than 0.9 m in depth, had 1.9 and 4.1 times more foraging use than expected by chance, for females and ducklings respectively. Where large invertebrates were relatively abundant, the association with shallow water was weaker, implying that abundant food facilitated foraging across a wider range of water depths. Contrary to expectations, males and females expended similar foraging effort on breeding lakes. We discuss various interpretations of this result, and recommend tracking studies to help resolve these. There was no evidence that foraging effort of pre-breeding females or broods varied seasonally. Our study highlights the value of shallow water and large invertebrates to breeding Common Scoters. Conservation action should therefore seek to protect and enhance these habitat elements, for example via management of water levels or fisheries.
Times Cited in Web of Science Core Collection: 2 Total Times Cited: 2 Cited Reference Count: 76
Keywords: BIRDS; SURVIVAL; CONSERVATION; SURF SCOTERS; BEHAVIOR; FOOD; DIVING DUCKS; INTERSPECIFIC AGGRESSION; LIMITATION; MOVEMENT

From a research study to a conservation partnership: Developing approaches to restoring common scoter populations - Hancock, M. H.; Robson, H. J.; Smith, T. D.; Stephen, A.; Byrne, P.; MacLennan, A.; Klein, D.; Mitchell, C.; Griffin, L. R.; Hilton, G.; Dobson, H.; Douse, A. (AQUATIC CONSERVATION-MARINE AND FRESHWATER ECOSYSTEMS, 2020)
Like many sea-duck populations, the British breeding population of common scotersMelanitta nigrahas declined markedly. In 2009, a study was established to measure factors affecting lake use by breeding scoters, to inform conservation measures. That study, published inAquatic Conservation: Marine and Freshwater Ecosystems(AQC) in 2016, showed that lakes used by scoters had relatively more shallow water and large invertebrates. Furthermore, lakes with abundant large invertebrates had relatively few brown troutSalmo trutta. These results probably reflect the importance of foraging habitat (shallow water), prey abundance (large invertebrates), and competition for prey (trout abundance) in influencing scoter lake use. To develop this study, additional research, and scoter conservation measures, we formed a long-term partnership, comprising nature conservation non-governmental organizations, statutory agencies, fisheries managers and the regional hydropower company. The partnership meets regularly to coordinate and review research and develop conservation measures, building on the earlier lake-use study. At key scoter lakes managed for hydropower, the partnership negotiated a revised water level management regime, favouring shallow water availability in the breeding season. This regime was informed by additional research, showing the value of certain islands for nesting scoters, and water level requirements to maintain these as islands. In a different key scoter area - an extensive near-natural peatland where recreational angling takes place - the partnership established a trial of increased brown trout angling, with increased fish removal, to determine whether this would increase invertebrate prey abundance and benefit breeding scoters. Both conservation interventions are currently being evaluated by detailed monitoring. Overall, the earlier study published in AQC, was important in strengthening and informing our researcher-practitioner partnership, as we collaborated within an adaptive management framework to reverse scoter declines. Long-term interdisciplinary partnerships are likely to have an important role to play in general, for the successful conservation of aquatic biodiversity. 1.2.3.4.5.
Times Cited in Web of Science Core Collection: 3 Total Times Cited: 3 Cited Reference Count: 17
Keywords: foraging; ADAPTIVE MANAGEMENT; hydropower; lakes; macroinvertebrates; Scotland; trout; waterbirds

Genetically distinct isloates of Clostridium botulinum toxin type E associated with a large outbreak of botulism in birds and fish from Lake Erie - Hannett, G. E.; Stone, W.; Bopp, D.; Culligan, W.; Davis, S.; Okoniewski, J. (Abstracts of the General Meeting of the American Society for Microbiology, 2003)
From November 2000, to November 2002, a large outbreak of botulism among aquatic birds occurred in eastern Lake Erie. Approximately 7,000 bird deaths in New York State in 2002 have been attributed to this outbreak of botulism. Species of birds affected include Common Loons, Horned Grebes, Red-Breasted Mergansers, Long-Tailed Ducks, Ring-Billed Gulls, Herring Gulls, Bald Eagles, and Greater Black-Backed Gulls. Most outbreaks of avian botulism are caused by type C botulism, but this outbreak was caused by type E botulism. Type E botulism toxin was detected by mouse toxin neutralization tests in 13 samples from 4 different species of birds, and 2 samples from different species of fish. Sediment samples taken from Lake Erie in 2001 (depth range of 6 to 100 feet) were also examined for the presence of Clostridium botulinum as determined by toxin detection in broth cultures with mouse toxin neutralization assay and PCR: 9 of 10 sediment samples were positive for type E botulism toxin by both a mouse toxin neutralization assay and PCR. Nineteen isolates of Clostridium botulinum were cultured from the birds and fish. Fourteen of these isolates produced type E toxin, as determined by mouse toxin neutralization. Five isolates were not toxic for mice, and PCR analysis of these isolates revealed they were negative for the type E botulism toxin gene. Fourteen isolates were typed by pulsed field gel electrophoresis and this analysis showed 12 different DNA patterns that had greater than 3 band differences, and 3 isolates that differed by 3 or fewer bands. This study shows that type E Clostridium botulinum is present in the sediments of Lake Erie, large numbers of different bird and fish species are involved in this outbreak, and multiple genetically distinct strains of Clostridium botulinum are involved.
Keywords: Nonbreeding Seasons; Clangula hyemalis; Long-tailed Duck; Disease; Mergus serrator; Red-breasted merganser

Color Marking of Goosanders Mergus-Merganser at the Danish Breeding Grounds - Hansen, S. G. (Dansk Ornitologisk Forenings Tidsskrift, 1977)
Marking of 3 breeding female goosanders by placing color rings on the legs was made for the 1st time in Denmark in the summer of 1976. Previously used marking methods are discussed. By marking the birds with colored leg rings made of colored slips of semi-rigid Darvic plastic it was possible to recognize the ring in daylight and identify the perching bird at a distance up to 400 m using a telescope (25.times.). The minimum distance one is able to approach the bird at Danish breeding grounds is 300-400 m. The colors used were yellow, blue, light green and red. The 1st 3 are more appropriate since red is difficult to recognize on the bird's red leg. The rings did not bother the bird. After ringing the females returned to the nest and completed breeding. The method may be applicable only in areas with a low population density, because the number of combinations of color and right/left leg is limited. Where the population density is higher, wing tags have been used.
Keywords: Breeding Season; Techniques; Common merganser; Mergus merganser

Shell Thickness and Residues of Dieldrin Dde and Poly Chlorinated Bi Phenyl in Eggs of Danish Goosanders Mergus-Merganser - Hansen, S. G.; Kraul, I. (Ornis Scandinavica, 1981)
Eggs of Danish goosanders (44) collected from 1973-1976 were examined for shell thickness and residues of the persistent organochlorines: dieldrin, DDE and PCB [polychlorinated biphenyl]. A thinning of .apprx. 22% of the shell thicknes of eggs from 1973-1976 compared to eggs from 1870-1933 occurred and the following levels of the quantitated chemicals were found (arithmetic means and ranges in mg kg-1 on wet weight basis): dieldrin 0.12 (not detectable-0.48), DDE 3.9 (0.8-8.6) and PCB 13.5 (4.0-22.2). Both the shell thickness and the residues show a tendency of decrease (1973-1976). No significant correlations between the chemical residues and the shell thickness could be found. It is suggested that the actual registrated amounts of organochlorinated hydrocarbons are too small to affect the shell thickness and by this way of no influence on the size of the breeding population. The possibility of a correlation between these residues and the decreased breeding population observed during the years from 1938 to 1973-1976 is discussed.
Keywords: Breeding Season; Contaminants; Common merganser; Mergus merganser

Influence of Streamflow on Reproductive Success in a Harlequin Duck (Histrionicus histrionicus) Population in the Rocky Mountains - Hansen, W.; Bate, L.; Gniadek, S.; Breuner, C. (WATERBIRDS, 2019)
Aspects of streamflow and reproductive success of Harlequin Ducks (Histrionicus histrionicus) were measured to explore how variation in streamflow impacts reproduction, and to consider how climate change might influence these parameters in the future. A 24-year data set (1990-2013) of Harlequin Duck breeding season surveys conducted on Upper McDonald Creek in Glacier National Park (GNP), Montana, USA was used to assess how annual variation in the proportion of broods to pairs (reproductive success) relates to streamflow. Between 1990 and 2013, GNP staff and volunteers conducted 102 spring surveys and 112 brood surveys counting 896 total ducks, 212 pairs. 56 broods, and 278 ducklings. Four streamflow metrics (pre-inculcation streamflow - corresponding with nutrient acquisition and nest site selection, hydrographic peaks - corresponding with nest site selection and availability, value of the greatest single hydrographic peak post average peak flow - corresponding with risk of a nest washing out, and average streamflow during incubation - corresponding with foraging condition for an incubating female) were all negatively related to reproductive success. The first three of these metrics are predicted to become more extreme with climate change, with potential negative effects on breeding Harlequin Ducks.
Times Cited in Web of Science Core Collection: 1 Total Times Cited: 1 Cited Reference Count: 46
Keywords: CLIMATE-CHANGE; SURVIVAL; ABUNDANCE; FLOW; Harlequin Duck; Glacier National Park; INDEX; reproductive success; streamflow

Stress and Reproduction in Harlequin Ducks - Hansen, W. K.; Bate, L. J.; Chastel, O.; Breuner, C. W. (Integrative and Comparative Biology, 2014)
Hansen, W. K. Bate, L. J. Chastel, O. Breuner, C. W. Annual Meeting of the Society-for-Integrative-and-Comparative-Biology Jan 03-07, 2014 Austin, TX Soc Integrat & Comparat Biol 1

Feather and faecal corticosterone concentrations predict future reproductive decisions in harlequin ducks (Histrionicus histrionicus) - Hansen, W. K.; Bate, L. J.; Landry, D. W.; Chastel, O.; Parenteau, C.; Breuner, C. W. (Conservation Physiology, 2016)
Understanding sources of reproductive variation can inform management and conservation decisions, population ecology and life-history theory. Annual reproductive variation can drive population growth rate and can be influenced by factors from across the annual cycle (known as carry-over effects). The majority of studies, however, focus solely on the role of current environmental events. Past events often influence future reproductive decisions and success but can be logistically difficult to collect and quantify, especially in migratory species. Recent work indicates that glucocorticoids may prove good indicators to evaluate carry-over effects across life-history transitions. Here, we evaluated three different measures of glucocorticoid physiology (feathers, faeces and plasma) to evaluate the predictability of future breeding decision in the harlequin duck (Histrionicus histrionicus). We collected tail and back feathers, plasma and faeces for glucocorticoid analysis, and fitted female harlequin ducks with very high-frequency transmitters to track their breeding decisions. Both back feathers (moulted immediately before the current season) and faecal glucocorticoid metabolites were identified as important predictive factors of reproductive decisions; high concentrations of glucocorticoid metabolites in back feathers and faeces predicted a higher likelihood of reproductive deferral for the year. Although back and tail feather corticosterone concentrations were correlated, tail feathers (moulted at the end of the previous breeding season) did not predict breeding decisions. Plasma corticosterone concentrations were collected over too broad a time range after capture to be useful in this study. This study demonstrates the utility of non-invasive corticosterone metrics in predicting breeding decisions and supports the use of feathers to measure carry-over effects in migratory birds. With this technique, we identified the prenuptial moult as an important life-history phase that contributes to reproductive decisions. Identification of critical life-history phases is paramount to efficient management of species.
Hansen, Warren K. Bate, Lisa J. Landry, Devin W. Chastel, Olivier Parenteau, Charline Breuner, Creagh W.
Keywords: Behavior; Breeding Season; Histrionicus histrionicus; Physiology; Harlequin Duck

Water-fowl of the forested portions of the Canadian Pre-Cambrian Shield and the Palaeozoic basin - Hanson, Harold C.; Rogers, Murray; Rogers, Edward S. (Canadian Field Nat, 1949)
Field studies of the populations of mallard, black duck, gadwall, baldpate, blue-winged teal, green-winged teal, shoveller, wood duck, red head, canvasback, ring-necked duck, greater scaup, lesser scaup, white-winged scoter and ruddy duck were made in 1946, 1947 and 1948 in the areas of the Pre-Cambrian Shield and Palaeozoic basin in Ontario and Quebec. Data are presented showing the number of individual birds per 100 miles traveled. The literature on duck populations in other sections of the shield and basin is reviewed. Relatively large numbers of game ducks breed on or just adjacent to the periphery of the Palaeozoic basin and Pre-Cambrian Shield. However, it appears that the major part of the interior of an area of Canada bounded on the north by the limit of trees and on the east, south and west by the perimeter of the Pre-Cambrian Shield must, with the exception of the black duck and in a few places the mallard, be considered an area relatively unproductive of game ducks. || ABSTRACT AUTHORS: H. A. Senn
Keywords: Breeding Season; Abundance, Distribution, and Trends; Sea Ducks - General

The Breeding Population of the Common Eider Somateria-Mollissima in Ostfold County Norway - Hanssen, O. J. (Fauna (Oslo), 1979)
In a census of the population of the common eider in Ostfold, southern Norway (May 1978), 1868 individuals were counted. The highest density was in the outer archipelago, where the eiders breed on islands with Calluna vulgaris and low, creeping shrubs of Juniperus communis. To escape predation from the mink Lutreola lutreola and the fox Vulpes vulpes, they prefer to breed in the colonies of herring gulls, Larus argentatus. The census was made before the males leave the breeding places and migrate out to the open sea (according to weekly counts at Akeroya Bird Observatory). The estimate of the breeding population was established on the basis of observed males. The countings at Akeroya also showed that many of the males observed in the outer archipelago were non-breeding individuals. A correction coefficient (0.5) was used in some areas. The breeding population of the common eider on the Ostfold coast was estimated at slightly over 700 pairs.
Keywords: Breeding Season; Abundance, Distribution, and Trends; Common Eider; Somateria mollissima

Changes in the Abundance of Common Eiders Somateria-Mollissima in Ostfold Southeastern Norway During the Last 20 Years - Hanssen, O. J. (Fauna (Oslo), 1980)
The mean numbers of common eiders observed at Akeroya, Ostfold, southeastern Norway, from April 15th to May 1st are estimated for the 8 yr period 1963-1980. A regression analysis of the means indicates that the population has increased by 8.2%/yr since 1963. Published estimates of the breeding population of common eider on Akeroya in 1963, 1965, 1974 and 1977-1980 only indicate a slight increase in population size in the same period. Regression analysis gives the best prediction of increase in population size. Three possible reasons for the increase in eider population are briefly discussed. More effective protection and increase in food abundance may be the most important factors.
Keywords: Breeding Season; Abundance, Distribution, and Trends; Common Eider; Somateria mollissima

Seasonal Variations in the Occurrence of Common Eider Somateria-Mollissima at Akeroya Ostfold Southeast Norway - Hanssen, O. J. (Fauna Norvegica Series C Cinclus, 1981)
The seasonal variations in the occurrence of common eider at Akeroya were studied in the years 1978-1980, and the most important differences between the various sex and age categories are discussed. Only a few 2nd-yr males are observed at the Ostfold coast inthe breding season while a significant number of 2nd-yr females probably function as aunts in the protection of the ducklings. This may be a valuable adaption, as the juvenile males to not use the food resources on the breeding grounds, and the juvenile females gain experience in protecting the young. As the autumn and winter population on the Ostfold coast seems to consist chiefly of adult females, autumn shooting may have serious consequences for the local breeding population. Shooting should thus not be permitted before ringing and migration studies have been conducted.
Keywords: Breeding Season; Abundance, Distribution, and Trends; Common Eider; Nonbreeding Seasons; Somateria mollissima

Costs of an immune challenge and terminal investment in a long-lived bird - Hanssen, Sveinn Are (Ecology (Washington D C), 2006)
An induced immune challenge can have two counteracting effects on an individual's reproductive investment. (1) The resource demand could increase to "fuel" the immunologic reaction, which in turn can lead to an adaptive decrease in investment in resource-costly activities, such as reproduction. One the other hand, (2) the individual could assume that the immune activity it experiences is indicative of a serious infection. The latter can lead to an adaptive increase in reproductive investment in response to the reduced prospects of survival and future reproduction, so called "terminal investment." To measure such life-history-related consequences of increased immune activity, one group of incubating female Common Eiders (Somateria mollissima) was injected with a nonpathogenic antigen (sheep red blood cells, SRBC) while controls were injected with sterile saline. The eider is a long-lived sea-duck. Females, who incubate the eggs and care for young without assistance from the male, engage in facultative anorexia during incubation leading to a large reduction in body mass. Eiders can abandon their young to other females at the cost of reduced young survival. The immune challenge resulted in a larger mass loss, a prolonged incubation period, and reduced return rate, demonstrating both short- and long-term costs of immune challenge. Additionally, in response to what might have been interpreted as reduced survival chances in immune-challenged females, these females more often tended their own brood after hatching, despite having suffered higher costs during incubation.
Keywords: Breeding Season; Common Eider; Somateria mollissima; Physiology

Incubation start and egg size in relation to body reserves in the common eider - Hanssen, Sveinn Are; Engebretsen, Halvor; Erikstad, Kjell Einar (Behavioral Ecology and Sociobiology, 2002)
Avian incubation is often initiated before all eggs are laid. In altricial birds this has been proposed to facilitate brood reduction through asynchronous hatching. However, in precocial birds eggs normally hatch synchronously even if incubation has started before all eggs are laid. Patterns of incubation start may be the adaptive trait selected for both in altricial and precocial species. Several hypotheses have been proposed to explain the timing of incubation start in birds. Decreasing egg-size after incubation start may be adaptively related to an early incubation start, either to ensure synchronous hatching or to decrease fitness cost of late hatched eggs. We have measured individual body condition, egg size and start of incubation in common eider Somateria mollissima, a precocial sea-duck which does not feed during the incubation period. Females in poor body condition start to incubate earlier in the laying sequence than those in good body condition. Furthermore females in poor body condition lay smaller final eggs than females in good body condition. The laying of smaller eggs late in the sequence is therefore probably related to energetic or nutritional state. We propose that females in poor body condition start to incubate early to shorten the nest period in order to reduce their mass loss, but at the cost of reduced size and growth of the ducklings from the eggs laid after incubation start. Females in good body condition on the other hand postpone incubation start at the cost of a longer incubation period and a higher mass loss to the benefit of synchronized hatching and a higher survival of ducklings.
Keywords: Breeding Season; Common Eider; Somateria mollissima; Productivity; Energetics and Nutrition

The long-term consequences of egg predation - Hanssen, S. A.; Erikstad, K. E. (Behavioral Ecology, 2013)
Times Cited: 1 Hanssen, Sveinn Are Erikstad, Kjell Einar Hanssen, Sveinn Are/C-9989-2009 Hanssen, Sveinn Are/0000-0003-1792-435X 1
Keywords: Behavior; Breeding Season; Somateria mollissima; Productivity; Common eider

Differential investment and costs during avian incubation determined by individual quality: An experimental study of the common eider (Somateria mollissima) - Hanssen, Sveinn Are; Erikstad, Kjell Einar; Johnsen, Vigdis; Bustnes, Jan Ove (Proceedings of the Royal Society Biological Sciences Series B, 2003)
Individuals of different quality may have different investment strategies, shaping responses to experimental manipulations, thereby rendering the detection of such patterns difficult. However, previous clutch-size manipulation studies have infrequently incorporated individual differences in quality. To examine costs of incubation and reproductive investment in relation to changes in clutch size, we enlarged and reduced natural clutch sizes of four and five eggs by one egg early in the incubation period in female common eiders (Somateria mollissima), a sea duck with an anorectic incubation period. Females that had produced four eggs (lower quality) responded to clutch reductions by deserting the nest more frequently but did not increase incubation effort in response to clutch enlargement, at the cost of reduced hatch success of eggs. Among birds with an original clutch size of five (higher quality), reducing and enlarging clutch size reduced and increased relative body mass loss respectively without affecting hatch success. In common eiders many females abandon their own ducklings to the care of other females. Enlarging five-egg clutches led to increased brood care rate despite the higher effort spent incubating these clutches, indicating that the higher fitness value of a large brood is increasing adult brood investment. This study shows that the ability to respond to clutch-size manipulations depends on original clutch size, reflecting differences in female quality. Females of low quality were reluctant to increase investment at the cost of lower hatch success, whereas females of higher quality apparently have a larger capacity both to increase incubation effort and brood care investment.
Keywords: Breeding Season; Common Eider; Somateria mollissima; Productivity