Red-breasted merganser: Mergus serrator - Titman, Rodger T. (Birds of North America, 1999)
Keywords: Breeding Season; Nonbreeding Seasons; Mergus serrator; Red-breasted merganser

The winter abundance and distribution of birds in western peter the Great Bay in the Sea of Japan - Tiunov, I. M.; Burkovsky, O. A. (Russian Journal of Marine Biology, 2016)
The data on the abundance and distribution of sea birds and waterfowl at the coast of southern Primorye and distribution diagrams of the sea ducks along the surveyed coast in winter season are given. The dependence of the presence of the birds in certain coastal areas on the winter ice condition was revealed.
Tiunov, I. M. Burkovsky, O. A.
Keywords: Melanitta fusca; White-winged Scoter; Histrionicus histrionicus; Clangula hyemalis; Long-tailed Duck; Bucephala clangula; Common Goldeneye; Habitat; Mergus serrator; Abundance, Distribution, & Trends; Nonbreeding season; Red-breasted Merganser; Harlequin Duck

Drivers of Spatiotemporal Variation in Survival in a Flyway Population: A Multi-Colony Study - Tjornlov, R. S.; Ens, B. J.; Ost, M.; Jaatinen, K.; Karell, P.; Larsson, R.; Christensen, T. K.; Frederiksen, M. (FRONTIERS IN ECOLOGY AND EVOLUTION, 2020)
Spatio-temporal variation in population dynamics of migratory populations is shaped by exposure to different environments during the annual cycle. Hence, exposure to similar environments should translate into synchrony in vital rates. Despite a wide-ranging breeding population, the Baltic/Wadden Sea flyway population of eiders (Somateria m. mollissima) shares wintering grounds in the southern Baltic Sea, inner Danish waters and the Wadden Sea; different colonies within this flyway population are therefore likely to exhibit some degree of synchrony in vital rates. Here we used capture-recapture-recovery data to investigate the impact of hunting, winter climate (the North-Atlantic Oscillation Index), winter temperature, nitrogen runoff, autumn-winter body condition of blue mussels Mytilus spp., natural predation and epidemic disease (avian cholera) on annual survival of adult females in ten study colonies distributed between Netherlands and Finland. Moreover, we tested how the degree of similarity in spatial winter distributions affected the degree of similarity in annual survival among colonies. None of the covariates universally affected female survival. While the quality of blue mussels in the wintering area explained almost 40% of the variation in survival of eiders breeding on Christianso in the south-western Baltic Sea, incidence of epidemic disease explained >60% in two affected colonies. Furthermore, the spatial winter distribution did not appreciably influence annual survival rates in these 10 colonies. The lack of universal effects of spatial winter distribution and winter conditions on survival suggests that local breeding conditions may be more important, and hence prime targets for conservation efforts. Better monitoring of e.g., food quality, predation pressure and epidemic disease at the time of breeding could be the key to better understand the population dynamics in this endangered flyway population.
Times Cited in Web of Science Core Collection: 6 Total Times Cited: 6 Cited Reference Count: 62
Keywords: EIDERS SOMATERIA-MOLLISSIMA; COMMON EIDER; CLIMATE; MASS; WADDEN SEA; WINTER; PASTEURELLA-MULTOCIDA; wintering area; AVIAN CHOLERA; capture-recapture; colony-specific; environmental covariate; female survival; SCALE; spatiotemporal variation; WATER TEMPERATURE

Impacts of avian cholera on survival of Common Eiders Somateria mollissima in a Danish colony - Tjornlov, R. S.; Humaidan, J.; Frederiksen, M. (Bird Study, 2013)
Times Cited: 0 Tjornlov, Rune Skjold Humaidan, Jakob Frederiksen, Morten Frederiksen, Morten/A-7542-2008 Frederiksen, Morten/0000-0001-5550-0537 0
Keywords: Breeding Season; Somateria mollissima; Survival; Disease; Common eider

Consequences of past and present harvest management in a declining flyway population of common eiders Somateria mollissima - Tjornlov, R. S.; Pradel, R.; Choquet, R.; Christensen, T. K.; Frederiksen, M. (ECOLOGY AND EVOLUTION, 2019)
Harvested species population dynamics are shaped by the relative contribution of natural and harvest mortality. Natural mortality is usually not under management control, so managers must continuously adjust harvest rates to prevent overexploitation. Ideally, this requires regular assessment of the contribution of harvest to total mortality and how this affects population dynamics. To assess the impact of hunting mortality on the dynamics of the rapidly declining Baltic/Wadden Sea population of common eiders Somateria mollissima, we first estimated vital rates of ten study colonies over the period 1970-2015. By means of a multi-event capture-recovery model, we then used the cause of death of recovered individuals to estimate proportions of adult females that died due to hunting or other causes. Finally, we adopted a stochastic matrix population modeling approach based on simulations to investigate the effect of past and present harvest regulations on changes in flyway population size and composition. Results showed that even the complete ban on shooting females implemented in 2014 in Denmark, where most hunting takes place, was not enough to stop the population decline given current levels of natural female mortality. Despite continued hunting of males, our predictions suggest that the proportion of females will continue to decline unless natural mortality of the females is reduced. Although levels of natural mortality must decrease to halt the decline of this population, we advocate that the current hunting ban on females is maintained while further investigations of factors causing increased levels of natural mortality among females are undertaken. Synthesis and applications. At the flyway scale, continuous and accurate estimates of vital rates and the relative contribution of harvest versus other mortality causes are increasingly important as the population effect of adjusting harvest rates is most effectively evaluated within a model-based adaptive management framework.
Times Cited in Web of Science Core Collection: 6 Total Times Cited: 8 Cited Reference Count: 56
Keywords: demography; RATES; SURVIVAL; WADDEN SEA; MORTALITY; MARK; WATERBIRDS; SEX-RATIO; CMR modeling; hunting bag statistics; multi-event model; PASTEURELLOSIS; population dynamics; prospective population scenario; RING RECOVERY; sex ratio

Assessing the extent to which temporal changes in waterbird community composition are driven by either local, regional or global factors - Tomankova, I.; Boland, H.; Reid, N.; Fox, A. D. (Aquatic Conservation-Marine and Freshwater Ecosystems, 2013)
Times Cited: 0 Tomankova, Irena Boland, Helen Reid, Neil Fox, Anthony D. Fox, Anthony/I-7465-2013 0
Keywords: Population Dynamics

Pairing decisions in the Harlequin Duck: Costs and benefits - Torres, Roxana; Cooke, Fred; Robertson, Gregory J.; Boyd, W. Sean (Waterbirds, 2002)
In waterfowl, the male costs and female benefits hypothesis considers that the timing of pairing will depend on the balance between the costs and benefits for each sex. Females may benefit by increasing their access to food and social status, and by decreasing harassment from conspecifics, while maintaining a pair bond for a long period should be costly to males. To investigate costs and benefits of early pairing in the Harlequin Duck (Histrionicus histrionicus), we compared time budgets and frequency of interactions (agonistic, courtship, and mate guarding behavior) from paired and unpaired males and females. A total of 400 thirty-minute focal-animal sampling sessions were used for the analysis. Overall, feeding time did not differ between paired and unpaired birds of both sexes. However, regardless of their reproductive status, females spent about 15% more time feeding than males throughout the winter. While diving, paired males spent 4% less time underwater than unpaired males, but no difference was found between paired and unpaired females. Males spent more time on the surface between dives than females, yet the differences between paired and unpaired birds were not significant. Paired males were engaged in more interactions (mainly mate guarding) than unpaired males. Interactions received by paired and unpaired females did not differ overall, however, from late October to early May, interactions with paired females decreased, while interactions directed to unpaired females increased. Thus the pair bond, though being apparently costly to males, did not obviously benefit females by increasing feeding time. Early pairing in the Harlequin Duck may result from other factors, such as the advantages that pair reunion may confer.
Keywords: Behavior; Nonbreeding Seasons; Harlequin duck; Histrionicus histrionicus

PREDATION FROM BOTH STARFISH (ASTERIAS RUBENS) AND EIDERS (SOMATERIA MOLLISSIMA) ON SUSPENDED MUSSELS (MYTILUS EDULIS) IN AN INTEGRATED MARICULTURE PRODUCTION IN INNER DANISH WATERS - Torring, D.; Andersen, P.; Dolmer, P.; Carl, J.; Soegren, C.; Pedersen, M. (Journal of Shellfish Research, 2015)
Torring, Ditte Andersen, Per Dolmer, Per Carl, Jonathan Soegren, Christina Pedersen, Mathilde
Keywords: Behavior; Common Eider; Somateria mollissima; Trophic Interactions; Nonbreeding season

Sources of variation in endohelminth parasitism of common eiders over-wintering in the Canadian Arctic - Tourangeau, J.; Provencher, J. F.; Gilchrist, H. G.; Mallory, M. L.; Forbes, M. R. (POLAR BIOLOGY, 2019)
Documenting how climate change will affect Arctic ecosystems and food web dynamics requires an understanding of current sources of variation in species distributions, frequency, and abundance. Host-parasite interactions are expected to be altered in the coming decades under warming conditions. However, in many Polar Regions, there is little information describing parasite-host assemblages. We examine how gastrointestinal helminths of northern common eider ducks (Somateria mollissima sedentaria) in the low Arctic vary with host age, sex and sampling year. We found that the prevalence of an acanthocephalan (Profilicollus sp.) varied in eiders with age, sex and year, while a cestode (Microsomacanthus sp.) varied with host sex. Two other species of endohelminths (Lateriporus sp., Corysonoma sp.) were not found to vary with sex, age or sampling year, and another species (Microphallus sp.) did not vary with sex or age. Our results highlight the complexity inherent in Arctic host-parasite assemblages, and the need for more detailed studies to better understand how changing climatic conditions may affect species distributions, frequency or abundance.
Times Cited in Web of Science Core Collection: 4 Total Times Cited: 5 Cited Reference Count: 51
Keywords: CLIMATE-CHANGE; Arctic; SOMATERIA-MOLLISSIMA; MERCURY; ECOLOGY; DYNAMICS; BEHAVIOR; Bird; SEX; BIASED PARASITISM; Non-migratory; Polar; Polynya; Resident

Effects of intrinsic and extrinsic factors on survival of white-winged scoter (Melanitta fusca deglandi) ducklings - Traylor, Joshua J.; Alisauskas, Ray T. (Auk, 2006)
In waterfowl, offspring survival and the effects of extrinsic (i.e. weather, hatching date) and intrinsic (i.e. physical and nutritional traits of individual females and ducklings, brood sizes) factors on it are poorly understood. In 2000 and 2001, we estimated duckling and brood survival of White-winged Scoters (Melanitta fusca deglandi) at Redberry Lake, Saskatchewan, Canada, to 30 days of age to examine relationships between duckling survival and (1) hatch date, (2) initial brood size at hatch, (3) duckling size and body condition at hatch, (4) offspring sex, (5) maternal female size and body condition at hatch, and (6) weather. We estimated Survival with Cormack-Jolly-Seber models, in program MARK, from observations of individually marked adult females (n = 94) and ducklings (n = 664). Most mortality (i.e. 0.80 and 0.95 for each year, respectively) occurred within six days of hatch in both years. Duckling Survival probability decreased with advancing hatch date; increased with larger initial brood sizes; was higher for larger, better-conditioned ducklings; and increased with favorable weather. Brood survival decreased with advancing hatch date, increased with larger initial brood sizes, and increased with favorable weather. For 2000 and 2001., Our models predict survival probabilities of ducklings (0.0061 and 0.0027, respectively) and broods (0.015 and 0.00048, respectively) that are lower than any previously reported. We suspect that intense gull (Larus spp.) predation shortly after hatch had the largest influence on duckling survival, though results also underscore the significance of intrinsic factors.
Keywords: Breeding Season; Melanitta fusca; White-winged Scoter; Productivity; Survival

Multistate modeling of brood amalgamation in White-winged Scoters Melanitta fusca deglandi - Traylor, J. J.; Alisauskas, R. T.; Kehoe, F. P. (Animal Biodiversity and Conservation, 2004)
Keywords: Behavior; Breeding Season; Melanitta fusca; White-winged Scoter; Techniques

Nesting ecology of White-winged Scoters (Melanitta fusca deglandi) at Redberry Lake, Saskatchewan - Traylor, Joshua J.; Alisauskas, Ray T.; Kehoe, F. Patrick (Auk, 2004)
Population surveys indicate a trend of declining abundance of scoters (Melanitta spp.) in North America. Little is known about changes in life-history traits that may be responsible for the recent population decline of White-winged Scoters (Melanitta fusca deglandi). Therefore, we studied nesting ecology of White-winged Scoters at Redberry Lake, Saskatchewan, during the summers of 2000-2001. We found 198 nests and examined nest-site selection by comparing habitat features of successful nests, depredated nests, and random sites. Discriminant function analysis differentiated habitat features-measured at hatch-of successful nests, deprecated nests, and random sites; lateral (r = 0.66) and overhead (r = 0.35) concealment were microhabitat variables most correlated with canonical discriminant functions. We also modeled daily survival rate of nests as a function of year, linear and quadratic trends with nest age, nest initiation date, and seven microhabitat variables. Nest survival from a time-constant model (i.e. Mayfield nest-success estimate) was 0.35 (95% CL: 0.27, 0.43). Estimates of nest success were lower than those measured at Redberry Lake in the 1970s and 1980s. Nest survival increased throughout the laying period and stabilized during incubation, and showed positive relationships with nest concealment and distance to water and a negative relationship with distance to edge. Considering those factors, a model-averaged estimate of nest survival was 0.24 (95% CL: 0.09, 0.42). We concluded that White-winged Scoters selected nesting habitat adaptively, because (1) successful sites were more concealed than depreciated sites; (2) nest sites (both successful and depredated) had higher concealment than random sites; and (3) nest sites were on islands, where success is greater than on the mainland.
Keywords: Breeding Season; Melanitta fusca; White-winged Scoter; Productivity; Habitat

Ecological correlates of duckling adoption among white-winged scoters Melanitta fusca: strategy, epiphenomenon, or combination? - Traylor, Joshua J.; Alisauskas, Ray T.; Kehoe, F. Patrick (Behavioral Ecology and Sociobiology, 2008)
Young waterfowl can frequently join foster females shortly after hatch, resulting in post-hatch brood amalgamation. Much uncertainty remains about physiological or ecological factors that motivate adoption including potential costs and benefits to fostered offspring as well as to females that either lose or accept young. Several hypotheses have been put forth to explain adoption. In this paper, we examine the salvage strategy (SSH) and accidental-mixing (AMH) hypotheses. According to the SSH, females abandon or lose their young due to substantial energetic constraints from incubation and brood rearing. The AMH posits that adoption results from local ecological conditions on breeding areas (i.e., adverse weather conditions, high brood densities) which act to separate offspring and mothers. We used multistate modeling to estimate relationships between probabilities of adoption by white-winged scoter (Melanitta fusca) ducklings from natal to foster females and a set of hypothesized ecological covariates. Results showed that most adoption occurred within 6 days of hatch; additionally, likelihood of adoption was positively related to inclement weather and negatively related to hatch date, size, and condition of natal females, and duckling condition. We conclude that adoption in this population is consistent with both the salvage strategy and accidental-mixing hypotheses. Ultimately, we suggest that adoption in our study population was foremost an outcome of intense gull predation but also of local environmental conditions.
Keywords: Behavior; Breeding Season; Melanitta fusca; White-winged Scoter

Harlequin Ducks in Labrador - Trimper, Perry G.; Thomas, Peter W.; Chubbs, Tony E. (Waterbirds, 2008)
Labrador represents a significant portion of the breeding range for the Northwest Atlantic population of the Harlequin Duck (Histrionicus histrionicus). The region comprises almost 300,000 kill of wilderness area with habitat for breeding, molting and staging activity. The wilderness quality of Labrador has also posed several challenges in terms Of understanding the status of this species. Expensive and logistically-challenging survey programs have only recently (i.e., last 20 years) targeted Harlequin Ducks but due to the co-ordination amongst agencies and proponents, all appreciation of the range, numbers,and timing of movements for this species in Labrador has been developed. Over 800 helicopter survey hours have been completed on at least 111 river systems/sections during late May-early June (July in northern-most areas) front 1987-2008. Presence of the species was widespread and confirmed oil approximately 67% of areas examined. It is estimated that 395 breeding pairs Occur Oil rivers where presence has been confirmed and the majority of potential habitat for this species has been examined ill Labrador. The actual number of breeding pairs, their success and other population limiting factors remain unclear. Regardless, Harlequin Ducks arc common in Labrador and the population appears to be stable or increasing.
Keywords: Breeding Season; Harlequin duck; Histrionicus histrionicus

Long-term Coastal Breeding Bird Monitoring in the Boston Harbor Islands, 2007-2019 - Trocki, C. L.; Weed, A. S.; Kozlowski, A.; Broms, K. (NORTHEASTERN NATURALIST, 2021)
The National Park Service with support from numerous partners and community volunteers, has implemented long-term monitoring of coastal breeding birds in the Boston Harbor Islands since 2007. The objectives of the monitoring are to assess long-term trends in the abundance of priority coastal breeding species among the islands to inform conservation practices and park management. A combination of boat- and ground-based surveys are used to estimate the number of incubating Larus argentatus (Herring Gull), Larus marinus (Great Black-backed Gull), Phalacrocorax auritus (Double-crested Cormorant). Haematopus palliatus (American Oystercatcher), Somateria mollissima (Common Eider), and tern species annually. Ground-based nest counts are conducted for Common Eider and wading birds (Plegadis falcinellus [Glossy Ibis], Nycticorax nycticorax [Black-crowned Night Heron], Ardea alba [Great Egret] and Egretta thula [Snowy Egret]) on a 2-3-year rotation on islands that are accessible for landing by boat. The objectives of this study were to present count data from this monitoring and assess trends in annual counts of cormorants. gulls, and eiders estimated during boat-based surveys from 2007 to 2019. Changes in annual nesting of Double-crested Cormorants, Herring Gulls, and Great Black-backed Gulls estimated by boat-based surveys varied over time and by island, but in the park overall, all 3 species appear to have stable breeding colonies. Boat-based monitoring indicates that counts of tending Common Eider females and ducklings are declining in the areas where they forage near the Outer Islands. Ground-based monitoring has indicated that the largest wading-bird colony has consistently been located on Sarah Island and that Black-crowned Night Herons are the dominant driver in overall numbers and on all islands, except for Sheep Island. where they were overshadowed by an increase in Snowy Egrets in 2016 and 2018. As the long-term monitoring continues, we intend to compare its results to historical and regional data to better understand how populations have and are responding to environmental change in the harbor and to better understand how coastal breeding birds utilize natural communities within the park to inform park management decision-making.
Times Cited in Web of Science Core Collection: 1 Total Times Cited: 1 Cited Reference Count: 43
Keywords: COMMON EIDERS; SOMATERIA-MOLLISSIMA; GULLS LARUS-ARGENTATUS; MAINE; MARINUS

Ingested Shot in Waterfowl Harvested on the Upper Mississippi USA National Wildlife Refuge - Trost, R. E. (Wildlife Society Bulletin, 1980)
Keywords: Sea Ducks - General; Contaminants

Cytochrome P450 1A induction in sea ducks inhabiting nearshore areas of Prince William Sound, Alaska - Trust, Kimberly A.; Esler, Daniel; Woodin, Bruce R.; Stegeman, John J. (Marine Pollution Bulletin, 2000)
Following the Exxon-Valdez oil spill, hepatic rates of EROD activity and thus, P450 1A expression, were significantly higher in harlequin ducks (Histrionicus histrionicus) and Barrow's goldeneyes (Bucephala islandica) from oiled areas of Prince William Sound, Alaska when compared to birds from unoiled sites. Polychlorinated biphenyl exposure did not account for areal differences in P450 1A induction in harlequin ducks. Background hydrocarbon levels in Prince William Sound were negligible prior to the 1989 oil spill, but remnant Exxon-Valdez oil was still present in nearshore habitats of the spill zone coincident with our study. We conclude that P450 1A induction in sea ducks from areas oiled during the Exxon-Valdez oil spill was likely due to exposure to residual oil. We speculate that biochemical and physiological changes in individuals chronically exposed to oil may be constraining population recovery of some sea duck species affected by the spill.
Keywords: Nonbreeding Seasons; Harlequin duck; Histrionicus histrionicus; Contaminants; Barrow's Goldeneye; Bucephala islandica

Contaminant exposure and biomarker responses in spectacled eiders (Somateria fischeri) from St. Lawrence Island, Alaska - Trust, K. A.; Rummel, K. T.; Scheuhammer, A. M.; Brisbin, I. L., Jr.; Hooper, M. J. (Archives of Environmental Contamination and Toxicology, 2000)
Effects of chemical contaminant exposure may be contributing to the decline of spectacled eiders (Somateria fischeri) nesting in coastal areas of western Alaska. We evaluated chemical exposure and potential effects in 20 male eiders collected near St. Lawrence Island, Alaska. Analytes included metals, trace elements, chlorinated organics, and 137Cesium (137Cs). Effects of contaminant exposure were evaluated using histopathology and biochemical measures of porphyrin profiles, cytochrome P450 activities, and metallothionein (MT) concentrations. Copper, cadmium, and selenium concentrations were elevated in spectacled eiders when compared to literature values for other marine birds. Only a few samples had trace concentrations of chlorinated organic compounds. Muscle 137Cs levels were all below the average minimum quantifiable concentration of 0.079 Bq/g. No histopathological lesions were associated with elevated contaminant concentrations in liver, kidney, or testes. Protoporphyrin was found in highest concentration in both the liver and kidneys, followed by coproporphyrin and uroporphyrin, respectively. Hepatic uroporphyrin concentrations correlated significantly to hepatic arsenic concentrations. Mean activities of hepatic EROD, MROD, BROD, and PROD were consistent with other avian species. Comparisons of cadmium/MT ratios from this study to published literature ratios in seven marine avian species suggest that, although adult male spectacled eiders have elevated liver concentrations of certain MT-inducing metals, their MT concentrations are not as strongly induced as would be predicted based on literature values. Despite elevated metal concentrations, the apparent good health of the St. Lawrence Island birds suggests that should these contaminants be a factor in population declines, they likely act by decreasing fecundity or survival of young rather than via direct health impacts on adult male spectacled eiders.
Keywords: Somateria fischeri; Spectacled Eider; Contaminants

Epidemiology of avian influenza viruses in wild birds in Mongolia - Tseren-Ochir, E. O.; Damdinjav, B.; Sharkhuu, T.; Kang, H. M.; Sakoda, Y.; Purevsuren, B.; Ruuragchaa, S.; Lee, Y. J.; Kida, H.; Khishgee, B.; Sengee, S. (International Journal of Infectious Diseases, 2010)
Keywords: Sea Ducks - General; Disease

A Physiologically Based Oiling Model (PBOM) to Predict Thermoregulatory Response in Birds - Tuarze, P.; Stephenson, M.; Mazzocco, P.; Knopper, L. (ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY, 2021)
When birds are exposed to oil, their ability to thermoregulate is impaired as a result of damage to the insulative properties of their feathers. If an oiled bird is unable to maintain thermal homeostasis, hypothermia and death can follow rapidly. Physiological responses to oiling depend on several variables including environmental conditions (e.g., ambient air and water temperatures), life history of bird species (e.g., body size and habitat selection), and foraging strategies (e.g., divers, surface feeders, shorebirds). The most widely used approach to assess the effect of spilled oil on birds is the US Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) Type A Natural Resource Damage Assessment (NRDA) Model for Coastal and Marine Environments. This approach addresses body size and time spent in a hypothetical slick but lacks the flexibility to assess other variables related to physiological response. We developed a dynamic physiologically based oiling model (PBOM) for birds to address this need. The PBOM has been validated against empirical data from a dose-response study in which common eiders were exposed to Statfjord A crude oil. The PBOM can be used to predict time to hypothermia for birds of differing body size and habitat preferences, in environments ranging from Arctic to subtropical. The model presently includes 5 representative bird species: common eider, spotted sandpiper, great blue heron, dovekie, and American white pelican, but could be adapted to represent almost any bird. Environ Toxicol Chem 2020;00:1-10. (c) 2020 SETAC
Times Cited in Web of Science Core Collection: 0 Total Times Cited: 0 Cited Reference Count: 29
Keywords: Birds; Physiology; EIDERS SOMATERIA-MOLLISSIMA; Oil spills; PLUMAGE; BUOYANCY; Ecological risk assessment; Environmental modeling; METABOLISM; Thermoregulation

Packing of broods and "injury-feigning" of velvet-scoters - Tucker, B. W. (British Birds, 1940)
Observations on Melanitta f. jusca off a Baltic island. A pack of 90 young birds was seen under the charge of one or more adult 22- A 2 with a brood on the water performed a variant "injury-feigning," half flying, half pattering, round the boat. || ABSTRACT AUTHORS: D. S. Lehrman
Keywords: Behavior; Breeding Season; Melanitta fusca; White-winged Scoter

Some Ecological Factors Affecting Winter Wildfowl Distribution on Inland Waters in England and Wales Uk and the Influence of Water Based Recreation - Tuite, C. H.; Hanson, P. R.; Owen, M. (Journal of Applied Ecology, 1984)
Multiple regression analyses are used to examine the distribution of 9 common freshwater wildfowl in Britain. Six independent variables related to the ecology of inland waters are used in the regression models. The amount of variation accounted for by the regressions varied considerably between species and between months for the same species. The regression coefficients and r2 values are summarized. The significance of the coefficients is discussed in terms of the migration patterns and feeding ecology of the different species. Most relationships were in concordance with those expected, based on known habits and requirements of the birds. For example, large sites tended to hold more widlfowl than smaller ones and relationships with the crinkliness of the shore were probably due to the fact that many sites are primarily roosts and that large reservoirs have relatively simple perimeters. Chi-squared analyses were used to test the effects of the presence of different types of water-based recreation in terms of the observed number of birds compared to the number predicted by the regression models. Winter wildfowl distribution seems to be affected by water-based recreation but the impact on different species varies considerably. There is also substantial variation apparent between activities in terms of their disturbance effect. The most susceptible species to disturbance from reaction were teal, shoveler and goldeneye; the most tolerant were mute swan, tufted duck, pochard and mallard. The greatest deleterious impact on winter wildfowl numbers was associated with the presence of coarse fishing, sailing and rowing. The presence of birdwatching, which is frequently associated with active conservation management, was the commonest activity category associated with higher-than-expected numbers of most species. Shooting was not shown to have great impact, but this was due to the choice by hunters of good wildfowl sites rather than any positive effect. Conditions were favorable for inland wildfowl in recent years and the fact that most recreation on water is carried out largely in the summer has also meant that the impact of recreational activities was not as great as was feared. If the recent trend toward increased public participation in water sports continues, the impact on wildfowl may have to be reexamined.
Keywords: Conservation; Nonbreeding Seasons; Bucephala clangula; Common Goldeneye; Habitat

The role of the invasive bivalve Ensis directus as food source for fish and birds in the Dutch coastal zone - Tulp, Ingrid; Craeymeersch, Johan; Leopold, Mardik; van Damme, Cindy; Fey, Frouke; Verdaat, Hans (Estuarine Coastal and Shelf Science, 2010)
The razor clam Ensis directus was introduced to Europe presumably as larvae in ballast water around 1978. Starting in the German Bight it spread northward and southward along the continental coastline. Currently it is the most common shellfish species in the Dutch coastal zone, where it mainly occurs in the Voordelta and off the Wadden Sea islands. The mean density of E. directus in the Dutch coastal zone increased from around 2-5 individuals m(-2) in the late '90's to around 12-19 individuals m(-2) from 2002 onwards. Diet studies show that E. directus makes up a significant proportion in the current diet of plaice, sole, dab, flounder and dragonet and in the diet of eider and common scoter. In recent years E. directus contributed 20-100% of the total wet weight in fish stomachs. The proportion E. directus in the diet increases with fish length. Based on stomach contents of oiled and beached birds and of faeces samples the recent frequency of occurrence is 85-90% in eider and 26% in common scoter. Also waders, gulls and corvids prey on E. directus but the contribution to the diet is still unquantified. Because of its great burying depth the species is not easily accessible. Fish either profit from massive die-offs that regularly occur, or they extract (probably only the smaller) individuals from the sediment. Sea ducks can extract E. directus from the sediment, while shorebirds and gulls feed on dying E. directus washing up on the shore. E. directus is possibly an important food item for fish and seabirds when they occur in high densities and in the right size classes. Since the availability depends greatly on massive die-offs, shell size, burying depth and water depth, it is probably not a very reliable food source. Judging from the role E. directus currently plays for the higher trophic levels, its introduction must have caused a major change in the food relations in its distribution area. (C) 2010 Elsevier Ltd. All rights reserved.
Keywords: Common Eider; Nonbreeding Seasons; Somateria mollissima; Trophic Interactions; Black Scoter; Melanitta nigra

Systematic relationships among some anatini as derived from restriction-endonuclease analysis of a repeated DNA component - Tuohy, James M.; McHugh, Kevin P.; De Kloet, Siwo R. (Auk, 1992)
We recently isolated and cloned a highly repeated retropseudogenelike DNA sequence (RBMI) from the genome of the Red-breasted Merganser (Mergus serrator). This sequence was used to probe Southern blots of restriction-enzyme-digested DNA from members of the waterfowl tribe Anatini in order to infer phylogenetic relationships. The digested DNA of all the species studied contained major and minor RBMI-like components. Some RBMI-like components were common to all the species examined, others were only found in groups of species, and still others were specific to individual species. The Mallard (Anas platyrhynchos) and the American Black Duck (A. rubripes) could be differentiated on the basis of RBMI-probed Southern blots. Thus, the RBMI sequence can be used to distinguish very closely related species. We suggest that the Anatini consist of three major groups: the mallard pintail group; the gadwall-wigeon group; and the blue-winged ducks. The Versicolor Teal (A. versicolor) had major elements in common with both the blue-winged ducks and the mallard-pintail group. The Baikal Teal (A. formosa) and the Marbled Teal (Marmaronetta angustirostris) do not appear to be members of any of these three groups.
Keywords: Taxonomy; Mergus serrator; Red-breasted merganser

Survival of Surf Scoters and White-Winged Scoters during Remigial Molt - Uher-Koch, B. D.; Esler, D.; Dickson, R. D.; Hupp, J. W.; Evenson, J. R.; Anderson, E. M.; Barrett, J.; Schmutz, J. A. (Journal of Wildlife Management, 2014)
Quantifying sources and timing of variation in demographic rates is necessary to determine where and when constraints may exist within the annual cycle of organisms. Surf scoters (Melanitta perspicillata) and white-winged scoters (M. fusca) undergo simultaneous remigial molt during which they are flightless for >1 month. Molt could result in reduced survival due to increased predation risk or increased energetic demands associated with regrowing flight feathers. Waterfowl survival during remigial molt varies across species, and has rarely been assessed for sea ducks. To quantify survival during remigial molt, we deployed very high frequency (VHF) transmitters on surf scoters (n=108) and white-winged scoters (n=57) in southeast Alaska and the Salish Sea (British Columbia and Washington) in 2008 and 2009. After censoring mortalities potentially related to capture and handling effects, we detected no mortalities during remigial molt; thus, estimates of daily and period survival for both scoter species during molt were 1.00. We performed sensitivity analyses in which mortalities were added to the dataset to simulate potential mortality rates for the population and then estimated the probability of obtaining a dataset with 0 mortalities. We found that only at high survival rates was there a high probability of observing 0 mortalities. We conclude that remigial molt is normally a period of low mortality in the annual cycle of scoters. The molt period does not appear to be a constraint on scoter populations; therefore, other annual cycle stages should be targeted by research and management efforts to change population trajectories. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.
Uher-Koch, Brian D. Esler, Daniel Dickson, Rian D. Hupp, Jerry W. Evenson, Joseph R. Anderson, Eric M. Barrett, Jennifer Schmutz, Joel A.
Keywords: Melanitta fusca; White-winged Scoter; Melanitta perspicillata; Surf Scoter; Molt; Survival; SDJV funded; Nonbreeding season

Interacting effects of latitude, mass, age, and sex on winter survival of Surf Scoters (Melanitta perspicillata): implications for differential migration - Uher-Koch, B. D.; Esler, D.; Iverson, S. A.; Ward, D. H.; Boyd, W. S.; Kirk, M.; Lewis, T. L.; VanStratt, C. S.; Brodhead, K. M.; Hupp, J. W.; Schmutz, J. A. (Canadian Journal of Zoology, 2016)
We quantified variation in winter survival of Surf Scoters (Melanitta perspicillata (L., 1758)) across nearly 30 degrees of latitude on the Pacific coast of North America to evaluate potential effects on winter distributions, including observed differential distributions of age and sex classes. We monitored fates of 297 radio-marked Surf Scoters at three study sites: (1) near the northern periphery of their wintering range in southeast Alaska, USA, (2) the range core in British Columbia, Canada, and (3) the southern periphery in Baja California, Mexico. We detected 34 mortalities and determined that survival averaged lower at the range peripheries than in the range core, was lower during mid-winter than during late winter at all sites, and was positively correlated with body mass within locations. Although neither age nor sex class had direct effects, mass effects led to differential survival patterns among classes. When simultaneously incorporating these interacting influences, adult males of mean mass for their location had highest survival at the northern range periphery in Alaska, whereas adult females and juveniles had higher survival at the range core and the southern periphery. Our observations help to explain patterns of differential migration and distribution reported for this species and highlight seasonal periods (mid-winter) and locations (range peripheries) of elevated levels of mortality for demographically important age-sex classes (adult females).
Uher-Koch, Brian D. Esler, Daniel Iverson, Samuel A. Ward, David H. Boyd, W. Sean Kirk, Molly Lewis, Tyler L. VanStratt, Corey S. Brodhead, Katherine M. Hupp, Jerry W. Schmutz, Joel A.
Keywords: Melanitta perspicillata; Surf Scoter; Survival; SDJV funded; Nonbreeding season

On the wintering population of the goosander and the smew (Mergus merganser and Mergus albellus) in the Oder estuary - Uhlig, Rolf (Beitraege zur Vogelkunde, 1993)
Keywords: Nonbreeding Seasons; Common merganser; Mergus merganser

Status and distribution of breeding common scoters Melanitta nigra nigra in Britain and Ireland in 1995 - Underhill, Mark C.; Gittings, Tom; Callaghan, Des A.; Hughes, Baz; Kirby, Jeff S.; Delany, Simon (Bird Study, 1998)
The status and distribution of Common Scoters Melanitta nigra nigra in Britain and Ireland were determined from a survey in April-June 1995. Three visits were made to all known, and a sample of potential, breeding sites. A total of 439 birds was located, from which the British and Irish population was estimated at 195 pairs (100 in Ireland, 95 in Britain). In Ireland, three sites held 100 pairs or 51% of the population. In Britain, birds were spread over 61 sites in 23 10-km squares, all in Scotland. Breeding Common Scoters are somewhat more abundant in Britain and Ireland than hitherto thought. However, this is due mainly to comprehensive survey coverage in 1995 and, over the past 30 years, Common Scoters have actually suffered both population decline and range contraction. The Irish population declined from 180 to 100 pairs between 1967 and 1981, but has since remained stable. In Britain, Common Scoters have ceased to breed on Shetland, in Central Scotland, and in Dumfries and Galloway. Historical data are lacking, but in the Flow Country numbers have declined from some 50 pairs in 1988 to 35 pairs in 1995. All birds in Ireland, but only half of those in Britain were on protected sites. Given the Common Scoter's threatened status in Britain and Ireland and since the population dynamics of the species are largely unknown, annual monitoring of numbers and productivity is required to determine population trends and establish natural limits of population fluctuation. As Common Scoters in Britain and Ireland are threatened both by factors operating over whole water catchments (deteriorating water quality resulting from eutrophication and afforestation) and at individual sites (competition with introduced Roach, predation by American Mink), integrated catchment management plans, including site safeguard measures, seem necessary for the effective conservation of the species.
Keywords: Breeding Season; Abundance, Distribution, and Trends; Black Scoter; Melanitta nigra

Amphibious vision - Optical design model of the hooded merganser eye - Urban, I.; Uwurukundo, X.; Stumpf, D.; Frey, K.; Reichenbach, A.; Francke, M.; Bruning, R.; Brunner, R. (VISION RESEARCH, 2020)
A comprehensive schematic eye model of the hooded merganser is introduced for the first time to advance the understanding of amphibious vision. It is comprised of two different configurations, the first one modeling its visual system in air (unaccommodated state) and the second one representing the case where the eye is immersed in water (accommodated state). The model was designed using available data of former studies, image analysis and the implementation of feasible assumptions that serve as starting values. An optimization process incorporating an optical design program is used to vary the starting values with the aim of finding the setup offering the best acuity. The image quality was measured using the root-mean-square radius of the focal spot formed on the retina. The resulting schematic eye model comprises all relevant optical specifications, including aspherical geometrical parameters for cornea and lens, distances between the surfaces, the gradient index distribution of the lens, the retinal specifications and the object distance in both media. It achieves a spot radius of 4.20 mu m for the unaccommodated state, which meets the expectations derived by the mean ganglion cell density and comparison with other animals. In contrast, under water the determined spot radius of 11.48 mu m indicates an acuity loss. As well as enhancing our understanding of the vision of the hooded merganser, the schematic eye model may also serve as a simulation basis for examing similar animal eyes, such as the cormorant or other fish hunting birds.
Times Cited in Web of Science Core Collection: 0 Total Times Cited: 0 Cited Reference Count: 45
Keywords: Accommodation; Amphibious vision; CRYSTALLINE LENS; Gradient index lens; Hooded merganser eye model; PURSUIT; REFRACTIVE-INDEX; RESOLUTION

Population dynamics of waterfowl communities influenced by a new river impoundment (Perach, Lower Inn, southern Bavaria) - Utschick, Hans (Ornithologischer Anzeiger, 1996)
In 1977 the Perach dam on the Inn river started operation. Changes within the local waterfowl community were analysed and compared with the dynamics at two adjacent reservoirs within a 13-year period (1975-88). At the Perach reservoir ducks first used feeding grounds near the barrage, later shifting to areas more upstream due to sedimentation dynamics. Over all, this was true for Pochard and Teal. Mute Swan and waders preferred the shallower parts of the reservoir, Goldeneye and Cormorant those where the river turns to reservoir conditions. Little Grebe, Coot and smaller dabbling ducks intensively used flat old-river-loops reflooded by increased groundwater levels. At two larger downstream reservoirs, where waterfowl is much more abundant, bird numbers decreased after starting the Perach dam for 1-2 years due to the temporarily unbalanced sedimentation and nutrient deposition regime, mainly mudfauna-feeders and herbivores. Later, this was compensated by increasing Mallard numbers. To date the waterfowl community of the new Perach reservoir is of low value for nature conservation due to its low bird numbers and species composition which is typical for poorly structured riverlike impoundments of common type, but on the formerly dry old-river-loops the proportion of endangered species is increasing. Those habitats should be managed by optimizing the flooding system during high water discharge periods.
Keywords: Abundance, Distribution, and Trends; Sea Ducks - General; Bucephala clangula; Common Goldeneye

Fish-duck interactions in boreal lakes in Finland as reflected by abundance correlations - Vaananen, V. M.; Nummi, P.; Poysa, H.; Rask, M.; Nyberg, K. (Hydrobiologia, 2012)
Times Cited: 4 Vaananen, Veli-Matti Nummi, Petri Poysa, Hannu Rask, Martti Nyberg, Kari 4
Keywords: Breeding Season; Bucephala clangula; Common Goldeneye; Trophic Interactions

Nest and brood stage association between ducks and small colonial gulls in boreal wetlands - Vaananen, V. M.; Poysa, H.; Runko, P. (Ornis Fennica, 2016)
Heterospecific grouping is often associated with reduced predation. One example of this phenomenon is birds breeding in association with more aggressive species. Here we report a study of the association between breeding ducks and small colonial gulls during the nesting and brood-rearing periods in boreal wetlands in Finland. Dabbling duck nests were rarely found within gull colonies, while Tufted Duck (Aythya fuligula) and Pochard (Aythya ferina) nests were exclusively found within gull colonies. During the brood stage, the broods of most duck species were found more often than expected within the colony areas of small gulls, such as the Black-headed Gull (Chroicocephalus ridibundus) and Little Gull (Hydrocoleus minutus). Dabbling duck broods in particular were associated with gulls. In diving ducks, Tufted Duck broods preferred gull defence areas, whereas Common Goldeneye (Bucephala clangula) broods did not. We suggest that colonies of small gulls may be much more important for ducks than previously thought. In recent years, Black-headed Gull populations have decreased in Finland, and the populations of Tufted Duck and Pochard have concurrently decreased. We recommend that the nesting site requirements of small colonial gulls should be taken into account in wetland restoration and when building new wetlands.
Vaananen, Veli-Matti Poysa, Hannu Runko, Pentti
Keywords: Behavior; Breeding Season; Bucephala clangula; Common Goldeneye

Body weight and feather growth of male Barrow's Goldeneye during wing molt - Van De Wetering, Debbie; Cooke, Fred (Condor, 2000)
We studied the timing, duration, and rate of wing molt of male Barrow's Goldeneye (Bucephala islandica). The mean daily change in primary feather length was 2.6%, which is consistent with rates reported for other waterfowl species. The mean length of the flightless period was 31 days (range: 27-34 days), excluding the pre-shedding interval. Wing molt extended from early July to mid-September. Peak wing molt occurred between 20 July and 23 August. The mean body weight of adult males decreased significantly during wing molt. Heavier birds had greater remigial growth rates and experienced more substantial declines in body weight than lighter birds, suggesting that body reserves may be used to increase the rate of remigial growth.
Keywords: Nonbreeding Seasons; Molt; Physiology; Barrow's Goldeneye; Bucephala islandica

A Stochastic Analysis of the Display Behavior of the Red-Breasted Merganser Mergus-Serrator - Van Der Kloot, W.; Morse, M. J. (Behaviour, 1975)
Keywords: Behavior; Mergus serrator; Red-breasted merganser

Herd immunity drives the epidemic fadeout of avian cholera in Arctic-nesting seabirds - van Dijk, J. G. B.; Iverson, S. A.; Gilchrist, H. G.; Harms, N. J.; Hennin, H. L.; Love, O. P.; Buttler, E. I.; Lesceu, S.; Foster, J. T.; Forbes, M. R.; Soos, C. (SCIENTIFIC REPORTS, 2021)
Avian cholera, caused by the bacterium Pasteurella multocida, is a common and important infectious disease of wild birds in North America. Between 2005 and 2012, avian cholera caused annual mortality of widely varying magnitudes in Northern common eiders (Somateria mollissima borealis) breeding at the largest colony in the Canadian Arctic, Mitivik Island, Nunavut. Although herd immunity, in which a large proportion of the population acquires immunity to the disease, has been suggested to play a role in epidemic fadeout, immunological studies exploring this hypothesis have been missing. We investigated the role of three potential drivers of fadeout of avian cholera in eiders, including immunity, prevalence of infection, and colony size. Each potential driver was examined in relation to the annual real-time reproductive number (R-t) of P. multocida, previously calculated for eiders at Mitivik Island. Each year, colony size was estimated and eiders were closely monitored, and evaluated for infection and serological status. We demonstrate that acquired immunity approximated using antibody titers to P. multocida in both sexes was likely a key driver for the epidemic fadeout. This study exemplifies the importance of herd immunity in influencing the dynamics and fadeout of epidemics in a wildlife population.
Times Cited in Web of Science Core Collection: 0 Total Times Cited: 0 Cited Reference Count: 66
Keywords: COMMON EIDERS; EIDERS SOMATERIA-MOLLISSIMA; SURVIVAL; REPRODUCTION; INFECTIOUS-DISEASES; PASTEURELLA-MULTOCIDA; LONG-LIVED BIRD; GEESE; RAPID EVOLUTION; SEASONALITY

Trends in benthivorous waterbirds in the Dutch Wadden Sea 1975-2002: largedifferences between shellfish-eaters and worm-eaters - van Roomen, Marc; van Turnhout, Chris; van Winden, Erik; Koks, Ben; Goedhart, Paul; Leopold, Mardik; Smit, Cor (Limosa, 2005)
In this paper trends in the numerical presence of 18 benthivorous waterbird species in the Dutch Wadden Sea (Figure 1) in the period 1975-2002 are analysed, using all available counts (Figure 2) and U-Index to impute missing counts. Three species have decreased in numbers, ten species have increased, and five species have fluctuated around a stable mean (Table 1, Figure 3). However, for ten species the trend in the period 1975/76-1990/91 differed significantly from that during 1991/92-2001/02. This concerns especially species that mainly feed on either worms or shellfish. Furthermore, worm-eating species and shellfish-eating species show opposite trends, a difference that is significant for the period 1991/92-2001/02. All four species which depend on bivalves have decreased (Common Eider, Eurasian Oystercatcher, Red Knot and European Herring Gull), whereas five out of six worm-eating species have increased, The larger the contribution of shellfish in the diet, the larger the population decrease in 1991/92-2001/02. Other studies have shown that the recent decrease in Common Eider and Eurasian Oystercatcher numbers are at least partly caused by deteriorating feeding opportunities. Intertidal mussel beds have largely disappeared in the early nineties (due to overfishing, poor spatfall and possibly winter storms) and cockles were heavily exploited by commercial mechanised fisheries. For Red Knot especially the disturbance of the sediment by mechanised cockle fisheries is important with a range of effects on the quality and quantity of their food. The recent, broad increase of numbers of worm-eating species may be linked to a shift in the ecosystem (reduced shellfish stocks, increased worm stocks) but the mechanisms underlying this change remain to be identified fully.
Keywords: Abundance, Distribution, and Trends; Common Eider; Nonbreeding Seasons; Somateria mollissima; Trophic Interactions

Host Parasite Relations of Dendritobilharzia-Pulverulenta Trematoda Schistosomatidae and Anatids - Vande Vusse, F. J. (Journal of Parasitology, 1979)
D. pulverulenta were recovered (average of 2.5 worms per host) from arteries of 12 spp. of anatids [whistling swan (Cygnus columbianus columbianus), wood duck (Aix sponsa), common teal, mallard (Anas platyrhynchos), blue-winged teal (A. discors), shoveler (A. clypeata), redhead, lesser scaup (Aythya affinis), bufflehead (Bucephala albeola), common goldeneye (B. clangula), red-breasted merganser (Mergus serrator) and common merganser (M. merganser)]. Rapid development of adults is indicated, and they maintain position and move within arteries without suckers or other obvious means of attachment. Males and females were found in close association, but never in copula. Anatid hosts can be divided into 2 groups which follow established taxonomic lines: normal hosts, in which worms inhabit the lower dorsal aorta and femoral arteries almost exclusively, and deposit viable eggs in the submucosa of the lower 3/4 of the large intestine (tribes Aythini, inland divers and Mergini, sea ducks); and abnormal hosts, in which worms are more widely distributed within the arterial system, and eggs that do not embryonate are deposited in a variety of tissues (tribes Anserini, geese and swans; Anatini, dabbling ducks; and Cairinini, perching ducks).
Keywords: Sea Ducks - General; Parasites

Seabirds foraging at floating seaweeds in the Northeast Atlantic - Vandendriessche, Sofie; Stienen, Eric W. M.; Vincx, Magda; Degraer, Steven (Ardea, 2007)
The influence of floating seaweed patches on the distribution and behaviour of seabirds was investigated using the European Seabirds At Sea database (ESAS). The percentage of observations that seabirds were observed with floating seaweed differed among species, depending on the mode of foraging. The results indicate that surface feeding species that make shallow dives (terns and Red-breasted Mergansers Mergus serrator) benefit most from the presence of floating seaweeds and their associated macro- and ichthyofauna. Species hunting for pelagic and bottom-dwelling prey (divers, Guillemots Uria aalge, Razorbills Alca torda, Puffins Fratercula arctica, Gannets Sula bassana and Cormorants Phulacrocorax carbo), and especially benthos feeders (Common Scoters Melanitta nigra and Eiders Somuteria mollissima) were frequently seen in association with floating seaweeds, while opportunists and scavengers like gulls and skuas were recorded on few occasions. Petrels and shear-waters (surface-seizing, pursuit-plunging, pursuit-diving) were seldomly seen in association with floating seaweeds. The most common behavioural activities of the birds associated with floating seaweed were found to be surface pecking, actively searching, and pursuit plunging.
Keywords: Behavior; Common Eider; Somateria mollissima; Habitat; Mergus serrator; Red-breasted merganser; Black Scoter; Melanitta nigra

WHY SEADUCKS FORAGE IN MUSSEL FARMS? PREFERENCES AND EFFICIENCIES WHEN FORAGING ON CULTIVATED OR INTERTIDAL MUSSELS - Varennes, E.; Guillemette, M. (Journal of Shellfish Research, 2015)
Varennes, Elisabeth Guillemette, Magella
Keywords: Behavior; Common Eider; Somateria mollissima; Trophic Interactions; Nonbreeding season

Sea duck predation in mussel farms: the best nets for excluding common eiders safely and efficiently - Varennes, E.; Hanssen, S. A.; Bonardelli, J.; Guillemette, M. (Aquaculture Environment Interactions, 2013)
Times Cited: 0 Varennes, Elisabeth Hanssen, Sveinn Are Bonardelli, John Guillemette, Magella Hanssen, Sveinn Are/C-9989-2009 Hanssen, Sveinn Are/0000-0003-1792-435X 0
Keywords: Conservation; Nonbreeding Seasons; Trophic Interactions; Common eider; somateria mollissima

SEA DUCK PREDATION IN MUSSEL FARMS: THE BEST NETS FOR EXCLUDING COMMON EIDERS SAFELY AND EFFICIENTLY - Varennes, E.; Hanssen, S. A.; Bonardelli, J.; Guillemette, M. (Journal of Shellfish Research, 2015)
Common Eider; Somateria mollissima; Nonbreeding season; Behavior; Trophic Interactions; Conservation
Varennes, Elisabeth Hanssen, Sveinn Are Bonardelli, John Guillemette, Magella

Blue mussel (Mytilus edulis) quality of preferred prey improves digestion in a molluscivore bird (Common Eider, Somateria mollissima) - Varennes, E.; Hanssen, S. A.; Bonardelli, J. C.; Guillemette, M. (Canadian Journal of Zoology, 2015)
Benthivorous predators like sea ducks rely on abundant but low-quality food. Because they ingest whole blue mussels (Mytilus edulis L., 1758), including shells, they have to consume large quantities of food to maintain energy balance. Digestive processes may therefore limit energy assimilation in these predators, although selecting mussel types that minimize shell ingestion may improve foraging profitability. To test this prediction, we first quantified mussel quality from different sizes and habitats by measuring energy content and various features of mussel morphology. Then, we conducted digestive experiments on captive Common Eiders (Somateria mollissima (L., 1758)) fed with various mussel types to determine their impact on Eiders' digestion. Aquacultured and small mussels were of better quality, because of higher energy content and less resistant shells. These mussel characteristics allowed faster digestive processes for an equal digestibility compared with large intertidal mussels. Previous studies showed that aquacultured and small mussels were generally preferred by sea ducks. Hence, prey-selection behaviours and digestive processes seem closely connected in these highly digestive-constrained predators.
Varennes, Elisabeth Hanssen, Sveinn A. Bonardelli, John C. Guillemette, Magella
Keywords: Common Eider; Somateria mollissima; Energetics and Nutrition; Trophic Interactions; Nonbreeding season

A large molluscivore bird (Common Eider, Somateria mollissima) is able to discriminate quality of blue mussels (Mytilus edulis) based on size and provenance - Varennes, E.; Hanssen, S. A.; Bonardelli, J. C.; Guillemette, M. (Canadian Journal of Zoology, 2015)
Molluscivore birds that forage on abundant but low-quality food have to ingest large quantities of food to achieve energy balance. Such a strategy is often associated with important digestive constraints limiting predator's ingestion. Thus, these predators may use prey selection to ingest better-quality individuals among a generally low-quality prey population. Using captive Common Eiders (Somateria mollissima (L., 1758)) diving in a constant environment, we were able to examine their preferences for blue mussels (Mytilus edulis L., 1758) of varying qualities (different sizes or provenances). In addition, we studied the consequences prey selection had on Eiders' energy intake rates and ingestion of flesh and shell material. Eiders selected 10-20 mm mussels and were able to discriminate and to select cultivated mussels from intertidal mussels. Prey selection allowed, in certain conditions of prey-size abundance, higher flesh and energy intake rates without increasing the ingestion of shell material. This study confirmed the energetic advantage that Eiders have when foraging in aquaculture sites, which explain the large depredation of preferred mussel sizes.
Varennes, Elisabeth Hanssen, Sveinn A. Bonardelli, John C. Guillemette, Magella
Keywords: Behavior; Common Eider; Somateria mollissima; Energetics and Nutrition; Trophic Interactions

Functional response curves of avian molluscivores: high intake rates maintained even at low prey density - Varennes, E.; Hanssen, S. A.; Bonardelli, J. C.; Guillemette, M. (Marine Ecology Progress Series, 2015)
Despite its low energy density, the blue mussel Mytilus edulis is a regular prey of various seaduck species. As a result, seaducks must ingest large quantities of mussels to meet their energy requirements. In this study, we modeled the functional response curve for a large avian molluscivore, the common eider Somateria mollissima, by measuring intake rates of captive individuals foraging in diving tanks under different mussel densities and at different attachment strengths. We estimated the mean maximum intake rate to be 45 prey min(-1) (with a mean bottom time +/- SD of 5.034 +/- 3.793 s), which is relatively high compared to intake rates of other diving duck species and prey types. However, we found no significant effects of density and attachment strength on intake rates, indicating that eiders can maintain maximum intake rates even at low mussel densities. These results could explain the depletion of mussel beds sometimes observed in the wild, as well as the large negative impact that seaducks may have in aquaculture farms.
Varennes, Elisabeth Hanssen, Sveinn A. Bonardelli, John C. Guillemette, Magella
Keywords: Behavior; Common Eider; Somateria mollissima; Trophic Interactions

Stealing bivalves from common eiders: kleptoparasitism by glaucous gulls in spring - Varpe, Oystein (Polar Biology, 2010)
Here I report on glaucous gulls (Larus hyperboreus), an opportunistic, generalist predator, stealing bivalves from a diving duck, the common eider (Somateria mollissima). The study took place in spring, the pre-breeding period of the common eider, in an Arctic fjord (Adventfjorden) at western Spitsbergen, Svalbard. Eiders were abundant, their presence predictable, and they fed on large prey requiring surface handling-all factors facilitating food theft. Only adult glaucous gulls attended the eider flocks. The glaucous gulls brought stolen prey ashore. Amongst these the bivalve Mya neoovata (Myidae) was common. The probability that an eider flock was attended by glaucous gulls declined as the season progressed and increased with the foraging activity of the eiders. Eider flock size and the degree of aggregation within flocks were poor predictors of gull presence. However, eider flocks attended by a single gull were smaller than flocks attended by more than one gull. Common eiders are capital breeders which build up large energy reserves prior to breeding. Kleptoparasitism, therefore, may have a negative impact on eider energy acquisition in early spring. For the glaucous gull, kleptoparasitism may be important as few other food sources are available this time of the season.
Keywords: Common Eider; Nonbreeding Seasons; Somateria mollissima; Trophic Interactions

Deaths of Sea Birds Following the Creeping Oil Pollution on Helgoland West Germany in Spring 1979 - Vauk, G. (Vogelwarte, 1980)
During Jan.-April, 1979, 232 birds were found dead on Helgoland. Deaths were caused by the effects of oiling. In contrast to earlier findings the highest losses occurred in the ducks (common scoter); grebes (red-necked grebe) and guillemots also constituted a high proportion of the oil victims. The hard winter with freezing conditions led to a special concentration of marine and fresh water birds on the open sea around the island. Waders and a blackbird also fell victim to oil that was washed ashore. Oil was sampled from the plumage of 3 birds and analyzed to ascertain its origin. Very likely the oil did not originate from the North Sea oilfields but from drifting raw oil. Light oiling of a greater black-backed gull could be overcome.
Keywords: Nonbreeding Seasons; Contaminants; Black Scoter; Melanitta nigra

Oil Threat to Aquatic Birds Along the Yukon Coast Canada - Vermeer, K.; Anweiler, G. G. (Wilson Bulletin, 1975)
Keywords: Melanitta perspicillata; Surf Scoter; Contaminants

Populations, biomass and food habits of ducks on the Fraser Delta intertidal area, British Columbia - Vermeer, Kees; Levings, Colin D. (Wildfowl, 1977)
Hundreds of thousands of ducks, mostly Mallard Anas platyrhynchos Pintail A. acuta, American Wigeon A. americana, Green-winged Teal A. crecca carolinensis and Greater Scaup Aythya marila visit the Fraser Delta intertidal area from October through January. Surf Scoters Melanitta perspicillata are most numerous in August and early September. Scaup and scoters appear to prefer Boundary Bay over Sturgeon and Roberts Bank. The total duck biomass on the tidal flats has a peak of 9 kilograms per hectare in November, Mallard and American Wigeon accounting for more than half.Most dabbling ducks fed on marsh and other plants. Of six diving duck species invstigated, Black M. nigra, Surf and White-winged Scoters M. fusca deglandi and Oldsquaws Clangula hyemalis fed primarily on bivalves, Common Goldeneyes Bucephala clangula on crustaceans and Greater Scaup on algae. The food habits differ with respect to feeding location as well as time of season. Oldsquaws used mostly subtidal waters, Surf Scoters between 0 and 3 fathoms below chart datum, White-winged Scoters the lower intertidal zone, Greater Scaup a muddy substrate closest to the shoreline and sheltered in Boundary Bay.
Keywords: Abundance, Distribution, and Trends; Sea Ducks - General; Nonbreeding Seasons; Trophic Interactions

Trace Metals in Sea Ducks of the Fraser River Delta Inter Tidal Area British-Columbia Canada - Vermeer, K.; Peakall, D. B. (Marine Pollution Bulletin, 1979)
Surf Scoters Melanitta perspicillata and Greater Scaup Aythya marila and samples of species which comprise the major part of their diets [Ulva sp., Enteromorpha sp., Triglochin maritima, Scirpus paludosus, S. validus], from Iona Island and Roberts Bank tidal flats, near Vancouver, British Columbia, were analyzed for metal residues. Significantly higher Ag, Cu, Pb and Zn levels were found in Greater Scaup than Surf Scoters. The latter species had higher Hg levels. Differences in residue levels between the species reflect interspecific variation in prey as well as feeding habitat. Significantly higher Ag, Hg, Pb and Zn in Surf Scoters and Ag and Pb in Greater Scaup observed at Iona Island than at Roberts Bank can be explained by higher levels of those metals occurring in a more metal-contaminated prey and sediment near the Iona Island sewer outfall. Ducks feeding on organisms in different intertidal zones show different accumulation of metal residues and constitute valuable indicators of pathways of toxic chemicals in specific estuarine regions.
Keywords: Nonbreeding Seasons; Melanitta perspicillata; Surf Scoter; Contaminants

Food Habits of Wintering Waterfowl on the Great Salt Lake, Utah - Vest, Josh L.; Conover, Michael R. (Waterbirds, 2011)
Two invertebrates, brine shrimp (Artemia franciscana) and brine flies (Ephydridae), occur in great densities in the Great Salt Lake (GSL) but it is unknown whether ducks forage extensively on them during winter or rely on freshwater food. Common Goldeneye (Bucephala clangula), Northern Shoveler (Anas clypeata) and Green-winged Teal (Anas crecca) were collected from the GSL during winters 2004-05 and 2005-06 to evaluate their food habits. Brine shrimp and brine flies comprised more than 70% of the winter diet of these ducks. Common Goldeneyes consumed mainly brine fly larvae (68% based on dry weight biomass), which live primarily along the substrate. Northern Shovelers fed on brine shrimp cysts (52%) and adult brine shrimp (20%) while Green-winged Teal consumed mainly brine shrimp cysts (80%). In some years, up to half of the brine shrimp cysts in the GSL are commercially harvested. Care should be taken so that this commercial harvest does not adversely impact ducks that depend on these brine shrimp cysts for winter food. Received 23 June 2010, accepted 4 November 2010.
Keywords: Conservation; Nonbreeding Seasons; Bucephala clangula; Common Goldeneye; Trophic Interactions

Trace Element Concentrations in Wintering Waterfowl from the Great Salt Lake, Utah - Vest, J. L.; Conover, M. R.; Perschon, C.; Luft, J.; Hall, J. O. (Archives of Environmental Contamination and Toxicology, 2009)
The Great Salt Lake (GSL) is an important region for millions of migratory waterbirds. However, high concentrations of some trace elements, including Hg and Se, have been detected within the GSL, and baseline ecotoxicological data are lacking for avian species in this system. We collected common goldeneye (Bucephala clangula), northern shoveler (Anas clypeata), and greenwinged teal (A. crecca) from the GSL during the winters of 2004-2005 and 2005-2006 to evaluate sources of variation in liver trace element concentrations. Hg concentrations were among or exceeded the highest values reported in the published literature for common goldeneye, northern shoveler, and green-winged teal. Average Hg (total) concentrations of common goldeneye peaked in midwinter, whereas average Se concentrations peaked during late winter. During late winter, 100% and 88% of female goldeneye contained elevated concentrations of Hg [>= 1.0 mu g/g wet weight (ww)] and Se (>= 3.0 mu g/g ww), respectively, and 5% and 14% contained potentially harmful amounts of Hg (>= 30.0 mu g/g ww) and Se (> 10.0 mu g/g ww), respectively. Similarly, 30% and 16% of male goldeneye contained potentially harmful concentrations of Hg and Se, respectively. Concentrations of Hg and Se were elevated in 100% and 79%, respectively, of northern shoveler samples (sexes combined) collected during February. We suggest that waterfowl contain biologically concerning amounts of Hg and Se during winter while on the GSL and further research is needed to evaluate the effect of these elements on GSL waterbirds.
Keywords: Nonbreeding Seasons; Bucephala clangula; Common Goldeneye; Contaminants

Helminths in common eiders (Somateria mollissima): Sex, age, and migration have differential effects on parasite loads - Vestbo, S.; Hindberg, C.; Forbes, M. R.; Mallory, M. L.; Merkel, F.; Steenweg, R. J.; Funch, P.; Gilchrist, H. G.; Robertson, G. J.; Provencher, J. F. (INTERNATIONAL JOURNAL FOR PARASITOLOGY-PARASITES AND WILDLIFE, 2019)
In birds, parasites cause detrimental effects to the individual host, including reduced survival and reproductive output. The level of parasitic infection can vary with a range of factors, including migratory status, body size, sex, and age of hosts, or season. Understanding this baseline variation is important in order to identify the effects of external changes such as climate change on the parasitic load and potential impacts to individuals and populations. In this study, we compared the infection level (prevalence, intensity, and abundance) of gastrointestinal parasites in a total of 457 common eiders (Somateria mollissima) from four different sampling locations (Belcher Islands, Cape Dorset, West Greenland and Newfoundland), and explored the effects of migration, sex and age on levels of parasitism. Across all samples, eiders were infected with one nematode genus, two acanthocephalan genera, three genera of cestodes, and three trematode genera. Migratory phase and status alone did not explain the observed variation in infection levels; the expectation that post-migratory eiders would be more parasitized than pre-migratory eiders, due to the energetic cost of migration, did not fit our results. No effect of age was detected, whereas effects of sex and body size were only detected for certain parasitic taxa and was inconsistent with location. Since gastrointestinal helminths are trophically-transmitted, future studies of the regional and temporal variation in the diet of eiders and the associated variation and infestation level of intermediate hosts might further explain the observed variation of the parasitic load in eiders in different regions.
Times Cited in Web of Science Core Collection: 6 Total Times Cited: 6 Cited Reference Count: 76
Keywords: BIRDS; Migration; DUCK; Seabird; LIFE-CYCLES; MARINE; SPECIES RICHNESS; INFECTIONS; Arctic parasitology; Body size; Gastrointestinal parasites; INEQUALITIES; INTERMEDIATE HOST; PROFILICOLLIS-BOTULUS ACANTHOCEPHALA; PROPENSITY

Eiders as Long Distance Connectors in Arctic Networks - Vestbo, S.; Hindberg, C.; Olesen, J. M.; Funch, P. (CROSS-CULTURAL RESEARCH, 2019)
As hunters and gatherers, humans have always exploited a wide variety of natural resources. Hunting, in particular, focuses upon individual species. The relationships between human and game are most often seen as isolated entities, for example, human-bison, human-whale, human-seabird or human-mammoth. However, hunting interactions are embedded in large and complex ecological networks. Seabirds such as the common eider (Somateria mollissima) have been and are still being hunted by both indigenous people of the Arctic and Europeans. Due to anthropogenic pressures, including hunting, several common eider populations have declined during the 20th century, even as much as up to 10-fold. Here, we review the ecological role of the common eider in Arctic networks and the diversity of human-eider interactions, underlining its importance for both humans and nonhumans. We place these interactions in a wider ecological context and discuss how human activities affecting eiders propagate through the Arctic ecological network and can cause far-reaching ecological effects.
Times Cited in Web of Science Core Collection: 3 Total Times Cited: 3 Cited Reference Count: 84
Keywords: Somateria mollissima; COMMON EIDERS; PREDATION; FOOD; DIET; HUMAN DISTURBANCE; NESTING SUCCESS; DUCKLINGS SOMATERIA-MOLLISSIMA; ecological network; eiderdown; exploitation; FOXES ALOPEX-LAGOPUS; ISLAND; NORTHWEST-TERRITORIES; subsistence

Does Water Temperature Affect the Timing and Duration of Remigial Moult in Sea Ducks? An Experimental Approach - Viain, A.; Guillemette, M. (Plos One, 2016)
Aquatic birds have high cost of thermoregulation, especially during the moulting period, yet the effect of water temperature on the moulting strategy of aquatic birds has rarely been studied. Our general hypothesis is that energy savings associated with lower thermoregulation costs would be allocated to moulting processes. We predicted that aquatic birds moulting in warm water would have a higher level of body reserves, a faster growth rate of feathers, and an earlier remigial moult onset compared with birds moulting in cold water. We used the common eider (Somateria mollissima dresseri), a large sea duck, as the model species. Captive individuals were experimentally exposed to warm (18 degrees C) and cold (8 degrees C) water treatments during a three year period with individuals swapped between treatments. We found a similar feather growth rate for the two water temperature treatments and in contrast to our predictions, eiders exposed to warm water had a lower body mass and showed a delayed onset of remigial moult of approximately 7 days compared with those exposed to cold water. Our data indicate that body mass variations influence the timing of moult in unexpected ways and we suggest that it likely controls the occurrence of wing moult through a hormonal cascade. This study emphasizes the importance of improving our knowledge of the effects of water temperature on remigial moult of aquatic birds, to better assert the potential effects of global warming on their survival.
Viain, Anouck Guillemette, Magella
Keywords: Common Eider; Molt; Somateria mollissima; Nonbreeding season

Body and organ mass dynamics during remigial moult in a wing-foot-propelled diving sea duck: the Common Eider (Atlantic) (Somateria mollissima dresseri) - Viain, A.; Guillemette, M.; Savard, J. P. L. (Canadian Journal of Zoology, 2015)
Body and organ dynamics, during remigial moult, have been mainly explored on geese, dabbling ducks, and foot-propelled diving ducks, but weakly on sea ducks. This study investigated the internal changes in a wing-foot-propelled sea duck to determine the adaptive strategies implemented. Forty-five male Common Eiders (Atlantic) (Somateria mollissima dresseri Sharpe, 1871), collected in the Gulf of St. Lawrence, were dissected; their body mass, muscle mass, and organ sizes were measured. We tested three hypotheses: (1) S. m. dresseri use a strategic reduction of body mass to reduce the flightlessness duration; (2) organs will exhibit changes consistent with a trade-off between function and maintenance to save and reallocate energy and proteins to feather growth; (3) S. m. dresseri would show lower flight muscle reduction than foot-propelled diving ducks. Somateria mollissima dresseri did not lose body mass, which does not support the first hypothesis. Atrophy of the heart followed by hypertrophy and opposite changes in leg muscle mass and gizzard mass are consistent with the second hypothesis. Flight muscle mass showed lower variations than in other ducks, validating the third hypothesis. We also suggest that the lipid depletion observed early in the moult could be a strategy to reduce foraging effort and minimize the risk of damaging the growing feathers.
Viain, A. Guillemette, M. Savard, J. -P. L.
Keywords: Common Eider; Molt; Somateria mollissima; Physiology; Nonbreeding season

Do Seaducks Minimise the Flightless Period?: Inter- and Intra-Specific Comparisons of Remigial Moult - Viain, A.; Savard, J. P. L.; Gilliland, S.; Perry, M. C.; Guillemette, M. (Plos One, 2014)
Remigial moult is one of the crucial events in the annual life cycle of waterfowl as it is energetically costly, lasts several weeks, and is a period of high vulnerability due to flightlessness. In waterfowl, remigial moult can be considered as an energy-predation trade-off, meaning that heavier individuals would minimise the flightless period by increasing feather growth rate and energy expenditure. Alternatively, they could reduce body mass at the end of this period, thereby reducing wing-loading to increase flight capability. We studied timing of remigial moult, primary growth rates, flightlessness duration, and the pattern of body mass variation in 5 species of captive seaducks (Melanitta fusca, M. perspicillata, Clangula hyemalis, Histrionicus histrionicus, and Somateria mollissima) ranging in size from 0.5 to 2.0 kg. Their feather growth rates weakly increased with body mass (M-0.059) and no correlation was found at the intra-specific level. Consequently, heavier seaduck species and especially heavier individuals had a longer flightless period. Although birds had access to food ad libidum, body mass first increased then decreased, the latter coinciding with maximum feather growth rate. Level of body mass when birds regained flight ability was similar to level observed at the beginning of remigial moult, suggesting they were not using a strategic reduction of body mass to reduce the flightlessness duration. We suggest that the moulting strategy of seaducks may be the result of a compromise between using an intense moult strategy (simultaneous moult) and a low feather growth rate without prejudice to feather quality. Despite the controlled captive status of the studied seaducks, all five species as well as both sexes within each species showed timing of moult reflecting that of wild birds, suggesting there is a genetic component acting to shape moult timing within wild birds.
Viain, Anouck Savard, Jean-Pierre L. Gilliland, Scott Perry, Matthew C. Guillemette, Magella
Keywords: Common Eider; Melanitta fusca; White-winged Scoter; Melanitta perspicillata; Surf Scoter; Histrionicus histrionicus; Molt; Clangula hyemalis; Long-tailed Duck; Somateria mollissima; Physiology; Nonbreeding season; Harlequin Duck

Distribution and Population Status of Harlequin Ducks Histrionicus-Histrionicus Wintering in Eastern North America - Vickery, P. D. (Wilson Bulletin, 1988)
Keywords: Abundance, Distribution, and Trends; Nonbreeding Seasons; Harlequin duck; Histrionicus histrionicus

Remaining genetic diversity in Brazilian Merganser (Mergus octosetaceus) - Vilaca, S. T.; Redondo, R. A. F.; Lins, L. V.; Santos, F. R. (Conservation Genetics, 2012)
Times Cited: 1 Vilaca, Sibelle Torres Redondo, Rodrigo A. F. Lins, Livia Vanucci Santos, Fabricio R. Santos, Fabricio/H-2370-2011 Santos, Fabricio/0000-0001-9088-1750 1
Keywords: Conservation; Brazilian Merganser; Mergus octosetaceus

Common Goldeneye Bucephala clangula as a breeding bird in the Netherlands: Population development and habitat use - Voskamp, Paul; Driessen, Joris (Limosa, 2003)
The Common Goldeneye has established a small breeding population in the Netherlands from 1984 onwards. We consider this settlement as a natural one, since it is in line with the expansion of the species' breeding range in Western Europe. The first breeding attempts were recorded in the valley of the river IJssel, a branch of the river Rhine. Outside this area only a few breeding pairs were found. In the IJssel area the population grew to a maximum of 14 pairs in 1992. After 1992 the population stabilised around eight pairs, with an increase to 11 pairs in 1999, caused by an expansion to the north of the IJssel area. Breeding results were low during peak years, but stabilised at approximately 65% successful pairs. Ponds and small lakes close to the river, preferably bordered by old trees or deciduous forest, form the breeding habitat. Nest sites can be quite far from the water, in this study up to 2.5 km. Unlike other new settlements of this species this population did not strongly depend on nest boxes. Most breeding attempts were recorded in natural tree cavities and cavities in pollard trees, that are common in the traditional riverine landscape of the Netherlands. Goldeneyes were faithful to breeding sites, especially to those with good results in the previous breeding seasons: 17 out of 27 nests were used for more than one year. Eighteen out of 24 breeding sites were outside the area that is regularly flooded by the river, but most females raised their young in wetlands situated close to the river. This means that females had to guide their young across a dike, which is in most cases a busy motorway. Ducklings that were not led to the river floodplain had a significantly lower survival rate. This could be the reason why females undertake these potentially dangerous and long (up to 3.4 km) journeys with their young. Possibly the ponds and lakes outside the river area are good feeding habitat for adult Goldeneyes, with little underwater vegetation. Ducklings, however, suffer high predation risk in these waters and have difficulties seeking cover from the aggression of territorial Coots Fulica atra. It is unknown why the Goldeneye breeding population has not yet expanded into other areas of the Netherlands that seem suitable for the species. Competition with Mandarin duck Aix galericulata, which has similar nest site preferences, is discussed as a possible explanation.
Keywords: Breeding Season; Abundance, Distribution, and Trends; Bucephala clangula; Common Goldeneye; Habitat

The Occurrence of Sea Ducks in Danish Fresh Waters 1965-1976 - Waehrens, G. T. (Dansk Ornitologisk Forenings Tidsskrift, 1978)
The occurrence of seaducks in fresh waters in Denmark is poorly known. The brent goose Branta bernicla is exceptional in fresh water. There were only 4 observations of resting birds. The scaup Aythya marlia is scarce, observed mainly in northern Jutland and Zealand most often more than 5 km inland. Longtailed duck Clangula hyemalis is very scarce in fresh water, being observed near the Limfjord. The velvet scoter Melanitta fusca is very rare in fresh water. The common scoter Melanitta nigra is more regular, particularly in Jutland and northeastern Zealand. Most Jutlandic birds are seen along the zone between the eastern coast of Himmerland and the Waddensea, on passage between two important winter quarters. The Eider Somateria mollissima is scarce and observed mainly in Zealand and Jutland. The red-breasted merganser Mergus serrator is the seaduck most regularly seen on fresh water. The species appears in small parties and is mostly seen in Jutland. Observations are from the whole year, although they peak in March-April and Oct.-Nov.
Keywords: Abundance, Distribution, and Trends; Sea Ducks - General; Nonbreeding Seasons

Human Exposure to Mercury from Goosander Eggs Containing Methyl Mercury - Wahlberg, P.; Karppanen, E.; Henriksson, K.; Nyman, D. (Acta Medica Scandinavica, 1971)
Keywords: Contaminants; Common merganser; Mergus merganser

Migrational Homing and Survival of Adult Female Eiders in Maine USA - Wakeley, J. S.; Mendall, H. L. (Journal of Wildlife Management, 1976)
Banding data for the American race of the common eider (Somateria mollissima dresseri) in Penobscot Bay, Maine [USA], were analyzed to estimate the rates of migrational homing and mortality of adult females from 1964-1973. Nearly all surviving females homed to the same breeding island year after year. Mortality rates, estimated from life tables based on live recaptures and on hunting season recoveries, were 27 and 19%, respectively, which are lower than published figures for most other waterfowl species. The combination of strong migrational homing and low mortality rate suggests that islands important to breeding eiders will continue to be productive in the foreseeable future, if they are preserved from exploitation and protected from human intrusion during the nesting season.
Keywords: Breeding Season; Common Eider; Somateria mollissima; Dispersal; Survival; Population Delineation

Brood parasitism and nest takeover in common eiders - Waldeck, Peter; Andersson, Malte (Ethology, 2006)
Conspecific brood parasitism (CBP) is an alternative breeding tactic that occurs in many brood-tending animals and can have important fitness effects for both host and parasite. We use protein fingerprinting of egg albumen to distinguish the eggs from different females and to estimate the frequency, pattern and tactics of CBP and other forms of mixed maternity in a Hudson Bay population of common eiders (Somateria mollissima sedentaria). Mixed clutches, containing eggs from more than one female, occurred in 31% of the 86 nests studied that progressed to clutch completion. Other females than the host laid 8% of the eggs. In 11 (41%) of the mixed clutches another female laid before the host started laying, corroborating the hypothesis that takeover of nests started by other females accounts for many of the mixed clutches in this population. Our results also indicate that traditional non-molecular methods of identifying foreign eggs may considerably underestimate the frequency of mixed clutches.
Keywords: Behavior; Breeding Season; Common Eider; Somateria mollissima

Spatial relatedness and brood parasitism in a female-philopatric bird population - Waldeck, Peter; Andersson, Malte; Kilpi, Mikael; Ost, Markus (Behavioral Ecology, 2008)
The spatial structure of relatedness between individuals in a population can be crucial for social selection and evolution. Here we analyze a female alternative reproductive tactic, conspecific brood parasitism, in relation to spatial relatedness among females in a Baltic Sea population of the common eider Somateria mollissima. The role of relatedness in brood parasitism is debated: some models predict parasite avoidance of related hosts, others predict host-parasite relatedness. We estimate pairwise relatedness from protein fingerprinting of egg albumen in 156 nests, with pairwise nest distances ranging from 1 to 6 km. Relatedness increases significantly from the longest distances to an average of r approximate to 0.09 below 20 m. Brood parasitism is common, and average pairwise relatedness between host and parasite is estimated at 0.18-0.21. Parasites thus do not avoid relatives, and combined with the findings of a similar study in another eider population, the results show that mean host-parasite relatedness is higher than that among close neighbors. High host-parasite relatedness is therefore not an effect of natal philopatry alone; some other form of kin bias is also involved. Recognition and association between birth nest mates is a candidate mechanism for further study.
Keywords: Behavior; Breeding Season; Common Eider; Somateria mollissima

Host-parasite relatedness in a brood-parasitic colonial bird - Waldeck, P.; Anderssson, M. (Journal of Ornithology, 2006)
Keywords: Behavior; Breeding Season; Common Eider; Somateria mollissima

Brood parasitism, female condition and clutch reduction in the common eider Somateria mollisima - Waldeck, P.; Hagen, J. I.; Hanssen, S. A.; Andersson, M. (Journal of Avian Biology, 2011)
Times Cited: 1 Waldeck, Peter Hagen, Jeanette Iren Hanssen, Sveinn Are Andersson, Malte Hanssen, Sveinn Are/C-9989-2009 Hanssen, Sveinn Are/0000-0003-1792-435X 1
Keywords: Behavior; Breeding Season; Productivity; Common eider; somateria mollissima

Indeterminate laying and flexible clutch size in a capital breeder, the common eider - Waldeck, Peter; Hanssen, Sveinn Are; Andersson, Malte (Oecologia (Berlin), 2011)
Clutch size control in capital breeders such as large waterfowl has been much debated. Some studies have concluded that clutch size in ducks is determined before the start of laying and does not change in response to egg additions or removals. The response, however, may depend on the timing of tests, and experiments may have been too late for females to alter the number of eggs. We here study clutch size responses to predation of first and second eggs in the common eider, using protein fingerprinting of egg albumen to verify that the same female continues laying in the nest after predation. Sixty of 79 females with early egg predation (one or both of the two first eggs) deserted the nest. Among the 19 females that stayed and continued laying, the mean number of eggs produced was 4.4, significantly higher than the 3.7 in non-predated nests. The staying females had similar egg size and clutch initiation date as females that deserted, and their body mass and clutch initiation date was similar to that of females whose clutches were not predated. Even capital-breeding common eiders may therefore be indeterminate layers, as many females in which early eggs are removed lay more eggs than others. A previous study has shown that they can reduce their laying if eggs are added. Our results add to increasing evidence that ducks have more flexible egg production than previously thought.
Keywords: Behavior; Breeding Season; Common Eider; Somateria mollissima; Productivity; Physiology; Energetics and Nutrition

Brood parasitism in a population of common eider (Somateria mollissima) - Waldeck, Peter; Kilpi, Mikael; Ost, Markus; Andersson, Malte (Behaviour, 2004)
The common eider differs from many other ducks in being a colonial 'capital' breeder, producing eggs from stored resources. These traits are expected to influence the occurrence of conspecific brood parasitism (CBP), which is particularly common in waterfowl. We analysed CBP in an eider population in the central Baltic Sea 2001-2002, using non-destructive egg albumen sampling combined with protein fingerprinting. This technique greatly increases the detection of parasitic eggs compared to more traditional methods. Parasitic eggs occurred in 20-22% of 164 nests studied, 6% of 754 eggs being laid by other than the host female. Parasitism increased with nest density, was rather evenly distributed over the laying season, and occurred both early and late in the laying sequence of the host. Protein fingerprinting showed that host females laid up to seven eggs, more than previously reported. Among 33 parasitised nests 22 had one parasitic egg, nine had two and two had three. In all but one case all parasitic eggs within a nest were laid by the same female. Although colonial breeding facilitates CBP, it is less frequent in this eider population than in several other diving ducks. Possible contributing reasons are the relatively small clutch size and start of incubation after egg 2 or 3, limiting the time window for successful parasitism.
Keywords: Behavior; Breeding Season; Common Eider; Somateria mollissima

Effects of winter water temperature on mass loss in Baltic blue mussels: Implications for foraging sea ducks - Waldeck, P.; Larsson, K. (Journal of Experimental Marine Biology and Ecology, 2013)
Times Cited: 1 Waldeck, P. Larsson, K. 1
Keywords: Nonbreeding Seasons; Clangula hyemalis; Long-tailed Duck; Trophic Interactions; Common eider; somateria mollissima

Eucotyle clangulae n. sp., a new digenetic trematode, from the kidney of Clangula hyemalis (L.) - Walden, Henrik W. (Arkiv Zool, 1961)
The material was not in very good condition, as it originated from a long-tailed duck (C. hyemalis) which had been killed on the Baltic coast of Sweden after being severely exposed to oil pollution on a ship, and the author did not see the body until 5 days later. The description is therefore based on only 1 good specimen, but the characters were checked with the other more or less autolyzed specimens found with it. No sp. of Eucotyle has ever been found previously in Sweden. Data are given on the hosts in which spp. of this genus have been recorded.
Keywords: Clangula hyemalis; Long-tailed Duck; Parasites

Herring Gulls Larus argentatus in Common Eider Somateria mollissima feeding flocks - a discerning kleptoparasite - Waltho, Chris M. (Wildfowl, 2009)
In Scotland, feeding flocks of Common Eider Somateria mollissima are regularly attended by Herring Gulls Larus argentatus which attack and steal food from the eiders. This study describes the prey brought to the surface by the eiders, their prey handling behaviour, subsequent attacks by gulls, and the outcome of such attacks. The majority of the prey was Blue Mussel Mytilus edulis (80%) but Green Urchin Psammechinus miliaris, Shore Crab Carcinus maenas and Common Starfish Asterias rubens were also taken. Attack frequency was not related to the occurrence of each type of prey in the eiders' diet, except that gulls were only observed attacking eiders for non-mussel prey. Attacks were most frequent (79%), and most successful (i.e. losses to gulls were highest), against eiders with starfish (73% of prey lost) and crabs (50% of prey lost). In contrast, losses of urchins (4%) and mussels (0%) were low. Despite starfish accounting for < 4% of Common Eider prey, gulls won sufficient (73%) to make kleptoparasitism a common feature of feeding flocks of eiders in this study area. These results indicate that Herring Gulls are highly selective in their attacks on Common Eider, and in the prey that are targeted.
Keywords: Common Eider; Somateria mollissima; Trophic Interactions

Polychlorinated biphenyls in eggs of spectacled eiders (Somateria fischeri) from the Yukon-Kuskokwim Delta, Alaska - Wang, D.; Huelck, K.; Atkinson, S.; Li, Q. X. (Bulletin of Environmental Contamination and Toxicology, 2005)
Keywords: Breeding Season; Somateria fischeri; Spectacled Eider; Contaminants

Validating quantitative fatty acid signature analysis to estimate diets of spectacled and Steller's eiders (Somateria fischeri and Polysticta stelleri) - Wang, Shiway W.; Hollmen, Tuula E.; Iverson, Sara J. (Journal of Comparative Physiology B Biochemical Systemic and Environmental Physiology, 2010)
Fatty acid (FA) signature analysis has been used to study foraging ecology and food webs in marine ecosystems. This powerful method provides information about diets over an extended time period (e.g., 2-4 weeks), rather than just the most recent meal as with most traditional approaches. Using consumer FA signatures, along with a comprehensive database of diet FA signatures, and accounting for consumer FA metabolism, it is possible to estimate the proportions of diet items in the consumer's diet using quantitative FA signature analysis (QFASA). However, before applying QFASA to free-ranging populations, ideally, controlled feeding studies are performed to determine FA deposition and turnover characteristics. We conducted feeding experiments to validate QFASA in captive spectacled eiders (Somateria fischeri) and Steller's eiders (Polysticta stelleri) as a minimally invasive method for studying the diets of these threatened species. We determined FA deposition in eider adipose tissue relative to long-term diet, and developed calibration coefficients (CCs) to account for eider lipid metabolism. Using these CCs with subsequent diet trials, QFASA accurately indicated diet and diet switches. QFASA estimates also indicated that turnover of dietary FAs was not complete by 21 or 29 days, and confirmed that diets could be estimated over an extended period of > 29 days. Thus, our understanding of diet can be backtracked to more than a month in captive feeding eiders. We conclude that applying QFASA techniques to eiders and other birds in the wild has the potential to provide valuable information about their diets at various life history stages.
Keywords: Somateria fischeri; Spectacled Eider; Techniques; Trophic Interactions; Polysticta stelleri; Steller's eider

Egg yolk fatty acids as a proxy to quantify diets of female Spectacled Eiders (Somateria fischeri) - Wang, S. W.; Hollmen, T. E.; Iverson, S. J. (Canadian Journal of Zoology, 2014)
Determining the diets of threatened Spectacled Eiders (Somateria fischeri (Brandt, 1847)) in relation to life-history stages will provide information to help identify and characterize their critical habitats. Quantitative fatty acid signature analysis (QFASA) is a novel tool that estimates the proportion of diet items in consumers from their fat depots. We conducted feeding experiments to validate the use of QFASA to estimate the mixed diets of captive female Spectacled Eiders using egg yolk fatty acids (FA) collected in 2008 and 2009. Calibration coefficients (CCs) for individual FA were developed to account for FA modification (due to eider lipid metabolism) from diets of eiders into egg yolk. We also compared the FA profiles between fertile and infertile eggs. Egg yolk FA profiles did not differ significantly between infertile and fertile eggs collected in either year. Using the CCs developed from eggs collected in 2008, QFASA closely estimated the 2009 diet composition of eiders. We conclude that using infertile eggs has the potential to provide a noninvasive method to elucidate diets of breeding female Spectacled Eiders and possibly other avian species, and to provide insight into understanding the sources (i.e., marine wintering or freshwater breeding habitat) and timing (i.e., prebreeding or breeding) of nutrient acquisition during reproduction.
Wang, Shiway W. Hollmen, Tuula E. Iverson, Sara J.
Keywords: Somateria fischeri; Spectacled Eider; Energetics and Nutrition; Techniques

Using citizen-science data to identify local hotspots of seabird occurrence - Ward, E. J.; Marshall, K. N.; Ross, T.; Sedgley, A.; Hass, T.; Pearson, S. F.; Joyce, G.; Hamel, N. J.; Hodum, P. J.; Faucett, R. (Peerj, 2015)
Seabirds have been identified and used as indicators of ecosystem processes such as climate change and human activity in nearshore ecosystems around the globe. Temporal and spatial trends have been documented at large spatial scales, but few studies have examined more localized patterns of spatiotemporal variation, by species or functional group. In this paper, we apply spatial occupancy models to assess the spatial patchiness and interannual trends of 18 seabird species in the Puget Sound region (Washington State, USA). Our dataset, the Puget Sound Seabird Survey of the Seattle Audubon Society, is unique in that it represents a seven-year study, collected with a focus on winter months (October-April). Despite historic declines of seabirds in the region over the last 50 years, results from our study are optimistic, suggesting increases in probabilities of occurrence for 14 of the 18 species included. We found support for declines in occurrence for white-winged scoters, brants, and 2 species of grebes. The decline of Western grebes in particular is troubling, but in agreement with other recent studies that have shown support for a range shift south in recent years, to the southern end of California Current.
Ward, Eric J. Marshall, Kristin N. Ross, Toby Sedgley, Adam Hass, Todd Pearson, Scott F. Joyce, Gerald Hamel, Nathalie J. Hodum, Peter J. Faucett, Rob
Keywords: Melanitta fusca; White-winged Scoter; Melanitta perspicillata; Surf Scoter; Histrionicus histrionicus; Bucephala clangula; Common Goldeneye; Bucephala albeola; Bufflehead; Abundance, Distribution, & Trends; Nonbreeding season; Harlequin Duck

North east Scottish counts of Goldeneye, Goosander, Redbreasted Merganser and Cormorant in 1944-50 compared with 1988-97 - Watson, A.; Marquiss, M.; Cosgrove, P. J. (Scottish Birds, 1998)
Unpublished counts of Goldeneyes, sawbill ducks and Cormorants are presented from part of the River Deveron and other sites in north east Scotland in 1944-50 and 1997, and compared with published data from 1988-90 and 1996. The Deveron held many Goldeneyes in the 1940s, and also many other waterfowl, especially when lochs were frozen. The proportion of adult drake Goldeneyes on estuaries, at sea, and on the coastal Loch of Strathbeg exceeded that on inland waters. The numbers of Goldeneyes and Goosanders on the Deveron were higher during periods of hard frost. Adult drake Goosanders formed a minority on the Deveron and on Haddo House lakes, but a majority on Loch of Strathbeg and on Lochs Davan and Kinord. Adult drake Mergansers were in a minority on all sites. Counts from the Don estuary in 1989-90 showed no material change in Goldeneye numbers or the proportion of adult drakes since 1944-50. Counts in 1996 and 1997 show more Goldeneyes and Goosanders than on the same parts of the River Deveron in 1944-50, fewer Mergansers, and few Cormorants in both periods. Many sawbills and Cormorants were culled on the Deveron in both periods.
Keywords: Abundance, Distribution, and Trends; Nonbreeding Seasons; Bucephala clangula; Common Goldeneye; Common merganser; Mergus merganser; Mergus serrator; Red-breasted merganser

Variation in the morphology of adult Apatemon gracilis Rudolphi, 1819 (Digenea: Strigeidae) reared in different avian hosts - Watson, Jennifer J.; Pike, A. W. (Systematic Parasitology, 1993)
Adult Apatemon gracilis (Rudolphi, 1819) were reared experimentally in three different avian hosts: herring gulls Larus argentatus Gmelin, domestic chicks Gallus gallus (L.) and eider ducklings Somateria mollissima (L.) Comparison of size, body proportions and fecundity were made between these and specimens obtained from a naturally infected goosander Mergus merganser L. The eider duck proved to be a suitable experimental host, rearing adults of comparable size and fecundity to those from the natural host. The growth and development of the parasite in domestic chicks and herring gulls were significantly reduced. Similar conditions are likely to exist in the natural environment and this should be taken into consideration when choosing experimental hosts for use in the laboratory or when identifying species.
Keywords: Breeding Season; Common Eider; Somateria mollissima; Parasites

Egg-laying time and laying interval in the common eider - Watson, Michelle D.; Robertson, Gregory J.; Cooke, Fred (Condor, 1993)
We determined the time of day at which eggs were laid and the laying interval (time between laying of successive eggs in a clutch) in the Hudson Bay race of the Common Eider (Somateria mollissima sedentaria), at La Perouse Bay, Churchill, Manitoba (58 degree 24'N, 94 degree 24'W). Nests were found at the one-egg stage and were subsequently visited three times daily. Analysis of the nest contents at each visit allowed us to estimate mean egg-laying times as well as the mean time at which eggs were lost to predators. The estimated mean egg-laying hour was 13:49 (CST, 95% CL 12:30-15:06). We detected no selective advantage to laying at this time based on the timing of egg predation. The average egg-laying interval was 27.7 +- 3.4 hr. Laying intervals decreased with increasing clutch sizes. For clutches of four and five eggs, the estimated interval between the last two eggs was significantly longer than that for intervals between all other eggs, all other comparisons between intervals were not significantly different. If last-laid eggs were excluded the mean laying interval for all eggs was 26.1 +- 4.3 hr, confirming that the last egg in a clutch takes longer to produce. We suggest that longer laying intervals of last-laid eggs may be related to hormonal changes associated with the onset of incubation.
Keywords: Breeding Season; Common Eider; Somateria mollissima; Physiology

Year-to-year correlations in blood metal levels among individuals of two species of North American sea ducks - Wayland, M.; Alisauskas, R. T.; Kellett, D.; Traylor, J.; Swoboda, C.; Neugebauer, E.; Mehl, K. (Environmental Pollution, 2007)
Sea duck populations have declined in North America. Contaminants, especially metals, have been listed as possible contributing factors. Sea ducks are long-lived. Thus, individuals chronically exposed to elevated metal levels may be at greatest risk. Information about long-term exposure (>= 1 year) of individuals to metals is absent. To address this information gap, we examined year-to-year correlations among individual White-Winged Scoters and King Eiders in levels of blood cadmium, lead, mercury and selenium. Positive correlations (r >= 0.43), were found in six, five, five and two of seven correlations for cadmium, selenium, lead and mercury. Thus, certain individuals of these species may be exposed over two or more years to higher levels of cadmium, selenium and lead (but apparently not mercury) than other individuals. Single blood samples are appropriate metrics of exposure for studies that examine long-term effects of certain metals on these birds.
Keywords: Breeding Season; Melanitta fusca; White-winged Scoter; Contaminants; King Eider; Somateria spectabilis

Survival rates and blood metal concentrations in two species of free-ranging North American sea ducks - Wayland, Mark; Drake, Kiel L.; Alisauskas, Ray T.; Kellett, Dana K.; Traylor, Joshua; Swoboda, Cindy; Mehl, Katherine (Environmental Toxicology and Chemistry, 2008)
Populations of several species of North American sea ducks have declined in the past few decades. Exposure to environmental contaminants, particularly metals, has been proposed as one of many possible factors contributing to these declines. Population dynamics are influenced by survival rates and breeding effort. In the present study, we examined the relationships between blood metal concentrations (Cd, Pb, Se, and Hg) and apparent annual survival and recapture probabilities (the latter as a surroaate for breeding effort) in adult females of two sea duck species, the king eider (Somateria spectabilis) and the white-winged scoter (Melanitta fusca), both of which have experienced declines in continental population during in recent years. No support was found for the hypothesis that exposure of white-winged scoters to these metals or of king eiders to Cd, Se, and Pb adversely affected probabilities of apparent annual survival. We detected a weak negative relationship (<(<(beta)over bar>)over cap> = -0.833) between Hg and annual survival of king ciders, but the 90% confidence interval of the slope estimate overlapped zero (-2.439 to +0.672). Recapture probabilities were unrelated to concentrations of Cd, Se, and Pb in either species. Evidence indicated that Hg concentrations affected recapture probability in white-winged scoters ((beta) over cap = -194.77; 90% confidence interval, -203.770 to -185.778). Mercury levels were low in both species, and blood samples may not adequately represent long-term exposure to Hg. Therefore, conclusions regarding Hg effects on these birds should be considered with caution.
Keywords: Breeding Season; Melanitta fusca; White-winged Scoter; Contaminants; King Eider; Somateria spectabilis; Survival

Concentrations of cadmium, mercury and selenium in blood, liver and kidney of common eider ducks from the Canadian arctic - Wayland, M.; Garcia-Fernandez, A. J.; Neugebauer, E.; Gilchrist, H. G. (Environmental Monitoring and Assessment, 2001)
We determined concentrations of selected trace elements in livers, kidneys and blood samples from common eiders (Somateria mollissima borealis) from the eastern Canadian arctic during 1997 and 1998. Concentrations of total mercury and organic mercury were generally low in the livers of these birds (less than 6 and 4 mug g-1 dry wt, respectively). Selenium ranged between 11-47 mug g-1 in livers. Renal cadmium concentrations were among the highest ever published for this species (range: 47-281 mug g-1). The regressions of log-transformed concentrations of these trace elements in blood samples on those in liver or kidney were significant (all P-values <0.05) and positive. However, except for organic mercury (R2=0.83), the co-efficients of determination were low to moderate (range of R2: 0.26-0.52), suggesting poor to moderate predictive capability. Furthermore, the relationships between total mercury in blood and liver changed between 1997 and 1998, suggesting that it would not be possible to predict consistently, concentrations of mercury in blood from those in liver based on samples taken in one year. Blood samples can be used to determine concentrations of these trace elements in common eiders (and probably other sea duck species as well). The use of blood samples is especially warranted when it is undesirable to kill the animal such as when working with rare or endangered sea duck species or when the objective is to relate trace element exposure to annual survival rates. However, the predictive equations developed here should not be used to predict expected concentrations in one type of tissue from those in the other.
Keywords: Common Eider; Contaminants; Somateria mollissima

Trace elements in king eiders and common eiders in the Canadian arctic - Wayland, M.; Gilchrist, H. G.; Dickson, D. L.; Bollinger, T.; James, C.; Carreno, R. A.; Keating, J. (Archives of Environmental Contamination and Toxicology, 2001)
We determined concentrations of selected trace elements in tissues of king and common eiders at three locations in the Canadian arctic. Renal and hepatic cadmium concentrations in king eiders at a location in the eastern arctic were among the highest ever recorded in eider ducks: there, they were higher in king eiders than in common eiders. Cadmium concentrations were lower in king eiders from the western arctic than in those from the east. In the western arctic, cadmium concentrations did not differ between species. Hepatic mercury and zinc were higher in king eiders than in common eiders. Zinc and selenium were higher in eiders from the western arctic than in those from the eastern arctic. Trace element concentrations in these two duck species were below published toxicity thresholds. Positive correlations in trace element concentrations in both species were found between total and organic hepatic mercury, renal and hepatic cadmium as well as hepatic zinc, copper, mercury, and cadmium. Body mass of common but not king eiders and spleen mass of both species were negatively correlated with mercury concentrations. In common eiders, the number of nematode parasites was positively correlated with total and organic mercury. Histopathological evidence of kidney or liver lesions that are typical of trace metal poisoning was not found. We did not find evidence to support the hypothesis that trace metal exposure may be contributing to adverse effects on the health of individuals of these species.
Keywords: Breeding Season; Common Eider; Contaminants; Somateria mollissima; King Eider; Somateria spectabilis

Immune function, stress response, and body condition in arctic-breeding common eiders in relation to cadmium, mercury, and selenium concentrations - Wayland, M.; Gilchrist, H. G.; Marchant, T.; Keating, J.; Smits, J. E. (Environmental Research, 2002)
We examined relationships between trace metal concentrations in tissues of common eider ducks (cadmium, mercury, and selenium) and selected biomarkers of health (stress response, immune function, and body condition). This study was conducted at an eider nesting colony in the Canadian arctic in 1998 and 1999. Capture-induced stress, measured as the rise in corticosterone concentrations following capture, was positively related (P = 0.03) to renal cadmium concentration in 1998 when incubating eiders were sampled, but not in 1999 when prenesting eiders were sampled. Stress response was inversely related (P = 0.02) to selenium concentrations in 1999. Following capture and blood sampling in 1999, eiders were placed in a flight pen on-site for eight days in order to examine immune function. Cell-mediated immunity, measured as the skin-swelling response to an intradermal injection of phytohemagglutinin-P, (PHA-P), was positively related (P = 0.003) to hepatic selenium. The heterophil:lymphocyte ratio was inversely related (P = 0.08) to hepatic selenium. In 1998, selenium was positively related to body mass (P = 0.01), abdominal fat mass (P = 0.07), kidney mass (P = 0.03), and liver mass (P = 0.07). In 1999, hepatic mercury was negatively related to abdominal fat mass (P = 0.01), spleen mass (P = 0.07) and body mass at capture (P = 0.09) in prenesting eiders.
Keywords: Breeding Season; Common Eider; Nonbreeding Seasons; Contaminants; Somateria mollissima; Physiology; Energetics and Nutrition

Concentrations of cadmium, mercury and selenium in common eider ducks in the eastern Canadian arctic: Influence of reproductive stage - Wayland, Mark; Gilchrist, H. Grant; Neugebauer, Ewa (Science of the Total Environment, 2005)
Concentrations and total organ content of mercury, selenium and cadmium, as well as liver, kidney and body mass were determined in female common ciders from 1997 to 2000 at the East Bay Migratory Bird Sanctuary in the eastern Canadian arctic. In 1997 and 1999, female ciders were collected during the pre-nesting period when they eat copious amounts of food and gain substantial weight in preparation for the rigours of nesting. In 1998 and 1999, female ciders were collected during the mid to late stages of the nesting period when they eat very little, if at all, and, as a consequence undergo dramatic weight loss. Total body mass, liver mass and kidney mass were highest in pre-nesting birds, especially in 1997. They were significantly lower in nesting birds collected in 1998 and 2000. In contrast, mercury and cadmium concentrations were lowest in pre-nesting birds collected in 1997 and 1999 and increased to significantly higher concentrations in nesting birds collected in 1998 and 2000. In contrast to these results, the total contents of mercury in liver and cadmium in kidney did not change significantly over the 4-year period. Hepatic selenium concentrations were relatively stable over the 4-year study period while changes in the total content of selenium in the liver paralleled changes in liver mass and body mass. The results suggest that mercury and cadmium concentrations in female common eiders change in response to normal changes in body and organ mass that occur during the reproductive period. Thus, it may be important to consider body condition or reproductive stage when using common ciders (and perhaps other species of sea ducks) in biomonitoring studies or when interpreting concentrations of metals in tissues in terms of the risk they pose to these ducks. Crown Copyright (c) 2005 Published by Elsevier B.V All rights reserved.
Keywords: Breeding Season; Common Eider; Nonbreeding Seasons; Contaminants; Somateria mollissima

Movements and survival of common goldeneye broods near Sudbury, Ontario, Canada - Wayland, Mark; McNicol, Donald K. (Canadian Journal of Zoology, 1994)
We examined movements and survival of Common Goldeneye (Bucephala clangula) broods in a highly acidified area on the Canadian Precambrian Shield near Sudbury, Ontario, during 1989 and 1990. When data from the 2 years were combined, a total of 16 females had led their broods from nesting to rearing lakes, while only 4 had raised their broods on the nesting lake. Initial brood-rearing lakes contained a greater biomass of invertebrate prey and were closer to neighbouring lakes than corresponding nesting lakes. Eight broods undertook 17 secondary movements between rearing lakes. These movements were not related to differences between lakes in prey biomass or distance to neighbouring lakes. Daily survival rates of age-class I and age-class II ducklings did not differ between years. When data from the 2 years were combined, it was found that duckling survival was not related to brood movements or prey biomass. Duckling survival was higher on clustered lakes than on isolated lakes. The availability of alternate brood-rearing lakes with sufficient invertebrate prey, in addition to the primary brood-rearing lake, may be an important factor influencing Common Goldeneye brood movements and survival in our study area.
Keywords: Breeding Season; Bucephala clangula; Common Goldeneye; Dispersal; Survival; Habitat

Biomarker responses in nesting, common eiders in the Canadian arctic in relation to tissue cadmium, mercury and selenium concentrations - Wayland, Mark; Smits, Judit E. G.; Gilchrist, H. Grant; Marchant, Tracy; Keating, Jonathan (Ecotoxicology, 2003)
Populations of many North American sea ducks are declining. Biomarkers may offer valuable insights regarding the health and fitness of sea ducks in relation to contaminant burdens. In this study we examined body condition, immune function, corticosterone stress response, liver glycogen levels and vitamin A status in relation to tissue concentrations of mercury, selenium and cadmium in female common eiders during the nesting period. The study was conducted in the eastern Canadian arctic during July, 2000. Hepatic mercury, selenium and renal cadmium concentrations ranged 1.5-9.8, 6.5-47.5 and 74-389 mug/g, dry wt, respectively. Mercury concentrations were negatively related to dissection body mass, heart mass and fat mass. Cadmium concentrations were negatively related to mass at capture and dissection mass after controlling for the mercury concentration-dissection mass relationship. Cell-mediated immunity was assessed by the skin swelling reaction to an injection of phytohemagglutinin-P, and was unrelated to metal concentrations. After adjusting the corticosterone concentration to account for the time between capture and sampling, there was a negative relationship between the residual corticosterone concentration and selenium. Liver glycogen concentrations were not significantly related to metal concentrations. Mercury concentrations were positively related to those of hepatic retinol and retinyl palmitate and the ratio of the retinol to retinyl palmitate in liver. They were negatively related to the ratio of plasma to liver retinol. Our findings do not indicate that exposure to metals may have adversely affected the health of these birds. They do, however, suggest that more research is required to elucidate mechanisms by which exposure to these metals could impact body condition.
Keywords: Breeding Season; Common Eider; Contaminants; Somateria mollissima

Behavioral Implications of the Defense of a Shoveler Anas-Clypeata Brood by Common Eiders Somateria-Mollissima - Weatherhead, P. J. (Condor, 1979)
Keywords: Behavior; Breeding Season; Common Eider; Somateria mollissima

Natal philopatry and local resource competititon in the common goldeneye (and reply) - Weatherhead, Patrick J. (Journal of Avian Biology, 1998)
Keywords: Breeding Season; Bucephala clangula; Common Goldeneye; Dispersal; Habitat

Breeding birds in the Canton of Zurich: Status and population trends between 1986/88 and 1999/00. - Weggler, Martin; Widmer, Michael (Vierteljahrsschrift der Naturforschenden Gesellschaft in Zuerich, 2001)
We evaluate the status of all breeding birds in the Canton of Zurich and document changes in distribution and population sizes between 1986/88 and 1999/00. Our evaluation is based on a recensus of all breeding birds in 154 representative study plots (40-60 ha) in 1999 after a first census conducted in the years 1986/88. For rare species and wetland birds we used data from a continuous bird monitoring project carried out since 1993. Since the last extensive survey in the years 1986/88 a total of 142 breeding bird species were detected in the Canton of Zurich. Seven species (Black-necked Grebe, Ruddy Shelduck, Goosander; Peregrine Falcon, Common Tern, Meadow Pipit and Stonechat) have recently colonised or recolonised our study area while five species (Eagle Owl, Water Pipit, Northern Wheatear, Lesser Grey Shrike, Woodchat Shrike) disappeared. A total of 117 species bred regularly and another 18 do so irregularly. Between 1986/88 and 1999 20 out of 57 widespread and common species showed a positive population trend in at least one out of three main habitats (arable land, human settlements, forest). Another 19 species decreased in number, 17 species remained stable and one species showed different trends in different habitats.
Keywords: Breeding Season; Abundance, Distribution, and Trends; Sea Ducks - General; Common merganser

Regime shifts in marine ecosystems of the North Sea and Wadden Sea - Weijerman, Mariska; Lindeboom, Han; Zuur, Alain F. (Marine Ecology Progress Series, 2005)
Wide-scale and sudden shifts in several biological and environmental systems of NW Europe have been reported in recent years, and attributed to a range of factors, both climatic and anthropogenic. To examine whether there is any evidence of coinciding region-wide environmental shifts, we gathered existing long-term data series on a wide range of physical and biological parameters from the 1960s to the present and, following the methods of a similar recent study on North Pacific regime shifts, we analysed the data using principal component analysis and regime shift analysis to identify the extent and timing of regime shifts in NW Europe. The end-point of a regime (i.e. the year) was determined using a sliding window in regime shift analysis. Additionally we applied chronological clustering to the (1) combined data, (2) biological data and (3) environmental data. In all 3 cases, the same regimes were identified. Our results indicate that substantial regime shifts occurred in the marine ecosystem in 1979 and 1988 and perhaps also in 1998, although results were less clear-cut in the latter case. These regime shifts were most evident among the biological data series, but they appeared to have been triggered by earlier shifts in a number of environmental factors. Salinity and weather conditions played an important role in the 1979 shift, while in the 1988 shift, temperature and weather conditions were the predominant factors. Our results confirm those of the North Pacific study, with concomitant changes in physical and biological indices. This indicates a shift in climate-ocean interactions throughout the entire temperate zone of the Northern Hemisphere.
Keywords: Sea Ducks - General

Antimicrobial activity of the Anseriform outer eggshell and cuticle - Wellman-Labadie, Olivier; Picman, Jaroslav; Hincke, Maxwell T. (Comparative Biochemistry and Physiology Part B Biochemistry & Molecular Biology, 2008)
The avian eggshell is a complex, multifunctional biomineral composed of a calcium carbonate mineral phase and an organic phase of lipids and proteins. The outermost layer of the eggshell, the eggshell cuticle, is an organic layer of variable thickness composed of polysaccharides, hydroxyapatite crystals, lipids and glycoprotein. In addition to regulating gas exchanges, the eggshell cuticle may contain antimicrobial elements. In this study, we investigated the antimicrobial activity of eggshell cuticle and outer eggshell protein extracts from four Anseriform species: wood duck (Aix sponsa), hooded merganser (Lophodytes cucullatus), Canada goose (Branta canadensis) and mute swan (Cygnus olor). Cuticle and outer eggshell protein was extracted by urea or HCl treatment of eggs. C-type lysozyme, ovotransferrin and an ovocalyxin-32-like protein were detected in all extracts. Cuticle and outer eggshell protein extracts inhibited the growth of Staphylococcus aureus, Escherichia coli D31, Pseudomonas aeruginosa and Bacillus subtilis. The presence of active antimicrobial proteins within the avian cuticle and outer eggshell suggests a role in antimicrobial defense. Protein extracts from the cavity nesting hooded merganser were especially potent. The unique environmental pressures exerted on cavity-nesting species may have led to the evolution of potent antimicrobial defenses. (c) 2008 Elsevier Inc. All rights reserved.
Keywords: Breeding Season; Physiology; Hooded Merganser; Lophodytes cucullatus

Composition, Shell Strength, and Metabolizable Energy of Mulinia lateralis and Ischadium recurvum as Food for Wintering Surf Scoters (Melanitta perspicillata) - Wells-Berlin, A. M.; Perry, M. C.; Kohn, R. A.; Paynter, K. T.; Ottinger, M. A. (Plos One, 2015)
Decline in surf scoter (Melanitta perspicillata) waterfowl populations wintering in the Chesapeake Bay has been associated with changes in the availability of benthic bivalves. The Bay has become more eutrophic, causing changes in the benthos available to surf scoters. The subsequent decline in oyster beds (Crassostrea virginica) has reduced the hard substrate needed by the hooked mussel (Ischadium recurvum), one of the primary prey items for surf scoters, causing the surf scoter to switch to a more opportune species, the dwarf surfclam (Mulinia lateralis). The composition (macronutrients, minerals, and amino acids), shell strength (N), and metabolizable energy (kJ) of these prey items were quantified to determine the relative foraging values for wintering scoters. Pooled samples of each prey item were analyzed to determine composition. Shell strength (N) was measured using a shell crack compression test. Total collection digestibility trials were conducted on eight captive surf scoters. For the prey size range commonly consumed by surf scoters (6-12 mm for M. lateralis and 18-24 mm for I. recurvum), I. recurvum contained higher ash, protein, lipid, and energy per individual organism than M. lateralis. I. recurvum required significantly greater force to crack the shell relative to M. lateralis. No difference in metabolized energy was observed for these prey items in wintering surf scoters, despite I. recurvum's higher ash content and harder shell than M. lateralis. Therefore, wintering surf scoters were able to obtain the same amount of energy from each prey item, implying that they can sustain themselves if forced to switch prey.
Wells-Berlin, Alicia M. Perry, Matthew C. Kohn, Richard A. Paynter, Kennedy T., Jr. Ottinger, Mary Ann
Keywords: Melanitta perspicillata; Surf Scoter; Energetics and Nutrition; Nonbreeding season

Strong impact of wintering waterbirds on zebra mussel (Dreissena polymorpha) populations at Lake Constance, Germany - Werner, S.; Mortl, M.; Bauer, H. G.; Rothhaupt, K. O. (Freshwater Biology, 2005)
Werner, S Mortl, M Bauer, HG Rothhaupt, KO

Biodiversity and energy transfer to top trophic levels in two contrasting Arctic fjords - Weslawski, Jan Marcin; Kwasniewski, Slawomir; Stempniewicz, Lech; Blachowiak-Samolyk, Katarzyna (Polish Polar Research, 2006)
The food and foraging strategy of fifteen species of seabirds and sea mammals from two high Arctic fjords were analysed. One of the fjords, Kongsfjord, is strongly influenced by warm waters from the Atlantic, while Hornsund is of a more Arctic character. Prey species in the Atlantic waters were more diverse (82 species and 16 functional groups) compared to those of Arctic waters (67 prey species and 14 functional groups). The consumption of top predators from Hornsund in the peak season of July was estimated at 2.86*10(6) MJ, while that in Kongsljord was 1.35*10(6) MJ. For the analysed function of the ecosystem (the transfer of energy to the top trophic levels) the specific character of prey species is of key importance and not the diversity, abundance or biomass per se. Lower species diversity and biomass in Arctic waters is compensated for by the occurrence of larger individuals of these species, which permits top predators to prey directly on lower trophic levels.
Keywords: Common Eider; Somateria mollissima; Trophic Interactions

Summer diet of seabirds from the Frans Josef Land archipelago, Russian Arctic - Weslawski, Jan M.; Stempniewicz, Lech; Galaktionov, Kiryl (Polar Research, 1994)
Food samples from 102 seabirds from eight species (fulmar Fulmarus glacialis, common eider Somateria mollissima, glaucus gull Larus hyperboreus, kittiwake Rissa tridactyla, arctic tern Sterna paradisaea, Brunnich's guillemot Uria lomvia, black guillemot Cepphus grylle, little auk Alle alle) were collected during the period August 1991-1993 in the southern part of the Frans Josef Land archipelago, 80 degree N, 53 degree E. The pelagic amphipod Parathemisto libellula and polar cod Boreogadus saida were the two most commonly taken food items (frequency of occurrence over 50% and weight contribution more than 70%). Ice-associated crustaceans contributed to some 10% of the weight in the samples. In general, the food composition was very similar to that reported from Svalbard. However, birds from Frans Josef Land fed on a lower diversity of prey compared to Svalbard populations.
Keywords: Breeding Season; Common Eider; Somateria mollissima; Trophic Interactions

Polycyclic aromatic hydrocarbons (PAHs) reduce hepatic beta-oxidation of fatty acids in chick embryos - Westman, O.; Norden, M.; Larsson, M.; Johansson, J.; Venizelos, N.; Hollert, H.; Engwall, M. (Environmental Science and Pollution Research, 2013)
Times Cited: 0 Westman, Ola Norden, Marcus Larsson, Maria Johansson, Jessica Venizelos, Nikolaos Hollert, Henner Engwall, Magnus 0
Keywords: Contaminants

Testing the effectiveness of an aquatic hazing device on waterbirds in the San Francisco Bay estuary of California - Whisson, Desley A.; Takekawa, John Y. (Waterbirds, 2000)
Aquatic hazing devices recently have been developed as a possible means of deterring waterbirds from oil spills, thereby reducing casualties. However, the effectiveness of these devices has not been examined with rigorous statistical tests. We conducted a study in the San Francisco Bay estuary to develop a design for testing the effectiveness of an aquatic hazing device on waterbirds in open water. Transects marked with poles at 100-m intervals up to 800 m from the hazing device were established at two sites separated by three km in the north bay. Alternating two-day test and control periods were conducted at each site. Observers in over-water blinds counted the number, species and behavior (swimming, diving, or preening) of birds on transects each day. Aerial surveys of birds within four km of the device were conducted at the beginning of each test. For both aerial and ground surveys, a three-way mixed model analysis of variance test was used to examine trial, distance from the device, and treatment (device on or off) fixed effects, and site as a random effect on numbers of Greater and Lesser scaup (Aythya affinis and A. marila), Surf Scoter (Melanitta perspicillata), and all other waterbirds. We could not detect a significant deterrent effect of the hazing device in either aerial surveys of all ducks of scaup (all ducks, F28.33 = 1.1; Scaup, F28.230 = 0.9, all n.s.; 3-factor ANOVA), or ground surveys for all ducks or scaup (all ducks, F28.23 = 1.0; scaup, F28.230 = 0.9, all n.s.; 3-factor ANOVA). There was a significant trial-by-treatment interaction for Surf Scoters (F4.9 = 5.4, P = 0.02; 3-factor ANOVA), but Surf Scoter numbers fluctuated greatly among trials so the effect of the device on this species was not clear. Birds did not alter their behavior when the device was active. In general, although aquatic hazing devices have potential to reduce waterbird mortality in oil spills, the tested device was not effective as a deterrent for waterfowl in experimental trials on the estuary.
Keywords: Nonbreeding Seasons; Melanitta perspicillata; Surf Scoter; Techniques

Hooded Merganser Kills a Meadow Vole - White, D. H. (Wilson Bulletin, 1975)
Keywords: Trophic Interactions; Hooded Merganser; Lophodytes cucullatus

Residues of Environmental Pollutants and Shell Thinning in Merganser Eggs - White, D. H.; Cromartie, E. (Wilson Bulletin, 1977)
Clutches of merganser eggs were collected in 1973 and 1975 to determine whether levels of organochlorines and Hg might be responsible for possible population declines and to compare eggshell measurements with those of early museum collections. One egg/clutch was selected randomly for chemical analysis. Overall, residues of DDE, PCB [polychlorinated biphenyl] and Hg were low in hooded merganser [Lophodytes cucullatus] eggs; locality means for DDE ranged from 0.07-13.2 ppm, PCB means ranged from 0.44-4.91 ppm, and Hg means ranged from 0.16-1.49 ppm on a wet-weight basis. Residues of DDE and PCB appeared to be high in red-breasted [Mergus serrator] and common merganser [M. merganser] eggs. DDE averaged 15.7 ppm in red-breasted merganser eggs and PCB averaged 44.6 ppm; common merganser eggs contained an overall mean of 19.5 ppm DDE and 61.0 ppm PCB. Hooded merganser eggs from the Midwest [USA] had thinned 8.3%, but the change was not significant. Highly significant shell thinning was detected in red-breasted and common merganser eggs; red-breasted merganser eggs were 17.7% thinner and those of common mergansers were 23.5% thinner than museum collections.
Keywords: Breeding Season; Contaminants; Common merganser; Mergus merganser; Mergus serrator; Red-breasted merganser; Hooded Merganser; Lophodytes cucullatus

Local feeding of kingfishers and mergansers - White, H. C. (Jour Biol Bd Canada, 1937)
On the Margaree and Apple rivers, Nova Scotia, the belted kingfisher [Megaceryle alcyon] feeds upon the fishes that are most available within its feeding range. In the estuaries many spp. are taken; ascending a river the number becomes less until only salmon and trout (Sal-velinus), or trout alone, constitute the food. By rearing a young bird it was determined that the American merganser [Mergus americanus] pursues its prey by sight under water, being able to see a distance of from 10 feet (3m.) to 2 feet (0.6 m.) or less, depending upon the clearness of the water. The bird consumes daily on the average more than 1/3 of its weight. In nature the broods are reared up stream where young salmon are the dominant fish and constitute the major food item, with trout next. When the supply becomes scarce they shift down stream and in the estuary take the various fishes occurring there. The young red-breasted mergansers [M. senator] were found feeding over areas not frequented by young salmon, and the adults were confined largely to the estuary. They fed on the species available, which sometimes consisted largely of young salmon. || ABSTRACT AUTHORS: Auth. abst
Keywords: Trophic Interactions; Mergus serrator; Red-breasted merganser

Food and natural history of mergansers on salmon waters in the Maritime Provinces of Canada - White, H. C. (Bull Fish Res Bd Canada, 1957)
This study of the life history and feeding habits of mergansers is the 2d of a series on the relation of fish-eating birds to the production of Atlantic salmon and trout. The principal species considered is the American merganser (Mergus merganser americanus). A relatively small amount of work has been done on the red-breasted merganser (Mergus serrator). Only once was the hooded merganser (Lophodytes cucullatus) within the area of the salmon studies. Work on the American merganser is based on observations in the field and on captive and tame birds. Specimens for food analyses have been collected over a period of many years from Maritime Provinces of Nova Scotia and New Brunswick.
Keywords: Trophic Interactions; Common merganser; Mergus merganser; Mergus serrator; Red-breasted merganser; Hooded Merganser; Lophodytes cucullatus

Spatial ecology of long-tailed ducks and white-winged scoters wintering on Nantucket Shoals - White, T. P.; Veit, R. R. (ECOSPHERE, 2020)
We examine the long-term co-occurrence of long-tailed ducks (Clangula hyemalis) and white-winged scoters (Melanitta fusca) wintering at the Nantucket Shoals off Massachusetts, USA, and ask: (1) What oceanographic features attract these aggregations? (2) How are distributions of prey and sea ducks related to one another? and (3) What is the explanation for the spatial association between these two species? A winter concentration of long-tailed ducks on the order of 3 x 10(5) birds have been present near Nantucket Island and the Nantucket Shoals since the 1970s, and there is evidence of some concentration there since the late 1800s. Despite the difference in diet, the two duck species overlap in spatial distribution in relation to a prominent tidal front on the west side of Nantucket Shoals where nested swarms of pelagic amphipods and massive clam beds occur in persistent broadscale concentrations. Gammarid amphipods were collected seasonally by bongo tows over 39 yr (1977-2016), and Atlantic surf clams and ocean quahogs were collected by hydraulic dredge over a 34-yr timescale (1982-2016). Long-tailed ducks and white-winged scoters were counted during systematic low-level aerial surveys. Both long-tailed ducks and white-winged scoters associated with amphipod and clam aggregations at similar scales, and tracked amphipod and clam concentrations at larger spatial scales, up to similar to 30 km. These multi-scalar nested associations suggest that the sea ducks foraged within a hierarchical patch system structured by the tidal regime, and concentrated in areas of spatially anchored recurring prey, with highest densities in southwest areas. Enhanced concentrations of prey within a relatively narrow zone on Nantucket Shoals provide a predictable food resource to wintering sea ducks whose populations are in decline. As supported by our generalized additive models, we propose that the positive spatial associations among these species are at least partly explained by local enhancement or facilitation, whereby each species of duck derives foraging benefit from noting the location of aggregations of the other. This interaction will be important to the designation of marine protected areas.
Times Cited in Web of Science Core Collection: 8 Total Times Cited: 8 Cited Reference Count: 142
Keywords: long-tailed duck; COMMON EIDERS; SEA DUCKS; HABITAT USE; sea duck; SEABIRDS; SURF SCOTERS; feeding ecology; aerial surveys; FORAGING BEHAVIOR; white-winged scoter; Atlantic Ocean; ecotone; GEORGES-BANK; local enhancement; Nantucket Shoals; SOUTHERN FLANK; spatial anchor; spatial synchrony; TIDAL FRONTS

Feeding Ecology of Long-tailed Ducks Clangula hyemalis Wintering on the Nantucket Shoals - White, Timothy P.; Veit, Richard R.; Perry, Matthew C. (Waterbirds, 2009)
A substantial proportion, perhaps 30%, of the North American breeding population of Long-tailed Ducks (Clangula hyemalis) winter in the vicinity of Nantucket Island, Massachusetts. These birds spend the night on Nantucket Sound and commute during daylight hours to the Nantucket Shoals, which extend about 65 km offshore from the southeastern corner of Nantucket. Strip transects done from a single-engine plane in 1997 and 1998 indicated that Long-tailed Ducks foraged over the shallower (<= 20 m depth) portions of the Nantucket Shoals, up to 70 km offshore. Diet analyses of ten birds collected in February 1999 and five in December 2006 showed that they fed principally (106.6 +/- 42.0 individuals per crop) on Gammarus annulatus, a pelagic amphipod that often forms large aggregations, and is consumed by several species of fish and marine mammals. Our findings emphasize the importance of conservation of the Nantucket Shoals and the prevention of oil spills or other potentially harmful accidents.
Keywords: Nonbreeding Seasons; Clangula hyemalis; Long-tailed Duck; Trophic Interactions

Estimating Waterfowl Densities in a Flooded Forest: A Comparison of Methods - Whiting, R. Montague, Jr.; Cornes, J. Paul (Southeastern Naturalist, 2009)
During winter, aerial surveys are used to estimate densities of ducks that occupy open-water habitats However, such surveys are ineffective for sampling forest-dwelling species, especially Aix sponsa (Wood Ducks), Aims platyrhynchos (Mallards), and Lophodytes cucullatus (Hooded Mergansers) We evaluated fixed-radius plot (FRP) and Reynolds and Goodrum variable-radius plot (VRP) methods for estimating waterfowl densities in a flooded hardwood bottomland We constructed 15 elevated blinds on the Angelina River flood plain in eastern Texas and established a 1-ha FRP around each blind, color-coded markers were placed at fixed intervals from each blind Observers surveyed waterfowl from blinds for 21 mornings during January March, 1990 For FRPs, species, sex, and time a bird entered and exited the plot were recorded For VRPs, similar data and estimated observer-to-bird distance were recorded. Data were arranged in a randomized block design and tested using 1-way analyses of variances Wood Ducks, Mallards, and Hooded Mergansers comprised 68, 18, and 10% of the birds recorded, respectively Wood Duck density estimates (per ha) for FRP, Reynolds VRP, and Goodrum VRP methods were 0.65, 0 49, and 1.00 (P < 0 001), respectively, for Mallards, estimates were 0 27, 0 20, and 0 33 (P < 0 001), respectively; and estimates were 0 09, 0.13, and 0 15 (P = 0.003) for Hooded Mergansers, respectively. Based on ease of implementation, complexity of data analyses, and precision of density estimates, the FRP and Goodrum VRP methods are recommended for sampling waterfowl in flooded forests
Keywords: Nonbreeding Seasons; Techniques; Habitat; Hooded Merganser; Lophodytes cucullatus

Population estimates and hunter harvest of diving ducks in Northeastern Puget Sound, Wash - Wick, William Q.; Jeffrey, Robert G. (Murrelet, 1966)
Diving ducks comprise about one-third of the total January population of waterfowl in Northeastern Puget Sound. They furnish, however, less than 4% of the annual waterfowl harvest. Scoters, scaups, buffleheads, and goldeneyes totalled 97% of the 1958-64 January diving duck aerial sampling counts which we tallied at an average of nearly 66,000 birds. Scaups, goldeneyes, and buffleheads constituted about 80% of the average annual bag of 5800 diving ducks during the 1951-59 period. || ABSTRACT AUTHORS: Authors
Keywords: Abundance, Distribution, and Trends; Nonbreeding Seasons; Bucephala albeola; Bufflehead

Applying ecological risk assessment to environmental accidents: Harlequin ducks and the Exxon Valdez oil spill - Wiens, John A. (Bioscience, 2007)
Ecological risk assessment is a systematic way to evaluate the likelihood that an environmental accident has caused significant ecological consequences. I apply this framework retrospectively to evaluate a scenario linking the Exxon Valdez oil spill to population effects on harlequin ducks (Histrionicus histrionicus) through hydrocarbon contamination of mussels in spill-affected shorelines of Prince William Sound, Alaska. By evaluating the plausibility of each step of this scenario in turn, it becomes apparent that it is highly unlikely the oil spill is having continuing effects on harlequins through this pathway. This case study shows how ecological risk assessment can help clarify potential cause-effect relationships in an emotionally and socially charged situation.
Keywords: Nonbreeding Seasons; Harlequin duck; Histrionicus histrionicus; Contaminants

Assessing Cause-Effect Relationships in Environmental Accidents: Harlequin Ducks and the Exxon Valdez Oil Spill - Wiens, John A.; Day, Robert H.; Murphy, Stephen M.; Fraker, Mark A. (Current Ornithology, Vol 17, 2010)
Keywords: Nonbreeding Seasons; Harlequin duck; Histrionicus histrionicus; Contaminants

Ecosystem-based management of predator-prey relationships: Piscivorous birds and salmonids - Wiese, Francis K.; Parrish, Julia K.; Thompson, Christopher W.; Maranto, Christina (Ecological Applications, 2008)
Predator-prey relationships are often altered as a result of human activities. Where prey are legally protected, conservation action may include lethal predator control. In the Columbia River basin (Pacific Northwest, USA and Canada), piscivorous predators have been implicated in contributing to a lack of recovery of several endangered anadromous salmonids ( Oncorhynchus spp.), and lethal and nonlethal control programs have been instituted against both piscine and avian species. To determine the consequences of avian predation, we used a bioenergetics approach to estimate the consumption of salmonid smolts by waterbirds ( Common Merganser, California and Ring-billed Gull, Caspian Tern, Double-crested Cormorant) found in the mid-Columbia River from April through August, 2002-2004. We used our model to explore several predator-prey scenarios, including the impact of historical bird abundance, and the effect of preserving vs. removing birds, on smolt abundance. Each year, < 1% of the estimated available salmonid smolts (interannual range: 44 830-109 209; 95% CI = 38 000-137 000) were consumed, 85-98% away from dams. Current diet data combined with historical gull abundance at dams suggests that past smolt consumption may have been 1.5-3 times current numbers, depending on the assumed distribution of gulls along the reaches. After the majority (80%) of salmonid smolts have left the study area, birds switch their diet to predominantly juvenile northern pikeminnow (Ptychocheilus oregonensis), which as adults are significant native salmonid predators in the Columbia River. Our models suggest that one consequence of removing birds from the system may be increased pikeminnow abundance, which - even assuming 80% compensatory mortality in juvenile pikeminnow survival - would theoretically result in an annual average savings of just over 180 000 smolts, calculated over a decade. Practically, this suggests that smolt survival could be maximized by deterring birds from the river when smolts are present, allowing bird presence after the diet switch to act as a tool for salmonid-predator control, and conducting adult-pikeminnow control throughout. Our analysis demonstrates that identifying the strength of ecosystem interactions represents a top priority when attempting to manage the abundance of a particular ecosystem constituent, and that the consequences of a single-species view may be counterintuitive, and potentially counterproductive.
Keywords: Conservation; Breeding Season; Trophic Interactions; Common merganser; Mergus merganser

The extent of chronic marine oil pollution in southeastern Newfoundland waters assessed through beached bird surveys 1984-1999 - Wiese, Francis K.; Ryan, Pierre C. (Marine Pollution Bulletin, 2003)
The Grand Banks south of Newfoundland provide year-round feeding habitat for tens of millions of seabirds of numerous species, an abundance and diversity unparalleled in the North Atlantic. Dense ship traffic routes traverse this productive environment as vessels travel the Great Circle Route between Europe and North America. Oiled seabirds have washed up on beaches in Newfoundland for many decades. Most oil on their feathers is heavy fuel oil mixed with lubricants, the mixture found in bilges of large vessels. Beached bird surveys conducted between 1984 and 1999 indicate that chronic oil pollution along the southeast coast of Newfoundland is among the highest in world. Sixty two percent of all dead birds found over the 16-year period had oil on their feathers; 74% during the last five years. Auks, especially Thick-billed Murres (Uria lomvia), are the most affected. The mean number of oiled birds per kilometer was 0.77 and thus higher than in other regions of the world during a comparable time period (0.02-0.33). Oiling rates correlated with weather patterns and degree of the regional murre hunt, indicate that illegal dumping of oil may occur year round, and point out that it is critical to assess all possible environmental and anthropogenic factors influencing the number of clean and oiled dead birds found on beaches before inferring trends in oiling rates over time.
Keywords: Sea Ducks - General; Contaminants

Foraging activities of the snowy owl (Nyctea scandiaca) during a period of low Lemming population - Wiggins, I. L. (Auk, 1953)
Owls observed feeding on injured Somateria spectabills (King Eider) and red phalaropes, Phalaropus fulicarius. || ABSTRACT AUTHORS: L. M. Bartlett
Keywords: King Eider; Somateria spectabilis; Trophic Interactions

Wintering seafowl in Scapa Flow, Orkney, October 1998 to March 1999 - Williams, E. J. (Scottish Birds, 2000)
Monthly counts of all seafowl were carried out in Scapa Flow for the 6 months from October 1998 to March 1999, utilising both shore and boat based observations. Thirty species were recorded and the maximum number of individuals of all species recorded in any month was 14,886. Two species, Great Northern Diver and Slavonian Grebe, were present at levels of international importance, and a further 11 species were present at levels of national importance. The maximum of 781 Great Northern Divers recorded was an unprecedented figure for this species in any single locality in the UK and represents 26% of the GB and 15.6% of the European winter population respectively. Slavonian Grebes peaked at 124, representing 31% of the GB and 2.5% of the European winter population. The other species of national importance were Red-throated Diver, 1.2% of GB winter population, Black-throated Diver (8.1%), Red-necked Grebe (14%), Shag (9%), Wigeon (1.4%), Teal (1%), Eider (3%), Long-tailed Duck (6.7%), Goldeneye (1.7%), Red-breasted Merganser (6.2%), and Black Guillemot (2.6%). Surface feeding duck numbered c6,300 and diving duck c4,200. Wigeon was the most abundant species with a maximum of 3,895. Overall numbers of most species exceeded those recorded during previous surveys in 1974-78 and in 1988-89.
Keywords: Abundance, Distribution, and Trends; Sea Ducks - General; Nonbreeding Seasons

Polychlorinated Biphenyls and 2,3,7,8-Tetrachlorodibenzo-p-dioxin Equivalents in Eggs of Red-Breasted Mergansers Near Green Bay, Wisconsin, USA, in 1977-78 and 1990 - Williams, L. L.; Giesy, J. P.; Verbrugge, D. A.; Jurzysta, S.; Heinz, G.; Stromborg, K. (Archives of Environmental Contamination and Toxicology, 1995)
The hypothesis that the concentrations of 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents (TEqs) contributed by non-ortho- and mono-ortho-substituted (coplanar) PCB congeners have changed relative to total concentrations of PCBs over time was tested by analyzing eggs of red-breasted mergansers collected from the same locality in 1977-78 and in 1990. Twelve eggs from each time period were analyzed for coplanar PCBs, using a porous graphitic carbon HPLC column and GC-ECD. TEqs were calculated from coplanar PCB concentrations and bioassay-derived toxic equivalency factors. Median total PCB concentrations decreased from 25 to 13 mu-g/g, fresh weight (fw), and TEqs decreased from 320 pg/g to 160 pg/g, fw. The relative potency of the PCB mixtures, expressed as the ratio of TEqs contributed by the coplanar PCB congeners to total PCBs, did not change, nor did the ratio of concentrations of coplanar congeners to total PCBs. Thus, the relative potency of the mixture of PCBs in the eggs has not changed even as the concentrations declined significantly. The greater relative potency of TEqs relative to that which would be expected from the Aroclor mixtures released into the environment is due to selective bioaccumulation, biomagnification, and metabolism, rather than as a result of differential weathering as a function of time.
Keywords: Breeding Season; Contaminants; Mergus serrator; Red-breasted merganser

Annual winter site fidelity of Barrow's Goldeneyes in the Pacific - Willie, M.; Esler, D.; Boyd, W. S.; Bowman, T.; Schamber, J.; Thompson, J. (JOURNAL OF WILDLIFE MANAGEMENT, 2020)
Coastal regions on the Pacific north coast of North America provide important wintering habitat for many species of sea ducks. Although winter range and habitat preferences are well described for most species, fidelity to coastal wintering sites is generally undocumented. Fidelity is an important factor necessary for understanding interactions with coastal developments and activities and corresponding management strategies. We used data from Barrow's goldeneyes (Bucephala islandica), a sea duck that winters predominantly in nearshore habitats along the Pacific north coast, to investigate inter-annual fidelity to, and intra-annual fidelity within, coastal wintering sites. Between 2006 and 2015, we marked goldeneyes on breeding, molting, and wintering sites with satellite transmitters. We retained 4,931 locations in coastal habitats from 221 goldeneyes across 4 coastal regions for our analyses. These birds demonstrated high inter-annual fidelity to coastal wintering sites; 75% of selected wintering sites were within 29 km of sites used the previous winter. Inter-annual fidelity to wintering sites was similar between sex and age classes but differed by coastal region. Goldeneyes from southcentral Alaska, USA, expressed greater inter-annual fidelity relative to birds from northern or southern British Columbia, Canada, and southeast Alaska. Goldeneyes also expressed high intra-annual fidelity within wintering sites, with 75% of individuals averaging within-season movements of <= 9 km. Intra-annual fidelity was lesser for female than male goldeneyes but did not differ between hatch-year and after-hatch-year birds. We found regional variation in intra-annual fidelity, with goldeneyes from southcentral Alaska expressing greater intra-annual fidelity compared to birds from other regions. High inter- and intra-annual winter site fidelity by Barrow's goldeneyes suggests that, at a population level, habitat use is predictable and can be used to inform risk assessment or to evaluate factors affecting habitat choice. Also, low dispersal among wintering sites suggests that recovery from population perturbations, whether caused by natural or anthropogenic events, will be protracted. (c) 2019 The Wildlife Society.
Times Cited in Web of Science Core Collection: 4 Total Times Cited: 4 Cited Reference Count: 41
Keywords: HARLEQUIN DUCKS; Bucephala islandica; satellite telemetry; CONSERVATION; Alaska; SEA; EIDERS; PHILOPATRY; wintering; movement; AREAS; Barrow's goldeneye; AROMATIC-HYDROCARBON EXPOSURE; British Columbia; BUCEPHALA-ISLANDICA; fidelity

Spatial variation in polycyclic aromatic hydrocarbon exposure in Barrow's goldeneye (Bucephala islandica) in coastal British Columbia - Willie, M.; Esler, D.; Boyd, W. S.; Molloy, P.; Ydenberg, R. C. (MARINE POLLUTION BULLETIN, 2017)
Barrow's goldeneyes are sea ducks that winter throughout coastal British Columbia (BC). Their diet consists primarily of intertidal blue mussels, which can accumulate PAHs; accordingly, goldeneyes may be susceptible to exposure through contaminated prey. In 2014/15, we examined total PAH concentrations in mussels from undeveloped and developed coastal areas of BC At those same sites, we used EROD to measure hepatic CYP1A induction in goldeneyes. We found higher mussel PAH concentrations at developed coastal sites. Regionally, goldeneyes from southern BC, which has relatively higher coastal development, had higher EROD activity compared to birds from northern BC Our results suggest goldeneyes wintering in coastal BC were exposed to PAHs through diet, with higher exposure among birds wintering in coastal areas with greater anthropogenic influence. These results suggest the mussel-goldeneye system is suitable as a natural, multi-trophic-level indicator of contemporary hydrocarbon contamination, occurrence and exposure useful for establishing oil spill recovery endpoints. (C) 2017 Elsevier Ltd. All rights reserved.
Times Cited in Web of Science Core Collection: 9 Total Times Cited: 9 Cited Reference Count: 65
Keywords: ALASKA; HARLEQUIN DUCKS; Bucephala islandica; SEABIRDS; SEA; MARINE BIRDS; MORTALITY; MIGRATORY BIRD; British Columbia; Biomarker; CANADA; CONTAMINATION; CYP1A; Hydrocarbon; Mussel; VALDEZ OIL-SPILL

Survival of breeding pacific common eiders on the Yukon-Kuskokwim Delta, Alaska - Wilson, Heather M.; Flint, Paul L.; Moran, Christine L.; Powell, Abby N. (Journal of Wildlife Management, 2007)
Populations of Pacific common ciders (Somateria mollissima v-nigrum) breeding in Alaska, USA, have declined markedly over the past 40 years. We studied survival of adult female Pacific common eiders using capture-recapture of nesting hens at 3 sites on the Yukon-Kuskokwim Delta (YKD), Alaska from 1994 to 2004. We used data consisting of 268 recapture events from 361 uniquely marked individuals to investigate temporal, geographic, and environmental variation in adult female survival. Our results suggest apparent annual survival of adult ciders from the YKD was high (0.892, SE = 0.022) and spatially and temporally invariant (sigma(2) = 0.005), a pattern consistent with other long-lived marine birds. Moreover, our results suggest adult survival may be functionally fixed for Pacific common eiders, and at the present, adult survival may be relatively unresponsive to environmental or management perturbations. Our data did not support hypothesized variation in survival relative to mortality factors such as predation on breeding grounds, physiologic costs of reproduction, and wintering conditions. Although changes in adult survival likely have a large potential effect on prospective population growth, our results suggest viable management actions aimed at increasing survival may be extremely limited.
Keywords: Breeding Season; Common Eider; Somateria mollissima; Survival; SDJV funded

Coupling contaminants with demography: Effects of lead and selenium in Pacific common eiders - Wilson, Heather M.; Flint, Paul L.; Powell, Abby N. (Environmental Toxicology and Chemistry, 2007)
We coupled intensive population monitoring with collection of blood samples from 383 nesting Pacific common eiders (Somateria mollisima v-nigrum) at two locations in Alaska (USA) from 2002 to 2004. We investigated annual, geographic, and within-season variation in blood concentrations of lead and selenium; compared exposure patterns with sympatrically nesting spectacled eiders (Sornateria fischeri); and examined relationships with clutch size, egg viability, probability of hatching, and apparent survival of adult females. Lead concentrations were elevated in 3.6% of females, and all individuals exhibited elevated selenium, most (81%) at concentrations associated with death in captive waterfowl. Blood lead and selenium concentrations varied both within and among site-years and were lower than those of spectacled ciders. During incubation, blood lead concentrations in females increased significantly (possibly via re-release of stored lead from bone), whereas selenium concentrations decreased (likely because of natural excretion). Probability of a nest containing at least one nonviable egg was positively related to blood selenium in hens, but adverse effects in other life-history variables were not supported. Although reproduction appeared to be sensitive to selenium toxicity, our data suggest that high rates of nonviability are unlikely in this population and that selenium-related reductions to clutch size would be inconsequential at the scale of overall population dynamics. We conclude that Pacific common eiders and other wild marine birds likely have higher selenium tolerances than freshwater species and that interspecific differences in exposure levels may reflect differences in reproductive strategies.
Keywords: Breeding Season; Common Eider; Contaminants; Somateria mollissima; Productivity; Survival

Population Ecology of Breeding Pacific Common Eiders on the Yukon-Kuskokwim Delta, Alaska - Wilson, H. M.; Flint, P. L.; Powell, A. N.; Grand, J. B.; Moran, C. L. (Wildlife Monographs, 2012)
Times Cited: 0 Wilson, Heather M. Flint, Paul L. Powell, Abby N. Grand, J. Barry Moran, Christine L. 0
Keywords: Breeding Season; Somateria mollissima; Productivity; Population Dynamics; Survival; SDJV funded; Common eider

Concentrations of metals and trace elements in blood of spectacled and king eiders in northern Alaska, USA - Wilson, Heather M.; Petersen, Margaret R.; Troy, Declan (Environmental Toxicology and Chemistry, 2004)
In 1996, we measured concentrations of arsenic, barium, cadmium, lead, mercury, and selenium in blood of adult king (Somateria spectabilis) and spectacled (Somateria fischeri) eiders and duckling spectacled eiders from northern Alaska, USA. Concentrations of selenium exceeded background levels in all adults sampled and 9 of 12 ducklings. Mercury was detected in all adult spectacled eiders and 5 of 12 ducklings. Lead concentrations were above the clinical toxicity threshold in one duckling (0.64 ppm) and two adult female spectacled eiders (0.54 and 4.30 ppm). Concentrations of cadmium and mercury varied between species; barium, cadmium, mercury, and selenium varied between sexes. In female spectacled eiders, mercury concentrations increased during the breeding season and barium and selenium levels decreased through the breeding season. Selenium declined at 2.3 +- 0.9% per day and levels were lower in spectacled eiders arriving to the breeding grounds in northern Alaska than in western Alaska. The variation in selenium levels between breeding areas may be explained by differences in timing and routes of spring migration. Most trace elements for which we tested were not at levels currently considered toxic to marine birds. However, the presence of mercury and elevated lead in ducklings and adult female spectacled eiders suggests these metals are available on the breeding grounds.
Keywords: Breeding Season; Somateria fischeri; Spectacled Eider; Contaminants; King Eider; Somateria spectabilis

Factors influencing trematode parasite burdens in mussels (Mytilus spp) from the north Atlantic ocean across to the north Pacific - Wilson, J. G.; Galaktionov, K. V.; Sukhotin, A. A.; Skirnisson, K.; Nikolaev, K. E.; Ivanov, M. I.; Bustnes, J. O.; Saville, D. H.; Regel, K. V. (Estuarine Coastal and Shelf Science, 2013)
Times Cited: 1 Wilson, J. G. Galaktionov, K. V. Sukhotin, A. A. Skirnisson, K. Nikolaev, K. E. Ivanov, M. I. Bustnes, J. O. Saville, D. H. Regel, K. V. 1 SI
Keywords: Parasites

Properties of Blood, Porphyrins, and Exposure to Legacy and Emerging Persistent Organic Pollutants in Surf Scoters (Melanitta perspicillata) Overwintering on the South Coast of British Columbia, Canada - Wilson, L. K.; Harris, M. L.; Trudeau, S.; Ikonomou, M. G.; Elliott, J. E. (Archives of Environmental Contamination and Toxicology, 2010)
The surf scoter (Melanitta perspicillata) is a little-studied species of North American sea duck. Estimates suggest it has experienced a precipitous decline in breeding numbers over the latter half of the past century. To investigate the potential role of contaminant uptake and toxicity in the population decline, this study undertook to measure blood chemistry, porphyrin concentrations, EROD, and organic contaminants in mature surf scoters wintering in the Strait of Georgia, BC, Canada. Hepatic organochlorine pesticide, polychlorinated dibenzo-p-dioxin, polychlorinated dibenzofuran, polychlorinated biphenyl (PCB), polybrominated diphenyl ether, and nonylphenol concentrations were relatively low; for example, I TEQs pound (toxic equivalents) for PCBs, dioxins, and furans combined ranged from 4.7 ng/kg wet weight in reference-site (Baynes Sound) birds to 11.4 ng/kg wet weight in birds from Vancouver Harbour. Nonetheless, elevated EROD activity indicated that birds in Howe Sound were responding to an Ah-receptor-mediated stressor, which was also affecting hematocrit values and possibly vitamin A status. In addition, a low proportion of lymphocytes in individuals across locations in early spring samples was associated with poor body condition. The apparent loss of fitness just prior to the onset of northerly migrations to breeding grounds is of particular concern. Compromised health of mature birds at this point in the season might impact negatively on the productivity and survival of some individuals, particularly those overwintering in Howe Sound.
Keywords: Nonbreeding Seasons; Melanitta perspicillata; Surf Scoter; Contaminants

Sex determination of duck embryos: observations on syrinx development - Wilson, R. E.; Sonsthagen, S. A.; Franson, J. C. (Avian Biology Research, 2013)
Times Cited: 0 Wilson, Robert E. Sonsthagen, Sarah A. Franson, J. Christian 0
Keywords: Techniques; Sea Ducks

Use of wood duck decoys in a study of brood parasitism - Wilson, Steven F. (Journal of Field Ornithology, 1993)
Plastic Wood Duck (Aix sponsa) hunting decoys were used to test the effect of conspecifics near simulated nests on nest site selection by brood parasitic females. Wood Duck and Common Goldeneye (Bucephala clangula) eggs were laid in simulated nests only when Wood Duck decoys were floating nearby (P lt 0.05). Two of the parasitized nests were later incubated. Decoys may be effective in simulating the presence of ducks in other behavioral studies involving waterfowl.
Keywords: Behavior; Breeding Season; Bucephala clangula; Common Goldeneye; Techniques

Inverted Flight of White-Winged Scoters Melanitta-Deglandi During Courtship Flight - Wilson, W. J. (American Birds, 1980)
Keywords: Behavior; Melanitta fusca; White-winged Scoter

Use of legs and feet for control by scoters during aerial courtship - Wilson, William J. (Wilson Journal of Ornithology, 2008)
Scoters (Melanitta spp.) exhibit extraordinary maneuvers during courtship flight. attitudes which are not commonly seen in flight. Scoters drop their legs and spread webbed feet these maneuvers There appears to be a correlation between how the feet of scoters meet the airflow and the maneuver in progress.
Keywords: Behavior; Melanitta fusca; White-winged Scoter; Melanitta perspicillata; Surf Scoter; Black Scoter; Melanitta nigra

Feeding ecology of the diving ducks pochard (Aythya fernia), tufted dick (A. fuligula), scaup (A. marila) and goldeneye (Bucephala clangula) overwintering on Lough Neagh, Northern Ireland - Winfield, Ian J.; Winfield, Denise K. (Freshwater Biology, 1994)
1. The diets of pochard (Aythya ferina), scaup (A. marila) and goldeneye (Bucephala clangula) overwintering on Lough Neagh are dominated by chironomid larvae, while molluscs are more important in that of tufted duck (A. fuligula). 2. Inshore areas of Lough Neagh offer poor feeding conditions for these diving ducks because chironomid larvae and molluscs are of small individual body size or low abundance. These factors lead to all four ducks foraging at least in part at depths greater than those usually exploited. 3. Due to their common consumption of molluscs, the diet of tufted duck shows a higher overlap with that of an introduced roach (Rutilus rutilus) population than with any other duck or fish species. 4. The feeding ecology of tufted duck and roach in Lough Neagh may form an example of distant competition and be at least partly responsible for recent fluctuations in the numbers of tufted duck.
Keywords: Nonbreeding Seasons; Bucephala clangula; Common Goldeneye; Trophic Interactions

The birds of St. Matthew Island, Bering Sea - Winker, Kevin; Gibson, Daniel D.; Sowls, Arthur L.; Lawhead, Brian E.; Martin, Philip D.; Hoberg, Eric P.; Causey, Douglas (Wilson Bulletin, 2002)
St. Matthew Island (60degree 24' N, 172degree 42' W) and its small nearby satellites, Hall Island and Pinnacle Rock, are isolated in the northcentral Bering Sea. This infrequently visited location occupies a geographic position with a deep Bering Land Bridge history and is in an area of interdigitation of the Old World, New World, and Beringian avifaunas. It is known for its three Beringian endemics, a bird (McKay's Bunting, Plectrophenax hyperboreus), a small mammal, and a plant. This level of endemism is striking for a high-latitude island. The only previous summary of the avifauna of St. Matthew island (Hanna 1917) included 37 species. Our report considers more than 125 species and synthesizes data on presence and absence, abundance, and phenology. Because visits have been infrequent and concentrated during summer, our understanding of migration in this region remains poor, but the area is clearly affected by both the Old and New world migration systems. There is sufficient evidence to show that some profound changes among the island's breeding birds have occurred during the past century. In particular, the breeding range of Glaucous-winged Gulls (Larus glaucescens) has been extended north to include St. Matthew, a change that is correlated with a northward shift in the extent of sea ice (Maslanik et al. 1996). King and Common eiders (Somateria spectabilis and S. mollissima) also have shown substantial changes in summer abundance. Other changes in the summer avifauna (e.g., among shorebirds) may reflect the dynamics of edge-of-range phenomena. Because of its central position in a region undergoing profound climate change and its demonstrated track record in showing avifaunal shifts, St. Matthew Island may represent an important bellwether for monitoring the biological effects of further climate change in the northern Bering Sea.
Keywords: Abundance, Distribution, and Trends; Common Eider; Sea Ducks - General; King Eider

Conjugations with Glutathione Distribution of Enz Glutathione S Aryl Transferase in Wild Birds Pheasant Coot Great Crested Grebe Goosander Eider Tufted Duck Common Gull - Wit, J. G. (European Journal of Pharmacology, 1968)
Keywords: Common Eider; Somateria mollissima; Physiology; Common merganser; Mergus merganser

Massive prey recruitment and the control of rocky subtidal communities on large spatial scales - Witman, J. D.; Genovese, S. J.; Bruno, J. F.; McLaughlin, J. W.; Pavlin, B. I. (Ecological Monographs, 2003)
Witman, JD Genovese, SJ Bruno, JF McLaughlin, JW Pavlin, BI

Arctic seabird food chains explored by fatty acid composition and stable isotopes in Kongsfjorden, Svalbard - Wold, A.; Jaeger, I.; Hop, H.; Gabrielsen, G. W.; Falk-Petersen, S. (Polar Biology, 2011)
Times Cited: 3 Wold, Anette Jaeger, Iris Hop, Haakon Gabrielsen, Geir Wing Falk-Petersen, Stig 3
Keywords: Breeding Season; Techniques; Trophic Interactions; Sea Ducks

Aggregative Response of Common Mergansers Mergus-Merganser Predicting Flock Size and Abundance on Vancouver Island Canada Salmon Streams - Wood, C. C. (Canadian Journal of Fisheries and Aquatic Sciences, 1985)
The abundance of common mergansers (M. merganser) was monitored on 4 salmon-producing streams on the east coast of Vancouver Island, British Columbia, during the spring and summer of 1980-1983. Merganser abundance declined steadily from March-June but increased following recruitment of juvenile birds. Mergansers congregated on streams where juvenile salmonid migrations were enhanced by hatcheries or spawning channels. Movement between streams was evident from inverse trends in abundance on 3 adjacent streams differing in juvenile salmonid production. At least 8 of 12 mergansers resighted after being marked and released on the Big Qualicum River visited other nearby streams. Flock-size distributions predicted by an equilibrium arrival-departure model were consistent with those observed during May-mid-June, but not those during late June. Social interactions and reduced flight activity appeared to influence dispersion to a greater extent during late June-Aug. so that assumptions of the model were violated. A similar model was used to predict aggregation patterns on hatchery streams from observed relationships between fish availability and frequencies of arrival and departure. The aggregation model provides a parsimonious explanation of merganser aggregation patterns during March-June and is a potentially useful tool for designing fish release schedules to minimize predation by mergansers.
Keywords: Breeding Season; Abundance, Distribution, and Trends; Common merganser; Mergus merganser

Food-Searching Behavior of the Common Merganser Mergus-Merganser Ii. Choice of Foraging Location - Wood, C. C. (Canadian Journal of Zoology, 1985)
Factors influencing the choice of foraging location by the common merganser (Mergus merganser) were investigated by baiting three adjacent, enclosed sections of a natural stream with various densities of juvenile coho salmon (Oncorhynchus kisutch). Merganser abundance within 1 km of the enclosure site increased from < 3 to > 10 birds within 1 week of stocking the enclosures with 43-g coho smolt. Although abundance declined gradually thereafter (as expected from seasonal trends on other nearby streams), the frequency of visits to the enclosure site continued to increase for 22 d until the enclosures were stocked predominately with smaller (2-g) coho fry. Visits were more frequent when other mergansers were already present at the site. Also, the proportion of mergansers flying overhead that landed near a decoy "flock" increased with decoy flock size. In general, the duration of visits to the site was not affected by the number of birds present. Visit duration increased exponentially with increasing fish density and decreased with searching time required until first capture. Mergansers spent more time searching in the most profitable enclosure. Allocation of searching time among the enclosures was not consistent with a "giving up time" decision rule; however, mergansers appeared to follow an area-restricted search pattern both within and among the enclosures.
Keywords: Behavior; Trophic Interactions; Common merganser; Mergus merganser

Dispersion of Common Merganser Mergus-Merganser Breeding Pairs in Relation to the Availability of Juvenile Pacific Salmon Oncorhynchus-Sp in Vancouver Island Streams Canada - Wood, C. C. (Canadian Journal of Zoology, 1986)
Common merganser (Mergus merganser) breeding pairs and broods were censused on eight coastal streams on Vancouver Island to evaluate the relative importance of the number of potential breeding pairs, stream size, and the availability of juvenile Pacific salmon in limiting merganser breeding density. The number of potential breeding pairs did not limit nesting density on at least one stream where juvenile salmon populations were enhanced by a hatchery and spawning channel. At distances > 1 km above tidal influence, breeding pairs were evenly dispersed along the streams during the peak egg-laying and incubation period at maximum densities of 0.4-1.4 pairs/km. Maximum breeding pair counts were higher and more variable among streams on the lower kilometer of freshwater (1-9 pairs) and on tidal waters near the stream outlets (4-9 pairs). Stream size accounted for only a part of the variation in breeding pair counts. The estimated number of broods produced on each stream was highly correlated (r = 0.95) with both drainage area and juvenile salmon production, including production from hatcheries. Possible mechanism relating the dispersion of breeding pairs to the availability of juvenile salmon are discussed. A "food assessment" hypothesis, whereby breeding pairs chose a nesting stream on the basis of prey availability during the nesting season, could not be rejected on the basis of predictions about hatching dates and duckling survival. This hypothesis has serious implications for mortality of wild salmonids in hatchery-enhanced streams.
Keywords: Breeding Season; Abundance, Distribution, and Trends; Common merganser; Mergus merganser; Habitat

Predation of Juvenile Pacific Salmon by the Common Merganser Mergus-Merganser on Eastern Vancouver Island Canada I. Predation During the Seaward Migration - Wood, C. C. (Canadian Journal of Fisheries and Aquatic Sciences, 1987)
Predation of juvenile salmonids by the common merganser (Mergus merganser) was investigated during the period of seaward migration in two streams where fish populations are enhanced by spawning channels and hatcheries. Observations of foraging behaviour and crop-gullet content indicated that, during this period, mergansers foraging on freshwater reaches of the streams ate juvenile salmonids almost exclusively whereas those foraging on tidal waters rarely ate salmonids. Maximum rates of salmonid mortality were estimated by assessing merganser abundance and the pattern of foraging activity on fresh versus tidal waters. Maximum mortality rate declined as fish abundance increased (i.e. mortality was depensatory) in all cases where the effects of prey size-selection could be ignored owing to an overwhelming abundance of one prey species. Bounds on maximum mortality rate by species for the entire migration period were computed under different hypotheses about the prey size-selection habits of mergansers; maximum mortality rate did not exceed 10% for any salmonid species over the entire seaward migration.
Keywords: Trophic Interactions; Common merganser; Mergus merganser

Predation of Juvenile Pacific Salmon by the Common Merganser Mergus-Merganser on Eastern Vancouver Island Canada Ii. Predation of Stream-Resident Juvenile Salmon by Merganser Broods - Wood, C. C. (Canadian Journal of Fisheries and Aquatic Sciences, 1987)
Predation of stream-resident juvenile salmonids by broods of the common merganser (Mergus merganser) was investigated in three streams of eastern Vancouver Island from 1980 to 1982. Daily fish consumption by merganser ducklings was estimated to range from 80% of body weight for ducklings at 10 d of age to 40% of body weight for those at 40 d of age. Merganser ducklings were never observed to eat juvenile salmonids on tidal waters, but did eat them on the freshwater reaches of streams studied. Typically, broods inhabited only the freshwater reaches of their natal stream while young, but spent progressively more time foraging on tidal waters as they grew older. The biomass of broods (and hence potential consumption) on fresh water was estimated by reconstructing the history of individual broods from census data. These results suggest that merganser broods consumed on the order of 82,000-131,000 coho salmon (Oncorhynchus kisutch) fry in the Big Qualicum River between June 10 and August 25. This is equivalent to 24-65% of the observed wild smolt production from this system, assuming that these fry would otherwise have survived as well as uneaten fry.
Keywords: Breeding Season; Trophic Interactions; Common merganser; Mergus merganser

Food-Searching Behavior of the Common Merganser Mergus-Merganser I. Functional Responses to Prey and Predator Density - Wood, C. C.; Hand, C. M. (Canadian Journal of Zoology, 1985)
The hunting performance of the common merganser (Mergus merganser) was evaluated in relation to prey density and merganser flock size by stocking three enclosed sections of a natural stream with known densities of juvenile coho salmon (Oncorhynchus kisutch). Two size classes of coho were stocked: smolt averaging 43 g at densities of 0.02-0.65/m2, fry averaging 2 g at 0.08-1.6/m2 and various mixtures of smolt and fry at a combined density of 0.65/m2. The stream enclosures differed in the amount of cover available to fish. Mergansers were less successful at capturing coho smolt or fry in the enclosures with cover from undercut banks. Smolt exposed to mergansers earlier that day were less vulnerable than smolt with no previous exposure. The feeding success of individual mergansers was not significantly affected by flock size for flocks of 25 birds or less. A smoothly asymptotic functional response (type II) was observed under all experimental conditions. Coho smolt were selected over coho fry. It is concluded that a merganser's average daily food requirement (ca. 400 g) can be satisfied at smolt densities of 0.02-0.30/m2 depending on the availability of cover for smolt and their previous exposure to mergansers.
Keywords: Behavior; Trophic Interactions; Common merganser; Mergus merganser

Long-term trends in the survival rates of adult female Common Eider Somateria mollissima at three colonies in Iceland - Wood, K. A.; Thorstensen, S.; Ludviksson, S. J.; Brides, K.; Petersen, A. (IBIS, 2021)
Identifying temporal and spatial patterns in demography is critical to understanding long-term fluctuations in population size. Common Eider Somateria mollissima numbers have shown a long-term decline, resulting in the species being uplisted in 2015 to 'Endangered' within European Union countries. Obtaining improved estimates of survival rates of Common Eiders (and other seaducks) has been identified as a priority to improve our understanding of the demographic causes of the observed global decreases in population size and to inform conservation efforts. In this study, we used long-term (1982-2017) mark-recovery data on 3018 individuals from three breeding colonies in Iceland to quantify the spatial and temporal variation in the annual true survival rates of adult female Common Eider. Model comparison using an information-theoretic approach indicated that true survival and recovery rates varied between years and colonies but showed no consistent temporal pattern across the three colonies. Geometric mean (+/- se) annual true survival across our three breeding colonies was 0.916 +/- 0.017 (95% confidence interval (CI) = 0.819-0.961), with a mean life expectancy of 11.8 years (95% CI 5.4-25.2). Our survival estimates were relatively high compared with those reported previously for many other Common Eider populations, which may reflect their protected status, low predation pressure and high food availability on Iceland and its surrounding waters. Our findings provide spatially and temporally explicit demographic information needed to help conservationists understand the local and global declines in Common Eider populations.
Times Cited in Web of Science Core Collection: 3 Total Times Cited: 3 Cited Reference Count: 81
Keywords: demography; BIRDS; ECOLOGY; MASS MORTALITY; POPULATIONS; DIET; MODEL SELECTION; NUMBERS; seaducks; FISHERIES; DENSITY; life history; mark–; recovery data; TIME; true survival probability; vital rates

INDIRECT EFFECTS, PREY SUSCEPTIBILITY, AND HABITAT SELECTION - IMPACTS OF BIRDS ON LIMPETS AND ALGAE - Wootton, J. T. (Ecology, 1992)
WOOTTON, JT

Effects of birds on sea urchins and algae: A lower-intertidal trophic cascade - Wootton, J. T. (Ecoscience, 1995)
Wootton, JT

Estimates and tests of per capita interaction strength: Diet, abundance, and impact of intertidally foraging birds - Wootton, J. T. (Ecological Monographs, 1997)
Wootton, JT

Seasonal Fluctuations and Movements of the Common Eider Somateria-Mollissima at the Norwegian Skagerrak Coast - Wranes, E. (Fauna Norvegica Series C Cinclus, 1982)
Population censuses within an area .apprx. 10 km east of Kristiansand, south Norway, from 1970 to 1973, and ringing recoveries, show that the eiders migrate from their breeding areas to molt and winter in Danish waters. Aerial counts show that the same seasonal population fluctuations seem to occur on the entire Skagerak coast. After molting in the Kattegat area, most of the eiders remain in Danish waters until Feb.-March before returning. The majority of the autumn and winter population of the Skagerak coast probably consists of the local breeders.
Keywords: Abundance, Distribution, and Trends; Common Eider; Nonbreeding Seasons; Molt; Somateria mollissima; Dispersal

Evidence of spring staging and migration route of individual breeding harlequin ducks, Histrionicus histrionicus, in Southern British Columbia - Wright, Kenneth G.; Robertson, Gregory J.; Goudie, R. Ian (Canadian Field-Naturalist, 1998)
An individually marked pair of Harlequin Ducks (Histrionicus histrionicus) were observed on moulting and spring staging and the male also on breeding grounds in southern British Columbia.
Keywords: Nonbreeding Seasons; Harlequin duck; Histrionicus histrionicus; Migration

The distribution, phenology, and prey of Harlequin Ducks, Histrionicus histrionicus, in a Cascade Mountain stream, Oregon - Wright, Kristopher K.; Bruner, Howard; Li, Judith L.; Jarvis, Robert; Dowlan, Steve (Canadian Field-Naturalist, 2000)
We examined the phenology, abundance, and in-stream habitat use of Harlequin Ducks (Histrionicus histrionicus) and their primary prey, the caddisfly larvae Dicosmoecus gilvipes, in a Cascade Mountain stream from 1994-1997. Harlequins and D. gilvipes inhabited the stream from late April through late July, and both frequented areas with high proportions of bedrock. When broods were present in late June and July, D. gilvipes made up over 80% of harlequin diets. Although harlequins foraged intensively on D. gilvipes, we found no direct relationship between harlequin distribution and caddisfly abundance at nine 50 m study sites. After a severe flood in early 1996, we observed reductions in overall harlequin numbers, a seasonal delay in brood development, and a decrease in abundance of D. gilvipes.
Keywords: Breeding Season; Abundance, Distribution, and Trends; Harlequin duck; Histrionicus histrionicus; Trophic Interactions

Biostrome communities and mercury and selenium bioaccumulation in the Great Salt Lake (Utah, USA) - Wurtsbaugh, W. A.; Gardberg, J.; Izdepski, C. (Science of the Total Environment, 2011)
Times Cited: 0 Wurtsbaugh, Wayne A. Gardberg, Jodi Izdepski, Caleb Wurtsbaugh, Wayne/G-6856-2011; Schneider, Larissa/C-9863-2012 0
Keywords: contaminants; Nonbreeding Seasons; Sea Ducks

Alert time reflects the negative impacts of human disturbance on an endangered bird species in Changbai Mountain, China - Xu, W. Y.; Gong, Y.; Wang, H. T. (GLOBAL ECOLOGY AND CONSERVATION, 2021)
Human proximity often has negative consequences for wildlife. In response to human disturbance, animals may display a variety of potentially costly behavioural responses, such as vigilance or flight, which were often used as measures of fearfulness and to indicate varying habituation levels. With rapid human development, the globally endangered Scaly-sided Merganser (Mergus squamatus) may be vulnerable to anthropogenic interference. However, human-induced disturbances to a local breeding population have not been quantified. In this study, we tested how flight initiation distance (FID) and behavioural budget (alert time (AT) in particular) changes in relation to human presence in this species in Changbai Mountain, China. The results showed that individuals who experienced greater levels of human disturbance had shorter FIDs, which indicate that the local population may be habituated to human approach. However, this species spent more time being vigilant in its behavioral budget, which suggested that some other human-induced stimuli may impose negative effects on the species. This study will allow managers to better understand the response of this endangered species to different human-induced disturbances and provided scientific basis for local wildlife managers to establish buffer distance for SSME in Changbai Mountain.
Times Cited in Web of Science Core Collection: 4 Total Times Cited: 5 Cited Reference Count: 71
Keywords: SIZE; BEHAVIORAL-RESPONSES; PREDATION RISK; FLIGHT INITIATION DISTANCE; Mergus squamatus; COMMON; Endangered species; TOLERANCE; Behavioural response; Habituation; Human disturbance; NOISE; TRADE-OFF; VIGILANCE

Assessing abiotic correlations of an indicator species with sympatric riparian birds in a threatened submontane river-forest system using joint species modelling - Xu, W. Y.; Gong, Y.; Wang, L.; Yao, J. Y.; Wang, H. T. (DIVERSITY AND DISTRIBUTIONS, 2023)
Aim: To assess the abiotic correlations between indicator species and others in the community. Additionally, we evaluated the importance of environmental variables in driving the co-occurrence patterns of the coexisting riparian bird species within a threatened aquatic and terrestrial system. Location: Seven classic submontane rivers in riparian ecosystems of the Changbai Mountains in eastern Jilin Province, China, elevation ranging from 351 to 942 m. Methods: Joint species distribution models (JSDMs) were applied to examine the relative importance of abiotic and potential species associations driving the abundance and cooccurrence of bird species along submontane riparian zones. The abiotic factors were examined with a focus on the scaly-sided Merganser and the coexisting bird species potentially sharing or interacting within the same niche. Results: We found that the co-occurrence patterns of submontane riparian bird species were dominantly driven by numerous positive correlations when incorporating abiotic variables. The scaly-sided Merganser exhibited the greatest number of correlations with other species and exhibited significant responses to most of the measured environmental variables. Land cover diversity, proportion of gravel bars, and channel width were the most common environmental factors affecting riparian bird species distribution. Conclusions: Using JSDM, we found that the indicator roles of the scaly-sided Merganser are mainly derived from shared environmental responses with coexisting riparian bird species; moreover, the composition of submontane riparian bird communities is affected by both environmental variables and potential species associations. Our results verified the central role of the scaly-sided Merganser as an indicator species in submontane riparian ecosystems due to their strict physical environment preferences and extensive connections with other sympatric riparian bird species, primarily through shared environmental intersections. Our results emphasize the crucial necessity for simultaneously considering environmental predictors and potential species associations in modelling species distributions and to better realizing the roles of indicators in practical applications.
Times Cited in Web of Science Core Collection: 0 Total Times Cited: 0 Cited Reference Count: 50
Keywords: COMMUNITIES; RESPONSES; MANAGEMENT; DIVERSITY; HABITAT SELECTION; ASSEMBLAGES; biological interactions; BREEDING-SEASON; indicator species; joint species distribution models; riparian habitat; scaly-sided Merganser; VEGETATION; WOODPECKERS

Modelling suitable breeding habitat and GAP analysis for the endangered Scaly-sided Merganser Mergus squamatus: implications for conservation - Xu, W. Y.; Solovyeva, D.; Vartanyan, S.; Zheng, H. F.; Pronkevich, V.; Gong, Y.; Wang, H. T. (BIRD CONSERVATION INTERNATIONAL, 2021)
The Scaly-sided Merganser Mergus squamatus is a globally 'Endangered' species breeding in north-east Asia. Limited by information on the geographic distribution of suitable habitat, the conservation management programme has not been comprehensive or spatially explicit for the breeding population. This study combines potentially important environmental variables with extensive data on species occurrence to create the first species distribution model for the breeding Scaly-sided Merganser, followed by a GAP analysis to highlight the unprotected areas containing suitable habitat. The predictive map showing the most suitable breeding habitat for the Scaly-sided Merganser covered broad-leaved deciduous forest distributed in six provincial regions in south-east Russia, north-east China, and North Korea. The conservation GAP, i.e. 90% (38,813 km(2)) of highly suitable habitat, is mainly concentrated in the Sikhote-Alin and Changbai mountain ranges. This study suggests that prioritizing conservation of unprotected broad-leaved deciduous riverine forests within the above two mountainous regions should be included in international conservation planning, and the remaining suitable patches need to be preserved to allow range expansion in future. This predictive map improves the expert global assessment of breeding Scaly-sided Merganser distribution and provides a basic reference for establishing conservation areas or implementing conservation actions for the breeding Scaly-sided Merganser in north-east Asia.
Times Cited in Web of Science Core Collection: 0 Total Times Cited: 0 Cited Reference Count: 58
Keywords: WETLANDS; DUCKS; PATTERNS; IMPACTS; Mergus squamatus; NESTING BIRDS; AVAILABILITY; breeding habitat suitability; GAP analysis; habitat distribution; RANGE; RESOURCE; UNCERTAINTIES

The indicator roles of endangered scaly sided merganser (Mergus squamatus) in submontane rivers of Changbai Mountains, China - Xu, W. Y.; Wang, L.; Gong, Y.; Wang, H. T. (ECOLOGICAL INDICATORS, 2021)
Submontane sections of riparian forest habitats are potential focal points of biodiversity but are often the least conserved units of riparian habitats. This is especially concerning in the Northeast Forest Region of China, which has undergone drastic deforestation and river alteration. Effective evaluation and supervision of the suitability of riparian forest habitat and species richness are labor- and time-consuming and could be compensated by using indicator species. In this work, we verified whether the endangered Scaly-sided merganser (SSME) can be used as a qualified indicator of the habitat characteristics and biodiversity of submontane river valleys in the Changbai Mountains area of China. Environmental variables and the richness of riparian species were compared between the river sections settled and unsettled by the SSME. Breeding SSME occurred in river sections with wider channels, larger gravel bars, greater coverage of riverine forests and showed a more concentric inhabitation pattern in wider, deeper, more sinuous and forested riparian habitats. In addition, the probability of occurrence and abundance of the SSME was positively correlated with the species richness of birds, fish and macroinvertebrates as well as the total mass of sampled fish. The correlation of the SSME with the richness of riparian animals and featured riparian habitats and its high public attention profile make it a good candidate for an umbrella and flagship species, which could be an especially valuable surrogate for the protection and monitoring of the habitats and species in the Changbai Mountains area and, probably, other habitats in Northeast Asia. This study adds to the evidence supporting the effectiveness of piscivorous species in indicator roles, suggesting that the indicator roles of mergansers and other fish-eating species deserve verification to complementarily assess important habitats that are difficult to monitor by other means in riparian ecosystems.
Times Cited in Web of Science Core Collection: 3 Total Times Cited: 3 Cited Reference Count: 82
Keywords: CONSERVATION; ECOLOGY; MODEL SELECTION; Mergus squamatus; AREAS; ECOSYSTEM; BIODIVERSITY; BIRD ASSEMBLAGES; Breeding habitats; Changbai Mountains; FORESTS; PERSPECTIVE; PREDATORS; River valleys; Riverine forest

Predation by diving ducks on the biofouling mussel Musculista senhousia in a eutrophic estuarine lagoon - Yamamuro, M.; Oka, N.; Hiratsuka, J. (Marine Ecology Progress Series, 1998)
Yamamuro, M Oka, N Hiratsuka, J

Hemolytic anemia in wild seaducks caused by marine oil pollution - Yamato, Osamu; Goto, Ikuo; Maede, Yoshimitsu (Journal of Wildlife Diseases, 1996)
Clinico-pathological examinations were conducted on wild white-winged scoters (Melanitta fusca) contaminated with fuel oil (Bunker C oil) from a capsized cargo ship in February 1993 in Japan. The erythrocyte count, hemoglobin concentration and hematocrit value in the oiled seaducks all were decreased and numerous immature erythrocytes were observed in blood smears. In addition, hemosiderosis was observed in the liver, kidney, and lung of some birds. We propose that the seaducks suffered from hemolytic anemia induced by ingestion of oil, which occurs when the birds preen their oiled plumage.
Keywords: Melanitta fusca; Nonbreeding Seasons; White-winged Scoter; Contaminants

Diving and Foraging in the Common Eider - Ydenberg, R.; Guillemette, M. (Ornis Scandinavica, 1991)
We recorded the duration of successive dives and pauses during sequences of foraging by wintering Common Eiders Somateria mollissima in the Gulf of St. Lawrence (Quebec, Canada). The length of each pause on the surface between dives increases at an increasing rate with the length of the preceding dive. Based on this relationship, the deviation from the estimated surface time (DEVEST, for short) was computed for each dive. DEVEST is positively correlated over short series of dive-cycles. The significance of these results is discussed and compared with an earlier study on Western Grebes Aechmophorus occidentalis.
Keywords: Behavior; Common Eider; Nonbreeding Seasons; Somateria mollissima

Steller's eider Polysticta stelleri nesting between the Taimyr and the Yamal Peninsulas, Siberia - Yesou, Pierre; Lappo, Helena G. (Alauda, 1992)
Steller's Eider Polysticta stelleri have been found breeding, at a very low density and probably on a regular basis, on the Taimyr, Gydan and Yamal peninsulas, regions which were long thought to be outside this species' breeding range. Whether these discoveries are indicative of a true westward range extension in uncertain, they may simple be due to a recent improvement in the knowledge of the avifauna of these areas. We include information on the breeding habitat, clutch size and egg size, and give an improved description of the recently hatched duckling.
Keywords: Breeding Season; Abundance, Distribution, and Trends; Polysticta stelleri; Steller's eider

Weights of 10 Species of Ducks Captured at Ohtig Lake Alaska August 1962 - Yocom, C. F. (Murrelet, 1970)
Keywords: Sea Ducks - General; Nonbreeding Seasons; Molt; Energetics and Nutrition

Costs and Benefits to Red-Breasted Mergansers Nesting in Tern and Gull Colonies - Young, A. D.; Titman, R. D. (Canadian Journal of Zoology, 1986)
The costs and benefits to Red-breasted Mergansers (Mergus serrator) nesting in a Common Tern (Sterna hirundo) colony and a Herring Gull (Larus argentatus) and Great Black-backed Gull (L. marinus) colony were studied from 5 June to 17 August 1984 on islands off the east coast of New Brunswick [Canada] Merganser nests outside larid colonies were preyed upon significantly more than nests in the tern colony while no difference was found with nests in the gull colony. Nests in the tern colony were more densely concentrated and more likely to be abandoned. Clumped nests in the tern colony were not initiated in greater synchrony than dispersed nests. The merganser-gull nesting association is discussed. We postulate that the protective benefit for merganser nests in tern colonies accounts for the evolution of the nesting association.
Keywords: Breeding Season; Productivity; Habitat; Mergus serrator; Red-breasted merganser

Intraspecific Nest Parasitism in Red-Breasted Mergansers - Young, A. D.; Titman, R. D. (Canadian Journal of Zoology, 1988)
We studied intraspecific nest parasitism in an island nesting population of Red-breasted Mergansers (Mergus serrator) in New Brunswick [Canada]. Of the nests examined, 64% contained eggs from more than one female. This estimate is probably low because the criteria to detect parasitism were conservative. Parasitized nests were initiated, on average, 3 days earlier than normal nests. Parasitic laying occurred throughout the nesting season. A larger proportion of egg hatched from normal (89%) than from parasitized (75%) nests because 14% of the eggs in parasitized nests were laid during the host's incubation period and failed to hatch in time. A greater percentage of eggs hatched from parasitized nests during the peak nesting period. Parasitized and normal nests produced the same number of ducklings. There was no difference in the percentage of dead, infertile, and lost eggs from normal compared to parasitized nests. The number of nests containing at least one dead egg increased with clutch size. Most host females accepted parasitic eggs during incubation without deserting. Incubation was prolonged on parasitized nests and on nests with low synchronization of embryo development. Nest parasitism is a common reproductive tactic in at least some female Red-breasted Mergansers.
Keywords: Behavior; Breeding Season; Mergus serrator; Red-breasted merganser

Autumn waterbird migration over Lake Superior: Numbers, species, and timing - Youngman, J. A.; Flaspohler, D. J.; Knowlton, J. L.; Dombroski, L. J. (JOURNAL OF GREAT LAKES RESEARCH, 2017)
The Great Lakes are used as a migratory corridor and for feeding by tens of thousands of waterbirds each spring and fall, yet little species-specific information is available regarding numbers, seasonal timing, and connectivity along the route. The objective of this study was to use land-based surveys to quantify fall migration at two important landmarks in Lake Superior for an assemblage of waterbirds from three orders (Anseriformes, Gaviiformes, and Podicipediformes). Both the Keweenaw Peninsula (KP) and Whitefish Point (WP) showed a temporal pattern of high numbers (peaking at 9000 and 16,000, respectively) in the first 3 h after dawn and a decline (dropping to 1000 and 5000, respectively) over the following 5 h, although the decline was far more abrupt at KP than at WP. Fall totals for WP were nearly 85,000 individual waterbirds, and for KP about 34,500. Species abundance rankings were generally similar for both locations, with the most common species being long-tailed duck (Clangula hyemalis), red-necked grebe (Podiceps grisegena), greater scaup (Aythya marila), and red-breasted merganser (Mergus serrator). Most species were far more numerous at WP than at KP, with long-tailed ducks being 65 times more numerous. A notable exception was redhead (Aythya americana), which was 33% more numerous at KP than at WP. We suggest that during the fall, Lake Superior acts as a geographic funnel concentrating waterbirds from northwest to southeast and that details of the composition, timing and amplitude of this phenomenon are important considerations for any nearshore Great Lakes development. (C) 2017 International Association for Great Lakes Research. Published by Elsevier B.V. All rights reserved.
Times Cited in Web of Science Core Collection: 1 Total Times Cited: 1 Cited Reference Count: 30
Keywords: BIRDS; Sea duck; GREAT-LAKES; Great Lakes; Keweenaw Peninsula; Loon; Red-necked grebe; Whitefish Point

Zinc toxicosis in diving ducks - Zdziarski, Jacqueline M.; Mattix, Mark; Bush, R. Mitchell; Montali, Richard J. (Journal of Zoo and Wildlife Medicine, 1994)
Zinc toxicosis was diagnosed in four species of diving ducks associated with the ingestion of pennies and fence clips containing zinc. Clinical signs included weight loss, depression, anorexia, and posterior paresis. A presumptive diagnosis of zinc toxicosis was made in one Bahama pintail (Anas bahamensis bahamensis) and two redhead ducks (Aythya americana) that had ingested metal fence clips. Diagnosis was based on complete recovery of the ducks after endoscopic removal of the clips, which contained 96% zinc. Assays for zinc and other minerals were performed on four Barrow's goldeneyes (Bucephala islandica) that died and one American merganser (Mergus merganser americanus) survivor. All of the animals had ingested one or two pennies. Two of four goldeneyes, from which serum was available, had elevated zinc concentrations of 12.6 and 13.1 mu-g/ml (normal range, 1.84-4.65 mu-g/ml, n = 8); all four goldeneyes had liver zinc concentrations ranging from 242 to 548 mu-g/g (normal, 35.9 mu-g/g, wet weight basis, n = 1). The American merganser from which a penny was removed endoscopically from the gizzard had an elevated serum zinc concentration of 16.6 mu-g/ml. Pertinent pathologic findings in the four goldeneyes included necrotizing ventriculitis. Pennies in various stages of dissolution were present in the ventriculus. The pancreas had degenerative lesions that resulted in acinar atrophy and ductular proliferation.
Keywords: Contaminants; Common merganser; Mergus merganser; Barrow's Goldeneye; Bucephala islandica

Impact of a dam on wintering waterbirds' habitat use - Zeng, Q.; Lu, C.; Li, G.; Guo, Z. B.; Wen, L.; Lei, G. C. (ENVIRONMENTAL CONSERVATION, 2018)
The degradation, alteration and depletion of riparian habitats caused by river regulation are among critical conservation concerns. Aquatic and riparian habitats support not only river-dwelling biota such as macroinvertebrates and fish, but also waterbirds, the top predators in the aquatic food web. Despite the intimate relationships between fish and waterbirds, the two groups are often investigated separately. Using an integrative approach, we examined the effects of dams on fish and scaly-sided merganser (Mergus squamatus), an endangered, iconic riverine species, where the lack of knowledge about habitat preferences greatly hampers long-term conservation efforts. Our analysis quantified three causal links: (1) water depth had direct, comparable, negative effects on both fish and waterbirds, and the path coefficients for fish and birds are -0.31 and -0.46, respectively; (2) river landscape heterogeneity directly and positively affected fish and waterbirds, and the path coefficients for fish and birds are 0.63 and 0.19, respectively; and (3) depth and river landscape also exerted indirect effects on waterbirds through their impacts on fish abundance, and the path coefficients for fish and birds are -0.15 and 0.28, respectively. Our findings could contribute to the rational spatial planning and sustainable operation of dams in that maintaining instream habitat availability and heterogeneity would benefit the whole riverine ecosystem.
Times Cited in Web of Science Core Collection: 5 Total Times Cited: 6 Cited Reference Count: 51
Keywords: ABUNDANCE; habitat; BEHAVIOR; RESPONSES; FOOD; PREY; RIVER; THREATS; BIODIVERSITY; dam; REMOVAL; river ecosystem; scaly-sided merganser; STREAMS; waterbird

Contribution of citizen science towards cryptic species census: "many eyes" define wintering range of the Scaly-sided Merganser in mainland China - Zeng, Q.; Wei, Q.; Lei, G. C. (AVIAN RESEARCH, 2018)
Background: Citizen science has tremendous potential in advancing scientific knowledge and improving natural resource management. To detect the wintering distribution of the endangered species Scaly-sided Merganser (Mergus squamatus), national wintering surveys were organized by China Birdwatching Association. Methods: The surveys of M. squamatus were conducted in three successive winters from 2014 to 2016. A total of 2019 people from 102 organizations participated in the surveys. With three groups of 13 environmental variables, species distribution model for its wintering distribution of each year was developed using random forest. Schoener's D index was used to compare the distribution of M. squamatus in 3 years. Results: Totally, 441, 634 and 1138 individuals of M. squamatus were recorded in 2014, 2015 and 2016 respectively. Two main sites in Dabie Mountain and East Qinling mountains were verified and the wintering range of M. squamatus was defined. The wintering range was found to be highly identical for the 3 years. Conclusions: The highly overlapped distribution range among years suggested that the wintering range of M. squamatus was relatively stable. Well organized and coordinated citizen science can be used to define distribution range and improve species conservation.
Times Cited in Web of Science Core Collection: 8 Total Times Cited: 11 Cited Reference Count: 52
Keywords: Citizen science; ABUNDANCE; PATTERNS; CONSERVATION; Mergus squamatus; MERGUS-SQUAMATUS; BIODIVERSITY; ATLAS; BREEDING BIRD SURVEY; DATA-INTENSIVE SCIENCE; Random forest; REGRESSION; Wintering distribution

Population Size and Sex Ratio of Wintering Scaly-Sided Merganser Mergus squamatus in the Poyang Lake Water System, Jiangxi Province, China - Zhi, Y. J.; Shao, M. Q. (PAKISTAN JOURNAL OF ZOOLOGY, 2019)
The line transect method was used to examine the population size and sex ratio of the scaly-sided merganser Mergus squamatus (the merganser) in four rivers of the Poyang Lake water system, Jiangxi province, China. Spatial and temporal variations in population size were ascertained for this endangered species. The Xiuhe, Fuhe and Raohe river systems exhibited large steady populations, with the maximum size ranging from 25 to 68 individuals for each river. Restoration and maintenance of suitable habitats for the scaly-sided merganser is imminent as the species is at risk of extinction due to its small population size. The total sex ratio of the merganser during the study period was 0.397 (n = 790) and the average sex ratio was 0.43 +/- 0.26 (n = 148) for each group, similar to the results obtained in previous years in Jiangxi province (0.378-0.4588). These data indicate that the wintering sex ratio of the merganser has been relatively steady over this period. The current results also revealed temporal and spatial variation in the sex ratio of mergansers, which is common among other duck species. The lower sex ratio in Xiuhe River indicated that the population in this river may include more sub-adults. Long-term data should be collected to test whether female mergansers are more likely to migrate north. The sex ratio of the merganser exhibited a tendency to decrease gradually from the early to late stages in each river, although only the Raohe River exhibited a significant difference among three stages, possibly due to differences in sexual migration time and mortality. We did not detect significant differences in the sex ratio of the scaly-sided merganser among different group sizes.
Times Cited in Web of Science Core Collection: 1 Total Times Cited: 1 Cited Reference Count: 26
Keywords: Mergus squamatus; Scaly-sided merganser; Population size; Poyang Lake water system; Sex ratio

Renesting by a Common Goldeneye - Zicus, M. C. (Journal of Field Ornithology, 1990)
Although renesting occurs in most North American waterfowl tribes, reports for the Mergini are mostly speculative and renesting by Common Goldeneyes (Bucephala clangula) has not been confirmed previously. A female goldeneye that abandoned a clutch of seven eggs while laying began laying a second clutch within a maximum of 19 d and successfully hatched it. Renesting is probably infrequent in Common Goldeneyes. Successful renesting requires a minimum of 6-7 additional weeks from renest initiation to hatch, but the nesting season is comparatively short across the breeding range. Lowered survival of late hatched young combined with a relatively low risk of nest predation may offer little advantage to renesting.
Keywords: Breeding Season; Bucephala clangula; Common Goldeneye; Productivity

Nesting Biology of Hooded Mergansers Using Nest Boxes - Zicus, M. C. (Journal of Wildlife Management, 1990)
I studied nesting by hooded mergansers (Lophodytes cucullatus) using nest boxes in an area of northcentral Minnesota having no previous nest box management. Boxes were scattered with a median density of about 0.8 boxes per km2, and from 39 to 87 nest boxes were examined yearly. Nearly half of the boxes contained merganser eggs each year; nest density was approximately 0.4 nests per km2. The proportion of nests that was incubated by mergansers did not vary among years and averaged 77.5 .+-. 2.8 (SE)%. In contrast, the proportion of merganser eggs laid that was incubated varied yearly (P < 0.001), ranging from 74.0 to 96.2%. Wood duck (Aix sponsa) and common goldeneye (Bucephala clangula) eggs also were found in some nests incubated by mergansers. Annual clutch size did not vary significantly and averaged 13.2 .+-. 0.5 (all eggs) and 13.0 .+-. 0.5 (merganser eggs). Nests left unincubated or incubated by goldeneyes or wood ducks contained fewer merganser eggs, on average, than those incubated by mergansers. From 63.7 to 100% of nests incubated by mergansers hatched depending on the year (P = 0.008) with predation being the controlling factor. Egg success did not vary annually, and a median of 94.7% of the merganser eggs in successful nests hatched each year. Proportions of all merganser eggs laid that hatched varied early (P < 0.001), ranging from 44.3 to 91.4%. Forty-five percent of incubated clutches contained > 13 eggs, and the average clutch size (13) exceeded that observed in other studies where nest box densities were greater. Most females changed nest sites in subsequent years; 9 of 13 movements were > 1.0 km. Intraspecific laying in a single nest was common and appeared to be related more to hooded merganser abundance than to nest box density and distribution.
Keywords: Breeding Season; Productivity; Hooded Merganser; Lophodytes cucullatus

Female hooded mergaser body mass during nesting - Zicus, Michael C. (Condor, 1997)
Body mass of female Hooded Mergansets (Lophodytes cucullatus) nesting in widely dispersed and newly erected wooden nest boxes in northcentral Minnesota was measured in 1982-1985. Median body mass during egg-laying was 635 g. Female mass during incubation varied significantly among years, but decreased monotonically at the same rate (1.0 g day-1) each year. Mass at the end of incubation (519-494 g) was 5.7 to 6.0% less than when incubation began. There was no indication that females having the greatest body mass began nesting earliest. However, females with the greatest body mass incubated the largest clutches and hatched the most young. Comparison of the observed body mass-clutch size relationship with one assumed to exist in the absence of intraspecific brood parasitism indicated that more parasitic eggs were laid in nests incubated by heavier females.
Keywords: Breeding Season; Energetics and Nutrition; Hooded Merganser; Lophodytes cucullatus

Undetected eggs: A waterfowl nest box survey problem? - Zicus, Michael C. (Canadian Field-Naturalist, 2000)
I assessed rates at which unhatched Wood Duck (Aix sponsa), Hooded Merganser (Lophodytes cucullatus), and Common Goldeneye (Bucephala clangula) eggs broke in and/or disappeared from nest boxes over winter. Eggs of different species remained intact at significantly different rates (P < 0.001). Evidence from unhatched Hooded Merganser eggs appeared to be most detectable (92-97%), followed by those of Wood Ducks (77-89%), and Common Goldeneyes (53-92%). These species are sometimes sympatric, and differential detection of unhatched eggs in winter nest box surveys could cause species differences in the proportion of nesting attempts detected as well as a differential positive bias in estimates of production from known nests.
Keywords: Breeding Season; Bucephala clangula; Common Goldeneye; Techniques; Hooded Merganser; Lophodytes cucullatus

Dde Pcb and Mercury Residues in Minnesota Common Goldeneye and Hooded Merganser Eggs 1981 - Zicus, M. C.; Briggs, M. A.; Pace, R. M., III (Canadian Journal of Zoology, 1988)
DDT and its metabolites, polychlorinated biphenyls (PCBs), and mercury (Hg) were measured in Hooded Merganser (Lophodyts cucullatus) and Common Goldeneye (Bucephala clangula) eggs after dead hens were found in clutches. DDE, PCBs, and Hg were detected in all eggs analyzed. Geometric mean concentrations of DDE were low in merganser and goldeneye eggs (0.62 and 0.52 ppm wet weight, respectively). Geometric mean PCB levels were also low, but were significantly higher (P < 0.01) in goldeneye eggs (1.52 vs. 0.66 ppm wet weight). Geometric mean Hg in merganser eggs approached a level for concern and was significantly greater (P < 0.01) than in goldeneye eggs (0.45 vs. 0.11 ppm wet weight, respectively). Merganser and goldeneye eggshells were 9.6 and 15.4% thinner, respectively, and their Ratcliffe indices were 6.0 and 9.2% lower, respectively, than measurements from eggs collected before DDT was in use. Residues and shell thicknesses had among- and within-nest variance structures that differed by species. DDE accounted for 21% of the variation in shell weight controlled for egg size in goldeneyes, but no relationship was evident for mergansers. No dead females were found in about 240 nest boxes monitored in 1982 and 1983 and it is unlikely that contaminant levels measured contributed to hen mortality. Egg breakage in successful nests was greater for goldeneyes than for mergansers or Wood Ducks (Aix sponsa).
Keywords: Breeding Season; Bucephala clangula; Common Goldeneye; Contaminants; Hooded Merganser; Lophodytes cucullatus

Cavity nesting waterfowl in Minnesota - Zicus, Michael C.; Hennes, Steven K. (Wildfowl, 1988)
Keywords: Breeding Season; Bucephala clangula; Common Goldeneye; Bucephala albeola; Bufflehead

Nest Prospecting by Common Goldeneyes - Zicus, M. C.; Hennes, S. K. (Condor, 1989)
We studied nest prospecting by Common Goldeneye (Bucephala clangula) females in north-central Minnesota. Adults unsuccessful in nesting, those with broods, and nonnesting yearlings were captured in nests while prospecting. Prospecting began in late May and continued into early July. Active nets received up to 25 prospecting visits per day with most visits occurring between 06:00 and 09:00 CDT. Adults appeared to prospect more (P < 0.05) in nest boxes that had contained successful nests during the current season than in those where nests abandoned or destroyed or those that were unused. Nestbox status had no apparent effect on prospecting by yearlings. Body mass of prospecting adults that were unsuccessful nesters and yearling nonnesters was similar and was significantly less (P < 0.05) than that of females still incubating nests or those with broods. Our observations support the claim that prospecting females are preparing for next breeding season, and we suggest that prospecting is a means of confirming information already gained during the current season. Prior knowledge of successful nest sites could explain the preferential use of previously successful nest boxes observed in a Swedish study.
Keywords: Behavior; Breeding Season; Bucephala clangula; Common Goldeneye

Diurnal time budgets of breeding Common Goldeneyes - Zicus, Michael C.; Hennes, Steven K. (Wilson Bulletin, 1993)
Keywords: Behavior; Breeding Season; Bucephala clangula; Common Goldeneye

Diurnal time budgets of Common Goldeneye brood hens - Zicus, Michael C.; Hennes, Steven K. (Wilson Bulletin, 1994)
Keywords: Behavior; Breeding Season; Bucephala clangula; Common Goldeneye

Common goldeneye nest attendance patterns - Zicus, Michael C.; Hennes, Steven K.; Riggs, Michael R. (Condor, 1995)
Common Goldeneye (Bucephala clangula) nest attendance was recorded on three Minnesota lakes, 1982-1985. Data were from 22 nests monitored 545 days. Hens increased time at nests and frequency of overnight sessions as incubation approached. Incubation recesses were diurnal; most occurred between 9:00 and 19:00 CST. Recesses were fewest and longest in early incubation, but total recess time was greatest in late incubation. Daily incubation constancy was highly variable, ranging from 36.7 to 96.3%. Lake and year effects influenced the number of daily recesses and total daily recess time. Mean recess length did not differ among lakes and years. Three females monitored in both 1984 and 1985 recessed more daily ( hivin x = 55 min) in 1984, and their yearly ranks were the same for all parameters suggesting strong hen effects. Incubation ranged from 28 to 30 days and was correlated (r = 0.72) with mean daily recess time. Nests incubated 29 and 30 days had mean total incubation times that differed by 13 min. While brooding young, incubation-like patterns were maintained but absences were fewer and shorter. Our results differed slightly from those reported for a recent Ontario study, but the differences may be due to analytical approaches.
Keywords: Behavior; Breeding Season; Bucephala clangula; Common Goldeneye

Factors influencing incubation egg-mass loss for three species of waterfowl - Zicus, Michael C.; Rave, David P.; Riggs, Michael R. (Condor, 2004)
Many bird eggs lose apprx15% of their fresh mass before pipping, but individual species have been reported to lose 10-23%. Most published estimates have been imprecise due to small sample sizes. Moreover, published estimates of within- or among-species variance components of mass loss are virtually unknown. We modeled the influence of nest type, clutch size, and egg size on daily mass loss of Mallard (Anas platyrhynchos), Common Goldeneye (Bucephala clangula), and Hooded Merganser (Lophodytes cucullatus) eggs and compared fractional mass loss among species. Mallard eggs in artificial nest cylinders lost more mass than those in ground nests, but were unaffected by nest initiation date. Average sized eggs in Mallard ground nests, Mallard cylinder nests, and Common Goldeneye and Hooded Merganser nest boxes lost 7.9 g (15.2%) 10.8 g (20.3%), 10.3 g (15.5%), and 9.2 g (15.8%) of fresh mass, respectively. For all species, daily mass loss increased as incubation progressed and was affected by an interaction between egg size and incubation time, but was not influenced by clutch size. Depending on species, smallest eggs lost 1.0-4.0% more of their fresh mass than did the largest. Egg-mass variability was partitioned into years, nests within years, and eggs within nests and years. Variability was evenly distributed among the variance components in Mallard ground nests; however, among-eggs within-nest variance predominated in nest cylinders. In contrast, among-nests variation was the dominant source for goldeneyes and mergansers. Nest-site selection and egg size likely involve trade-offs among optimum egg-mass loss and nest and hatchling survival.
Keywords: Breeding Season; Bucephala clangula; Common Goldeneye; Physiology; Hooded Merganser; Lophodytes cucullatus

Change in body mass of female common Goldeneyes during nesting and brood rearing - Zicus, Michael C.; Riggs, Michael R. (Wilson Bulletin, 1996)
We measured body mass of female Common Goldeneyes (Bucephala clangula) during nesting on fish bearing takes in northcentral Minnesota, in 1982-1985. Median body mass during egg laying was 775 g. Female mass during incubation varied among lakes and possibly years. Mass at the start of incubation (698-715 g) was 10.7-11.0% greater than that at hatching. Females regained most of the mass lost during incubation by the time they abandoned their class IIC or class III ducklings. Goldeneyes in Minnesota weighed less at the start of nesting than those studied on predominately fishless Ontario lakes; proportional mass loss during incubation was also substantially less than that reported in Ontario (approximately 20%). Differences in body mass dynamics may be related to the relative ease of food acquisition during nesting; foods might be acquired more easily in more productive wetlands despite the presence of fish.
Keywords: Breeding Season; Bucephala clangula; Common Goldeneye; Energetics and Nutrition

Goosander Mergus-Merganser Breeds in the Nestbox - Zintl, H. (Anzeiger der Ornithologischen Gesellschaft in Bayern, 1970)
Keywords: Breeding Season; Common merganser; Mergus merganser

Distribution patterns of wintering sea ducks in relation to the North Atlantic Oscillation and local environmental characteristics - Zipkin, E. F.; Gardner, B.; Gilbert, A. T.; O'Connell, A. F.; Royle, J. A.; Silverman, E. D. (OECOLOGIA, 2010)
Twelve species of North American sea ducks (Tribe Mergini) winter off the eastern coast of the United States and Canada. Yet, despite their seasonal proximity to urbanized areas in this region, there is limited information on patterns of wintering sea duck habitat use. It is difficult to gather information on sea ducks because of the relative inaccessibility of their offshore locations, their high degree of mobility, and their aggregated distributions. To characterize environmental conditions that affect wintering distributions, as well as their geographic ranges, we analyzed count data on five species of sea ducks (black scoters Melanitta nigra americana, surf scoters M. perspicillata, white-winged scoters M. fusca, common eiders Somateria mollissima, and long-tailed ducks Clangula hyemalis) that were collected during the Atlantic Flyway Sea Duck Survey for ten years starting in the early 1990s. We modeled count data for each species within ten-nautical-mile linear survey segments using a zero-inflated negative binomial model that included four local-scale habitat covariates (sea surface temperature, mean bottom depth, maximum bottom slope, and a variable to indicate if the segment was in a bay or not), one broad-scale covariate (the North Atlantic Oscillation), and a temporal correlation component. Our results indicate that species distributions have strong latitudinal gradients and consistency in local habitat use. The North Atlantic Oscillation was the only environmental covariate that had a significant (but variable) effect on the expected count for all five species, suggesting that broad-scale climatic conditions may be directly or indirectly important to the distributions of wintering sea ducks. Our results provide critical information on species-habitat associations, elucidate the complicated relationship between the North Atlantic Oscillation, sea surface temperature, and local sea duck abundances, and should be useful in assessing the impacts of climate change on seabirds.
Times Cited in Web of Science Core Collection: 40 Total Times Cited: 41 Cited Reference Count: 46
Keywords: Bayesian analysis; Climate change; COMMON EIDERS; SURVIVAL; POPULATION-DYNAMICS; ABUNDANCE; SIZE; MOVEMENTS; SURF SCOTERS; PHENOLOGY; FLUCTUATIONS; LARGE-SCALE CLIMATE; Negative binomial model

Fitting statistical distributions to sea duck count data: Implications for survey design and abundance estimation - Zipkin, E. F.; Leirness, J. B.; Kinlan, B. P.; O'Connell, A. F.; Silverman, E. D. (Statistical Methodology, 2014)
Determining appropriate statistical distributions for modeling animal count data is important for accurate estimation of abundance, distribution, and trends. In the case of sea ducks along the U.S. Atlantic coast, managers want to estimate local and regional abundance to detect and track population declines, to define areas of high and low use, and to predict the impact of future habitat change on populations. In this paper, we used a modified marked point process to model survey data that recorded flock sizes of Common eiders, Long-tailed ducks, and Black, Surf, and White-winged scoters. The data come from an experimental aerial survey, conducted by the United States Fish & Wildlife Service (USFWS) Division of Migratory Bird Management, during which east-west transects were flown along the Atlantic Coast from Maine to Florida during the winters of 2009-2011. To model the number of flocks per transect (the points), we compared the fit of four statistical distributions (zero-inflated Poisson, zero-inflated geometric, zero-inflated negative binomial and negative binomial) to data on the number of species-specific sea duck flocks that were recorded for each transect flown. To model the flock sizes (the marks), we compared the fit of flock size data for each species to seven statistical distributions: positive Poisson, positive negative binomial, positive geometric, logarithmic, discretized lognormal, zeta and Yule-Simon. Akaike's Information Criterion and Vuong's closeness tests indicated that the negative binomial and discretized lognormal were the best distributions for all species for the points and marks, respectively. These findings have important implications for estimating sea duck-abundances as the discretized lognormal is a more skewed distribution than the Poisson and negative binomial, which are frequently used to model avian counts; the lognormal is also less heavy-tailed than the power law distributions (e.g., zeta and Yule-Simon), which are becoming increasingly popular for group size modeling. Choosing appropriate statistical distributions for modeling flock size data is fundamental to accurately estimating population summaries, determining required survey effort, and assessing and propagating uncertainty through decision-making processes. Published by Elsevier B.V.
Zipkin, Elise F. Leirness, Jeffery B. Kinlan, Brian P. O'Connell, Allan F. Silverman, Emily D. Si
Keywords: Common Eider; Melanitta fusca; White-winged Scoter; Melanitta perspicillata; Surf Scoter; Clangula hyemalis; Long-tailed Duck; Somateria mollissima; Techniques; SDJV funded; Black Scoter; Nonbreeding season; Melanitta americana

Habitat choice of Steller's Eider Polysticta stelleri wintering at Lithuanian coast of the Baltic Sea - Zydelis, Ramunas (Acta Ornithologica (Warsaw), 2000)
The distribution of the globally threatened Steller's Eider was described in relation to marine benthic biotopes along Lithuanian coastline in the winters 1997/98 and 1998/99. Steller's Eiders demonstrated their preference towards diversity of benthic biotopes and tended to avoid entirely sandy bottom biotopes. The highest fractions in the winter diet of the Steller's Eider were made up by fish eggs (48.7%) and molluscs (42.6%).
Keywords: Nonbreeding Seasons; Trophic Interactions; Habitat; Polysticta stelleri; Steller's eider

Bycatch in gillnet fisheries - An overlooked threat to waterbird populations - Zydelis, Ramunas; Bellebaum, Jochen; Osterblom, Henrik; Vetemaa, Markus; Schirmeister, Bernd; Stipniece, Antra; Dagys, Mindaugas; van Eerden, Mennobart; Garthe, Stefan (Biological Conservation, 2009)
Bird mortality in fishing gear is a global conservation issue and it is recognised that bycatch in industrial longline and trawl fisheries threatens several seabird species. Little is known however about the effects of bycatch in small-scale gillnet fisheries on bird populations. Here we review 30 studies reporting bird bycatch in coastal gillnet fisheries in the Baltic Sea and the North Sea region in order to assess the magnitude of this problem and potential effects on bird populations. All species of diving birds that occur in the study region, including divers (loons), grebes, sea ducks, diving ducks, auks and cormorants, have been reported as dying in fishing nets. The cumulative bycatch estimate extracted from several localized studies providing such information, suggests that about 90,000 birds die in fishing nets annually, a number that is almost certainly a substantial underestimate. We conclude that it is likely that between 100,000 and 200,000 waterbirds are killed per year. Geographic and temporal patterns of bycatch generally matched species distribution and periods of presence. Also, bycatch rates varied depending on species' foraging technique and were influenced by net parameters and fishing depth. To evaluate effects of additive mortality on bird populations, we applied the Potential Biological Removal (PBR) concept to three species with the most extensive bycatch information. Agreeing with PBR assumptions we conclude that bycatch is a matter of concern for at least two of the three assessed species. We suggest that bycatch research in Europe and beyond should aim at unification of principles for bycatch assessment, setting new standards for the monitoring of waterbird populations so that vital rates and mortality data are recorded, and implementing quantifiable criteria for evaluating effects of fisheries bycatch. (C) 2009 Elsevier Ltd. All rights reserved.
Keywords: Conservation; Sea Ducks - General

Abundance and distribution of waterbirds on the west coast of Vancouver Island during spring 1999 and winter 2000 - Žydelis, R.; Boyd, W. S.; Breault, A.; Sullivan, T. M. (Technical Report Series, 2005)
This report presents the results of six aerial surveys of waterbirds conducted on the west coast of Vancouver Island during the spring of 1999 and the winter of 2000. The surveys covered approximately 50% of the 3900 km shoreline between Cape Scott and Port San Juan. During each survey, waterbird abundance was estimated in 274 pre-determined shorelinebased transects, each associated with a unique marine ecological unit (eco-unit). The replicated surveys of individual shoreline transects were processed to determine: 1) distribution and abundance of waterbirds on the near-shore portion of the west coast of Vancouver Island, 2) waterbird densities across marine ecological units and 3) seasonal variability in waterbird distribution and abundance. This report also identifies waterbird distribution and abundance at active spawning sites of Pacific Herring (Clupea pallasi) on the west coast. The purpose of the report is to provide spatial, habitat-based and species-specific information to wildlife managers or others interested in or involved with bird or near-shore management on the west coast of Vancouver Island. The number of waterbirds observed along the nearshore during the surveys ranged from 22,000 to 34,000 in winter, climbed to nearly 48,000 in early spring during herring spawn, and then dropped to 11,000 during the last spring survey. Gulls were the most abundant group of waterbirds found on the west coast (comprising 26% of all birds in winter and 41% in spring), followed by scoters (18% in winter and 32% in spring) and loons (7% in winter and 9% in spring). Waterbirds were present in all of the eco-units surveyed during winter. The marine ecounit LCLLM, which covered 36% of the surveyed area, supported 35% of all waterbirds sighted. In spring the two areas supporting the most birds were Barkley Sound and Hesquiat Harbour. The largest bird aggregations in spring were observed in eco-units MBLLS and MCHLM, which respectively comprise only 2.4% and 1.4% of the study area. The overall mean density of birds in winter was 14.2 individuals per linear kilometer of shoreline. Marine eco-unit LBHLM supported the highest bird density (24 individuals per kilometer of shoreline) during the winter while the highest spring bird abundances were observed in eco-units MBLLS and MCHLM. In the spring, the largest bird concentrations were found in the sections of Barkley Sound and Hesquiat Harbour where there were extensive Pacific herring spawns. The key groups of birds aggregating at herring spawn were loons, scoters and gulls.
Keywords: Melanitta fusca; White-winged Scoter; Melanitta perspicillata; Surf Scoter; Histrionicus histrionicus; Clangula hyemalis; Long-tailed Duck; Bucephala clangula; Common Goldeneye; Mergus merganser; Mergus serrator; Bucephala albeola; Bufflehead; Black Scoter; Bucephala islandica; Abundance, Distribution, & Trends; Nonbreeding season; Barrow’s Goldeneye; Common Merganser; Melanitta americana; Red-breasted Merganser; Harlequin Duck

Response of wintering Steller's Eiders to herring spawn - Zydelis, Ramunas; Esler, Daniel (Waterbirds, 2005)
Distributional and dietary responses of wintering Steller's Eiders (Polysticta stelleri) to spring spawning of Baltic Herring (Clupea harengus) were studied along the Lithuanian coast of the Baltic Sea. Herring spawn is patchy, but is abundant and energy-rich when present. The objective of this study was to determine whether Steller's Eiders modified their foraging sites and food habits to take advantage of spawn, or whether they were inflexible foragers as suggested by earlier studies. Steller's Eiders altered their habitat use during herring spawn, moving to habitats where fish spawning occurred. Also, diet analysis demonstrated that herring eggs became an important food when available. Although the importance of herring spawn for Steller's Eiders remains speculative, this study indicates that spawning sites could be important as a source of nutrients and energy for subsequent migration or reproduction, and should receive conservation consideration.
Keywords: Abundance, Distribution, and Trends; Nonbreeding Seasons; Trophic Interactions; Polysticta stelleri; Steller's eider

Habitat use by wintering surf and white-winged scoters: Effects of environmental attributes and shellfish aquaculture - Zydelis, Ramunas; Esler, Daniel; Boyd, W. Sean; LaCroix, Deborah L.; Kirk, Molly (Journal of Wildlife Management, 2006)
Shellfish aquaculture is an expanding industry in coastal British Columbia, Canada, and occurs in important wintering areas for surf scoters (Melanitta perspicillata) and white-winged scoters (M. fusca). We quantified habitat use by scoters in relation to natural environmental attributes and habitat modifications associated with shellfish aquaculture. We found that, despite the extensive clam and oyster farming in our study area, densities of wintering surf scoters and white-winged scoters were related primarily to natural environmental attributes, particularly intertidal area, clam density, and sediment type; shellfish aquaculture variables were generally poor predictors of bird densities. We conclude that current levels and forms of shellfish aquaculture in our study site were not an important determinant of scoter distribution and abundance, suggesting that winter scoter populations and the shellfish aquaculture industry may be mutually sustainable. We caution that intensification or further industrialization of shellfish aquaculture in British Columbia could eventually lead to detrimental effects if some threshold level of habitat modification is exceeded.
Keywords: Conservation; Melanitta fusca; Nonbreeding Seasons; White-winged Scoter; Melanitta perspicillata; Surf Scoter; Habitat; SDJV funded

Effects of off-bottom shellfish aquaculture on winter habitat use by molluscivorous sea ducks - Zydelis, Ramunas; Esler, Daniel; Kirk, Molly; Boyd, W. Sean (Aquatic Conservation, 2009)
1. Shellfish farming is an expanding segment of marine aquaculture, but environmental effects of this industry are only beginning to be considered.2. The interaction between off-bottom, suspended oyster farming and wintering sea Clucks in coastal British Columbia was studied. Specifically. the habitat use of surf scoters (Melanitta perspicillata) and Barrow's goldeneyes (Bucephala islandica), the most abundant sea duck species ill the Study area. was evaluated ill relation to natural environmental attributes and shellfish aquaculture.3. The extent of shellfish farming was the best-supported habitat variable explaining variation in surf scoter densities, and the only habitat attribute from the considered set that was a strong, predictor of Barrow's goldeneye densities. In both cases. the findings indicated strong positive relationships between densities of sea ducks and shellfish aquaculture operations. These relationships are presumably the result of large numbers of wild mussels (Mytilus trossulus) that settle and grow oil aquaculture structures and Lire preferred prey of these sea ducks.4. Previous work has shown that aquaculture Structures provide good conditions for recruiting and growing Mussels. including refuge from invertebrate predators. which in turn provides higher densities of higher quality prey for sea ducks than available in intertidal areas. This offers a rare example in which introduction of an industry leads to positive effects on wildlife populations, which is particularly important given persistent decline in numbers of many sea ducks. Copyright (C) 2008 John Wiley & Sons, Ltd.
Keywords: Conservation; Nonbreeding Seasons; Melanitta perspicillata; Surf Scoter; Trophic Interactions; Habitat; Barrow's Goldeneye; Bucephala islandica

Piscivorous birds as top predators and fishery competitors in the lagoon ecosystem - Zydelis, R.; Kontautas, A. (Hydrobiologia, 2008)
Piscivorous birds have received much attention with respect to competition with fisheries for resources. The majority of studies have been focused on cormorants Phalacrocoracidae, while predation by other piscivorous bird species has often been overlooked. This study was designed to supplement sociological research (Bell, 2004), which revealed that the fishermen community at the Lithuanian section of the Curonian Lagoon considers great cormorants Phalacrocorax carbo, but not other fish-eating birds, to be significant competitors of fish resources. In this paper, we estimate fish consumption by cormorants and other abundant piscivorous birds, and attempt to interpret this level of predation in relation to fish resources and commercial fishery landings. We estimate that four piscivorous bird species consumed nearly 700 tonnes of fish during the breeding season of 2001 and winter 2001/2002, which corresponds to similar to 9% of the total fish resources in our study area. Bird consumption equalled two-thirds of the amount of fish landed by commercial fishermen. However, we argue that direct competition between birds and humans for fish resources is low, because there is a size segregation of exploited fish stock segments and abundant fish species that dominate the diet of birds. Fish monitoring and commercial fish landings indicated no apparent changes in fish stock size and composition, which could be attributed to a recent increase in piscivorous birds. Great cormorants consumed the largest biomass of fish compared to other piscivorous bird species. However, total fish intake by grey herons Ardea cinerea, great-crested grebes Podiceps cristatus, and goosanders Mergus merganser combined, equalled that of cormorants. Our results do not support the common public perception that cormorant predation greatly exceeds that of other piscivorous birds, and is detrimental to commercial fisheries.
Keywords: Conservation; Trophic Interactions; Common merganser; Mergus merganser

Recent changes in the status of Steller's Eider Polysticta stelleri wintering in Europe: a decline or redistribution? - Zydelis, Ramunas; Lorentsen, Svein-Hakon; Fox, Anthony D.; Kuresoo, Andres; Krasnov, Yuri; Goryaev, Yuri; Bustnes, Jan Ove; Hario, Martti; Nilsson, Leif; Stipniece, Antra (Bird Conservation International, 2006)
Steller's Eider Polysticta stelleri has a restricted arctic breeding range. The world population declined to c. 220,000 individuals in the late 1990s from an estimated 400,000-500,000 in the 1960s. The species has a limited global wintering distribution, occurring in marine habitats in north-east Europe, islands close to Kamchatka in Russia, and the eastern Aleutian Islands and south-west Alaska. European wintering numbers were estimated at 30,000-50,000 in the early 1990s, when the population was considered of favourable conservation status. Recent census data from the most important European wintering sites show annual declines of 8% in Norway since 1984, 9% in Estonia since 1994 and 22% in Lithuania since 1995, suggesting an overall 65% reduction in Europe. Counts in 1994 suggested that 30-50% of the European population wintered in Russia at that time. Current census data from Russia show similar declines along monitored sections of the Kola Peninsula wintering grounds since 1994. Accounting for trends in Russia, the current European wintering population could possibly stand at 10,000-15,000 individuals (a more than a 50% decline in 10 years), qualifying this population as Endangered under IUCN criteria. The changes in Baltic/Norwegian wintering numbers did not correlate with changes in the extent of ice-free marine waters in the Kola Peninsula/White Sea areas, but changes in annual numbers in Norway were correlated with winter North Atlantic Oscillation indices. Variation in annual numbers in the Baltic Sea correlated with projected number of juveniles among wintering birds. However, none of the possible causes discussed in this paper could fully explain the decline in Steller's Eider, confirming the need for comprehensive monitoring of the population throughout its winter range and for cohesive demographic monitoring to target effective conservation action.
Keywords: Abundance, Distribution, and Trends; Nonbreeding Seasons; Polysticta stelleri; Steller's eider

Winter foraging of Long-tailed Ducks (Clangula hyemalis) exploiting different benthic communities in the Baltic Sea - Zydelis, Ramunas; Ruskyte, Dainora (Wilson Bulletin, 2005)
We studied the feeding ecology of Long-tailed Ducks (Clangula hyemalis) in two different marine benthic habitats in the Baltic Sea to determine whether there were differences in diet choice, foraging selectivity, body condition, and bird abundance. Our results corroborate earlier suggestions that Long-tailed Ducks exhibit ecological plasticity in selecting winter habitat and food. The majority of Long-tailed Ducks occurred in hard-bottom habitats where they relied on the bivalve Mytilus edulis; however, some of the population wintered in less productive, soft-bottom habitats where they employed a prey-selective foraging strategy, in which they fed on less abundant, but energy rich, crustaceans. Both strategies were apparently viable, as dissected birds in both habitats were in good body condition and had substantial fat reserves.
Keywords: Nonbreeding Seasons; Clangula hyemalis; Long-tailed Duck; Energetics and Nutrition; Trophic Interactions

The incidental catch of seabirds in gillnet fisheries: A global review - Zydelis, R.; Small, C.; French, G. (Biological Conservation, 2013)
Times Cited: 1 Zydelis, Ramunas Small, Cleo French, Gemma 1
Keywords: Conservation; Sea Ducks

Foraging behavior, ecology, and energetics of sea ducks - Žydelis, R. and S. E. Richman (Studies in Avian Biology, 2015)
Sea ducks spend the majority of their life in a cold, marine environment where they must dive, often to great depths, consuming enough food to maintain energy balance. The food consumed is hard shelled, cold, and of low energetic value; yet sea ducks excel when faced with many energetic and thermoregulatory challenges, especially for a relatively small-bodied marine endotherm. The energy cost of thermoregulation and intensive work required to collect daily rations are especially high for sea ducks at high latitudes where they must cope with limited daylight for foraging under harsh winter conditions. To offset these high energetic demands, sea ducks must optimize their decisions about habitat choice, foraging behavior, and prey selection. Foraging behavior strives to maximize gross energy gain and minimize costs to reach energy balance, sometimes under the most extreme of conditions such as the polynyas of the Belcher Islands and St. Lawrence Island. Studying sea ducks under these conditions is equally challenging but through the combined research effort of agencies, organizations, academics, and individuals, we have made great strides in gaining information on the foraging ecology of sea ducks. In this chapter, we review the general aspects of sea duck foraging ecology and diving behavior, foraging energetics, and modeling of energy balance. Each of these topics is discussed in detail, but it is not our intention to review all of the literature available, but rather to highlight the particular discoveries and developments that have greatly increased our understanding of the foraging ecology of sea ducks.
Keywords: Behavior; Energetics and Nutrition; Trophic Interactions