Reduced immunocompetence and cost of reproduction in common eiders - Hanssen, Sveinn Are; Folstad, Ivar; Erikstad, Kjell Einar (Oecologia (Berlin), 2003)
Immunocompetence may be especially important in long-lived species where infectious organisms may have detrimental effects upon future reproductive value of hosts. The resource demand for immunocompetence may reduce resource availability for reproduction and a tradeoff between these traits has therefore been proposed. Capital breeders, such as the common eider (Somateria mollissima), rely upon accumulated body reserves during reproduction. Eiders lose more than 40% of pre-breeding body mass during egglaying and incubation and many females abandon their ducklings to other females after hatching. Results from our observational study show that levels of leukocytes (i.e., lymphocytes, heterophils and heterophil/lymphocyte ratio) are not related to body mass early in the incubation period. However, eider females with low initial body mass showed signs of immunosuppression (i.e., decreased late levels of lymphocytes) and increased response towards stressors (i.e., increased heterophil/lymphocyte ratio) later in the incubation period. Moreover, females with low lymphocyte levels more frequently abandoned their brood, and females abandoning young had an increased return rate to the next breeding season. However, among brood abandoning females return rate was lower for the females with low lymphocyte levels. These results suggest that immunosuppression, as indicated by low lymphocyte levels, is a reproductive cost that may be partly compensated for by abandoning young.
Keywords: Breeding Season; Common Eider; Somateria mollissima; Productivity; Physiology

White plumage reflects individual quality in female eiders - Hanssen, Sveinn Are; Folstad, Ivar; Erikstad, Kjell Einar (Animal Behaviour, 2006)
Sexual selection predicts that males should signal their viability and health and this is often achieved with elaborate ornaments. However, females' phenotypic and genotypic quality may also be related to ornamental expression. We investigated the association between a female ornamental trait (white wing plumage) and female quality in the common eider, Somateria mollissima. Only females incubate and care for young, so male parental effort did not influence the females' condition, and the ornament is expressed only in females, so it is not a neutral correlated response to selection of the same ornament in males. We recorded the expression of this ornament in relation to the number of eggs laid and to mass loss and immunological status during incubation. Females that experienced a large mass loss and/or a reduction in immune cell levels (immunosuppression) had less white in the new wing bands produced after breeding. These results are the first to show a correlation between tolerance of reproductive costs and the expression of a strictly female ornament in a species with conventional sex roles. (c) 2005 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.
Keywords: Breeding Season; Common Eider; Somateria mollissima; Physiology

Costs of parasites in common eiders: Effects of antiparasite treatment - Hanssen, Sveinn Are; Folstad, Ivar; Erikstad, Kjell Einar; Oksanen, Antti (Oikos, 2003)
Parasites are exploiting their host for the resources required for the parasite's reproduction and survival. The effects of antiparasitic treatment during incubation on body mass and return rate in female common eiders Somateria mollissima were examined in a two year study (1998 and 1999). There was no effect of treatment on nest success, but unsuccessful females had lower body mass. Treatment had no effect on incubation time, mass-loss during incubation or return rate among successful birds. However, treatment lead to higher return rate among unsuccessful birds (treated = 69%, n = 13; controls = 18%, n = 11). This pattern remained significant also after including the birds that returned two years after the experiment. We suggest that the unsuccessful females are of lower quality and had higher costs from parasite infections than birds which completed incubation, and that the higher return rate for treated unsuccessful females may mean that costs of parasites are substantial, and that the potential fitness gain from investment in parasite defense and avoidance is large.
Keywords: Breeding Season; Common Eider; Somateria mollissima; Productivity; Parasites

Migration strategies of common eiders from Svalbard: implications for bilateral conservation management - Hanssen, S. A.; Gabrielsen, G. W.; Bustnes, J. O.; Brathen, V. S.; Skottene, E.; Fenstad, A.; Strom, H.; Bakken, V.; Phillips, R.; Moe, B. (POLAR BIOLOGY, 2016)
The Arctic is a highly seasonal environment with a harsh climate and extensive sea ice cover during the winter. Consequently, most Arctic-breeding seabirds migrate south to reach more benign environmental conditions. Knowledge of migration routes and wintering areas is integral for successful conservation of these globally important breeding populations. In this study, we deployed light-level geolocators on female common eiders Somateria mollissima breeding in Kongsfjorden, Svalbard, to track movements during the non-breeding season. We retrieved functioning loggers from 47 individual birds in 2009-2013 and mapped their migration routes and wintering areas. Thirty-six birds (77 %) wintered around the Icelandic coast and 11 (23 %) off the coasts of North Norway. Autumn migration took place between late August and late December, and spring migration from late March to late May. The migration (ca 1700 km to Iceland and 1300 km to North Norway) lasted for about 4 days in autumn and 3 days in spring. Later arrival resulted in later nest initiation, implying a carry-over effect of winter conditions on subsequent breeding. Birds that migrated to Norway departed later from Svalbard in autumn and consequently spent less time in the wintering area than individuals that migrated to Iceland. As just two countries, Iceland and Norway, appear to host all common eiders from Svalbard during the winter, the new information provided by this study on the core areas and timing of migration should provide the impetus for improved bilateral conservation management of this important Arctic breeding population of common eiders.
Times Cited in Web of Science Core Collection: 26 Total Times Cited: 26 Cited Reference Count: 54
Keywords: Conservation; TRACKING; Migration; Arctic; PERSISTENT ORGANIC POLLUTANTS; SOMATERIA-MOLLISSIMA; SIZE; MOVEMENTS; Common eider; HABITAT USE; ALBATROSSES; Geolocation; PETRELS; REVEALS; WINTER; Wintering area

Costs of immunity: immune responsiveness reduces survival in a vertebrate - Hanssen, Sveinn Are; Hasselquist, Dennis; Folstad, Ivar; Erikstad, Kjell Einar (Proceedings of the Royal Society Biological Sciences Series B, 2004)
Immune defences are undoubtedly of great benefit to the host, reducing the impact of infectious organisms. However, mounting immune responses also entails costs, which may be measured by inducing immune responses against artificial infections. We injected common eider (Somateria mollissima) females with three different non-pathogenic antigens, sheep red blood cells (SRBC), diphtheria toxoid and tetanus toxoid, early in their incubation period. In the group of females that mounted a humoral immune response against SRBC, the return rate was only 27%, whereas the group of females that did not mount a response against SRBC had a return rate of 72%. Moreover, responding against diphtheria toxoid when also responding against SRBC led to a further reduction in return rate. These results are repeatable, as the same effect occurred independently in two study years. The severely reduced return rate of females producing antibodies against SRBC and diphtheria toxoid implies that these birds experienced considerably impaired long-term survival. This study thus documents severe costs of mounting humoral immune responses in a vertebrate. Such costs may explain why many organisms suppress immunity when under stress or when malnourished, and why infections may sometimes be tolerated without eliciting immune responses.
Keywords: Breeding Season; Common Eider; Somateria mollissima; Physiology; Survival

Cost of reproduction in a long-lived bird: incubation effort reduces immune function and future reproduction - Hanssen, Sveinn Are; Hasselquist, Dennis; Folstad, Ivar; Erikstad, Kjell Einar (Proceedings of the Royal Society Biological Sciences Series B, 2005)
Life-history theory predicts that increased current reproductive effort should lead to a fitness cost. This cost of reproduction may be observed as reduced survival or future reproduction, and may be caused by temporal suppression of immune function in stressed or hard-working individuals. In birds, consideration of the costs of incubating eggs has largely been neglected in favour of the costs of brood rearing. We manipulated incubation demand in two breeding seasons (2000 and 2001) in female common eiders (Somateria mollissima) by creating clutches of three and six eggs (natural range 3-6 eggs). The common eider is a long-lived sea-duck where females do not eat during the incubation period. Mass loss increased and immune function (lymphocyte levels and specific antibody response to the non-pathogenic antigens diphtheria and tetanus toxoid) was reduced in females incubating large clutches. The increased incubation effort among females assigned to large incubation demand did not lead to adverse effects on current reproduction or return rate in the next breeding season. However, large incubation demand resulted in long-term fitness costs through reduced fecundity the year after manipulation. Our data show that in eiders, a long-lived species, the cost of high incubation demand is paid in the currency of reduced future fecundity, possibly mediated by reduced immune function.
Keywords: Breeding Season; Common Eider; Somateria mollissima; Productivity; Physiology; Energetics and Nutrition

A natural antipredation experiment: predator control and reduced sea ice increases colony size in a long-lived duck - Hanssen, S. A.; Moe, B.; Bardsen, B. J.; Hanssen, F.; Gabrielsen, G. W. (Ecology and Evolution, 2013)
Times Cited: 0 Hanssen, Sveinn A. Moe, Borge Bardsen, Bard-Jorgen Hanssen, Frank Gabrielsen, Geir W. Hanssen, Sveinn Are/C-9989-2009 Hanssen, Sveinn Are/0000-0003-1792-435X 0
Keywords: Behavior; Breeding Season; Abundance, Distribution, and Trends; Somateria mollissima; Common eider

Multicentury perspective assessing the sustainability of the historical harvest of seaducks - Hargan, K. E.; Gilchrist, H. G.; Clyde, N. M. T.; Iverson, S. A.; Forbes, M. R.; Kimpe, L. E.; Mallory, M. L.; Michelutti, N.; Smol, J. P.; Blais, J. M. (PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 2019)
Where available, census data on seabirds often do not extend beyond a few years or decades, challenging our ability to identify drivers of population change and to develop conservation policies. Here, we reconstruct long-term population dynamics of northern common eiders (Somateria mollissima borealis). We analyzed sterols together with stable nitrogen isotopes in dated pond sediment cores to show that eiders underwent broadscale population declines over the 20th century at Canadian subarctic breeding sites. Likely, a rapidly growing Greenland population, combined with relocation of Inuit to larger Arctic communities and associated increases in the availability of firearms and motors during the early to mid-20th century, generated more efficient hunting practices, which in turn reduced the number of adult eiders breeding at Canadian nesting islands. Our paleolimnological approach highlights that current and local monitoring windows for many sensitive seabird species may be inadequate for making key conservation decisions.
Times Cited in Web of Science Core Collection: 12 Total Times Cited: 12 Cited Reference Count: 48
Keywords: conservation; COMMON EIDERS; Arctic; SOMATERIA-MOLLISSIMA-BOREALIS; IMPACTS; SEA-ICE; seabirds; POPULATIONS; GREENLAND; biomarkers; FECAL STEROLS; MARINE; paleolimnology; SEDIMENTS

The role of male mate-guarding in pre-laying Common Eiders Somateria m. mollissima in the northern Baltic Sea - Hario, Martti; Hollmen, Tuula E. (Ornis Fennica, 2004)
During the two weeks prior to laying on the Finnish breeding grounds in the central Gulf of Finland, Baltic Common Eider males escorted their females constantly Towards the start of laying, males increased their vigilance by reducing their feeding rate from 70% to 0%. Concurrently, they lost weight. During the same time period, females kept their feeding rate constant at around 75%. Upon laying start, the initially even sex ratio of the population temporarily became male-biased when females disappeared to nests and emancipated males were still around. Yet, experimentally widowed females, feeding alone at this stage, were not harassed by the emancipated males and kept their clutch size and body weight similar to those of their previous nesting years. However, the hatching rate of the widows showed progressive decrease with the number of days from mate loss to laying. The viability of their mates' sperm varied from 1 to at least 20 days and this correlated with the proportion of viable eggs in their clutches. We suggest that male mate guarding is for fertilization assurance rather than for female protection during the pre-laying period at northern breeding grounds. - We did not observe any instance of paired males actively pursuing extra-pair copulations (EPC). We suggest that an inter-sexual conflict over copulations exists in our study population. Females may need repeated copulations because of variation in the duration of sperm viability. Males apparently rely on intense mate guarding as a means to safeguard paternity, resulting in a high rate of male refusals over mate solicitations (40%).
Keywords: Behavior; Common Eider; Nonbreeding Seasons; Somateria mollissima

Effects of mate removal on the fecundity of common eider Somateria mollissima females - Hario, Martti; Hollmen, Tuula E.; Morelli, Toni Lyn; Scribner, Kim T. (Wildlife Biology, 2002)
Behavioural observations, measurements of male and female reproductive success, and DNA microsatellite loci were used to investigate parentage of common eider Somateria mollissima clutches and productivity of widowed females in Finland. In an experimental study simulating spring harvest of male eiders, a total of 20 males were shot while attending 16 females (four males after rematings, 16 initial males) during the pre-laying and laying period in 1994. Of the 16 widowed females, 11 nested and five did not. Mean clutch size of breeding widows (4.55) did not differ from that of control females in the same year (4.47; N=32). However, the hatching success of widows was significantly lower than that of control females (53 vs 81%) because of a greater proportion of addled eggs and dead embryos (38% vs 11%). Male removal also appeared to change male and female behaviours resulting in higher incidence of intra-specific brood parasitism and mate replacement. Occurrence of foreign eggs averaged 9.5% during the treatment year but was not observed during a year without disturbance during mating and egg laying (1997). Behaviours of widowed females related to remating attempts varied from active seeking of new mates to total rejection of courting males. Rematings did not lead to full clutch fertilisation among widowed females. Neither did we observe evidence of immigration of new males into the hunting area to court the widows. Male removal clearly lowered the fecundity of eider females, reducing nesting success by 35% of long-term averages. The potential for remating appears to be reduced by the female-biased sex ratio caused by simulated male-only harvest.
Keywords: Breeding Season; Common Eider; Somateria mollissima; Productivity

Kin structure and choice of brood care in a Common Eider (Somateria m. mollissima) population - Hario, M.; Koljonen, M. L.; Rintala, J. (Journal of Ornithology, 2012)
Times Cited: 0 Hario, Martti Koljonen, Marja-Liisa Rintala, Jukka 0
Keywords: Behavior; Breeding Season; Somateria mollissima; Common eider

Survival of female common eiders Somateria m. mollissima in a declining population of the northern Baltic Sea - Hario, Martti; Mazerolle, Marc J.; Saurola, Pertti (Oecologia (Berlin), 2009)
In long-lived species, adult survival is the population parameter having the highest elasticity, and therefore, it can be expected to be least affected by climatic variations. We studied the dynamics and survival of breeding female common eiders Somateria mollissima mollissima in the Baltic Sea from 1960 to 2007. Using nest censuses and capture-recapture methods, we investigated: (1) the annual apparent survival (phi) of breeding females, (2) the survival-mediated population fluctuation, (3) weather effects on survival, and (4) long-term population trends. Based on capture histories of 6,393 females, average phi was 0.882 (95% confidence interval 0.864, 0.899). We found no relationship between population growth rate and survival. Furthermore, the highest ranking models, based on Akaike's information criterion, indicated no effect of the North Atlantic Oscillation index on the phi of eider females. Population size, assessed from nest counts, has been steadily declining since 1985. Despite the long time series (48 years), the overall variation in the phi rates remained comparatively narrow, at maximum ranging only 10% between 2 consecutive years. Results imply that declining female survival is not the driving force behind the population decline, and we hypothesize that the overall poor fledging success and the consequent low recruitment explain the decreasing trend of nest densities since 1985.
Keywords: Breeding Season; Abundance, Distribution, and Trends; Common Eider; Somateria mollissima; Survival

Does heavy investment in foraging implicate low food acquisition for female Common Eiders Somateria mollissima? - Hario, Martti; Ost, Markus (Ornis Fennica, 2002)
In the northern Baltic Sea, Common Eiders Somateria mollissima feed mainly on mussels, taken exclusively by diving. By comparing the rate at which food is ingested (prey mass taken per time unit) with the rate of digestion (gut contents divided by known transit time), we found that the digestion rate was the major constraint on energy assimilation of female Common Eiders in the western Gulf of Finland (Tvarminne), whereas in the central Gulf of Finland (Soderskar), the limiting factor was the ingestion rate. This indicates that females at Soderskar had to work harder to secure one meal. The density of Blue Mussels Mytilus edulis of suitable size for Common Eiders was significantly lower at Soderskar compared to Tvarminne and likely the main cause for the difference. We conclude that hyperphagia at the breeding grounds was possible among females at Tvarminne, but not among females at Soderskar. Nevertheless, these differences in feeding behaviour did not translate into differences in body weights at incubation onset or clutch size. This may be due to the insensitiveness of these parameters to the ambient conditions measured, or to the fact that 1997 was in fact a benign feeding year at Soderskar. Our results suggest that females of a migratory Common Eider population to a great extent rely on reserves accumulated on the wintering grounds, but that nutrients derived from the breeding grounds may be important for maintenance of body condition and for the overall health status of a laying female.
Keywords: Behavior; Common Eider; Nonbreeding Seasons; Somateria mollissima; Energetics and Nutrition

Fledgling production and population trends in Finnish common eiders (Somateria mollissima mollissima) - evidence for density dependence - Hario, Martti; Rintala, Jukka (Canadian Journal of Zoology, 2006)
We present a 57-year time series of a common eider, Somateria mollissima mollissima (L., 1758), population from one of the core monitoring areas in the Baltic Sea, the Soderskar bird sanctuary, Gulf of Finland. We applied permutation tests to inspect the relationships between breeding parameters and population density. Of the parameters studied, only fledging rate (during a 34-year period) showed a significant negative relationship with population size, indicating density dependence. Furthermore, the fledging rate responded strongly to the population growth rate and to the rate of recruitment. Clutch size and duckling (downy young entering the water) rate did not show negative density dependence. Thus, losses during brood rearing seem to be the regulatory factor. The population decline at Soderskar is similar to those recorded in many other monitoring sites around the southern coast of Finland. Compared with data from more productive sea districts in northwestern Europe (Dutch Wadden Sea and Scottish North Sea), the Finnish fledging rates do not seem excessively bad. There are indications of viral infections playing an increasingly central role in duckling mortality, whereas adult female mortality has not been affected.
Keywords: Breeding Season; Abundance, Distribution, and Trends; Common Eider; Somateria mollissima; Productivity; Population Dynamics

Age of first breeding in the Common Eider Somateria m. mollissima population in the northern Baltic Sea - Hario, Martti; Rintala, Jukka (Ornis Fennica, 2009)
The Baltic/Wadden Sea Common Eider (Somateria m. mollissima) population may have declined by one-third between 1991 and 2000, based on counts carried out on the species wintering grounds, Denmark in particular. However, less drastic reductions have been reported from the breeding grounds, mainly in Finland and Estonia. It has been hypothesized that this discrepancy might arise from an earlier debut breeding attempt of subadult individuals. An increase in adult mortality may allow a larger proportion of subadult individuals to start breeding and arrive to the breeding grounds at a younger age than before. Consequently, their numbers might mask the decline of the adult population. Accordingly, the decline of the entire population would then be discernable only on the joint wintering grounds in the south, where all age classes occur together. Yet this study found no tendency towards earlier debut breeding in a declining Eider population in the Gulf of Finland. On the contrary, debut breeding was delayed as the population declined and the adult mortality increased. Later debut breeding and diminished population size were both related to poor fledging success three years earlier (i.e., the mean maturation age), which in turn was an outcome of mass mortality among ducklings. Debutants originating from small year classes (resulting from heavy duckling losses) took more time to become mature and made a smaller contribution to the population growth rate than recruits of large year classes. Environmental conditions (e.g., food, pathogens) might affect the development of an individual, with late debutants having lower fitness than early debutants. The discrepancy between the size of the wintering stock and that of the breeding stock of Baltic/Wadden Sea Eiders might result from a decreasing fledging rate in the north and, to a lesser extent, from increased adult mortality.
Keywords: Breeding Season; Common Eider; Somateria mollissima; Productivity

Thirty-Year Trends in an Eider Population Timing of Breeding Clutch Size and Nest Site Preferences - Hario, M.; Selin, K. (Finnish Game Research, 1988)
The local common eider population (Somateria mollissinima) in the Soderskar archiopelago, Gulf of Finland, increased ten-fold during 1949-85. A particularly steep increase occurred during 1975-85, when the annual growth rate averaged 10%. The population growth seemed to cease by 1986. Concurrent with the steep population growth, there was a marked increase in mean clutch size with significantly less year-to-year variation than before. These changes have taken place partly in parallel with the slow changes in the timing of breeding. Breeding now starts two weeks earlir than it did 30 years ago. The changes in mean clutch size during different population phases are discussed. Preferences for open skerries vs. wooded islets as breeding sites have changed slightly in that the proportion of nests on open skerries increased during the steep population growth, whereas than on wooded islets decreased. No direct evidence for predation-induced selection towards any of the habitat types could be discussed.
Keywords: Breeding Season; Abundance, Distribution, and Trends; Common Eider; Somateria mollissima; Productivity; Habitat

Avian Cholera in the Eastern Canadian Arctic: Investigating Disease Origins and Reservoirs - Harms, N. J. (Arctic, 2011)
Times Cited: 0 Harms, N. Jane 0
Keywords: Breeding Season; Disease; Common eider; somateria mollissima

Exploring Health and Disease in Northern Common Eiders in the Canadian Arctic - Harms, N. J. (Arctic, 2012)
Times Cited: 0 Harms, N. Jane 0
Keywords: Breeding Season; Disease; Common eider; somateria mollissima

Impacts of piscivorous birds on salmonid populations and game fisheries in Scotland: a review - Harris, Catriona M.; Calladine, John R.; Wernham, Chris V.; Park, Kirsty J. (Wildlife Biology, 2008)
The Scottish populations of salmonids are important both ecologically and economically. Game fisheries for Atlantic salmon Salmo salar, sea trout Salmo trutta trutta and brown trout Salmo trutta fari are all highly acclaimed and generate substantial levels of income for Scotland, but many populations are in decline and efforts are being made to ensure the future sustainability of these species. These declines have led to a focus On the impact of piscivorous bird predation on fish populations. The purpose of our review was to assess the evidence for population-level impacts on salmonid populations, and/or economic impacts on Scottish game fisheries of predation by the four primary UK freshwater piscivorous bird species: cormorant Phalacrocorax carbo, goosander Mergus merganser, red-breasted merganser Mergus serrator and grey heron Ardea cinerea. There is evidence that these birds can, in some situations, remove large numbers of fish from stocked and natural fisheries. However, a lack of information on fish population levels, the numbers and species composition of feeding birds, and robust calculations of fish consumption has hampered the conversion of the results of the existing studies into useful quantitative measures of impact. As a consequence, few studies have demonstrated any reductions in numbers of breeding fish or fish productivity due to predation by piscivorous birds, or direct economic loss to fisheries in Scotland. We support a previous recommendation for a reiterative procedure of modelling, experimentation and remodelling to assess the impacts of piscivorous birds on fisheries. Wide-scale Studies of the movements of piscivorous birds, their feeding locations in relation to river characteristics, and the factors that make fish particularly vulnerable to predation are seen as important areas for future research.
Keywords: Conservation; Trophic Interactions; Common merganser; Mergus merganser; Mergus serrator; Red-breasted merganser

Vitamin A and contaminant concentrations in surf scoters (Melanitta perspicillata) wintering on the Pacific coast of British Columbia, Canada - Harris, M. L.; Wilson, L. K.; Trudeau, S. F.; Elliott, J. E. (Science of the Total Environment, 2007)
Surf scoters are part of a community of sea ducks on the western coast of North America that have shown signs of long-term, unexplained declines in breeding bird numbers. Substantial numbers of scoters; winter in the major harbours on the west coast, after breeding in the west-central northern boreal forest. To address the potential for contaminants to impact the health and survival of those birds, we investigated the condition and contamination of surf scoters during the winters of 1998-2001 at four foraging locations in the Strait of Georgia region of the Pacific coast of Canada. Vitamin A status was evaluated in liver and plasma samples collected from adults and juveniles, as part of a larger assessment of tissue contamination, body condition and biomarker responses. Individuals collected from a relatively contaminated site, Howe Sound, showed consistently low hepatic concentrations of retinol and retinyl palmitate forms of vitamin A, and gender-specific associations of retinyl palmitate with hepatic EROD activity. The relationship of hepatic retinol to retinyl palmitate was not constant across geographic locations, and a clear, linear relationship between the two fortris of vitamin A was only evident in birds from the relatively uncontaminated site. This study also identified strong positive relationships between vitamin A and tissue burdens of cadmium and zinc. The positive association between hepatic retinyl palmitate and renal cadmium is similar to one observed in laboratory rats, in which a mechanism of interference with the controlled release of retinol from the liver was suggested. Published by Elsevier B.V.
Keywords: Nonbreeding Seasons; Melanitta perspicillata; Surf Scoter; Contaminants

Spring Distribution of Marine Birds in the Gulf of Alaska USA - Harrison, C. S. (Condor, 1982)
Aerial surveys of marine birds were conducted in the Gulf of Alaska from March through June 1977. The surveys provide synoptic information on the relative seasonal abundance of seabirds and their use of the continental shelf and slope and deep oceanic areas. Northern fulmars (Fulmarus glacialis), sooty and short-tailed shearwaters (Puffinus griseus and P. tenuirostris), fork-tailed storm-petrels (Oceanodroma furcata), sea ducks, black-legged kittiwakes (Rissa tridactyla), murres (Uria spp.) and tufted puffins (Lunda cirrhata) were the most common of the 35 spp. observed in the Gulf. Most seabirds were found over the continental slope and oceanic waters in March. Densities, especially of shearwaters, increased as birds moved into waters over the continental shelf from April to June. Most species were associated with at least one other, and 11 statistically significant associations (P < 0.05) were found between the 8 most common species. Tufted puffins, Arctic terns and shearwaters were highly associated.
Keywords: Abundance, Distribution, and Trends; Sea Ducks - General; Nonbreeding Seasons

A case of congenital muscular hemiatrophy in a barrow's goldeneye - Harrison, Jeffery G.; Wayre, Philip (Bull Brit Ornithol Club, 1956)
A juvenile goldeneye was seen to have a pronounced limp, and on dissection it was discovered that it was suffering from underdevelopment of the muscles of the right side of the body, presumably due. to a congenital defect. || ABSTRACT AUTHORS: B. L. Sage
Keywords: Disease; Barrow's Goldeneye; Bucephala islandica

Trends and population dynamics of a Velvet Scoter (Melanitta fusca) population: influence of density dependence and winter climate - Hartman, G.; Kolzsch, A.; Larsson, K.; Nordberg, M.; Hoglund, J. (Journal of Ornithology, 2013)
Times Cited: 0 Hartman, Goran Kolzsch, Andrea Larsson, Karl Nordberg, Marcus Hoglund, Jacob 0
Keywords: Abundance, Distribution, and Trends; Melanitta fusca; Nonbreeding Seasons; Population Dynamics; white-winged Scoter

Quantitative Assessment of Current Risks to Harlequin Ducks in Prince William Sound, Alaska, from the Exxon Valdez Oil Spill - Harwell, M. A.; Gentile, J. H.; Parker, K. R.; Murphy, S. M.; Day, R. H.; Bence, A. E.; Neff, J. M.; Wiens, J. A. (Human and Ecological Risk Assessment, 2012)
Times Cited: 2 Harwell, Mark A. Gentile, John H. Parker, Keith R. Murphy, Stephen M. Day, Robert H. Bence, A. Edward Neff, Jerry M. Wiens, John A. 2
Keywords: Nonbreeding Seasons; Harlequin duck; Histrionicus histrionicus; Contaminants

Organo Chlorine and Metal Residues in Eggs of Waterfowl Nesting on Islands in Lake Michigan Off Door County Wisconsin USA 1977-78 - Haseltine, S. D.; Heinz, G. H.; Reichel, W. L.; Moore, J. F. (Pesticides Monitoring Journal, 1981)
One egg from each of 114 red-breasted merganser (Mergus serrator) nests in 1977 and 92 nests in 1978 was collected and later analyzed for organochlorines, polybrominated biphenyls (PBB), polychlorinated styrenes (PCS) and metals. One egg was also collected from each of the dabbling duck nests located. Egg (29) were analyzed for organochlorines and metals in 1977; 10 eggs were analyzed in 1978. All merganser eggs contained DDE, polychlorinated biphenyls (PCB) and dieldrin; all but 1 egg collected in 1978 contained DDT. DDE and PCB levels had declined since 1975 to a geometric mean of 7.4 ppm DDE and 20 ppm PCB in 1977 and 7.6 ppm DDE and 19 ppm PCB in 1978. Dieldrin residues in eggs had not declined from 1975 levels; the geometric mean was 0.78 ppm in 1977 and 0.76 ppm in 1978. Other organochlorines were present at low levels. Hg residues averaged > 0.50 ppm in merganser eggs and had not declined since 1975. Other metals were present at low levels. Dabbling ducks had lower organochlorine and Hg residues than mergansers; DDE and PCB were the only organochlorines present in the majority of eggs. Geometric means of PCB and DDT in dabbling duck eggs did not exceed 2.0 and 1.0 ppm, respectively. PBB and PCS were detected only in a few merganser eggs at low levels. Eggshell thickness for red-breasted merganser eggs averaged 0.359 mm in 1977 and 0.355 mm in 1978, which was 2-3% below pre-1946 thicknesses. Mallard (Anas platyrhynchos) eggshell thicknesses averaged 0.331 mm in 1977 and 0.337 mm in 1978.
Keywords: Breeding Season; Contaminants; Mergus serrator; Red-breasted merganser

Wetland use by white-winged scoters (Melanitta fusca) in the Mackenzie Delta region - Haszard, Shannon; Clark, Robert G. (Wetlands, 2007)
Reasons for apparent declines in populations of white-winged scoters (Melanitta fusca) in the northern boreal forest are not well understood, but some evidence suggests factors associated with the breeding grounds may be responsible. Climate warming or increased forest fire frequency could adversely affect upland or wetland breeding habitats or key food sources for breeding females or ducklings, which in turn may lower productivity. However, very little is known about wetland habitat preferences of scoters. Determining what habitat features scoters need to breed successfully and whether changes in boreal forest breeding habitat affect scoter productivity are important steps towards understanding their ecology and developing appropriate conservation initiatives. Thus, our overall goal was to characterize features of wetlands used by scoter pairs and broods. Additionally, we compared features of wetlands surrounded by recently burned versus unburned forest to investigate whether fire-induced changes in wetland productivity, water chemistry, or amphipod abundance could affect patterns of scoter habitat use. Scoter pairs and broods used wetlands with more abundant amphipods, a finding that is consistent with other waterfowl studies. However, unlike some previous waterfowl studies, we did not find consistent positive correlations between total phosphorus levels and amphipod abundance or wetland use by scoters. We did not detect differences in our measured water chemistry variables, indices of wetland productivity, or amphipod abundance between wetlands surrounded by burned versus unburned forest.
Keywords: Breeding Season; Melanitta fusca; White-winged Scoter; Habitat

The origins of moulting Goosanders on the Eden estuary - Hatton, P. Leslie; Marquiss, M. (Ringing & Migration, 2004)
Moulting Goosanders were counted on the Eden estuary, Fife, UK from 1979 to 1994, and some of these birds were caught and wing-tagged from 1992 to 1994. This paper documents changes in numbers of moulting birds, and their provenance, as determined from subsequent sightings. Goosanders only started to moult on the Eden estuary in the 1980s and their numbers have increased since the late 1980s. This increase also occurred elsewhere on other, geographically similar, Scottish east-coast estuaries. The birds are adult females, and many, though not all, seem faithful to their moult site. Moulting flocks persist from June to October, with a turnover of birds occurring during this period. The moulting birds are drawn primarily from wintering and breeding areas to the south and west of the Eden estuary, in southwest Scotland, England and Wales.
Keywords: Abundance, Distribution, and Trends; Nonbreeding Seasons; Molt; Common merganser; Mergus merganser; Population Delineation

Spatial diastereomer patterns of hexabromocyclododecane (HBCD) in a Norwegian fjord - Haukas, Marianne; Hylland, Ketil; Berge, John Arthur; Nygard, Torgeir; Mariussen, Espen (Science of the Total Environment, 2009)
Hexabromocyclododecane (HBCD) is the third most used brominated flame retardant globally, and has been found widely distributed in the environment. The present study reports concentrations and spatial patterns of alpha, beta and gamma-HBCD in a contaminated Norwegian fjord. Intertidal surface sediment and selected species from the marine food web were sampled at five locations in increasing distance from a known point source of HBCD. All sediment and biota samples were analyzed for the three HBCD diastereomers by liquid chromatography and mass spectrometry (LC/MS). The results demonstrated a HBCD gradient with decreasing concentrations at increasing distance from the point source in sediment and sedentary species, but less so in the species with large feeding ranges. Mean concentrations of Sigma HBCD at the closest/most remote locations relative to the point source were 9000/300 ng g(-1) TOC in sediment and 150/90 ng g(-1) lw in the species with largest feeding range (great black-backed gull). The HBCD diastereomer patterns were similar for each of the matrices (sediment, organisms) independent of distance from the source, indicating no difference in environmental partitioning between the diastereomers. However, the concentration ratio of diastereomers in each matrix ranged from 3:1:10 (alpha:beta:gamma) in the sediments to 55:1 (alpha:gamma) in the highest trophic level species, suggesting diastereomer-specific bioaccumulation in the organisms. (C) 2009 Elsevier B.V. All rights reserved.
Keywords: Common Eider; Contaminants; Somateria mollissima

Molts and Plumages of Ducks (Anatinae): An Evaluation of Pyle (2005) - Hawkins, G. L. (Waterbirds, 2011)
Times Cited: 2 Hawkins, Gerard L. 2
Keywords: Molt; Sea Ducks

Growth and morphology of captive female Common Eider Somateria mollissima ducklings - Hawkins, P. A. J.; Butler, P. J.; Woakes, A. J. (Wildfowl, 1999)
Five female Common Eider ducklings taken under licence from a population at the Isle of May, Firth of Forth, Scotland, were reared from eggs. Weekly measurements were made of the tibiotarsus, ulna, head, ninth primary, body mass, wing and foot area. The body components attained adult size in the following order: tibiotarsus (six weeks), ulna (seven weeks), foot area (eight weeks), body mass and head (nine weeks), wing area and wing loading (ten weeks) and ninth primary (eleven weeks). Paddle index (the ratio of foot area to body mass) remained relatively constant throughout development. Up to and including seven weeks old, body mass could be used as an estimate of age according to the relationship A = 0.005 MB + 0.015, where A = age (weeks) and MB = body mass (g) (R2 = 0.98). 'Feathering up' began by the second week and was completed during weeks seven to eight. There was no noticeable trough in the body mass curve when the ducks fledged at nine to 10 weeks.
Keywords: Breeding Season; Common Eider; Somateria mollissima; Physiology

Estimation of the rate of oxygen consumption of the common eider duck (Somateria mollissima), with some measurements of heart rate during voluntary dives - Hawkins, P. A. J.; Butler, P. J.; Woakes, A. J.; Speakman, J. R. (Journal of Experimental Biology, 2000)
The relationship between heart rate (fH) and rate of oxygen consumption (VO2) was established for a marine diving bird, the common eider duck (Somateria mollissima), during steady-state swimming and running exercise. Both variables increased exponentially with speed during swimming and in a linear fashion during running. Eleven linear regressions of VO2 (ml kg-1 min-1) on fH (beats min-1) were obtained: five by swimming and six by running the birds. The common regression was described by VO2=10.1+0.15fH (r2=0.46, N=272, P<0.0001). The accuracy of this relationship for predicting mean VO2 was determined for a group of six birds by recording fH continuously over a 2-day period and comparing estimated VO2 obtained using the common regression with (i) VO2 estimated using the doubly labelled water technique (DLW) and (ii) VO2 measured using respirometry. A two-pool model produced the most accurate estimated VO2 using DLW. Because of individual variability within mean values of VO2 estimated using both techniques, there was no significant difference between mean VO2 estimated using fH or DLW and measured VO2 values (P>0.2), although individual errors were substantially less when fH was used rather than DLW to estimate VO2. Both techniques are, however, only suitable for estimating mean VO2 for a group of animals, not for individuals. Heart rate and behaviour were monitored during a bout of 63 voluntary dives by one female bird in an indoor tank 1.7 m deep. Tachycardia occurred both in anticipation of and following each dive. Heart rate decreased before submersion but was above resting values for the whole of the dive cycle. Mean fH at mean dive duration was significantly greater than fH while swimming at maximum sustainable surface speeds. Heart rate was used to estimate mean VO2 during the dive cycle and to predict aerobic dive limit (ADL) for shallow dives.
Keywords: Common Eider; Somateria mollissima; Physiology; Energetics and Nutrition

Winter Waterfowl around Pickering Nuclear Generating Station Ontario Canada - Haymes, G. T.; Sheehan, R. W. (Canadian Field-Naturalist, 1982)
The distribution of waterfowl in the area of Pickering Nuclear Generating Station [Ontario, Canada] was studied between 17 Sept. 1979 and 16 April 1980. Dabbling ducks were most abundant in shoreline marshes when these were ice-free. Large concentrations of mallards, Anas platyrhynchos, black ducks, A. rubripes, common mergansers, Mergus serrator, greater scaup, Aythya marila and redheads, A. americana, were present around the station when the marshes were frozen. The station offers warmer water, protection from wind, and food for the waterfowl wintering in the area.
Keywords: Abundance, Distribution, and Trends; Sea Ducks - General; Nonbreeding Seasons; Common merganser

A blood survey of elements, viral antibodies, and hemoparasites in wintering Harlequin Ducks (Histrionicus histrionicus) and Barrow's Goldeneyes (Bucephala islandica) - Heard, Darryl J.; Mulcahy, Daniel M.; Iverson, Samuel A.; Rizzolo, Daniel J.; Greiner, Ellis C.; Hall, Jeff; Ip, Hon; Esler, Daniel (Journal of Wildlife Diseases, 2008)
Twenty-eight Harlequin Ducks (Histrionicus histrionicus) and 26 Barrow's Goldeneyes (Bucephala islandica) were captured in Prince William Sound, Alaska, between 1 and 15 March 2005. Blood was collected for quantification of element concentrations, prevalence of antibodies to several viruses, and hemoparasite prevalence and identification. Although we found selenium concentrations that have been associated with selenosis in some birds (>= 2.0 ppm ww), our findings contribute to a growing literature describing relatively high selenium in apparently healthy birds in marine environments. Avian influenza virus antibodies were detected in the plasma of 28% of the ducks. No antibodies against adenovirus, reovirus, or paramyxovirus 1 were detected. Several hemoparasite species were identified in 7% of ducks. Our findings are similar to those in other free-living marine waterfowl and do not indicate unusual concerns for the health of these species in this area in late winter.
Keywords: Nonbreeding Seasons; Harlequin duck; Histrionicus histrionicus; Disease; Parasites; Barrow's Goldeneye; Bucephala islandica

Presence of a Harlequin Duck Drake During Brood Rearing in Northern Labrador - Heath, Joel P. (Waterbirds, 2008)
Female Harlequin Ducks (Histrionicus histrionicus) incubate eggs and rear broods, while males normally depart the breeding grounds at the onset of incubation. On 27 July 2000, a male Harlequin Duck was observed in association with a female and brood of five ducklings on the Ikadlivik River in northern Labrador. The male maintained some distance (similar to 100 m) from the female and brood; however, upon appearance of a researcher, the group amalgamated and the male appeared to influence the behavior of the female and brood. Possible explanations for earl), male departure and this exception are discussed.
Keywords: Breeding Season; Harlequin duck; Histrionicus histrionicus

When foraging becomes unprofitable: energetics of diving in tidal currents by common eiders wintering in the Arctic - Heath, Joel P.; Gilchrist, H. Grant (Marine Ecology Progress Series, 2010)
A variety of ecological, physiological and environmental factors influence the energy budgets of diving animals. For common eiders Somateria mollissima sedentaria wintering in sea ice habitats in the Canadian Arctic, time and energy costs of diving increase exponentially with tidal current speed. Here we use literature estimates of diving energetics and underwater dive data to quantitatively model net energy gain per dive cycle as a function of current speed. The model indicates a strong non-linear decrease in the profitability of diving with increasing currents, predicting that net energy gain per dive cycle will reach zero and become unprofitable at 1.21 m s(-1) (at 11.3 m depth using baseline parameters from our study). As currents increase travel time, foraging time at the bottom decreases non-linearly, reaching a point where intake is inadequate to balance increasing diving and surface swimming costs. Sensitivity analysis indicates that this threshold is robust over a range of energy expenditure rates and is influenced most by energy intake rate, emphasising the importance of ecological factors such as prey abundance and quality. Eiders stop foraging and rest on the ice well below this threshold in weaker current regimes (similar to 0.8 m s(-1)), at about the point when profitability begins to decelerate. Behavioural time series of diving under constraints of strong tidal current regimes indicate that these eiders do occasionally dive in currents up to similar to 1.2 m s(-1), providing support for the energetic model. Eiders did not dive in faster currents, which could also be influenced by a physiological limit to swimming speed. We conclude that ocean currents can cause a non-linear decrease in net energy balance and are therefore an important and understudied consideration for diving animals. Many functional aspects of diving (e.g. locomotor costs or convective heat loss) have non-linear characteristics; these diminishing returns can be expected to play an important role in the dynamics of behavioural routines and the ability of organisms to respond to environmental variation.
Keywords: Behavior; Common Eider; Nonbreeding Seasons; Somateria mollissima; Energetics and Nutrition

Regulation of stroke pattern and swim speed across a range of current velocities: diving by common eiders wintering in polynyas in the Canadian Arctic - Heath, Joel P.; Gilchrist, H. Grant; Ydenberg, Ronald C. (Journal of Experimental Biology, 2006)
Swim speed during diving has important energetic consequences. Not only do costs increase as drag rises non-linearly with increasing speed, but speed also affects travel time to foraging patches and therefore time and energy budgets over the entire dive cycle. However, diving behaviour has rarely been considered in relation to current velocity. Strong tidal currents around the Belcher Islands, Nunavut, Canada, produce polynyas, persistent areas of open water in the sea ice which are important habitats for wildlife wintering in Hudson Bay. Some populations of common eiders Somateria mollissima sedentaria remain in polynyas through the winter where they dive to forage on benthic invertebrates. Strong tidal currents keep polynyas from freezing, but current velocity can exceed 1.5 m s(-1) and could influence time and energy costs of diving and foraging. Polynyas therefore provide naturally occurring flume tanks allowing investigation of diving strategies of free ranging birds in relation to current velocity. We used a custom designed sub-sea ice camera to non-invasively investigate over 150 dives to a depth of 11.3 m by a population of approximately 100 common eiders at Ulutsatuq polynya during February and March of 2002 and 2003. Current speed during recorded dives ranged from 0 to 1 m s(-1). As currents increased, vertical descent speed of eiders decreased, while descent duration and the number of wing strokes and foot strokes during descent to the bottom increased. However, nearly simultaneous strokes of wings and feet, and swim speed relative to the moving water, were maintained within a narrow range (2.28 +/- 0.23 Hz; 1.25 +/- 0.14 m s(-1), respectively). This close regulation of swim speed over a range in current speed of 1.0 m s(-1) might correspond to efficient muscle contraction rates, and probably reduces work rates by avoiding rapidly increasing drag at greater speeds; however, it also increases travel time to benthic foraging patches. Despite regulation of average swim speed, high instantaneous speeds during oscillatory stroking can increase dive costs due to drag. While most diving birds have been considered either foot or wing propelled, eider ducks used both wing and foot propulsion during descent. Our observations indicate that the power phase of foot strokes coincides with the transition between upstroke and downstroke of the wings, when drag is greatest. Coordinated timing between foot and wing propulsion could therefore serve to maintain a steadier speed during descent and decrease the costs of diving. Despite tight regulation of stroke and swim speed patterns, descent duration and total number of foot and wing strokes during descent increase non-linearly with increasing current velocity, suggesting an increase in energetic costs of diving.
Keywords: Behavior; Common Eider; Nonbreeding Seasons; Somateria mollissima

Can dive cycle models predict patterns of foraging behaviour? Diving by common eiders in an Arctic polynya - Heath, Joel P.; Gilchrist, H. Grant; Ydenberg, Ronald C. (Animal Behaviour, 2007)
There has been wide empirical and theoretical interest in how diving animals allocate time between obtaining oxygen at the surface and foraging at depth. Assuming diminishing returns in oxygen gain at the surface, classic diving models predict that time on the surface should increase, while time spent foraging at depth should first increase and then decrease as travel time increases. Controlled laboratory experiments have indicated partial support for predictions of diving models; however, their usefulness in understanding patterns of diving behaviour in the wild is still in question. We assessed the applicability of diving models to foraging patterns of common elders, Somateria mollissima sedentaria, wintering in the Canadian Arctic. Underwater footage was used to quantify time foraging at depth and duration of surface pauses in relation to changes in travel time induced by strong tidal currents. Consistent with predictions of diving models, bottom foraging time decreased with increasing travel time, while total dive duration was relatively constant at 58.47 +/- 5.32 s, close to the estimated aerobic dive limit for this species. However, durations of surface pauses were not associated with diving parameters, as anticipated from diving models. Durations of surface pauses were highly variable (183.05 +/- 158.06 s) and often considerably longer than necessary to replenish oxygen stores. While the duration of surface pauses predicted by diving models in relation to travel time may be an optimal strategy when obtaining oxygen at the surface is the predominant constraint to foraging, a variety of processes operating at different timescales can influence behavioural patterns in the wild. Preliminary analysis considering the rate of digestive processing suggests that foraging patterns of eiders could be simultaneously influenced by several different rate constraints. Therefore, while static modelling approaches are an important heuristic tool for elucidating mechanisms underlying diving behaviour, dynamic approaches, which can incorporate variables concerning multiple physiological and environmental states, will probably be required to fully understand complex foraging patterns observed in the wild. 2007 The Association for the study of Animal Behaviour. Published by Elsevier Ltd.
Keywords: Behavior; Common Eider; Nonbreeding Seasons; Somateria mollissima

Observation of a Golden Eagle, Aquila chrysaetos, attack on a Harlequin Duck, Histrionicus histrionicus, in northern Labrador - Heath, Joel P.; Goodyear, Geoff; Brazil, Joe (Canadian Field-Naturalist, 2001)
During an aerial survey on the Kingurutik River, northern Labrador, a Golden Eagle (Aquila chrysaetos) was observed attacking a female Harlequin Duck (Histrionicus histrionicus). Although the attack ended unsuccessfully, we believe this was only a result of disturbance by the presence of the helicopter. We overview previous reports of predation on Harlequin Ducks, and emphasize the need for further research investigating the importance of the influence of predators on populations of Harlequin Ducks.
Keywords: Breeding Season; Harlequin duck; Histrionicus histrionicus; Trophic Interactions

Differential use of similar habitat by Harlequin Ducks: trade-offs and implications for identifying critical habitat - Heath, Joel P.; Montevecchi, William A. (Canadian Journal of Zoology, 2008)
Interactions between ecological processes operating at different scales are critical aspects of habitat suitability requiring careful consideration in conservation planning. Our previous research indicated that local abundance and demographics of subpopulations of Harlequin Ducks (Histrionicus histrionicus (L., 1758)), structured in 11 river canyons in northern Labrador, were influenced by predation risk from nest-site-limited raptors. At demographic extremes, where raptors were absent, Harlequin Ducks were stable at high densities, with positive-projected growth, suggesting that they were at carrying capacity and a Source of emigrants. In contrast, where raptors were abundant, low density, highly variable populations of ducks approached local extinction in some years, with subsequent increases suggestive of immigration rescue effects. A comparison of resources for Harlequin Ducks indicated no differences in habitat availability among these putative "source" and "sink" Subpopulations. In the present study, we used multivariate analysis to identify habitat characteristics important for home-range use within these river canyons and to develop habitat suitability indices (HSI). Despite similar habitat availability, different characteristics were locally important. In a sink where predation risk was high, only danger-reducing habitat characteristics (i.e., overhang vegetation) were identified as important, whereas invertebrates was a predominant characteristic of the source HSI. Despite similar habitat availability, HSI developed in source and sink habitats would, respectively, over- and under-estimate regional habitat availability. Informed conservation and management strategies will therefore require integrating individual trade-offs about predation risk and resources into a multiscale context.
Keywords: Breeding Season; Harlequin duck; Histrionicus histrionicus; Dispersal; Population Dynamics; Habitat

Allocating Foraging Effort Across Multiple Time Scales: Behavioral Responses to Environmental Conditions by Harlequin Ducks Wintering at Cape St. Mary's, Newfoundland - Heath, Joel P.; Montevecchi, William A.; Robertson, Gregory J. (Waterbirds, 2008)
Foraging behavior of Harlequin Ducks (Histrionicus histrionicus) and its response to changing environmental conditions during winter was investigated at Cape St. Mary's, Newfoundland. Behavioral synchrony among individuals permitted continuous observations of flocks to be conducted, sometimes over entire (lays. Overall foraging effort of Harlequin Ducks was examined at two organizational levels: dive cycles (dive and Surface pause) and foraging cycles (foraging bout and rest bout). Overall foraging effort decreased at greater tide depths as Harlequin Ducks decreased the duration of foraging])out:. Dive:pause ratios did not change Within these shorter foraging bouts at high tides, however the duration of dives, pauses, and the total (live cycle all increased. Overall foraging effort decreased in response to increased wind/wave exposure due to a decrease in dive duration. Overall foraging effort did not change in response to decreasing ambient temperature; however the frequency of (live cycles decreased which Could decrease energy expenditure associated with post-dive thermoregulatory Costs. Overall foraging effort increased throughout the day, particularly ill the last foraging bout before the overnight fasting period. Interestingly, this strategy was accomplished by decreasing dive durations but increasing foraging bout duration. These opposite results across levels of behavioral organization are interpreted in the context of intermittent exercise and locomotion whereby decreasing effort at one level of energy expenditure could allow for increased effort at another. Therefore, different (and sometimes opposite) responses to environmental conditions can occur at different levels of behavioral organization. Even when overall foraging effort remains unchanged, the strategy employed can differ in its temporal allocation or frequency, which Could be important in balancing energy budgets tinder increased energetic costs and/or time constraints. These results, have particularly important implications for interpreting behavioral responses investigated at only a single level of behavior, extrapolating data front brief observation periods to longer time scales, and foraging models which only consider single levels of behavior such as the dive cycle.
Keywords: Behavior; Nonbreeding Seasons; Harlequin duck; Histrionicus histrionicus; Energetics and Nutrition

Population structure of breeding Harlequin Ducks and the influence of predation risk - Heath, J. P.; Robertson, G. J.; Montevecchi, W. A. (Canadian Journal of Zoology, 2006)
Landscape features can have an important influence on the characteristics of populations, often resulting in heterogeneity in demographic processes. Therefore, local measurements of population parameters may not reflect regional characteristics. We studied populations of Harlequin Ducks (Histrionicus histrionicus L., 1758) breeding in 11 river canyons in northern Labrador in relation to biophysical habitat characteristics and abundance of avian predators. Density and stability of Harlequin Duck populations varied among river canyons and were positively related (mean of 4.7 survey years per river). Both density and stability were negatively related to densities of raptorial birds. Raptor density was related to availability of suitable cliff ledges for nesting. Comparison of rivers with stable, high-density Harlequin Duck populations and those with variable, low-density populations revealed no detectable differences in habitat or prey availability. In a high-density population, observed stability but positive projected growth suggested the system was at carrying capacity and a source of emigrants. In contrast, unstable, low-density populations approached local extinction in some years, while large increases in subsequent years were suggestive of immigration. These findings demonstrate that breeding aggregations in different river canyons could represent an important unit of demographic structure. The abundance of raptors appears to be an important factor influencing local characteristics of Harlequin Duck populations. We discuss the potential influence of local demographic differences on regional population dynamics and their importance for conservation management strategies for migratory species.
Keywords: Breeding Season; Harlequin duck; Histrionicus histrionicus; Dispersal; Population Dynamics; Habitat

Consumption of fish and other prey items by Lake Erie waterbirds - Hebert, Craig E.; Morrison, Heather A. (Journal of Great Lakes Research, 2003)
Lake Erie provides valuable habitat for large populations of waterbirds that rely on fish and other aquatic biota for food. To better understand the relationship between waterbirds and their prey, it is important to quantify the role of waterbirds in the food web. Field observations of their population sizes and diet preferences were applied to a bioenergetics model to estimate consumption of fish and other items by waterbird species occupying the three basins of Lake Erie in the late 1990s. The total quantity of fishes consumed annually by resident and migrating birds on Lake Erie was 18,776 metric tons. Fish consumption by nesting and migrant waterbirds was greatest in the western basin of Lake Erie (14,784 metric tons/yr) followed by the eastern (2,078 metric tons/yr) and central (1,914 metric tons/yr) basins. Migrant populations of red-breasted mergansers consumed the most fish (6,612 metric tons/yr). These diving ducks consumed approximately 35% of the total amount of fish consumed by waterbirds on the lake. Nesting populations of double-crested cormorants (5,857 metric tons/yr), nesting populations of herring gulls (1,597 metric tons/yr), and migrant common mergansers (1,149 metric tons/yr), were the second, third, and fourth largest consumers of fish from Lake Erie, respectively. Waterbirds consume approximately four times more fish by weight than were harvested by Ontario's commercial fishery in 2000; however, in general, the species of fishes most often consumed by waterbirds are not of economic importance. However, there may be exceptions to this rule.
Keywords: Nonbreeding Seasons; Energetics and Nutrition; Trophic Interactions; Common merganser; Mergus merganser; Mergus serrator; Red-breasted merganser

Adaptive variation of airspeed in relation to wind, altitude and climb rate by migrating birds in the Arctic - Hedenstrom, Anders; Alerstam, Thomas; Green, Martin; Gudmundsson, Gudmundur A. (Behavioral Ecology and Sociobiology, 2002)
The power expenditure of flapping flight in birds is characterised by a U-shaped function of speed through the air. From this relationship and the assumption of limited power available from flight muscles, it is possible to predict changes in the birds' airspeed in relation to external factors such as wind. These predictions are derived from flight mechanical theory and optimality criteria concerning migration or transport flight economy. Using tracking radar we measured flight speeds of migrating birds at 12 sites along the Northwest Passage in arctic Canada. We analysed variation in airspeed (Va) in relation to the wind effect (Vg-Va, where Vg is the groundspeed), vertical speed (Vz), altitude (z) and the compensation for the amount of side wind (1/cosalpha, where alpha is the angle between track and heading). We found significant effects on the variation in Va for all four variables, revealed by multiple regression analysis, but the total variation explained was relatively small suggesting that other factors might be involved. The signs of the regression coefficients were as predicted, except for the effect of side wind where we found a negative relationship between Va and 1/cosalpha, possibly because our sample included an unknown mixture of bird species. We also compiled information from the literature from studies reporting analyses of the effects of the four variables on Va. Adjustment of Va in relation to the wind effect seems nearly omnipresent among birds, while the effects of vertical speed and altitude have been reported surprisingly few times. An increased Va with increasing alpha (and 1/cosalpha) has not been found yet, perhaps due to the lack of critical observation conditions.
Keywords: Behavior; Common Eider; Nonbreeding Seasons; Migration; Somateria mollissima

Identification of conservation units in the European Mergus merganser based on nuclear and mitochondrial DNA markers - Hefti-Gautschi, Barbara; Pfunder, Monika; Jenni, Lukas; Keller, Verena; Ellegren, Hans (Conservation Genetics, 2009)
The conservation status of small breeding areas of the Goosander (Mergus merganser merganser) in Central Europe is unclear. Geographic isolation of these areas suggests restricted gene flow to and from large North-European populations. On the other hand, migrating Goosanders from northern Europe join the Central European breeding population for wintering. To evaluate the conservation status of the small breeding areas we assessed the genetic structure of M. merganser populations in Europe by examining two nuclear marker systems (microsatellites and Single Nucleotide Polymorphisms, SNP) and mitochondrial (mtDNA) control region sequence variation for Goosanders in 11 sampling areas representing three of five distinct breeding areas and two subspecies (M. m. merganser and M. m. americanus). Overall population differentiation estimates including both subspecies were high, both based on mtDNA (Phi(ST) = 0.899; P < 0.0001) and nuclear markers (theta(ST) = 0.219; 95% CI 0.088-0.398, SNP and microsatellites combined). Within Europe, mtDNA revealed a strong overall (Phi(ST) = 0.426; P < 0.0001) and significant pairwise population differentiation between almost all comparisons. In contrast, both nuclear marker systems combined revealed only a small overall genetic differentiation (theta(ST) = 0.022; 95% CI 0.003-0.041). The strong genetic differentiation based on female-inherited mtDNA but not on biparentally inherited nuclear markers can be explained by sex-biased dispersal and strong female philopatry. Therefore, small breeding areas in Europe are endangered despite large male-mediated gene-flow, because when these populations decline, only males-but due to strong philopatry not females-can be efficiently supplemented by migration from the large North European populations. We therefore propose to manage the small breeding areas independently and to strengthen conservation efforts for this species in Central Europe.
Keywords: Breeding Season; Dispersal; Common merganser; Mergus merganser; Population Delineation

High resolution species distribution models of two nesting water bird species: a study of transferability and predictive performance - Heinanen, S.; Erola, J.; von Numers, M. (Landscape Ecology, 2012)
Times Cited: 0 Heinanen, Stefan Erola, Johnny von Numers, Mikael 0

High-resolution sea duck distribution modeling: Relating aerial and ship survey data to food resources, anthropogenic pressures, and topographic variables - Heinanen, S.; Zydelis, R.; Dorsch, M.; Nehls, G.; Skov, H. (CONDOR, 2017)
Anthropogenic developments in marine coastal zones potentially overlap with areas of conservation interest, including important areas for birds. Ideally, spatial patterns of species abundance should be considered at ecologically relevant spatial resolutions (high resolutions) to inform spatial planning and environmental assessments. Most planning so far, however, has relied on coarse-resolution distribution maps from atlas projects or models often based on limited datasets (few surveys), and relationships with environmental variables have rarely been taken into account, leaving many studies and recommendations vulnerable to criticism. We therefore combined the strengths of a detailed database of spatially explicit aerial and ship surveys with high-resolution environmental predictors and species distribution models to predict detailed density patterns for 3 sea duck species, as part of an environmental impact assessment (EIA) in the southern Baltic Sea. We also compared the results from 2 different survey platforms to assess potential differences. We related survey data for Common Eiders (Somateria mollissima), Long-tailed Ducks (Clangula hyemalis), and Common Scoters (Melanitta nigra) to topographic variables, food resources, and anthropogenic pressures using 2-step generalized additive models accounting for zero inflation, nonnormality, and nonlinearity. We accurately predicted distribution patterns (the area under the receiver operating characteristic curve [AUC]: 0.79-0.84) and abundances (Spearman's correlation: 0.36-0.62) at a resolution of 750 m. However, abundance predictions based on aerial survey data differed in magnitude in comparison with predictions from ship survey data, particularly for the frequently diving Long-tailed Duck. We suggest that the main source of the differing abundance estimates was differences in the input data collected using different survey platforms, rather than the modeling approach. A correction factor for birds missed during surveys due to diving activity would therefore increase the accuracy of abundance estimates. Our results show that it is possible to fit ecologically interpretable relationships between species and environmental variables, allowing for the creation of high-resolution predictions useful for management and conservation.
Times Cited in Web of Science Core Collection: 11 Total Times Cited: 11 Cited Reference Count: 70
Keywords: species distribution modeling; GAM; Common Eider; Long-tailed Duck; ABUNDANCE; CLANGULA-HYEMALIS; CONSERVATION; SEABIRDS; MARINE BIRDS; aerial surveys; WINTERING SURF; Common Scoter; habitat modeling; HABITAT MODELS; PREDICTION; SCOTER MELANITTA-NIGRA; ship surveys; SPECIES DISTRIBUTION

Diving times of a common goldeneye - Heintzelman, Donald S. (Wilson Bull, 1963)
The common goldeneye dove, on the average, for 14.15 seconds but there was a wide range of diving times exhibited. || ABSTRACT AUTHORS: T. W. Porter
Keywords: Behavior; Bucephala clangula; Common Goldeneye

Relationships of Environmental Contaminants to Reproductive Success in Red-Breasted Mergansers Mergus-Serrator from Lake Michigan USA - Heinz, G. H.; Haseltine, S. D.; Reichel, W. L.; Hensler, G. L. (Environmental Pollution Series A Ecological and Biological, 1983)
In 1977 and 1978, red-breasted mergansers M. serrator nesting on islands in northwestern Lake Michigan were studied to determine whether environmental contaminants had effected reproduction. Contaminants (17) were measured in randomly chosen eggs from 206 nests. A variety of statistical approaches were used to study the effects of individual contaminants and combinations of contaminants on reproductive measurements such as nest desertion, failure of eggs to hatch, death of newly hatched ducklings, percentage hatching success, number of ducklings leaving the nest and eggshell thickness. Relationships between the levels of some contaminants in blood samples of 39 incubating females and reproductive success were also determined. A small degree of eggshell thinning was attributed to DDE and a few other statistical tests were significant, but no contaminant or combination of contaminants seemed to have had a pronounced effect on reproduction.
Keywords: Breeding Season; Contaminants; Productivity; Mergus serrator; Red-breasted merganser

Species Differences in the Sensitivity of Avian Embryos to Methylmercury - Heinz, Gary H.; Hoffman, David J.; Klimstra, Jon D.; Stebbins, Katherine R.; Kondrad, Shannon L.; Erwin, Carol A. (Archives of Environmental Contamination and Toxicology, 2009)
We injected doses of methylmercury into the air cells of eggs of 26 species of birds and examined the dose-response curves of embryo survival. For 23 species we had adequate data to calculate the median lethal concentration (LC50). Based on the dose-response curves and LC(50)s, we ranked species according to their sensitivity to injected methylmercury. Although the previously published embryotoxic threshold of mercury in game farm mallards (Anas platyrhynchos) has been used as a default value to protect wild species of birds, we found that, relative to other species, mallard embryos are not very sensitive to injected methylmercury; their LC50 was 1.79 mu g/g mercury on a wet-weight basis. Other species we categorized as also exhibiting relatively low sensitivity to injected methylmercury (their LC(50)s were 1 mu g/g mercury or higher) were the hooded merganser (Lophodytes cucullatus), lesser scaup (Aythya affinis), Canada goose (Branta canadensis), double-crested cormorant (Phalacrocorax auritus), and laughing gull (Larus atricilla). Species we categorized as having medium sensitivity (their LC(50)s were greater than 0.25 mu g/g mercury but less than 1 mu g/g mercury) were the clapper rail (Rallus longirostris), sandhill crane (Grus canadensis), ring-necked pheasant (Phasianus colchicus), chicken (Gallus gallus), common grackle (Quiscalus quiscula), tree swallow (Tachycineta bicolor), herring gull (Larus argentatus), common tern (Sterna hirundo), royal tern (Sterna maxima), Caspian tern (Sterna caspia), great egret (Ardea alba), brown pelican (Pelecanus occidentalis), and anhinga (Anhinga anhinga). Species we categorized as exhibiting high sensitivity (their LC(50)s were less than 0.25 mu g/g mercury) were the American kestrel (Falco sparverius), osprey (Pandion haliaetus), white ibis (Eudocimus albus), snowy egret (Egretta thula), and tri-colored heron (Egretta tricolor). For mallards, chickens, and ring-necked pheasants (all species for which we could compare the toxicity of our injected methylmercury with that of published reports where methylmercury was fed to breeding adults and was deposited into the egg by the mother), we found the injected mercury to be more toxic than the same amount of mercury deposited naturally by the mother. The rank order of sensitivity of these same three species to methylmercury was, however, the same whether the methylmercury was injected or maternally deposited in the egg (i.e., the ring-necked pheasant was more sensitive than the chicken, which was more sensitive than the mallard). It is important to note that the dose-response curves and LC(50)s derived from our egg injections are useful for ranking the sensitivities of various species but are not identical to the LC(50)s that would be observed if the mother bird had put the same concentrations of mercury into her eggs; the LC(50)s of maternally deposited methylmercury would be higher.
Keywords: Contaminants; Hooded Merganser; Lophodytes cucullatus

Declines in organochlorines in eggs of red-breasted mergansers from Lake Michigan, 1977-1978 versus 1990 - Heinz, Gary H.; Miller, David S.; Ebert, Brain J.; Stromborg, Kenneth L. (Environmental Monitoring and Assessment, 1994)
From 1977-1978 to 1990, concentrations of polychlorinated biphenyls (PCBs) and most organochlorine pesticides declined in eggs of red-breasted mergansers (Mergus serrator) nesting on islands in northwestern Lake Michigan. Total PCBs decreased 60% (from 21 ppm in 1977-1978 to 8.5 ppm in 1990) and p,p'-DDE decreased 66% (from 6.5 to 2.2 ppm). Dieldrin decreased only 16% (from 0.82 to 0.69 ppm). In 1990, 79.1% of incubated eggs hatched, which was not significantly different from the 83.5% that hatched in 1977-1978.
Keywords: Breeding Season; Contaminants; Mergus serrator; Red-breasted merganser

Further declines in organochlorines in eggs of red-breasted mergansers from Lake Michigan, 1977-1978 versus 1990 versus 2002 - Heinz, Gary H.; Stromborg, Kenneth L. (Environmental Monitoring and Assessment, 2009)
From 1977-1978 to 1990, concentrations of polychlorinated biphenyls (PCBs) and most organochlorine pesticides declined in eggs of red-breasted mergansers (Mergus serrator) nesting on islands in northwestern Lake Michigan. Further declines took place between 1990 and 2002. Between 1977-1978 and 1990 total PCBs decreased 60% (from 21 to 8.5 mu g/g, wet weight). An additional decline of 46% took place between 1990 and 2002 (8.5 to 4.6 mu g/g). Between 1977-1978 and 1990 p,p (')-DDE decreased 66% (from 6.5 to 2.2 mu g/g), and from 1990 to 2002 an additional decline of 36% took place (from 2.2 to 1.4 mu g/g). Between 1977-1978 and 1990 dieldrin decreased only 16% (from 0.82 to 0.69 mu g/g), but from 1990 to 2002 a 96% decrease occurred (from 0.69 to 0.03 mu g/g).
Keywords: Breeding Season; Contaminants; Mergus serrator; Red-breasted merganser

Distribution and Habitat Use of Waterfowl Wintering in Oklahoma USA - Heitmeyer, M. E.; Vohs, P. A. Jr (Journal of Wildlife Management, 1984)
The distribution and habitats of waterfowl were studied in Oklahoma during winters 1978-1979 and 1979-1980. A stratified random sample of quarter sections of land area was used to sample wetland habitats and waterfowl wintering on small scattered wetlands in Oklahoma. Aerial and ground counts of waterfowl on large reservoirs and national wildlife refuges provided a perspective of the statewide role of smaller water basins in maintaining wintering waterfowl populations. Dabbling ducks preferred natural wetlands over man-made impoundments. Most common mergansers (Mergus merganser) wintered on reservoirs and most geese (Chen caerulescens, Branta canadensis) wintered on national wildlife refuges associated with large reservoirs. Numbers of dabbling ducks decreased on reservoirs during late winter and simultaneously increased on small natural wetlands. Small wetlands were differentially selected by paired and female mallards (Anas platyrhynchos) and were used primarily as feeding habitats. Dabbling ducks used palustrine wetlands more in 1979-1980 than in 1978-1979, apparently because of increased wetland numbers, hectares of surface water, diversity of wetland types, and emergent vegetation-open water interspersion of palustrine basins during 1979-1980. Protection of natural wetlands and unaltered rivers appears more ecologically beneficial to dabbling ducks wintering in Oklahoma than enhancing areas associated with large reservoirs and/or construction of farm ponds.
Keywords: Abundance, Distribution, and Trends; Sea Ducks - General; Nonbreeding Seasons; Common merganser; Habitat

Modeling the effectiveness of oil combating from an ecological perspective - A Bayesian network for the Gulf of Finland; the Baltic Sea - Helle, Inari; Lecklin, Tiina; Jolma, Ari; Kuikka, Sakari (Journal of Hazardous Materials, 2011)
Maritime traffic poses a major threat to marine ecosystems in the form of oil spills. The Gulf of Finland, the easternmost part of the Baltic Sea, has witnessed a rapid increase in oil transportation during the last 15 years. Should a spill occur, the negative ecological impacts may be reduced by oil combating, the effectiveness of which is, however, strongly dependent on prevailing environmental conditions and available technical resources. This poses increased uncertainty related to ecological consequences of future spills. We developed a probabilistic Bayesian network model that can be used to assess the effectiveness of different oil combating strategies in minimizing the negative effects of oil on six species living in the Gulf of Finland. The model can be used for creating different accident scenarios and assessing the performance of various oil combating actions under uncertainty, which enables its use as a supportive tool in decision-making. While the model is confined to the western Gulf of Finland, the methodology is adaptable to other marine areas facing similar risks and challenges related to oil spills. (C) 2010 Elsevier B.V. All rights reserved.
Keywords: Sea Ducks - General; Contaminants

Do state-mediated hormones predict reproductive decisions in Arctic-nesting common eiders? - Hennin, H. L.; Bety, J.; Gilchrist, H. G.; Love, O. P. (Integrative and Comparative Biology, 2012)
Times Cited: 0 Hennin, H. L. Bety, J. Gilchrist, H. G. Love, O. P. Annual Meeting of the Society-for-Integrative-and-Comparative-Biology (SICB) JAN 03-07, 2012 Charleston, SC 0 1
Keywords: Breeding Season; Physiology; Common eider; somateria mollissima

Energetic Physiology Mediates Individual Optimization of Breeding Phenology in a Migratory Arctic Seabird - Hennin, H. L.; Bety, J.; Legagneux, P.; Gilchrist, H. G.; Williams, T. D.; Love, O. P. (American Naturalist, 2016)
The influence of variation in individual state on key reproductive decisions impacting fitness is well appreciated in evolutionary ecology. Rowe et al. (1994) developed a condition-dependent individual optimization model predicting that three key factors impact the ability of migratory female birds to individually optimize breeding phenology to maximize fitness in seasonal environments: arrival condition, arrival date, and ability to gain in condition on the breeding grounds. While empirical studies have confirmed that greater arrival body mass and earlier arrival dates result in earlier laying, no study has assessed whether individual variation in energetic management of condition gain effects this key fitness-related decision. Using an 8-year data set from over 350 prebreeding female Arctic common eiders (Somateria mollissima), we tested this component of the model by examining whether individual variation in two physiological traits influencing energetic management (plasma triglycerides: physiological fattening rate; baseline corticosterone: energetic demand) predicted individual variation in breeding phenology after controlling for arrival date and body mass. As predicted by the optimization model, individuals with higher fattening rates and lower energetic demand had the earliest breeding phenology (shortest delays between arrival and laying; earliest laying dates). Our results are the first to empirically determine that individual flexibility in prebreeding energetic management influences key fitness-related reproductive decisions, suggesting that individuals have the capacity to optimally manage reproductive investment.
Hennin, Holly L. Bety, Joel Legagneux, Pierre Gilchrist, H. Grant Williams, Tony D. Love, Oliver P.
Keywords: Breeding Season; Common Eider; Somateria mollissima; Physiology; Energetics and Nutrition

Higher rates of prebreeding condition gain positively impacts clutch size: A mechanistic test of the condition-dependent individual optimization model - Hennin, H. L.; Dey, C. J.; Bety, J.; Gilchrist, H. G.; Legagneux, P.; Williams, T. D.; Love, O. P. (FUNCTIONAL ECOLOGY, 2018)
1. A combination of timing of and body condition (i.e., mass) at arrival on the breeding grounds interact to influence the optimal combination of the timing of reproduction and clutch size in migratory species. This relationship has been formalized by Rowe et al. in a condition-dependent individual optimization model (American Naturalist, 1994, 143, 689-722), which has been empirically tested and validated in avian species with a capital-based breeding strategy. 2. This model makes a key, but currently untested prediction; that variation in the rate of body condition gain will shift the optimal combination of laying date and clutch size. This prediction is essential because it implies that individuals can compensate for the challenges associated with late timing of arrival or poor body condition at arrival on the breeding grounds through adjustment of their life history investment decisions, in an attempt to maximize fitness. 3. Using an 11-year data set in arctic-nesting common eiders (Somateria mollissima), quantification of fattening rates using plasma triglycerides (an energetic metabolite), and a path analysis approach, we test this prediction of this optimization model; controlling for arrival date and body condition, females that fatten more quickly will adjust the optimal combination of lay date and clutch size, in favour of a larger clutch size. 4. As predicted, females fattening at higher rates initiated clutches earlier and produced larger clutch sizes, indicating that fattening rate is an important factor in addition to arrival date and body condition in predicting individual variation in reproductive investment. However, there was no direct effect of fattening rate on clutch size (i.e., birds laying on the same date had similar clutch sizes, independent of their fattening rate). Instead, fattening rate indirectly affected clutch size via earlier lay dates, thus not supporting the original predictions of the optimization model. 5. Our results demonstrate that variation in the rate of condition gain allows individuals to shift flexibly along the seasonal decline in clutch size to presumably optimize the combination of laying date and clutch size.
Times Cited in Web of Science Core Collection: 13 Total Times Cited: 13 Cited Reference Count: 82
Keywords: common eider; COMMON EIDERS; SOMATERIA-MOLLISSIMA; REPRODUCTION; clutch size; LIFE-HISTORY; BODY-MASS CHANGES; condition gain; DIFFERENTIAL ALLOCATION; EGG; fattening rate; individual optimization; laying date; path analysis; PLASMA METABOLITE PROFILES; TIME CONSTRAINTS; TRADE-OFFS; triglyceride

Pre-breeding energetic management in a mixed-strategy breeder - Hennin, H. L.; Legagneux, P.; Bety, J.; Williams, T. D.; Gilchrist, H. G.; Baker, T. M.; Love, O. P. (Oecologia, 2015)
Integrative biologists have long appreciated that the effective acquisition and management of energy prior to breeding should strongly influence fitness-related reproductive decisions (timing of breeding and reproductive investment). However, because of the difficulty in capturing pre-breeding individuals, and the tendency towards abandonment of reproduction after capture, we know little about the underlying mechanisms of these life-history decisions. Over 10 years, we captured free-living, arctic-breeding common eiders (Somateria mollissima) up to 3 weeks before investment in reproduction. We examined and characterized physiological parameters predicted to influence energetic management by sampling baseline plasma glucocorticoids (i.e., corticosterone), very-low-density lipoprotein (VLDL), and vitellogenin (VTG) for their respective roles in mediating energetic balance, rate of condition gain (physiological fattening rate) and reproductive investment. Baseline corticosterone increased significantly from arrival to the initiation of reproductive investment (period of rapid follicular growth; RFG), and showed a positive relationship with body mass, indicating that this hormone may stimulate foraging behaviour to facilitate both fat deposition and investment in egg production. In support of this, we found that VLDL increased throughout the pre-breeding period, peaking as predicted during RFG. Female eiders exhibited unprecedentedly high levels of VTG well before their theoretical RFG period, a potential strategy for pre-emptively depositing available protein stores into follicles while females are simultaneously fattening. This study provides some of the first data examining the temporal dynamics and interaction of the energetic mechanisms thought to be at the heart of individual variation in reproductive decisions and success in many vertebrate species.
Hennin, Holly L. Legagneux, Pierre Bety, Joel Williams, Tony D. Gilchrist, H. Grant Baker, Tyne M. Love, Oliver P.
Keywords: Breeding Season; Common Eider; Physiology; Energetics and Nutrition

Preparatory energetic management in a pre-breeding seaduck - Hennin, H. L.; Legagneux, P.; Bety, J.; Williams, T. D.; Gilchrist, H. G.; Baker, T. M.; Love, O. P. (Integrative and Comparative Biology, 2015)
Common Eider; Somateria mollissima; Breeding Season; Energetics and Nutrition; Physiology
Hennin, H. L. Legagneux, P. Bety, J. Williams, T. D. Gilchrist, H. G. Baker, T. M. Love, O. P. Annual Meeting of the Society-for-Integrative-and-Comparative-Biology (SICB) Jan 03-07, 2015 West Palm Beach, FL Soc Integrat & Comparat Biol 1

Plasma mammalian leptin analogue predicts reproductive phenology, but not reproductive output in a capital-income breeding seaduck - Hennin, H. L.; Legagneux, P.; Gilchrist, H. G.; Bety, J.; McMurtry, J. P.; Love, O. P. (ECOLOGY AND EVOLUTION, 2019)
To invest in energetically demanding life history stages, individuals require a substantial amount of resources. Physiological traits, particularly those related to energetics, can be useful for examining variation in life history decisions and trade-offs because they result from individual responses to environmental variation. Leptin is a protein hormone found in mammals that is proportional to the amount of endogenous fat stores within an individual. Recently, researchers have confirmed that a mammalian leptin analogue (MLA), based on the mammalian sequence of leptin, is present with associated receptors and proteins in avian species, with an inhibitory effect on foraging and body mass gain at high circulating levels. While MLA has been both quantified and manipulated in avian species, little is currently known regarding whether plasma MLA in wild-living species and individuals is associated with key reproductive decisions. We quantified plasma MLA in wild, Arctic-nesting female common eiders (Somateria mollissima) at arrival on the breeding grounds and followed them to determine subsequent breeding propensity, and reproductive phenology, investment, and success. Common eiders are capital-income breeding birds that require the accumulation of substantial fat stores to initiate laying and successfully complete incubation. We found that females with lower plasma MLA initiated breeding earlier and in a shorter period of time. However, we found no links between plasma MLA levels and breeding propensity, clutch size, or reproductive success. Although little is still known about plasma MLA, based on these results and its role in influencing foraging behaviors and condition gain, plasma MLA appears to be closely linked to reproductive timing and is therefore likely to underlie trade-offs surrounding life history decisions.
Times Cited in Web of Science Core Collection: 4 Total Times Cited: 4 Cited Reference Count: 55
Keywords: common eider; BODY CONDITION; clutch size; LIFE-HISTORY; PROTEIN; CONDITION-DEPENDENT MODEL; reproductive success; TRADE-OFFS; CHICKEN; ENDOCRINOLOGY; energetic demand; INDIVIDUAL OPTIMIZATION; leptin; MIGRATORY BIRD; plasma mammalian leptin analogue; RECEPTOR; reproductive phenology

Baseline glucocorticoids are drivers of body mass gain in a diving seabird - Hennin, H. L.; Wells-Berlin, A. M.; Love, O. P. (Ecology and Evolution, 2016)
Life-history trade-offs are influenced by variation in individual state, with individuals in better condition often completing life-history stages with greater success. Although resource accrual significantly impacts key life-history decisions such as the timing of reproduction, little is known about the underlying mechanisms driving resource accumulation. Baseline corticosterone (CORT, the primary avian glucocorticoid) mediates daily and seasonal energetics, responds to changes in food availability, and has been linked to foraging behavior, making it a strong potential driver of individual variation in resource accrual and deposition. Working with a captive colony of white-winged scoters (Melanitta fusca deglandi), we aimed to causally determine whether variation in baseline CORT drives individual body mass gains mediated through fattening rate (plasma triglycerides corrected for body mass). We implanted individuals with each of three treatment pellets to elevate CORT within a baseline range in a randomized order: control, low dose of CORT, high dose of CORT, then blood sampled and recorded body mass over a two-week period to track changes in baseline CORT, body mass, and fattening rates. The high CORT treatment significantly elevated levels of plasma hormone for a short period of time within the biologically relevant, baseline range for this species, but importantly did not inhibit the function of the HPA (hypothalamic-pituitary-adrenal) axis. Furthermore, an elevation in baseline CORT resulted in a consistent increase in body mass throughout the trial period compared to controls. This is some of the first empirical evidence demonstrating that elevations of baseline CORT within a biologically relevant range have a causal, direct, and positive influence on changes in body mass.
Hennin, Holly L. Wells-Berlin, Alicia M. Love, Oliver P.
Keywords: Melanitta fusca; White-winged Scoter; Physiology

Contaminants and Sea Ducks in Alaska and the Circumpolar Region - Henny, Charles J.; Rudis, Deborah D.; Roffe, Thomas J.; Robinson-Wilson, Everett (Environmental Health Perspectives, 1995)
Keywords: Sea Ducks - General; Contaminants

Using Inuit traditional ecological knowledge for detecting and monitoring avian cholera among Common Eiders in the eastern Canadian Arctic - Henri, D. A.; Jean-Gagnon, F.; Gilchrist, H. G. (ECOLOGY AND SOCIETY, 2018)
In recent decades, traditional ecological knowledge (TEK) has played an increasing role in wildlife management and biodiversity conservation in Canada and elsewhere. This study examined the potential contribution that Inuit TEK (which is one aspect of Inuit Qaujimajatuqangit or Inuit traditional knowledge) could offer to detect and monitor avian cholera and other disease-related mortality among Northern Common Eiders (Somateria mollissima borealis) breeding in the eastern Canadian Arctic. Avian cholera is an infectious disease (Pasteurella multocida) that has been a major conservation issue because of its potential to cause high rates of disease and mortality in several bird species in repeating epizootics; it has spread geographically in North America since the 1940s. In 2004, Inuit hunters from Ivujivik, Nunavik, Quebec, were the first to detect avian disease outbreaks among Northern Common Eiders nesting in northeastern Hudson Bay and western Hudson Strait. Laboratory analysis of bird tissues confirmed avian cholera in that region. From 2007 to 2009, we collected Inuit TEK about mortality among Common Eiders and other bird species north and west of where the outbreaks were first detected. During interviews in the communities of Kimmirut, Cape Dorset, Coral Harbour, and Igloolik, Nunavut, Canada (n = 40), Inuit participants reported seeing a total of 8 Common Eiders and 41 specimens of other bird species either sick or dead in northern Hudson Strait, Hudson Bay, and Foxe Basin. Most of the observed disease and mortality events were at sea, on sea ice, or on small nesting islands. Such events probably would have gone undetected by biologists, who were mainly monitoring avian cholera outbreaks on large nesting islands in that region. Inuit participants readily recalled details about the timing, location, and numbers of sick and dead birds that they observed. Some reported signs of disease that were consistent with avian cholera. Inuit also revealed knowledge of two past bird mass mortality events that took place about 60 years and a century ago. Those interviewed indicated that that bird mass mortality events potentially caused by avian cholera had not occurred in the study area prior to 2004, supporting the hypothesis that avian cholera emerged only recently in the eastern Canadian Arctic. This study demonstrated that TEK can be a valuable tool for monitoring future avian cholera outbreaks and other wildlife diseases in remote regions.
Times Cited in Web of Science Core Collection: 15 Total Times Cited: 15 Cited Reference Count: 75
Keywords: Common Eider; NORTH; POPULATION; avian cholera; CHALLENGES; community-based monitoring; DECLINES; DISEASE; Inuit Qaujimajatuqangit; Nunavik; Nunavut; PARTICIPATION; traditional ecological knowledge

Migration times, local movements, biometric parameters and the size and composition of the population of Steller's Eider Polysticta stelleri in Varangerfjord in Finnmark, Northern Norway - Henriksen, Gunnar; Lund, Erik (Fauna Norvegica Series C Cinclus, 1994)
This study had several aims: a) to use radio transmitter techniques to see if Steller's Eiders Polysticta stelleri make local movements in Varangerfjord, b) to find out when the birds arrive from their breeding ground and when they leave in the spring, c) to estimate the size and composition of both the winter and the summer population and finally, d) to obtain data on biometric parameters. We found that the Steller's Eiders start to arrive at their winter area in Varangerfjord in the second week of October, and leave during the first three weeks of May. Birds in the area after 1 June are likely to stay throughout the summer. The size of the winter population is estimated at about 15000 birds with a sex ratio close to 50:50, and the size of the summer population is estimated at about 1000 individuals, most of them being young females and subadult males. Data from birds with radio transmitters and other observations suggest that the Steller's Eiders during their winter stay move to a considerable extent within Varangerfjord. 46 Steller's Eiders were ringed, and at the same time we obtained biometrical measurements. Some of the data differ considerably from those obtained elsewhere in the world.
Keywords: Abundance, Distribution, and Trends; Nonbreeding Seasons; Physiology; Dispersal; Polysticta stelleri; Steller's eider

Molt Migration of Scoters at Cape Pierce Alaska USA - Herter, D. R.; Jonston, S. M.; Woodman, A. P. (Arctic, 1989)
There is presently little specific information on the molt migrations of scoters in the Nearctic. We conducted migration watches from 21 June to 31 July 1984 (total of 96 h) and from 5 to 15 July 1985 (total of 36 h) during daylight hours to estimate abundance and species composition of scoters engaged in a molt migrations at Cape Peirce, southeast Bering Sea, Alaska. We counted 22897 scoters moving west past the observation site in 1984, the year in which we probably made observations over most of the migration period. Allowing for daylight hours without watches, an estimated 66500 scoters passed in 1984. Peak passage occurred on 11 July in both years. Species composition of migrants in 1984 was approximately 77% white-winged scoters (Melanitta fusca), 12% surf scoters (M. perspicillata) and 11% black scoters (M. nigra). Most of the migrants were adult males, probably migrating from breeding grounds in Interior Alaska. Our findings suggest that a large and presently undescribed molting area of white-winged scoters exists somewhere in the waters of western Alaska or eastern Siberia.
Keywords: Melanitta fusca; Nonbreeding Seasons; White-winged Scoter; Melanitta perspicillata; Surf Scoter; Molt; Migration; Black Scoter; Melanitta nigra

Kin grouping is insufficient to explain the inclusive fitness gains of conspecific brood parasitism in the common eider - Hervey, S. D.; Barnas, A. F.; Stechmann, T. J.; Rockwell, R. F.; Ellis-Felege, S. N.; Darby, B. J. (MOLECULAR ECOLOGY, 2019)
Conspecific brood parasitism allows females to exploit other females' nests and enhance their reproductive output. Here, we test a recent theoretical model of how host females gain inclusive fitness from brood parasitism. High levels of relatedness between host and parasitizer can be maintained either by: (a) kin recognizing and parasitizing each other as a form of cooperative breeding or (b) natal philopatry and nest site fidelity facilitating the formation of kin groups, thereby increasing the probability of parasitism between relatives nesting in close proximity. To address these two hypotheses we genotyped feathers and hatch membranes of common eiders (Somateria mollissima) from western Hudson Bay, Canada, using a noninvasive sampling methodology. We found that most instances of brood parasitism do result in inclusive fitness gains. Furthermore, females with failed nests moved an average of 492 m from their previous year's nest site, while successful females only moved an average of 13 m. Therefore, we observed host-parasite relatedness can occur at levels higher than would be expected by chance even in the absence of kin grouping, suggesting that closely related females nesting near one another is not essential to maintain high host-parasitizer relatedness. In addition, kin grouping is only a transient phenomenon that cannot occur every year due to the propensity for females of failed nests to nest farther away from their nest site in subsequent years than females with successful nests, which provides support for kin recognition as a more likely mechanism to maintain high host-parasitizer relatedness over time.
Times Cited in Web of Science Core Collection: 4 Total Times Cited: 4 Cited Reference Count: 61
Keywords: GENETIC-STRUCTURE; inclusive fitness; INTRASPECIFIC NEST PARASITISM; POPULATION; MICROSATELLITE LOCI; common eiders; BINOMIAL REGRESSION; COMPUTER-PROGRAM; cooperative breeding; DISPERSAL; DUCK SOMATERIA-MOLLISSIMA; kin grouping; nest parasitism; nest site fidelity; RELATEDNESS; ZERO-INFLATED POISSON

Perfluorinated and other persistent halogenated organic compounds in European shag (Phalacrocorax aristotelis) and common eider (Somateria mollissima) from Norway: A suburban to remote pollutant gradient - Herzke, D.; Nygard, T.; Berger, U.; Huber, S.; Rov, N. (Science of the Total Environment, 2009)
Samples of two marine bird species, European shag (Phalacrocorax aristotelis) and common eider (Somateria mollissima) sampled at a remote coastal site in Norway were analysed for POPs and PFCs. Additionally samples of common eider were analysed from two other locations in Norway, representing a gradient from "densely populated" to "remote". The variety, concentration and distribution of lipophilic POPs in comparison to PFCs were investigated. PCBs were the dominating group of contaminants in the analysed egg samples. Shag eggs had median sum PCBs levels of 4580 ng/g l.w. in 2004. Six different PBDE congeners could be detected in the shag eggs. BDE 47 and 100 were the main contributors with 24 and 27 ng/g l.w. respectively, sum PBDEs was 90 ng/g l.w. Relatively high concentrations of chlordanes were found witha total sum of 903 ng/g l.w. Of other OCs, toxaphene 26 and 52 together (sum 657 ng/g l.w.) and HCB (165 ng/g l.w.) were contributing majorly to the egg burden. Sum HCHs were low; only 54 ng/g l.w. PFOS was the main PFC in egg, plasma and liver samples. Similar median levels of 29,32 and 27 ng/g w.w. were observed. PFOSA, PFHxS, and PFDcA were observed additionally in all shag samples at minor concentrations with the exception of elevated levels observed in liver for PFOSA and PFDcA with median levels of 7.6 and 7.9 ng/g w.w., respectively. In common eider eggs, the POP concentrations decreased up to 1/8th along the sampled spatial gradient from suburban to remote. of the 9 detected PFCs, PFOS dominated all samples by one order of magnitude, followed by PFOA. Sum PFC concentrations were twice as high at the two fjord sites compared to the remote site. Shorter chained PFCAs like PFOA and PFNA could be detected in the eider eggs whilst being absent in shag eggs. (C) 2009 Elsevier B.V. All rights reserved.
Keywords: Breeding Season; Common Eider; Contaminants; Somateria mollissima

The Shetland beached bird survey, 1979-2004 - Heubeck, M. (Marine Ornithology, 2006)
Results of monthly beached bird surveys in Shetland over a 26-year period are summarised. After initial high oiling rates in 1979, the incidence of oiled birds dropped to lower levels by winter 1980/81. Operational controls at the Sullom Voe Terminal to prevent deballasting at sea by visiting tankers almost certainly contributed to the reduction. Since then some periods of relatively high oiling rates have occurred, interspersed with increasingly longer periods of lower oiling rates. At all times since 1979, oiling rates compared favourably with those recorded from long-term beached bird surveys in the southern North Sea, particularly during 1999-2004. Recent analyses of oil samples from beaches and birds indicate that fuel oils predominate, whereas a majority of samples during 1979/80 were of crudes or crude sludges. In view of recent changes in crude oil throughput at the Sullom Voe Terminal, beached bird surveys remain an important tool for monitoring chronic oil pollution around the islands.
Keywords: Sea Ducks - General; Contaminants

Evidence of an increasing Hooded Merganser population in Massachusetts - Heusmann, H. W.; Early, T. J.; Nikula, B. J. (Wilson Bulletin, 2000)
The number of Hooded Merganser (Lophodytes cucullatus) broods hatching in nest houses on 53 study areas in Massachusetts increased by 289% from 1979-1983 to 1994-1998 and the number of areas used increased from 9 of 53 in 1979 to 26 of 53 by 1998. The number of Hooded Mergansers counted on 21 Massachusetts Christmas Bird Count circles from 1979-1983 to 1994-1998 increased by 225%. The increasing trend lines did not match; suggesting different populations. This appears to support reports of increasing Hooded Merganser populations by other northeastern state waterfowl biologists.
Keywords: Breeding Season; Abundance, Distribution, and Trends; Hooded Merganser; Lophodytes cucullatus

Hooded Mergansers (Lophodytes cucullatus) Use Nest Boxes Designed for Wood Ducks (Aix sponsa): A Changing Demographic - Heusmann, H. W.; Stolarski, J. T. (WILSON JOURNAL OF ORNITHOLOGY, 2017)
Increasing populations of Hooded Mergansers (Lophodytes cucullatus) (Heusmann et. al 2000) may be out-competing Wood Ducks (Aix sponsa) for nest boxes on some sites in Massachusetts. Hooded Mergansers' use increased from <= 2% of boxes in 1979 to 25% by 2013, while Wood Ducks' use increased from an average of 22% in 1979 to a peak of 65% by the mid-1990s and has since declined to 57%. We estimate that Hooded Mergansers may be important nest competitors on 13 of 51 study sites.
Times Cited in Web of Science Core Collection: 0 Total Times Cited: 0 Cited Reference Count: 39
Keywords: competition; Lophodytes cucullatus; POPULATION; Aix sponsa; Hooded Mergansers; MASSACHUSETTS; nest box; STATES; Wood Ducks

Expanded Common Eider (Somateria mollissima dresseri) breeding range in Massachusetts is likely the result of transplants - Heusmann, H. W.; Trocki, C. L. (WILSON JOURNAL OF ORNITHOLOGY, 2020)
The breeding range of the Common Eider (Somateria mollissima dresseril has been expanded south of its traditional range through the use of transplanted birds. Originally introduced to one coastal island in southeastern Massachusetts in the 1970s, eiders spread out to other islands and now >870 ciders nest on more than 20 islands along the Massachusetts coastline from Cape Ann to Boston Ilarbor to Buzzards Bay and may be further spreading south. Submitted 3 April 2019. Accepted 11 February 2020.
Times Cited in Web of Science Core Collection: 1 Total Times Cited: 1 Cited Reference Count: 38
Keywords: Common Eider; Somateria mollissima dresseri; breeding range; Massachusetts; transplants

The spring and fall migrations of scoters, Melanitta spp., at Confederation Bridge in the Northumberland Strait between New Brunswick and Prince Edward Island - Hicklin, Peter; Bunker-Popma, Katherine (Canadian Field-Naturalist, 2001)
With assistance from volunteer observers on both sides of the Confederation Bridge, we counted and identified the three species of scoters migrating through the Northumberland Strait between New Brunswick and Prince Edward Island in spring and fall in order to assess whether the presence of Confederation Bridge affected the migration of scoters through the Strait. The numbers of scoters using Northumberland Strait during migration were three times greater in spring than fall. In both spring and fall, Surf Scoters were the most abundant species followed by Black and White-winged scoters. Only 13% of the scoters flew across Confederation Bridge in spring, and 22% in the fall. It is assumed that the remainder of the birds flew either (1) around Prince Edward Island in order to reach the Gulf of St. Lawrence in spring and the Strait of Canso in the fall or (2) high above Confederation Bridge and were not seen by the observers.
Keywords: Conservation; Melanitta fusca; Nonbreeding Seasons; White-winged Scoter; Melanitta perspicillata; Surf Scoter; Migration; Black Scoter; Melanitta nigra

The incidence of embedded shot in waterfowl in Atlantic Canada and Hudson Strait - Hicklin, Peter W.; Barrow, W. R. (Waterbirds, 2004)
From 1989-1998, in Canada's Atlantic Provinces and eastern sub-arctic region, migrant Canada Geese (Branta canadensis), wintering American Black Duck (Anas rubripes), Mallard (A. platyrhynchos) and incubating Common Eider (Somateria mollissima) were captured and examined with a fluoroscope to determine if shotgun pellets were embedded in their tissues. Of 1,624 birds examined, 25% carried embedded shotgun pellets. The highest proportion of birds carrying pellets was recorded in the sample of female Common Eider captured on nests in Labrador, followed by female eiders nesting in Newfoundland, Quebec and Nova Scotia and migrant Canada Geese in spring in Prince Edward Island.
Keywords: Conservation; Breeding Season; Common Eider; Somateria mollissima

Wintering Harlequin Ducks on the Wolves Archipelago, Bay of Fundy - Hicklin, Peter W.; Barrow, William R. (Waterbirds, 2008)
Between November 1994 and November 1995, regular boat surveys for Harlequin Ducks (Histrionicus histrionicus) were conducted on The Wolves archipelago in New Brunswick, Bay of Fundy. The birds arrived in early November and departed by mid-May, reaching a peak of 38 birds in March. Sex ratios tended to be close to unity, consistent with observations in Maine in the mid-1990s. Juvenile age ratios were noticeably higher than those observed at other wintering sites, suggesting that the juvenile birds may prefer The Wolves archipelago as a wintering site. Overall, these surveys confirm the importance of The Wolves archipelago as a non-breeding area for this species.
Keywords: Abundance, Distribution, and Trends; Nonbreeding Seasons; Harlequin duck; Histrionicus histrionicus

Mind the wind: microclimate effects on incubation effort of an arctic seabird - Hilde, C. H.; Pelabon, C.; Guery, L.; Gabrielsen, G. W.; Descamps, S. (Ecology and Evolution, 2016)
The energetic costs of reproduction in birds strongly depend on the climate experienced during incubation. Climate change and increasing frequency of extreme weather events may severely affect these costs, especially for species incubating in extreme environments. In this 3-year study, we used an experimental approach to investigate the effects of microclimate and nest shelter on the incubation effort of female common eiders (Somateria mollissima) in a wild Arctic population. We added artificial shelters to a random selection of nesting females, and compared incubation effort, measured as body mass loss during incubation, between females with and without shelter. Nonsheltered females had a higher incubation effort than females with artificial shelters. In nonsheltered females, higher wind speeds increased the incubation effort, while artificially sheltered females experienced no effect of wind. Although increasing ambient temperatures tended to decrease incubation effort, this effect was negligible in the absence of wind. Humidity had no marked effect on incubation effort. This study clearly displays the direct effect of a climatic variable on an important aspect of avian life-history. By showing that increasing wind speed counteracts the energetic benefits of a rising ambient temperature, we were able to demonstrate that a climatic variable other than temperature may also affect wild populations and need to be taken into account when predicting the effects of climate change.
Hilde, Christoffer Hoyvik Pelabon, Christophe Guery, Lorelei Gabrielsen, Geir Wing Descamps, Sebastien
Keywords: Behavior; Breeding Season; Common Eider; Somateria mollissima

Size selection and competition for mussels, Mytilus edulis, by oystercatchers, Haematopus ostralegus, herring gulls, Larus argentatus, and common eiders, Somateria mollissima - Hilgerloh, Gudrun; Pfeifer, Dietmar (Ophelia, 2002)
Investigations on size selection of blue mussels, Mytilus edulis, and exploitation competition by ventral hammering oystercatchers, Haematopus ostralegus, herring gulls, Larus argentatus, and common eiders, Somateria mollissima, were carried out on various blue mussel beds on the tidal flats of Spiekeroog (Niedersachsen/Germany). The size-class was considered to be the ideal one, which would be selected if all size-classes were available. On one mussel bed the mussel sizes selected by oystercatchers were the most abundant mussel sizes, the median being 51 mm. It was concluded that the most abundant size-class corresponded to the ideal size-class which was much bigger than predicted for ventral hammering oystercatchers. If all mussels available were smaller than the ideal size, they selected the largest ones. Unlike oystercatchers, eiders did not select the largest mussels present when they were all smaller than the ideal size. Instead, they selected mussels that were only slightly longer than the median of the available mussels. As eiders dive for several mussels when they are feeding on small mussels, they are time-restricted and less selective than if diving for single large mussels. For herring gulls, the ideal mussel size seemed to be 20 mm. Mussel sizes selected by different bird species on the same mussel bed differed significantly. Each species chose other size-classes if the ideal size was not available. The species never competed for the same size-class on a mussel bed.
Keywords: Common Eider; Somateria mollissima; Trophic Interactions

Waterfowl Ecology and Avian Influenza in California: Do Host Traits Inform Us About Viral Occurrence? - Hill, Nichola J.; Takekawa, John Y.; Cardona, Carol J.; Ackerman, Joshua T.; Schultz, Annie K.; Spragens, Kyle A.; Boyce, Walter M. (Avian Diseases, 2010)
We examined whether host traits influenced the occurrence of avian influenza virus (AIV) in Anatidae (ducks, geese, swans) at wintering sites in California's Central Valley. In total, 3487 individuals were sampled at Sacramento National Wildlife Refuge and Conaway Ranch Duck Club during the hunting season of 2007-08. Of the 19 Anatidae species sampled, prevalence was highest in the northern shoveler (5.09%), followed by the ring-necked duck (2.63%), American wigeon (2.57%), bufflehead (2.50%), greater white-fronted goose (2.44%), and cinnamon teal (1.72%). Among host traits, density of lamellae (filtering plates) of dabbling ducks was significantly associated with AIV prevalence and the number of subtypes shed by the host, suggesting that feeding methods may influence exposure to viral particles.
Keywords: Sea Ducks - General; Nonbreeding Seasons; Disease

Waterfowl dynamics at Lake Tegernsee (upper Bavaria) from 1973 to 1997 - Hiller, Wolfgang (Ornithologischer Anzeiger, 1997)
At Lake Tegernsee, yearly numbers per counting period changed from 6900 individuals in 1973/74 to 11500 in 1990/91 and 6300 in 1996/97. The most important local reason for the varying numbers is the change in water quality. The decrease in numbers of the more adapted species (Mute Swan, Mallard, Coot) is due to the improvement of the sewage situation, together with the nutrient deposition and a "no feeding" campaign. However, mudfauna feeders (Tufted Duck, Pochard, Goldeneye) have increased since a stronger reproduction of Zebra Mussel Dreissena polymorpha at Lake Tegernsee in 1980. A considerable increase is to be noted with species catching fish (Great Crested Grebe, Red-necked Grebe, Black-necked Grebe, Goosander, Cormorant). There are enough small fish suitable for food and because of a higher visibility in the water they are easy to reach. The monthly distribution of the individuals shows that Lake Tegernsee is a stretch of water used by waterfowl especially for resting and spending the winter. The take rarely freezes and if it does so with delay and only for a short time. Setting up six quiet zones since 1985 seems to have had an extremely positive effect to the Great Crested Grebe as a breeding bird. Because of various leisure activities in summer, the number of other breeding waterfowl is relatively small.
Keywords: Abundance, Distribution, and Trends; Sea Ducks - General; Common merganser; Mergus merganser

The effect of changes in land use on waterfowl species turnover in Finnish boreal lakes - Hilli-Lukkarinen, M.; Kuitunen, M.; Suhonen, J. (Ornis Fennica, 2011)
Times Cited: 1 Hilli-Lukkarinen, Milla Kuitunen, Markku Suhonen, Jukka 1
Keywords: Breeding Season; Common Goldeneye; habitat; bucephala clangula

Aerial surveys of Greater White-fronted Geese Anser albifrons frontalis and other waterfowl in the Rasmussen Lowlands of the Central Canadian Arctic - Hines, J. E.; Kay, M. F.; Wiebe, M. O. (Wildfowl, 2003)
Helicopter surveys were carried out in June 1994-95 to determine the numbers and distribution of Greater White-fronted Geese Anser albifrons frontalis and other waterfowl in the Rasmussen Lowlands of the Central Canadian Arctic. The results provide information needed for the management of Greater White-fronted Geese as well as for evaluating the biological importance of the Rasmussen Lowlands as a potential protected area. Estimated numbers of waterfowl in the 6,265km2 survey area were 42,041 Lesser Snow Geese Anser caerulescens caerulescens, 23,516 Greater White-fronted Geese, 13,690 King Eiders Somateria spectabilis, 6,412 Canada Geese Branta canadensis hutchinsii, 5,427 Long-tailed Ducks Clangula hyemalis and 3,822 Tundra Swans Cygnus columbianus. Smaller numbers of several other species of aquatic and terrestrial birds were observed and minimum population estimates are reported for those species as well. Numbers of Lesser Snow, Greater White-fronted and Canada Geese have increased substantially in the Rasmussen Lowlands since the mid-1970s, but King Eiders and Long-tailed Ducks have declined markedly. The results support previous findings that the Rasmussen Lowlands is a critical breeding and summer area for Greater White-fronted Geese and other arctic-nesting waterfowl, and further strengthen the recommendations that this site should be protected.
Keywords: Breeding Season; Abundance, Distribution, and Trends; Sea Ducks - General; Long-tailed Duck

Status of Common Eiders, Somateria mollissima, nesting in the Digges Sound region, Nunavut - Hipfner, J. Mark; Gilchrist, H. Grant; Gaston, Anthony J.; Cairns, David K. (Canadian Field-Naturalist, 2002)
There is little information available on status of Common Eider, Somateria mollissima, populations nesting in Arctic Canada. We surveyed Common Eiders in the Digges Sound region, Nunavut, on 19-20 July 1999, for comparison with similar surveys in 1980-1983. On six islands for which data were available in both periods, there were 4-5 times as many nests in 1999 as in the early 1980s. The mean clutch size late in incubation in 1999 (3.3 eggs per nest) was similar to that in 1983 (3.2 eggs), but lower than in 1982 (3.9 eggs); timing of hatching was similar in the two periods. All three females caught during incubation were of the subspecies S. m. borealis. In contrast to Common Eiders S. m. sedentaria nesting in the Belcher Islands, Common Eiders nesting in the Digges Sound region appear to be faring well.
Keywords: Breeding Season; Abundance, Distribution, and Trends; Common Eider; Somateria mollissima

Differential contributions of endogenous and exogenous nutrients to egg components in wild Baltic Common Eiders (Somateria mollissima): A test of alternative stable isotope approaches - Hobson, K. A.; Jaatinen, K.; Ost, M. (Auk, 2015)
The relative importance of nutrients derived from feeding on breeding vs. nonbreeding grounds to the formation of eggs is crucial for predicting how the breeding success of migrating birds responds to changes in food availability during any part of their annual cycle. Eiders have been considered a classical capital breeder, but this assumption has rarely been tested. The measurement of naturally occurring stable isotopes in egg components, together with those in endogenous and exogenous nutrient endpoints, allow the estimation of the relative sources of nutrients to eggs, but these mixing models rely critically on appropriate isotopic discrimination factors that link egg isotope values with their source. A recent captive study using Spectacled Eiders (Somateria fischeri) provided estimates of these isotopic discrimination factors for income breeding. We applied these discrimination factors for investigating nutrient allocation strategies in Common Eiders (Somateria mollisima) breeding in the northern Baltic (Tvarminne, Finland) and wintering in Danish waters, sourced during 2009-2012. Our overall estimates of protein sources using isotopic mixing models were mixed for egg yolk (median: 44.5-56.5% endogenous) and overwhelmingly exogenous for egg albumen (0.4-0.7%). We tested our conclusions also with a single (delta N-15) model and with a more parsimonious delta C-13 discrimination factor between diet and egg albumen, and both supported little to no endogenous reserves being used for egg albumen. A strong positive correlation between egg lipid delta C-13 and lipid-free yolk delta C-13 suggests similar metabolic pathways between diet sources and these egg macromolecules. The applicability of isotope discrimination factors used in nutrient allocation studies derived from captive populations needs to be tested in wild populations. Our results support the idea that potential food limitation not only at the wintering areas, but also at the breeding grounds, can limit breeding success of Baltic Common Eiders, which are currently declining.
Hobson, Keith A. Jaatinen, Kim Ost, Markus
Keywords: Breeding Season; Common Eider; Somateria mollissima; Energetics and Nutrition

Tracing nutrient allocation to reproduction in Barrow's goldeneye - Hobson, Keith A.; Thompson, Jonathan E.; Evans, Matthew R.; Boyd, Sean (Journal of Wildlife Management, 2005)
Naturally occurring stable isotopes in foodwebs can be used to determine the relative contributions of endogenous and exogenous nutrients to avian eggs in cases where birds move between isotopically distinct biomes or habitats to breed. We measured delta C-13 and delta N-15 values in somatic muscle tissues and eggs of Barrow's goldeneye (Bucephala islandica) together with those isotope values in amphipods from wetlands used by birds breeding on the Chilcotin Plateau in central British Columbia, Canada. Females that had recently arrived on the breeding grounds had muscle tissue isotope values similar to those found in coastal wintering birds and were considerably more enriched in C-13 than were samples from local foodwebs. However, delta N-15 values of amphipods were highly variable among wetlands, resulting in a nondistinct exogenous delta N-15 endpoint: for our dual-isotope mixing model. Therefore, we only used the model based on delta C-13 values to estimate nutrient sources to eggs. In 2000, first-laid eggs were more enriched in both isotopes than fourth- or eighth-laid eggs. Considerable endogenous protein input to egg yolk and albumen was detected for the first laid egg (yolk: range = 0-92.7%, median = 23.7%; albumen: range = 0-78.6%, median = 28.7%) with less endogenous contribution of somatic lipids (first egg: range = 0-100%, median = 4.9%). Using archived tissue samples of muscle and developing ovarian follicles from birds collected in 1993-1994, we found no delta C-13 isotopic evidence for endogenous protein contribution to egg yolk. Our results demonstrate the utility of the stable isotope approach in cases where isotopic endpoints are well established. Barrow's goldeneye showed a mixed strategy of endogenous vs. exogenous nutrient allocation to reproduction that varied by individual females, laying order, and year. We encourage managers to use this approach to quantify nutrient allocations from various biomes to reproduction in waterfowl to better understand the importance of wintering sites to reproduction.
Keywords: Breeding Season; Nonbreeding Seasons; Energetics and Nutrition; Barrow's Goldeneye; Bucephala islandica

Aerial surveys of eiders and other waterbirds on the eastern Arctic coast of Russia - Hodges, J. I.; Eldridge, W. D. (Wildfowl, 2001)
Eiders and other waterbirds were surveyed between 1993-1995 along the eastern Arctic coast of Russia by fixed-wing aircraft to obtain baseline information on size and distribution of breeding populations. Population estimates were obtained for segments of the coast stretching from Kolyunchin Bay to the Lena River delta, a distance of 2,340 kms. The Spectacled Eider was the most abundant waterbird (146,245) with 46,276 (32%) recorded on the Indigirka River delta. Steller's Eiders were the second most abundant waterbird (128,760) with 60% recorded from the Indigirka River delta to the Yana River delta. King Eiders numbered 55,800 and were widely distributed. Common Eiders numbered 15,515 and were restricted to the eastern survey area. Population estimates for all waterbirds observed are presented. Numbers presented are not corrected for visibility bias of birds present but not seen. This survey, the first widespread systematic survey of the region, provided new information on Eider distribution and abundance, and provided baseline population data for future monitoring.
Keywords: Breeding Season; Somateria fischeri; Spectacled Eider; Abundance, Distribution, and Trends; Common Eider; Somateria mollissima; King Eider; Somateria spectabilis; Polysticta stelleri; Steller's eider

Parasites from Common Goldeneye Greater Scaup and Oldsquaw Collected on Boundary Bay British-Columbia February 1970 - Hodson, K.; Grimble, M. (Blue Jay, 1970)
Keywords: Nonbreeding Seasons; Clangula hyemalis; Long-tailed Duck; Bucephala clangula; Common Goldeneye; Parasites

Slipper Shells a Major Food Item for White-Winged Scoters - Hoff, J. G. (Wilson Bulletin, 1977)
Keywords: Melanitta fusca; White-winged Scoter; Trophic Interactions

Association of mercury and selenium with altered glutathione metabolism and oxidative stress in diving ducks from the San Francisco Bay region, USA - Hoffman, David J.; Ohlendorf, Harry M.; Marn, Carolyn M.; Pendleton, Grey W. (Environmental Toxicology and Chemistry, 1998)
Adult male greater scaup (Aythya marila), surf scoters (Melanitta perspicillata), and ruddy ducks (Oxyura jamaicensis) were collected from Suisun Bay and coastal Tomales Bay in the greater San Francisco Bay area to assess exposure to inorganic contaminants. Hepatic Se concentrations were highest in greater scaup (geometric mean = 67 ppm dry weight) and surf scoters (119 ppm) in Suisun Bay, whereas hepatic Hg was highest (19 ppm) in greater scaup and surf scoters from Tomales Bay. Hepatic Se and Hg were lower in ruddy ducks and did not differ between locations. Hepatic supernatants were assayed for enzymes related to glutathione metabolism and antioxidant activity, including glucose-6-phosphate dehydrogenase (G-6-PDH), glutathione peroxidase (GSH peroxidase), glutathione reductase (GSSG reductase), and glutathione-S-transferase (GSH transferase). Glutathione peroxidase activity was higher in surf scoters and ruddy ducks, and G-6-PDH was higher in greater scaup and surf scoters from Suisun Bay than Tomales Bay. Glutathione reductase (GSSG) was higher in SS from Suisun Bay. The ratio of oxidized glutathione (GSSG) to reduced glutathione (GSH) was greater in all species from Tomales Bay. The following significant relationships were found in one or more species with increasing hepatic Hg concentration: lower body, liver, and heart weights; decreased hepatic GSH concentration and G-6-PDH and GSH peroxidase activities; increased ratio of GSSG to GSH; and increased GSSG reductase activity. With increasing hepatic Se concentration, GSH peroxidase increased, but GSH decreased. It is concluded that measurement of associated enzymes in conjunction with thiol status may be a useful bioindicator to discriminate between Hg and Se effects. Concentrations of Hg and Se and the above variables affected have been associated with adverse effects on reproduction and neurological function in experimental studies with mallards.
Keywords: Nonbreeding Seasons; Melanitta perspicillata; Surf Scoter; Contaminants

Molt in Vagrant Black Scoters Melanitta-Nigra Wintering in Peninsular Florida USA - Hoffman, W.; Bancroft, G. T. (Wilson Bulletin, 1984)
Keywords: Abundance, Distribution, and Trends; Nonbreeding Seasons; Molt; Black Scoter; Melanitta nigra

DURATION AND PHENOLOGY OF REMIGIAL MOLT OF BARROW'S GOLDENEYE - Hogan, D.; Esler, D.; Thompson, J. E. (Condor, 2013)
Times Cited: 0 Hogan, Danica Esler, Daniel Thompson, Jonathan E. 0
Keywords: Nonbreeding Seasons; Molt; Barrow's Goldeneye; Bucephala islandica

VARIATION IN BODY MASS AND FORAGING EFFORT OF BARROW'S GOLDENEYES (BUCEPHALA ISLANDICA) DURING REMIGIAL MOLT - Hogan, D.; Esler, D.; Thompson, J. E. (Auk, 2013)
Times Cited: 1 Hogan, Danica Esler, Daniel Thompson, Jonathan E. 1
Keywords: Behavior; Nonbreeding Seasons; Molt; Barrow's Goldeneye; Bucephala islandica; energetics and Nutrition

Survival of Barrow's goldeneyes during remigial molt and fall staging - Hogan, D.; Thompson, J. E.; Esler, D. (Journal of Wildlife Management, 2013)
Times Cited: 2 Hogan, Danica Thompson, Jonathan E. Esler, Daniel 2
Keywords: Nonbreeding Seasons; Molt; Survival; Barrow's Goldeneye; Bucephala islandica

Discovery of Important Postbreeding Sites for Barrow's Goldeneye in the Boreal Transition Zone of Alberta - Hogan, D.; Thompson, J. E.; Esler, D.; Boyd, W. S. (Waterbirds, 2011)
Times Cited: 4 Hogan, Danica Thompson, Jonathan E. Esler, Daniel Boyd, W. Sean 4
Keywords: Abundance, Distribution, and Trends; Nonbreeding Seasons; SDJV funded; Barrow's Goldeneye; Bucephala islandica; habitat; molt

Bird skins in museum collections: Are they suitable as indicators of environmental metal load after conservation procedures? - Hogstad, O.; Nygard, T.; Gatzschmann, P.; Lierhagen, S.; Thingstad, P. G. (Environmental Monitoring and Assessment, 2003)
To find out whether modern conservation treatments alter the level of metals in feathers, we analysed the content of 10 metals in feathers before and after skins were washed with detergent and treated with Eulan U-33 (a commonly used preservative at museums). Feathers of 31 birds of Goshawk Accipiter gentilis, Eagle Owl Bubo bubo, Feral Pigeon Columba livia domest and Common Eider Somateria mollissima were analysed. We found that in most cases metals were partly washed out of the feathers, but the effects were related to species and type of feather. The value of bird skins as indicators of environmental metal load is therefore affected by this treatment. It is recommended that the conservation techniques used at museums should be reconsidered if skins are intended for specimen banking for future reference in environmental monitoring schemes and research.
Keywords: Common Eider; Contaminants; Somateria mollissima; Techniques

Winter Behavior of the Stellers Eider Polysticta-Stelleri - Hogstrom, S. (Var Fagelvarld, 1977)
Keywords: Behavior; Nonbreeding Seasons; Polysticta stelleri; Steller's eider

Observations on display and other forms of behaviour of certain Arctic birds - Hohn, E. O. (Auk, 1957)
Observations based on a 2-1/2-month stay on Bank's Island, Canadian Arctic. Descriptions of behavior include coitus in Lesser Snow Goose (Chen hyperborea), and courtship in King Eider (Semateria spectabilis), Little Brown Crane (Grus canadensis), Baird's Sandpiper (Erolia bairdii), Buff-Breasted Sandpiper (Tryrgites subruficollis), Sanderling (Crocethia alba). Simple behavior tests show e.g. that the male Rock Ptarmigan (Lagopus mutus) displays to the corpse of a female just shot. An incubating Black-bellied Plover (Squatarola squatarola) with an incubation period of 24 days, when its clutch was displaced was more attracted to nest scrape than to eggs and when immediate surroundings were changed seemed to locate scrape by its visual bearings of distant objects. || ABSTRACT AUTHORS: E. O. Hohn
Keywords: Behavior; Breeding Season; King Eider; Somateria spectabilis

Infectious bursal disease virus antibodies in Eider ducks and Herring Gulls - Hollmen, Tuula; Franson, J. Christian; Docherty, Douglas E.; Kilpi, Mikael; Hario, Martti; Creekmore, Lynn H.; Petersen, Margaret R. (Condor, 2000)
We measured antibodies to infectious bursal disease virus (IBDV) in blood of nesting Common Eider (Somateria mollissima) females and immature Herring Gulls (Larus argentatus) in the Baltic Sea, and in blood of Spectacled Eider (Somateria fischeri) females nesting in a remote area of western Alaska. Positive (gtoreq 1:16) IBDV titers occurred in 75% of the eiders and 45% of the Herring Gull chicks. In eiders, the prevalence of positive titers differed among locations. We found no evidence that IBDV exposure impaired the immune function of Herring Gull chicks, based on their response to inoculation of sheep red blood cells. We suggest that eider ducks and Herring Gulls have been exposed to IBDV, even in locations where contact with poultry is unlikely. The presence of this virus in wild bird populations is of concern because it causes mortality of up to 30% in susceptible poultry.
Keywords: Breeding Season; Somateria fischeri; Spectacled Eider; Common Eider; Somateria mollissima; Disease

Use of serum biochemistry to evaluate nutritional status and health of incubating common eiders (Somateria mollissima) in Finland - Hollmen, Tuula; Franson, J. Christian; Hario, Martti; Sankari, Satu; Kilpi, Mikael; Lindstrom, Kai (Physiological and Biochemical Zoology, 2001)
During 1997-1999, we collected serum samples from 156 common eider (Somateria mollissima) females incubating eggs in the Finnish archipelago of the Baltic Sea. We used serum chemistry profiles to evaluate metabolic changes in eiders during incubation and to compare the health and nutritional status of birds nesting at a breeding area where the eider population has declined by over 50% during the past decade, with bird, nesting at two areas with stable populations. Several change, in serum chemistries were observed during incubation, including (1) decreases in serum glucose, total protein, albumin beta-globulin, and gamma-globulin concentrations and (2) increases in serum uric acid, creatine kinase, and beta-hydroxybutyrate concentrations. However, these changes were not consistent throughout the 3-yr period, suggesting differences among years in the rate of carbohydrate, lipid, and protein utilization during incubation. The mean serum concentrations of free fatty acids, glycerol, and albumin were lowest and the serum alpha- and gamma-globulin levels were highest in the area where the eider population has declined, suggesting a role for nutrition and diseases in the population dynamics of Baltic eiders.
Keywords: Breeding Season; Common Eider; Somateria mollissima; Physiology

Isolation and characterization of a reovirus from common eiders (Somateria mollissima) from Finland - Hollmen, Tuula; Franson, J. Christian; Kilpi, Mikael; Docherty, Douglas E.; Hansen, Wallace R.; Hario, Martti (Avian Diseases, 2002)
Samples of brain, intestine, liver, lung, spleen, and bursa of Fabricius were collected from five common eider (Somateria mollissima) duckling carcasses during a die-off in the western Gulf of Finland (59degree50'N, 23degree15'E) in June 1996. No viral activity was observed in specific-pathogen-free chicken embryos inoculated with tissue suspensions, but samples of bursa of Fabricius from three birds were positive when inoculated into Muscovy duck (Cairina moschata) embryo fibroblasts. The isolates were characterized as nonenveloped RNA viruses and possessed several characteristics of the genus Orthoreovirus. Virus particles were icosahedral with a mean diameter of 72 nm and were stable at pH 3.0; their genome was separated into 10 segments by polyacrylamide gel electrophoresis. Mallard (Anas platyrhynchos) ducklings experimentally infected with the eider reovirus showed elevated serum activities of aspartate aminotransferase, creatine kinase, and lactate dehydrogenase enzymes and focal hemorrhages in the liver, spleen, and bursa of Fabricius. During 1997-99, the prevalence of neutralizing antibodies to the isolated virus ranged from 0 to 86% in 302 serum samples collected from incubating eider hens at three nesting areas along coastal Finland. The highest seroprevalence was found in Hanko in 1999, just weeks before reports of an uninvestigated mortality event resulting in the death of an estimated 98% of ducklings at that location. These findings raise the question of potential involvement of the virus in poor duckling survival and eider population declines observed in several breeding areas along coastal Finland since the mid-1980s.
Keywords: Breeding Season; Common Eider; Somateria mollissima; Disease

Lead poisoning and trace elements in common eiders Somateria mollissima from Finland - Hollmen, Tuula; Franson, J. Christian; Poppenga, Robert H.; Hario, Martti; Kilpi, Mikael (Wildlife Biology, 1998)
We collected carcasses of 52 common eider Somateria mollissima adults and ducklings and blood samples from 11 nesting eider hens in the Gulf of Finland near Helsinki in 1994, 1995 and 1996. Samples of liver tissue were analysed for arsenic, cadmium, chromium, copper, iron, lead, magnesium, manganese, mercury, molybdenum, selenium and zinc. Blood was analysed for lead, mercury and selenium. Most of the 21 adults examined at necropsy were emaciated with empty gizzards, and no ingested shotgun pellets or other metal were found in any of the birds. Three adult females had a combination of lesions and tissue lead residues characteristic of lead poisoning. Two of these birds had acid-fast intranuclear inclusion bodies in renal epithelial cells and high concentrations of lead (73.4 and 73.3 ppm; all liver residues reported on dry weight basis) in their livers. The third was emaciated with a liver lead concentration of 47.9 ppm. An adult male had a liver lead concentration of 81.7 ppm, which is consistent with severe clinical poisoning. Two other adults, one male and one female, had liver lead concentrations of 14.2 and 8.03 ppm, respectively. Lead concentrations in the blood of hens ranged from 0.11 to 0.63 ppm wet weight. Selenium residues of gtoreq60 ppm were found in the livers of five adult males. Selenium concentrations in the blood of hens ranged from 1.18 to 3.39 ppm wet weight. Arsenic concentrations of 27.5-38.5 ppm were detected in the livers of four adult females. Detectable concentrations of selenium, mercury and molybdenum were found more frequently in the livers of adult males arriving on the breeding grounds than in incubating females, while the reverse was true for arsenic, lead and chromium. Mean concentrations of selenium, copper and molybdenum were higher in the livers of arriving males than in the livers of incubating hens, but hens had greater concentrations of iron and magnesium. Concentrations of trace elements were lower in the livers of ducklings than in the livers of adults.
Keywords: Breeding Season; Common Eider; Contaminants; Somateria mollissima

An experimental study on the effects of polymorphiasis in common eider ducklings - Hollmen, Tuula; Lehtonen, Jukka T.; Sankari, Satu; Soveri, Timo; Hario, Martti (Journal of Wildlife Diseases, 1999)
Eight common eider (Somateria mollissima) ducklings were experimentally infected from 1 June through 13 June, 1995 with acanthocephalans (Polymorphus minutus) by allowing the birds to feed on Gammarus spp. (Gammarus oceanicus, G. salinus, G. zaddachi, and G. lacustris) containing acanthocephalan cystacanths. Uninfected Gammarus spp. were fed to a control group of seven ducklings. No mortality of ducklings occurred during the experiment. However, the infected ducklings gained weight more slowly than the control birds. After the 2 wk study period, the mean serum concentrations of total protein, albumin, beta-globulin, gamma-globulin, fructosamine and creatine kinase were lower in the infected group than in the controls. The mean (+-SE) number of acanthocephalans in the intestine of the infected ducklings was 21 (+-4). The parasites were attached to the mucosa of the posterior small intestine of the infected ducklings with a mixed inflammatory reaction consisting of heterophils and mononuclear lymphocytes surrounding the attachment sites.
Keywords: Breeding Season; Common Eider; Somateria mollissima; Physiology; Parasites

Molecular typing of Escherichia coli strains associated with threatened sea ducks and near-shore marine habitats of south-west Alaska - Hollmen, Tuula E.; DebRoy, Chitrita; Flint, Paul L.; Safine, David E.; Schamber, Jason L.; Riddle, Ann E.; Trust, Kimberly A. (Environmental Microbiology Reports, 2011)
P>In Alaska, sea ducks winter in coastal habitats at remote, non-industrialized areas, as well as in proximity to human communities and industrial activity. We evaluated prevalence and characteristics of Escherichia coli strains in faecal samples of Steller's eiders (Polysticta stelleri; n = 122) and harlequin ducks (Histrionicus histrionicus; n = 21) at an industrialized site and Steller's eiders (n = 48) at a reference site, and compared these strains with those isolated from water samples from near-shore habitats of ducks. The overall prevalence of E. coli was 16% and 67% in Steller's eiders and harlequin ducks, respectively, at the industrialized study site, and 2% in Steller's eiders at the reference site. Based on O and H antigen subtyping and genetic characterization by enterobacterial repetitive intergenic consensus polymerase chain reaction and pulsed-field gel electrophoresis, we found evidence of avian pathogenic E. coli (APEC) strains associated with both species and detected E. coli strains carrying virulence genes associated with mammals in harlequin ducks. Steller's eiders that carried APEC had lower serum total protein and albumin concentrations, providing further evidence of pathogenicity. The genetic profile of two E. coli strains from water matched an isolate from a Steller's eider providing evidence of transmission between near-shore habitats and birds.
Keywords: Conservation; Nonbreeding Seasons; Harlequin duck; Histrionicus histrionicus; Disease; Polysticta stelleri; Steller's eider

An adenovirus linked to mortality and disease in long-tailed ducks (Clangula hyemalis) in Alaska - Hollmen, Tuula E.; Franson, J. Christian; Flint, Paul L.; Grand, James B.; Lanctot, Richard B.; Docherty, Douglas E.; Wilson, Heather M. (Avian Diseases, 2003)
An adenovirus was isolated from intestinal samples of two long-tailed ducks (Clangula hyemalis) collected during a die-off in the Beaufort Sea off the north coast of Alaska in 2000. The virus was not neutralized by reference antiserum against known group I, II, or III avian adenoviruses and may represent a new serotype. The prevalence of the virus was determined in live-trapped long-tailed ducks at the mortality site and at a reference site 100 km away where no mortality was observed. Prevalence of adenovirus antibodies in serum samples at the mortality site was 86% compared to 10% at the reference site. Furthermore, 50% of cloacal swabs collected at the mortality site and only 7% of swabs from the reference site were positive for adenoviruses. In 2001, no mortality was observed at either of the study areas, and virus prevalence in both serum and cloacal samples was low, providing further evidence that the adenovirus was linked to the mortality event in 2000. The virus was used to infect long-tailed ducks under experimental conditions and resulted in lesions previously described for avian adenovirus infections and similar to those observed in long-tailed duck carcasses from the Beaufort Sea. The status of long-tailed ducks has recently become a concern in Alaska due to precipitous declines in breeding populations there since the mid-1970s. Our findings suggest that the newly isolated adenovirus is a disease agent and source of mortality in long-tailed ducks, and thus could be a contributing factor in population declines.
Keywords: Nonbreeding Seasons; Clangula hyemalis; Long-tailed Duck; Survival; Disease; SDJV funded

An adenovirus associated with intestinal impaction and mortality of male common eiders (Somateria mollissima) in the Baltic Sea - Hollmen, Tuula E.; Franson, J. Christian; Kilpi, Mikael; Docherty, Douglas E.; Myllys, Vesa (Journal of Wildlife Diseases, 2003)
We examined 10 common eider (Somateria mollissima) males found dead in 1998 during a die-off in the northern Baltic Sea off the southwestern coast of Finland. We diagnosed impaction of the posterior small intestine with mucosal necrosis as the cause of death in all 10 and isolated adenoviruses from cloacal samples of six birds. The adenovirus isolates were not neutralized by reference antisera to group I, II, or III avian adenoviruses. Cloacal swabs from 22 apparently healthy eider females nesting at the mortality area were negative for viruses. An adenovirus isolated from one of the eiders caused clinical signs of illness and gastrointestinal pathology in experimentally infected mallard (Anas platyrhynchos) ducklings. These findings suggest that the adenovirus contributed to the mortality of common eider males in the Finnish archipelago.
Keywords: Common Eider; Somateria mollissima; Survival; Disease

Infectious diseases, parasites, and biological toxins in sea ducks - Hollmén, T. E. and J. C. Franson (Studies in Avian Biology, 2015)
This chapter addresses disease agents in the broad sense, including viruses, bacteria, fungi, protozoan and helminth parasites, and biological toxins. Some of these agents are known to cause mortality in sea ducks, some are thought to be incidental findings, and the significance of others is yet poorly understood. Although the focus of the chapter is on free-living sea ducks, the study of disease in this taxonomic group has been relatively limited and examples from captive sea ducks and other wild waterfowl are used to illustrate the pathogenicity of certain diseases. Much of the early work in sea ducks consisted of anecdotal and descriptive reports of parasites, but it was soon recognized that diseases such as avian cholera, renal coccidiosis, and intestinal infections with acanthocephalans were causes of mortality in wild populations. More recently, adenoviruses, reoviruses, and the newly emergent Wellfleet Bay virus, for example, also have been linked to die-offs of sea ducks. Declining populations of animals are particularly vulnerable to the threats posed by disease and it is important that we improve our understanding of the significance of disease in sea ducks. To conclude, we offer our recommendations for future directions in this field.
Keywords: Disease; Parasites

Foraging behavior and resource partitioning by diving birds during winter in areas of strong tidal currents - Holm, Kathryn J.; Burger, Alan E. (Waterbirds, 2002)
We investigated the distribution and behavior of 21 species of diving birds wintering in tidally active nearshore ocean off southern Vancouver Island, British Columbia, Canada. Using vessel surveys in one site and land-based observations at a second site, we found significant differences in the use of tidally affected water types among and within three foraging guilds (piscivores, plankton feeders and benthic invertebrate predators) and five families (Gaviidae, Podicipedidae, Phalacrocoracidae, Anatidae, Alcidae). The only abundant plankton feeder, Ancient Murrelets (Synthliboramphus antiquus), foraged more frequently than other birds in areas of deeper water (>10 m) with fast tidal flow and turbulence. Their abundance and diving activity were significantly higher at maximum tide flow than at slack tides. Piscivores used both slack water and moderate currents in a wide range of depths but, apart from alcids and Pelagic Cormorants (Phalacrocorax pelagicus), avoided areas of high current and turbulence. Pigeon Guillemots (Cepphus columba) had higher abundance at tide phases with maximum current, and within a channel with strong tidal flow they showed repetitive upstream flights interspersed with downstream diving bouts. Fish-eating mergansers and most diving ducks taking benthic invertebrates foraged in relatively shallow (<10 m) and slack water, and avoided turbulence. Six species representing all three guilds showed changes in the use of depth categories as tides changed between slack and maximum current, and four species changed their behavior in different depth categories. Although there was considerable overlap in foraging niches, the differences in distribution and behavior of guilds, families, and species of diving birds indicate a degree of resource partitioning within tidally-driven water categories during winter.
Keywords: Behavior; Abundance, Distribution, and Trends; Sea Ducks - General; Nonbreeding Seasons

Effects of a Danish action plan on reducing shotgun wounding of Common Eider Somateria mollissima - Holm, T. E.; Haugaard, L. (Bird Study, 2013)
Times Cited: 0 Holm, Thomas E. Haugaard, Lars Holm, Thomas Eske /I-7473-2013 Holm, Thomas Eske /0000-0002-9654-2722 0
Keywords: Conservation; Nonbreeding Seasons; Somateria mollissima; Common eider

Habitat use in ducks breeding in boreal freshwater wetlands: a review - Holopainen, S.; Arzel, C.; Dessborn, L.; Elmberg, J.; Gunnarsson, G.; Nummi, P.; Poysa, H.; Sjoberg, K. (European Journal of Wildlife Research, 2015)
Breeding habitats strongly influence duck reproduction and survival. The boreal biome harbours a large share of the world's wetlands, which are important breeding sites for several duck species. Based on 98 studies in the peer-reviewed literature, we here synthesize and evaluate which habitat characteristics affect habitat use and reproduction of ducks breeding in boreal freshwater wetlands with respect to (1) species and guild (dabbling, diving and piscivorous ducks) and (2) breeding cycle stage (settling by pairs, nesting and brood rearing). We consider the following aspects related to habitat: wetland morphology and spatial aggregation, water characteristics, habitat structure and vegetation, and biotic interactions. Most of the peer-reviewed studies of duck habitat use in boreal wetlands are from North America and Fennoscandia, while nearly half of the boreal area lacks such studies. Few species dominate research thus far while several others have not been studied at all. Nest site use and success are mainly related to predator avoidance. Food resources and habitat structure are the key characteristics affecting habitat use by duck pairs and broods as well as breeding success, although there are differences between duck guilds. Among the commonly studied variables, there is little evidence that water characteristics affect duck habitat use or survival. The most notable knowledge gaps are found in the effects of anthropogenic activities on habitat use and breeding success of ducks. Because boreal breeding environments are increasingly affected by human activities, we underline the need for future studies combining climate variation with natural and anthropogenic disturbances.
Holopainen, Sari Arzel, Celine Dessborn, Lisa Elmberg, Johan Gunnarsson, Gunnar Nummi, Petri Poysa, Hannu Sjoberg, Kjell
Keywords: Breeding Season; Melanitta fusca; White-winged Scoter; Melanitta perspicillata; Surf Scoter; Bucephala clangula; Common Goldeneye; Mergus merganser; Habitat; Mergus serrator; Hooded Merganser; Lophodytes cucullatus; Bucephala islandica; Barrow’s Goldeneye; Common Merganser; Red-breasted Merganser

Sustainable management of migratory European ducks: finding model species - Holopainen, S.; Arzel, C.; Elmberg, J.; Fox, A. D.; Guillemain, M.; Gunnarsson, G.; Nummi, P.; Sjoberg, K.; Vaananen, V. M.; Alhainen, M.; Poysa, H. (WILDLIFE BIOLOGY, 2018)
Eurasian migratory duck species represent a natural resource shared between European countries. As is evident throughout human harvest history, lack of coordinated management and monitoring at appropriate levels often leads to 'the tragedy of the commons', where shared populations suffer overexploitation. Effective management can also be hampered by poor understanding of the factors that limit and regulate migratory populations throughout their flyways, and over time. Following decades of population increase, some European duck populations now show signs of levelling off or even decline, underlining the need for more active and effective management. In Europe, the existing mechanisms for delivering effective management of duck populations are limited, despite the need and enthusiasm for establishing adaptive management (AM) schemes for wildlife populations. Existing international legal agreements already oblige European countries to sustainably manage migratory waterbirds. Although the lack of coordinated demographic and hunting data remains a challenge to sustainable management planning, AM provides a robust decision-making framework even in the presence of uncertainty regarding demographic and other information. In this paper we investigate the research and monitoring needs in Europe to successfully apply AM to ducks, and search for possible model species, focusing on freshwater species (in contrast to sea duck species) in the East Atlantic flyway. Based on current knowledge, we suggest that common teal Anas crecca, Eurasian wigeon Mareca penelope and common goldeneye Bucephala clangula represent the best species for testing the application of an AM muddling approach to duck populations in Europe. Applying AM to huntable species with relatively good population data as models for broader implementation represents a cost effective way of starting to develop AM on a European flyway scale for ducks, and potentially other waterbirds in the future.
Times Cited in Web of Science Core Collection: 11 Total Times Cited: 14 Cited Reference Count: 114
Keywords: CLIMATE-CHANGE; DENSITY-DEPENDENCE; ABUNDANCE; POPULATIONS; ADAPTIVE MANAGEMENT; BREEDING WATERBIRDS; HARVEST; NORTH-AMERICAN WATERFOWL; TEAL ANAS-CRECCA; WIGEON

Associations between duck harvest, hunting wing ratios and measures of reproductive output in Northern Europe - Holopainen, S.; Christensen, T. K.; Poysa, H.; Vaananen, V. M.; Rintala, J.; Fox, A. D. (EUROPEAN JOURNAL OF WILDLIFE RESEARCH, 2018)
Ducks are important game species, hunted in several countries throughout their annual cycle. We investigated whether the size of the annual duck harvest in Finland and Denmark reflected annual reproductive output in three common quarry duck species. Finland represents an important breeding area and Denmark important staging/wintering grounds for common teal (Anas crecca), Eurasian wigeon (Mareca penelope) and common goldeneye (Bucephala clangula). We assessed whether (i) annual duck harvest in these two countries correlated with variation in Finnish reproductive output or adult population size during 1990-2016 and (ii) variation in reproductive output of Finnish ducks was reflected in the juvenile ratios of birds harvested in Finland (2005-2007, 2014-2016) or Denmark (1990-2016). We hypothesised that variation in Finnish reproductive output would positively affect the size and juvenile ratio of the harvest, and that this effect would be stronger closer to the breeding grounds. Our data showed that the annual harvest of goldeneye in Finland was positively correlated with reproductive output, a desirable basis for applying sustainable management to this species. Teal and wigeon have much longer, more complex flyways, and their harvest did not mirror the annual production of young, although the wigeon harvest in Denmark increased with increasing juvenile ratio there. For these populations, we need to better define population units if we are to be able to assess harvest sustainability. We urgently need to monitor duck breeding success and harvest at larger spatial scales to support a comprehensive analysis of how well the harvest reflects reproductive output.
Times Cited in Web of Science Core Collection: 4 Total Times Cited: 5 Cited Reference Count: 51
Keywords: Bucephala clangula; MALLARDS; SURVIVAL; POPULATION-DYNAMICS; CLIMATE; LIFE-HISTORY; SEX-RATIOS; LONG-TERM; Anas crecca; Flyway; Mareca penelope; SUSTAINABLE EXPLOITATION; Sustainable harvest; WIGEON ANAS-PENELOPE; Wing samples; WINTERING DISTRIBUTIONS

Lead and cadmium in birds in the Netherlands: A preliminary survey - Hontelez, L. C. M. P.; Van Den Dungen, H. M.; Baars, A. J. (Archives of Environmental Contamination and Toxicology, 1992)
Three birds species (Buteo buteo, Ardea cinerea, and Somateria mollissima) from the Netherlands were investigated for lead and cadmium concentrations using kidneys, livers and tibiae. A major purpose of this study was to gain insight into the exposure of the birds in the Netherlands to the two heavy metals. Secondly, the use of these birds as biomonitors for environmental pollution was studied. Common eiders contained a higher cadmium load in liver and kidney than buzzards and grey herons. Additionally, they contained a higher lead burden in bone than grey herons. The three bird species, all standing at the end of a different food chain, seem appropriate indicators for environmental contamination with heavy metals.
Keywords: Common Eider; Contaminants; Somateria mollissima

Information on waterfowl feather characteristics - Hopps, Eric C. (Transactions of the Illinois State Academy of Science, 2002)
Information on feather numbers and weights as well as dietary protein ingestion values for feather synthesis are fundamentally important to taxonomic and nutritional studies of waterfowl. In order to compare species-specific plumage characteristics in waterfowl, ten species of Anatinae (Anas platyrhynchos, Anas strepera, Anas americana, Anas crecca, Anas discors, Aix sponsa, Aythya affinis, Aythya collaris, Aythya americana, and Mergus cucullatus) were collected in the central Illinois River Valley during 1991 and 1992. Variations were found in total feather number, weight and estimated dietary protein requirements between species and sexes. Male and female plumage weight was positively correlated to body mass. Plumage weight was consistently greater in males than females and tended to be related to total body mass but was found not to be significant. Further investigations into waterfowl plumage characteristics and body surface area are recommended in order to elucidate potential physiological, behavioral or habitat related functions of waterfowl plumage.
Keywords: Physiology; Hooded Merganser; Lophodytes cucullatus

Spatio-temporal variation of avian foraging in the rocky intertidal food web - Hori, M.; Noda, T. (Journal of Animal Ecology, 2001)
Hori, M Noda, T

Effects of avian grazing on the algal community and small invertebrates in the rocky intertidal zone - Hori, M.; Noda, T.; Nakao, S. (Ecological Research, 2006)
Hori, Masakazu Noda, Takashi Nakao, Shigeru

Species composition of foraging birds in association with benthic fauna in four intertidal habitats of the Wadden Sea - Horn, S.; Schwemmer, P.; Mercker, M.; Enners, L.; Asmus, R.; Garthe, S.; Asmus, H. (ESTUARINE COASTAL AND SHELF SCIENCE, 2020)
About 10 to 12 million birds per year use the intertidal flats of the Wadden Sea in north-eastern Europe as a food source during their moulting, wintering or breeding season and as a stop-over site along the East Atlantic Flyway. The tidal flats are inhabited by a highly productive benthic fauna representing an important link between the marine microflora and -fauna and higher trophic levels such as birds. Due to differences in the food preference, bird species might distribute on different habitat types formed in the Wadden Sea. In the present study, the diversity of foraging birds was studied in four intertidal habitats (seagrass meadow, sand flat, mud flat, Elbe tidal flat) and their macrozoobenthic food sources were analysed. Samples of benthic macrofauna were taken seasonally while foraging birds were counted monthly at the studied sites. Results revealed different benthic communities in each of the studied sites with large variation in abundance and diversity of foraging birds. Peak numbers of birds during spring and autumn reflected migration through the region. While the majority of bird species shows an opportunistic habitat choice, some species (e.g. Bucephala clangula, Philomachus pugnax) were observed foraging at one site only. However, results revealed only a weak link between bird assemblages and benthic communities within the tidal flats. As indicated by clear relationships between bird species abundance and tidal stage, avian distribution patterns are probably also strongly dependent on abiotic factors such as distance to roosting sites, inundation time and anthropogenic influences. Therefore, it is not sufficient to study the distribution of favoured prey items in the tidal flats alone but additional information needs to be taken into account to understand the complex distribution patterns of birds in the intertidal environment.
Times Cited in Web of Science Core Collection: 13 Total Times Cited: 14 Cited Reference Count: 56
Keywords: SELECTION; ECOLOGY; FOOD; CHOICE; DIET; DUNLINS CALIDRIS-ALPINA; FEEDING BIRDS; INTERFERENCE; SHOREBIRD DISTRIBUTION; TIDAL FLATS

Comparing dietary preferences of Bufflehead ducklings in Western Canada through gut content and stable isotope analysis - Hornung, J. P.; Foote, A. L. (Aquatic Ecology, 2008)
Aquatic invertebrates are essential for duckling growth and development. We present results on the trophic status and dietary analysis of Bufflehead (Bucephala albeola) ducklings from the boreal breeding grounds of western Canada. We estimated dietary preference by comparing invertebrates found in Bufflehead diets to those identified in standardized dip net samples at their wetland feeding sites. Stable isotope ratios of Bufflehead and their prey were used as a second estimator of trophic position. Bufflehead ducklings preferentially foraged for larval Dytiscidae (predaceous diving beetles; 46% of total dietary biomass), Zygoptera larvae (damselflies; 14%) and non-Dytiscidae adult Coleoptera (5%; mainly Haliplidae). Results from stable isotope analyses supported these results; the separation between primary and secondary invertebrate consumers and ducklings was significant for all possible contrasts when considering nitrogen isotope ratios (Tukey HSD; P < 0.001). We iteratively explored all possible combinations of delta N-15 and delta C-13 data to generate a proportional range over which each food source may contribute to Bufflehead stable isotope signatures; these results suggested larval Zygoptera and larval Dytiscidae figure prominently in diets when accounting for isotope fractionation. The incorporation of prey availability into the metric of dietary preference, as opposed to the tabulation of ingested items alone, reduces the importance of invertebrate groups such as adult Dytiscidae as highlighted in previous studies.
Keywords: Breeding Season; Trophic Interactions; Bucephala albeola; Bufflehead

Food Habits of Flightless American Eiders (Somateria mollissima dresseri) in Quebec, Canada - Houle, K.; English, M. D. B.; Savard, J. P. L.; Mallory, M. L.; Giroux, J. F.; Craik, S. R. (NORTHEASTERN NATURALIST, 2017)
We provide the first quantitative study on the diet of Somateria mollissima dresseri (American Eider) undergoing the flightless wing molt. Twenty-nine adult females in wing molt were collected in the St. Lawrence Estuary and Gulf of St. Lawrence, QC, Canada. We identified a total of 510 prey items comprising 6 species of molluscs, echinoderms, and crustaceans from the esophagus and proventriculus of 15 birds. Mytilus edulis (Blue Mussel) was the most important prey for eiders as it occurred in 80% of the gullets and represented nearly 95% of the total aggregate prey mass, confirming the importance of this prey item for American Eiders throughout the annual cycle. The mean length of mussels consumed by eiders in the Estuary was nearly 4 times that of mussels ingested by birds in the Gulf; factors driving this difference remain unknown. Accordingly, we suggest that future work on the foraging ecology of flightess American Eiders examine how the size of mussels consumed by birds may be influenced by the distribution of various mussel size classes available on molting grounds in the St. Lawrence Estuary and in the Gulf of St. Lawrence.
Times Cited in Web of Science Core Collection: 3 Total Times Cited: 3 Cited Reference Count: 34
Keywords: COMMON EIDERS; SELECTION; SIZE; REMIGIAL MOLT; BODY; MUSSELS; MYTILUS-EDULIS; PREY; SEA DUCK; ST-LAWRENCE ESTUARY

Longevity of White-Winged Scoters - Houston, C. S.; Brown, P. W. (Bird-Banding, 1978)
Keywords: Melanitta fusca; White-winged Scoter; Survival

Recoveries of Saskatchewan Canada Banded White-Winged Scoters Melanitta-Fusca - Houston, C. S.; Brown, P. W. (Canadian Field-Naturalist, 1983)
Keywords: Breeding Season; Abundance, Distribution, and Trends; Melanitta fusca; White-winged Scoter; Population Delineation

Body molt of male Long-tailed Ducks in the near-shore waters of the north slope, Alaska - Howell, Mark D.; Grand, James B.; Flint, Paul L. (Wilson Bulletin, 2003)
We examined the timing and intensity of body molt in relation to stage of remige growth for postbreeding adult male Long-tailed Ducks (Clangula hyemalis) off the coast of northern Alaska. During this period, remige and rectrix feathers are molted simultaneously with body feathers during the prebasic molt, which results in a period of increased energetic and nutritional demands. We collected birds from late July through mid-August and recorded intensity of molt in eight regions: head and neck, back and rump, greater coverts, lesser coverts, flank and sides, breast, belly, and tail. Using nonlinear regression, we estimated the peak intensity and variation for each region in relation to ninth primary length. We found little evidence of molt in the head and neck region. The greater and lesser coverts, and back and rump reached peak molt intensities earliest and were followed by tail, breast, and belly. Molt intensity in the flank and side region was highly variable and indicated a more prolonged molting pattern in relation to other regions. While body molt occurs simultaneously with wing molt, we found that molt among regions occurred in a staggered pattern. Long-tailed Ducks may employ this staggered molting pattern to minimize the energetic and nutritional requirements of molt.
Keywords: Nonbreeding Seasons; Molt; Clangula hyemalis; Long-tailed Duck; Physiology

A comparison between aquatic birds of lakes and coastal rivers in Florida - Hoyer, Mark V.; Notestein, Sky K.; Frazer, Thomas K.; Canfield, Daniel E., Jr. (Hydrobiologia, 2006)
Aquatic birds were counted on five Gulf coast Florida rivers to determine if these river systems supported densities, biomass and species richness similar to those found on Florida lakes. Forty-two species were identified and for the species that were found on both Florida streams and lakes similar densities and biomass were encountered. As with Florida lakes, stream bird abundance and species richness were higher in winter months than in summer months, a consequence of migratory bird populations. Total bird abundance, biomass per unit of phosphorus, and species richness per unit of area were similar to data collected on Florida lakes. Thus, Florida rivers are capable of supplying sufficient resources to maintain bird densities, biomass and species richness values similar to lakes of equal size and nutrient concentrations and are therefore important habitats for aquatic bird populations. An examination of individual habitat characteristics indicates that water depth was inversely correlated and submersed aquatic vegetation was positively correlated with bird density, biomass and species richness within the river systems. While both habitat characteristics are important they are also inversely related making it difficult to separate the individual significance of each characteristic.
Keywords: Abundance, Distribution, and Trends; Sea Ducks - General; Nonbreeding Seasons

A broad cocktail of environmental pollutants found in eggs of three seabird species from remote colonies in Norway - Huber, S.; Warner, N. A.; Nygard, T.; Remberger, M.; Harju, M.; Uggerud, H. T.; Kaj, L.; Hanssen, L. (Environmental Toxicology and Chemistry, 2015)
Eggs of 3 seabird species, common eider (Somateria mollisima), European shag (Phalacrocorax aristotelis aristotelis), and European herring gull (Larus argentatus), were surveyed for a broad range of legacy and emerging pollutants to assess chemical mixture exposure profiles of seabirds from the Norwegian marine environment. In total, 201 chemical substances were targeted for analysis ranging from metals, organotin compounds, polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and associated metabolites, chlorinated paraffins, chlorinated and nonchlorinated organic pesticides, per- and polyfluoroalkyl substances (PFAS), dechlorane plus, octachlorostyrene, brominated flame retardants (BFRs), organophosphorous compounds, brominated and alkyl phenols, cyclic siloxanes, and phthalates. Of the chemicals targeted, 149 substances were found above the detection limits, with metals dominating the contaminant profile and comprising 60% of the total contaminant load. Polychlorinated biphenyls, pesticides, organophosphorous compounds, and PFAS were the dominant contaminant classes of organic pollutants found within the seabird species, with the highest loads occurring in herring gulls, followed by shag, and common eider. New generation pollutants (e.g., PFAS, organophosphorous compounds, and alkylphenols) were detected at similar or higher concentrations than the legacy persistent organic pollutants (POPs). Time trends of reported concentrations of legacy POPs appear to have decreased in recent decades from the Norwegian coastal environment. Concentrations of detected pollutants do not appear to have a negative effect on seabird population development within the sampling area. Additional stress caused by pollutants, however, may affect seabird health more at the individual level. Environ Toxicol Chem 2015;34:1296-1308. (c) 2015 SETAC
Huber, Sandra Warner, Nicholas A. Nygard, Torgeir Remberger, Mikael Harju, Mikael Uggerud, Hilde T. Kaj, Lennart Hanssen, Linda
Keywords: Common Eider; Contaminants; Somateria mollissima

Observations on the diving of the surf scoter (Melanitta perspicillata) - Humphrey, Philip S. (Auk, 1957)
Scoters can dive in any of the following ways (1) using the feet only, (2) using the feet for propulsion and half-extended motionless wings for "planes or rudders," (3) using both feet and half-extended wings for propulsion. || ABSTRACT AUTHORS: P. S. Humphrey
Keywords: Behavior; Melanitta perspicillata; Surf Scoter

Diving of a captive common eider - Humphrey, Philip S. (Condor, 1958)
Keywords: Behavior; Common Eider; Somateria mollissima

Harlequins Histrionicus histrionicus in a Rocky Mountain watershed I: Background and general breeding ecology - Hunt, Bill; Ydenberg, Ron (Wildfowl, 2000)
The Maligne Valley, a watershed draining into the Athabasca River in the Rocky Mountains, in Jasper National Park, Canada, is a breeding area for Harlequin Ducks (Histrionicus histrionicus). Based on peak counts, some 30 - 40 adults enter the valley each spring, arriving in early May along the Athabasca River. Numbers build steadily in the valley until the period of peak flow, and individuals are highly faithful to particular sections of the main watercourse. Feeding is intensive prior to nest initiation. Harlequins use lakes, outlets, rivers, and tributaries in the valley in a variety of ways. Along the Lower Maligne River, a few Harlequin pairs defend territories, but the majority of birds feed in aggregations at major lake outlets and inlets, likely highly productive places. On Maligne Lake birds feed in scattered pairs, generally situated at stream inlets. Females begin nesting in mid-June following peak flow, and males depart the valley shortly thereafter. Nests are placed along both the main course of the Maligne River and along several tributaries, but the upper and lower sections of the Maligne River accounted for 11 of the 14 broods located. Many females move their broods to two large lakes for rearing.
Keywords: Breeding Season; Harlequin duck; Histrionicus histrionicus; Productivity; Habitat

FUNGAL OSTEOMYELITIS IN TWO BUFFLEHEAD DUCKLINGS (BUCEPHALA ALBEOLA) - Hurley-Sanders, J. L.; Larsen, R. S.; Troan, B.; Loomis, M. (Journal of Zoo and Wildlife Medicine, 2015)
Over a 25-mo span from a single zoologic collection, two bufflehead ducklings (Bucephala albeola) presented with pelvic limb paresis and were euthanized. On postmortem examination, the first duckling had intralesional fungal hyphae consistent with Aspergillus sp. in the spinal vertebrae and within pulmonary granulomas. In the second duckling, evidence of a thoracic spinal lesion was detected antemortem by using thermographic imaging. At postmortem examination, fungal hyphae consistent with Mucor sp. were found within the vertebrae. Although fungal infections of the respiratory system are commonly reported in waterfowl, infections that involve the spinal cord and vertebrae are unusual. These cases highlight the importance of consideration of axial skeleton fungal disease in neurologic presentations and the use of thermography for noninvasive diagnostic screening.
Hurley-Sanders, Jennifer L. Larsen, R. Scott Troan, Brigid Loomis, Michael
Keywords: Disease; Bucephala albeola; Bufflehead

A probable extralimital post-breeding assembly of Bufflehead Bucephala albeola in southcentral North Dakota, USA, 1994-2002 - Igl, L. D. (Wildfowl, 2003)
The Bufflehead Bucephala albeola breeds predominantly in Canada and Alaska (USA). Evidence suggests that the species may have recently expanded its breeding range southward into central and south central North Dakota. This paper presents data on observations of Buffleheads during the breeding season in Kidder County, North Dakota, 1994-2002, and discusses the possibility that the species has not expanded its breeding range but rather has established an extralimital post-breeding staging area south of its typical breeding range.
Keywords: Breeding Season; Abundance, Distribution, and Trends; Bucephala albeola; Bufflehead

Predators, alternative prey and climate influence annual breeding success of a long-lived sea duck - Iles, D. T.; Rockwell, R. F.; Matulonis, P.; Robertson, G. J.; Abraham, K. F.; Davies, J. C.; Koons, D. N. (Journal of Animal Ecology, 2013)
Times Cited: 2 Iles, David T. Rockwell, Robert F. Matulonis, Paul Robertson, Gregory J. Abraham, Kenneth F. Davies, J. Chris Koons, David. N. 2
Keywords: Breeding Season; Somateria mollissima; Productivity; Population Dynamics; SDJV funded; Common eider

Long-term effects of forestry on birds of the eastern Canadian boreal forests: A comparison with Fennoscandia - Imbeau, Louis; Monkkonen, Mikko; Desrochers, Andre (Conservation Biology, 2001)
Logging is considered the most important threat to species in boreal forests. In contrast to eastern Canada, where most boreal forests remain largely untouched, in Fennoscandia it is possible to assess the cumulative, long-term effects of intensive forestry on wildlife. But harvesting of stands is rapidly changing Canadian boreal forests, which represent an important proportion of the world's boreal forests. We show that Fennoscandia and eastern Canada present striking similarities in terms of forest-age structure, natural-disturbance regime, and structure of bird assemblages, and we provide an assessment of the long-term effects of forestry on eastern Canadian birds of the boreal forest. We used life-history traits from habitat, nesting site, and geographical range to calculate an index of sensitivity to changes induced by modern forestry for boreal species of each region. Tropical migrants commonly found in eastern Canadian boreal forests have life-history traits that are not threat factors in relation to changes caused by modern forestry. Therefore, the general belief that tropical migrants in North America are more sensitive to landscape changes than those in Europe may not hold for species found in the boreal coniferous forests of eastern Canada. Nine Fennoscandian species present high levels of sensitivity, and at least eight eastern Canadian species are of similar concern. In both regions, most of the sensitive species are resident cavity nesters. Given the important similarities between the two regions, the northern expansion of commercial forestry in eastern Canada is likely to result in the significant decline of several resident species, as has occurred in Fennoscandia.
Keywords: Conservation; Breeding Season; Sea Ducks - General; Habitat

The effect of sediment dredging on the distribution of diving ducks at Lake Myvatn, Iceland - Inarsson, Arni; Mangnusdottir, Margret Lilja (Biological Conservation, 1993)
Sediment dredging in Lake Myvatn, Iceland, which commenced in 1967, poses a threat to the populations of breeding and moulting waterfowl in the area. Detailed mapping of diving ducks on the lake was carried out in order to evaluate the impact of the dredging. Densities of diving ducks in the dredged area were among the lowest in the lake. Positions of ducks diving for food were mapped in a 4.8-km-2 area in the North Basin of the lake, which included the area disturbed by dredging. In June 1990 relatively few dives were recorded in the dredged area except by red-breasted mergansers Mergus serrator. In August numerous dives were recorded in the dredged area, yet they were significantly fewer than outside the area. The loss of habitat is still small in comparison with fluctuations which occur in the breeding populations, but dredging in areas close to the present dredging activities will have a disproportionately large impact on the waterfowl populations.
Keywords: Conservation; Breeding Season; Sea Ducks - General; Nonbreeding Seasons; Molt; Habitat

The Prenesting Behavior and Time Budget of the Harlequin Duck Histrionicus-Histrionicus - Inglis, I. R.; Lazarus, J.; Torrance, R. (Wildfowl, 1989)
We describe the behaviour patterns, time budgets, diurnal rhythms and spacing patterns of the Harlequin Duck in the pre-nesting period. The study area was on the Laxa, a river in northeast Iceland, where the population is at a high density, containing pairs and unpaired males in the ratio 2:1. Birds spent much of their time resting on islands close to the water and dived for food in the fast stretches of the river. Females sat and preened more than males. They also had longer dive times. Agonistic and pre- and post-copulation displays are described. Males were not territorial but guarded their males vigorously. Females incited their males and joined them in agonistic encounters. Extra-pair copulation by paired males was not observed and unpaired males spent little time attempting to copulate with females. These mating strategies are discussed in the context of anatid strategies generally. The displays and time budget data are related to those of other ducks that inhabit fast-flowing rivers.
Keywords: Behavior; Breeding Season; Harlequin duck; Histrionicus histrionicus

Breeding status and aggressive communication in the Harlequin Duck Histrionicus histrionicus - Inglis, Ian R.; Lazarus, John; Torrance, Rebecca L. L. F. (Wildfowl, 2000)
The breeding behaviour of ducks reflects a number of conflicts, both between and within the sexes. While unpaired (single) birds attempt to obtain mates, already mated males may pursue the conflicting strategies of mate guarding and extra-pair courtship or copulation in order to sequester the mate while pursuing mating opportunities outside the pair bond. If females pursue the same strategies pair members will also be in conflict. We have sought to understand the nature of these complex interactions in the Harlequin Duck (Histrionicus histionicus), and in the present paper examine the conflict between paired and unpaired birds as it is manifest in agonistic encounters. Pairs are predicted by game theory models to dominate single males as a result of one or more competitive asymmetries and this prediction was supported, pairs both initiating and winning encounters against single males. Compared to pairs, single males were more likely to retreat and less likely to display back to an initiating display. Similarly, individuals were less likely to retreat in response to single male displays than to those of paired males or females. Displays in the order 'head nod away', 'head nod at' and 'extended neck' were increasingly likely to result in a win. Responding birds tended to match the initiator's display and males showed gradual escalation in their own displays. The greater use of 'extended neck' by females probably reflected its use for inciting. Single males used more high intensity display (extended neck) and less low intensity display (head nod) against other single males than against pairs, in accord with the game theory prediction that encounters between closely-matched opponents will be of higher intensity. As a consequence of the dominance of pairs over single males the latter may find it impossible to obtain a mate on the breeding ground. This dominance, together with close mate guarding by both sexes, and female fidelity, is responsible for the rarity or absence of extra-pair copulations and mate switching, and the consequent strict monogamy found in this species.
Keywords: Behavior; Nonbreeding Seasons; Harlequin duck; Histrionicus histrionicus

The near-closure of a lagoon in western Iceland: how accurate were predictions of impacts on environment and biota? - Ingolfsson, Agnar (Journal of Coastal Conservation, 2007)
The Environmental Impact Assessment (EIA) project instigated in connection with the near-closure of the large fjord-like lagoon Gilsfjorour in sub-arctic western Iceland with a road is described and discussed. Three phases were involved: a survey of pre-impact conditions of areas possibly affected as well as control areas, predictions of impacts of the road, and assessment of impacts up to 5-6 years after completion of the project. Emphasis was placed on birds and benthic flora and fauna. Although several predictions were upheld, others were not. The most unexpected changes were the elimination of kelp forest and some associated fauna inside the road as well as from large areas outside it. Feeding areas of the knot (Calidris canutus) and female eiders (Somateria mollissima) with ducklings also changed in unexpected ways. Unforeseen changes can partly be traced to inadequate knowledge of communities and their functioning in the area. The ecological requirements of many species involved, e.g. with respect to salinity, were imperfectly known. The predictions of engineers on the effects of the project on physical factors were not as accurate or detailed as desired. Some critical predictions of the engineers failed to make an impact on the ecologists, who then failed to predict some major changes in the biota, such as the disappearance of kelp forest outside the road. This study highlights some problems probably shared by many EIAs: (a) the near impossibility of finding suitable control areas, (b) the lack of ecological understanding of even common species, and possibly (c) inadequate communication between engineers and ecologists.
Keywords: Conservation; Breeding Season; Common Eider; Somateria mollissima; Habitat

Nine years after the Exxon Valdez oil spill: Effects on marine bird populations in Prince William Sound, Alaska - Irons, David B.; Kendall, Steven J.; Erickson, Wallace P.; McDonald, Lyman L.; Lance, Brian K. (Condor, 2000)
We compared post Exxon Valdez oil-spill densities of marine birds in Prince William Sound from 1989-1991, 1993, 1996, and 1998 to pre-spill densities from 1984-1985. Post-spill densities of several species of marine birds were lower than expected in the oiled area of Prince William Sound when compared to densities in the unoiled area. These negative effects continued through 1998 for five taxa: cormorants, goldeneyes, mergansers, Pigeon Guillemot (Cepphus columba), and murres. Black Oystercatchers (Haematopus bachmani) and Harlequin Ducks (Histrionicus histrionicus) exhibited negative effects in 1990 and 1991. Loons showed a weak negative effect in 1993. Black-legged Kittiwakes (Rissa tridactyla) showed relative decreases in 1989, 1996, and 1998 which may have been caused by shifts in foraging distribution rather than declines in populations. Glaucous-winged Gulls (Larus glaucescens) showed positive effects in most post-spill years. Murrelets and terns showed relative increases in 1993, 1996, and 1998. Generally, taxa that dive for their food were negatively affected, whereas taxa that feed at the surface were not. Effects for some taxa were dependent upon the spatial scale at which they were analyzed. Movements of birds and the mosaic pattern of oiling reduced our ability to detect oil-spill effects, therefore our results may be conservative. Several marine bird species were negatively affected at the population level and have not recovered to pre-spill levels nine years after the oil spill. The reason for lack of recovery may be related to persistent oil remaining in the environment and reduced forage fish abundance.
Keywords: Abundance, Distribution, and Trends; Sea Ducks - General; Nonbreeding Seasons; Contaminants

Important moulting areas for seabirds in Svalbard - Isaksen, Kjell; Bakken, Vidar (Norsk Polarinstitutt Meddelelser, 1995)
Geese, ducks and auks undergo synchronous moulting of the flight feathers in summer or autumn. During this 3-7 week period the flightless birds often gather in flocks and are very vulnerable to disturbances and oil spills. Pink-footed Geese (Anser brachyrhynchus), Barnacle Geese (Branta leucopsis) and Brent Goose (B. bernicla) moult while rearing their chicks in coastal areas with rich vegetation The male eiders (Somateria mollissima and S. spectabilis) and Long-tailed Ducks (Clangula hyemalis) leave the females in the incubation period and gather in moulting flocks in shallow areas along the coast. Common Guillemot (Uria aalge) and Brunnich's Guillemot (U. lomvia) young leave the breeding colony before they are able to fly. They are followed by the male patents in the swimming migration from the colony out to the rearing areas at sea. Maps showing the distribution of moulting eiders and guillemots with young observed during helicopter and ship surveys in the Svalbard area are presented.
Keywords: Abundance, Distribution, and Trends; Common Eider; Sea Ducks - General; Nonbreeding Seasons; Molt; Long-tailed Duck; King Eider

Breeding populations of seabirds in Svalbard - Isaksen, Kjell; Bakken, Vidar (Norsk Polarinstitutt Meddelelser, 1995)
The breeding distribution, estimates of population size and a brief summary of the biology of the breeding seabirds in Svalbard are given. For most species maps showing the known breeding colonies are given. Estimates of colony size are presented for the best known species. Most of the data is from the database of Barents Sea seabird colonies developed, by the Norwegian Polar Institute. Presently more than 500 colonies from Svalbard are registered in the database. Knowledge on size, development and breeding distribution of the seabird populations in Svalbard is most comprehensive for some of the typical colony-breeding species, such as Barnacle Goose (Branta leucopsis), Kittiwake (Rissa tridactyla), Common Guillemot (Uria aalge) and Brunnich's Guillemot (U. lomvia). Other species are less well known due to methodological difficulties with censusing breeding colonies (Fulmar Fulmarus glacialis and Little Auk Alle alle) or due to their dispersed breeding pattern (e.g. Long-tailed Duck Clangula hyemalis and Glaucous Gull Larus hyperboreus).
Keywords: Breeding Season; Abundance, Distribution, and Trends; Clangula hyemalis; Long-tailed Duck

Comparison of the effects and performance of four types of radiotransmitters for use with scoters - Iverson, S. A.; Boyd, W. S.; Esler, D.; Mulcahy, D. M.; Bowman, T. D. (Wildlife Society Bulletin, 2006)
Radiotransmitters are widely used in wildlife ecology, often providing data that cannot be collected using other methods. However, negative effects have been associated with the use of transmitters for some species. We evaluated the effects and performance of 4 radiotransmitter types for use with surf and white-winged scoters (Melanitta perspicillata and M. fusca): COEXT-coelomically implanted transmitters with external antennas, COINT-coelomically implanted transmitters with internal antennas, SUBCU -subcutaneous implants with external antennas, and PRONG-external mounts, attached by a subcutaneous anchor and glue, with external antennas. Survival was not related to radiotransmitter type during the immediate (14-d) post-release period when most deaths (8 of 12) occurred. Rates of signal disappearance (transmitters ceased to be detected in the study area) and transmitter shedding (transmitters recovered without sign of predation) were similar among types over 30- and 60-day intervals; however higher proportions of dorsally mounted radiotransmitters (SUBCU, PRONG) disappeared or were shed over course of the full 100-day monitoring period used in this study. All 4 radiotransmitter types allowed for relatively accurate location estimates, with linear error estimates (distance between actual and estimated location) averaging < 50 in when receivers were within 1 km of transmitters. However, signal strength was lower for COINT transmitters. Based on our results, we recommend COEXT transmitters for radiotelemetry studies > 2 months in duration and for satellite telemetry studies of scoters. However, SUBCU and PRONG are recommended as cost-effective alternatives in shorter-duration radiotelemetry studies.
Keywords: Melanitta fusca; Nonbreeding Seasons; White-winged Scoter; Melanitta perspicillata; Surf Scoter; Techniques

Site fidelity and the demographic implications of winter movements by a migratory bird, the harlequin duck Histrionicus histrionicus - Iverson, Samuel A.; Esler, Daniel (Journal of Avian Biology, 2006)
Understanding the degree of demographic connectivity among population segments is increasingly recognized as central to the fields of population ecology and conservation biology. However, delineating discrete population units has proven challenging, particularly for migratory birds as they move through their annual cycle. In this study, radio telemetry was used to assess movement rates among habitats by harlequin ducks Histrionicus histrionicus during the non-breeding season in Prince William Sound, Alaska. A total of 434 females were outfitted with radio transmitters over six years of data collection, and their signals tracked by aircraft. Using a spatially nested design, it was determined that 75% of radioed females remained in the bay or coastline area where they were originally trapped, 94% remained on the same island or mainland region of Prince William Sound where they began the winter period, and 98% remained within the 4500 km(2) study area as a whole. Home range analyses corroborated these findings, indicating that the scale of individual movements was small, with 95% kernel home range estimates averaging only 11.5 +/- 2.2 km(2). A simple demographic model, which incorporated estimates for population size, survival, and movement rates, was used to infer the degree of independence among population segments. Immigrant females were found to contribute little to population numbers in most areas, accounting for only 4% of the adult female population at a scale of approximately 100 km(2). These results have important implications for the scale of conservation action for the species and demonstrate that winter movements can have a strong influence local population dynamics.
Keywords: Nonbreeding Seasons; Harlequin duck; Histrionicus histrionicus; Dispersal; Population Dynamics; Population Delineation

Survival of female harlequin ducks during wing molt - Iverson, Samuel A.; Esler, Daniel (Journal of Wildlife Management, 2007)
Survival rates of waterfowl during wing molt have rarely been described, leading to uncertainty about the importance of this annual cycle stage for management. We quantified survival probability of 247 radiomarked female harlequin ducks (Histrionicus histrionicus) during wing molt in Prince William Sound, Alaska, USA. The daily survival rate (DSR) was extremely high (DSR = 0.999; 95% CI: 0.9941.000) during the 37-day interval over which remiges were replaced and individuals were rendered flightless. Our DSR estimate corresponded to a cumulative survival probability of 0.99 (95% CI: 0.81-1.00) for the 20 August-15 October postbreeding period as a whole, which is appreciably higher than estimates that have been derived for breeding or overwintering stages. We conclude that wing molt is a comparatively safe stage of the annual cycle for harlequin ducks that does not constrain population growth rate, with the implication for wildlife managers being that, in the absence of anthropogenic influences, management prescriptions may be most effective when focused on other stages of the annual cycle.
Keywords: Nonbreeding Seasons; Harlequin duck; Histrionicus histrionicus; Molt; Survival

Harlequin Duck population injury and recovery dynamics following the 1989 Exxon Valdez oil spill - Iverson, Samuel A.; Esler, Daniel (Ecological Applications, 2010)
The 1989 Exxon Valdez oil spill caused significant injury to wildlife populations in Prince William Sound, Alaska, USA. Harlequin Ducks (Histrionicus histrionicus) were particularly vulnerable to the spill and have been studied extensively since, leading to one of the most thorough considerations of the consequences of a major oil spill ever undertaken. We compiled demographic and survey data collected since the spill to evaluate the timing and extent of mortality using a population model. During the immediate aftermath of the spill, we estimated a 25% decrease in Harlequin Duck numbers in oiled areas. Survival rates remained depressed in oiled areas 6-9 years after the spill and did not equal those from unoiled areas until at least 11-14 years later. Despite a high degree of site fidelity to wintering sites, immigration was important for recovery dynamics, as the relatively large number of birds from habitats outside the spill zone provided a pool of individuals to facilitate numerical increases. On the basis of these model inputs and assumptions about fecundity rates for the species, we projected a timeline to recovery of 24 years under the most-likely combination of variables, with a range of 16 to 32 years for the best-case and worst-case scenarios, respectively. Our results corroborate assertions from other studies that the effects of spilled oil on wildlife can be expressed over much longer time frames than previously assumed and that the cumulative mortality associated with chronic exposure to residual oil may actually exceed acute mortality, which has been the primary concern following most oil spills.
Keywords: Nonbreeding Seasons; Harlequin duck; Histrionicus histrionicus; Population Dynamics; Population Model

Plumage characteristics as an indicator of age class in the Surf Scoter - Iverson, Samuel A.; Esler, Daniel; Boyd, W. Sean (Waterbirds, 2003)
We assessed reliability of plumage as an indicator of age class in the Surf Scoter (Melanitta perspicillata) for demographic and behavioral studies. Three age classes were distinguished among male Surf Scoters, based on the degree of concordance between plumage characteristics and known age-related features (bursal depth and tail feather notching). Males in their first year (1Y) were distinguishable from older males (>1Y) with nearly total accuracy. Discriminating between second year (2Y) and after second year (>2Y) males had an error rate of 11%. Female Surf Scoters could not be reliably aged using plumage characteristics. Field observations suggested the timing of feather changes is an important variable affecting accurate age class determination. First year male Surf Scoter plumage is brown and female-like at the time of fledging, and gradually becomes more adult male-like during the first year. Observations of plumage changes throughout the annual cycle on wild birds suggested that females and 1Y males may be confused in early autumn, and that 1Y males and 2Y males may be misidentified during late spring and summer. Further, variation in timing and speed of pre- and post-breeding molt among 2Y and older males is uncertain. Therefore, mid-January until the end of March is the period when age class determinations based on plumage are most reliable.
Keywords: Nonbreeding Seasons; Melanitta perspicillata; Surf Scoter; Techniques; SDJV funded

Winter philopatry of Harlequin Ducks in Prince William Sound, Alaska - Iverson, Samuel A.; Esler, Daniel; Rizzolo, Daniel J. (Condor, 2004)
We used capture-mark-recapture data to assess winter philopatry by Harlequin Ducks (Histrionicus histrionicus) in Prince William Sound. Alaska, during winters 1995-1997 and 2000-2001. Philo-patry was quantified using homing rates, which were estimated as the proportion of birds recaptured at their original site out of all recaptured birds. Between-year homing rates of 0.95 (95% CI: 0.87-1.00) and 1.00 (0.92-1.00) were estimated for females and males, respectively, at three locations on Montague Island. Similar homing rates were measured in western Prince William Sound, where estimates were 0.92 (0.80-0.98) for females and 0.96 (0.79-1.00) for males, with a scale of detected movements for all recapture birds ranging from 3-52 km. Our results indicate that wintering aggregations may be demographically independent at a much finer spatial scale than genetic data indicate, and that conservation efforts should recognize this degree of demographic separation among population segments.
Keywords: Nonbreeding Seasons; Harlequin duck; Histrionicus histrionicus; Dispersal; Population Delineation

Longer ice-free seasons increase the risk of nest depredation by polar bears for colonial breeding birds in the Canadian Arctic - Iverson, S. A.; Gilchrist, H. G.; Smith, P. A.; Gaston, A. J.; Forbes, M. R. (Proceedings of the Royal Society B-Biological Sciences, 2014)
Northern polar regions have warmed more than other parts of the globe potentially amplifying the effects of climate change on biological communities. Ice-free seasons are becoming longer in many areas, which has reduced the time available to polar bears (Ursus maritimus) to hunt for seals and hampered bears' ability to meet their energetic demands. In this study, we examined polar bears' use of an ancillary prey resource, eggs of colonial nesting birds, in relation to diminishing sea ice coverage in a low latitude region of the Canadian Arctic. Long-term monitoring reveals that bear incursions onto common eider (Somateria mollissima) and thick-billed murre (Uria lomvia) nesting colonies have increased greater than sevenfold since the 1980s and that there is an inverse correlation between ice season length and bear presence. In surveys encompassing more than 1000 km of coastline during years of record low ice coverage (2010-2012), we encountered bears or bear sign on 34% of eider colonies and estimated greater egg loss as a consequence of depredation by bears than by more customary nest predators, such as foxes and gulls. Our findings demonstrate how changes in abiotic conditions caused by climate change have altered predator-prey dynamics and are leading to cascading ecological impacts in Arctic ecosystems.
Iverson, Samuel A. Gilchrist, H. Grant Smith, Paul A. Gaston, Anthony J. Forbes, Mark R.
Keywords: Breeding Season; Common Eider; Somateria mollissima; Productivity; Trophic Interactions

Injecting epidemiology into population viability analysis: avian cholera transmission dynamics at an arctic seabird colony - Iverson, S. A.; Gilchrist, H. G.; Soos, C.; Buttler, II; Harms, N. J.; Forbes, M. R. (JOURNAL OF ANIMAL ECOLOGY, 2016)
1. Infectious diseases have the potential to spread rapidly and cause high mortality within populations of immunologically naive hosts. The recent appearance of avian cholera, a highly virulent disease of birds caused by the bacterium Pasteurella multocida, at remote Arctic seabird colonies is an emerging conservation concern. 2. Determining disease risk to population viability requires a quantitative understanding of transmission potential and the factors that regulate epidemic persistence. Estimates of the basic (R-0) and real-time (R-t) reproductive number are critical in this regard - enumerating the number of secondary infections caused by each primary infection in a newly invaded host population and the decline in transmission rate as susceptible individuals are removed via mortality or immunized recovery. 3. Here, we use data collected at a closely monitored common eider (Somateria mollissima) breeding colony located in the Canadian Arctic to examine transmission and host population dynamics. Specifically, we infer epidemic curves from daily mortality observations and use a likelihood-based procedure to estimate changes in the reproductive number over a series of annual outbreaks. These data are interpreted in relation to concurrent changes in host numbers to assess local extinction risk. 4. Consistent with expectations for a novel pathogen invasion, case incidence increased exponentially during the initial wave of exposure (R-0 = 2.5; generation time = 6.5 days +/- 1.1 SD). Disease conditions gradually abated, but only after several years of smouldering infection (R-t approximate to 1). In total, 6194 eider deaths were recorded during outbreaks spanning eight consecutive breeding seasons. Breeding pair abundance declined by 56% from the pre-outbreak peak; however, a robust population of >4000 pairs remained intact upon epidemic fade-out. Overall, outbreak patterns were consistent with herd immunity acting as a mitigating factor governing in the extent and duration of mortality. 5. Disease mortality is frequently modelled as a form of stochastic catastrophe in wildlife population assessments, whereas our approach gives shape to the functional response between transmission and host population dynamics. We conclude that increased emphasis on integrating epidemiological and population processes is essential to predicting the conservation impact of emerging infectious diseases in wildlife.
Times Cited in Web of Science Core Collection: 11 Total Times Cited: 11 Cited Reference Count: 53
Keywords: common eider; COMMON EIDERS; REPRODUCTION; HEALTH; avian cholera; disease ecology; epidemic curve; host-pathogen dynamics; INFECTIOUS-DISEASES; INFLUENZA; Pasteurella multocida; PASTEURELLA-MULTOCIDA; PATHOGEN; population viability; R-0; R-t; SOUTH-AFRICA; VACCINATION; WILDLIFE

Age and sex distributions of wintering Surf Scoters: Implications for the use of age ratios as an index of recruitment - Iverson, Samuel A.; Smith, Barry D.; Cooke, Fred (Condor, 2004)
We assessed age- and sex-specific distribution patterns of Surf Scoters (Melanitta perspicillata) wintering in southern coastal British Columbia, Canada, and evaluated potential biases associated with the use of male age ratios as an index of their recruitment. For surveys conducted during 2000 through 2002, annual variations in male age ratios were evident, with estimates ranging from 0.07 +/- 0.02 to 0. 13 +/- 0.03 (SE; first-year males:total males). Flock composition patterns indicated first-year males did not distribute independently, but tended to associate with other first-year males. With respect to habitat, male age-class proportions did not vary among shoreline substrate types, but higher proportions of first-year males were found in sites with low exposure to wind and waves (<50 km fetch). To determine the efficacy of male age ratios for indexing recruitment, we used a power analysis, which incorporated overdispersion in age-class segregation and determined the sample sizes required for precise estimates of the proportion of first-year male Surf Scorers. Samples of approximately 600-1000 total males were required to obtain 95% confidence limits within 5% of the estimated mean, with sampling accuracy leveling off at about 2% when 6000 or more males were aged. Recruitment among waterfowl species is typically modeled using the ratio of female recruits to breeding-age females. Based on the sex and male age-ratio estimates obtained in this study, we calculated a female age ratio of 0.23 (first-year females:adult females).
Keywords: Abundance, Distribution, and Trends; Nonbreeding Seasons; Melanitta perspicillata; Surf Scoter; Techniques; Habitat; SDJV funded

Isolation and characterization of 22 polymorphic microsatellite loci for the Barrow's goldeneye (Bucephala islandica) - Jaari, Sonja; Jaatinen, Kim; Merila, Juha (Molecular Ecology Resources, 2009)
We describe primers and polymerase chain reaction conditions to amplify 22 microsatellite loci from the Barrow's goldeneye (Bucephala islandica). The primers were tested on 27 individuals from a population breeding in British Columbia, Canada. The developed primer pairs yielded an average of 6.11 alleles per locus (range 2-12), an average observed heterozygosity of 0.70 (range 0.07-0.96) and a polymorphic information content of 0.07-0.88.
Keywords: Breeding Season; Techniques; Barrow's Goldeneye; Bucephala islandica

Relatedness and spatial proximity as determinants of host-parasite interactions in the brood parasitic Barrow's goldeneye (Bucephala islandica) - Jaatinen, Kim; Jaari, Sonja; O'Hara, Robert B.; Ost, Markus; Merila, Juha (Molecular Ecology, 2009)
Recent studies, which have found evidence for kin-biased egg donation, have sparked interest in re-assessing the parasitic nature of conspecific brood parasitism (CBP). Since host-parasite kinship is essential for mutual benefits to arise from CBP, we explored the role of relatedness in determining the behaviour of conspecific nest parasites and their hosts in nesting female Barrow's goldeneyes (Bucephala islandica), a duck in which CBP is common. The results revealed that the amount of parasitism increased with host-parasite relatedness, the effect of which was independent of geographical proximity of host and parasite nests. Proximity per se was also positively associated with the amount of parasitism. Furthermore, while hosts appeared to reduce their clutch size as a response to the presence of parasitic eggs, the magnitude of host clutch reduction also tended to increase with increasing relatedness to the parasite. Hence, our results indicate that both relatedness and spatial proximity are important determinants of CBP, and that host clutch reduction may be an adaptation to nest parasitism, modulated by host-parasite relatedness. Taken together, the results provide a demonstration that relatedness influences host and parasite behaviour in Barrow's goldeneyes, resulting in kin-biased egg donation.
Keywords: Behavior; Breeding Season; Barrow's Goldeneye; Bucephala islandica

Strategy selection under conspecific brood parasitism: an integrative modeling approach - Jaatinen, K.; Lehtonen, J.; Kokko, H. (Behavioral Ecology, 2011)
Times Cited: 3 Jaatinen, Kim Lehtonen, Jussi Kokko, Hanna Kokko, Hanna/C-7861-2009; Jaatinen, Kim/A-3221-2011 3
Keywords: Behavior; Breeding Season; Barrow's Goldeneye; Bucephala islandica

Annual variation in predation risk is related to the direction of selection for brain size in the wild - Jaatinen, K.; Moller, A. P.; Ost, M. (SCIENTIFIC REPORTS, 2019)
The direction of predator-mediated selection on brain size is debated. However, the speed and the accuracy of performing a task cannot be simultaneously maximized. Large-brained individuals may be predisposed to accurate but slow decision-making, beneficial under high predation risk, but costly under low risk. This creates the possibility of temporally fluctuating selection on brain size depending on overall predation risk. We test this idea in nesting wild eider females (Somateria mollissima), in which head volume is tightly linked to brain mass (r(2) = 0.73). We determined how female relative head volume relates to survival, and characterized the seasonal timing of predation. Previous work suggests that relatively large-brained and small-brained females make slow versus fast nest-site decisions, respectively, and that predation events occur seasonally earlier when predation is severe. Large-brained, late-breeding females may therefore have higher survival during high-predation years, but lower survival during safe years, assuming that predation disproportionately affects late breeders in such years. Relatively large-headed females outsurvived smaller-headed females during dangerous years, whereas the opposite was true in safer years. Predation events occurred relatively later during safe years. Fluctuations in the direction of survival selection on relative brain size may therefore arise due to brain-size dependent breeding phenology.
Times Cited in Web of Science Core Collection: 9 Total Times Cited: 9 Cited Reference Count: 48
Keywords: ECOLOGY; MODELS; EVOLUTION; STRATEGIES; FLIGHT INITIATION DISTANCE; COGNITION; FEMALE; HYPOTHESIS

Kin association during brood care in a facultatively social bird: active discrimination or by-product of partner choice and demography? - Jaatinen, K.; Noreikiene, K.; Merila, J.; Ost, M. (Molecular Ecology, 2012)
Times Cited: 3 Jaatinen, Kim Noreikiene, Kristina Merila, Juha Ost, Markus Jaatinen, Kim/A-3221-2011; Ost, Markus/C-7376-2008; Merila, Juha/A-4061-2008 Merila, Juha/0000-0001-9614-0072 3
Keywords: Breeding Season; Common eider; somateria mollissima; behavior

Experience attracts: the role of age in the formation of cooperative brood-rearing coalitions in eiders - Jaatinen, K.; Ost, M. (Animal Behaviour, 2011)
Times Cited: 9 Jaatinen, Kim Ost, Markus Jaatinen, Kim/A-3221-2011; Ost, Markus/C-7376-2008 9
Keywords: Behavior; Breeding Season; Common eider; somateria mollissima

Brood Size Matching: A Novel Perspective on Predator Dilution - Jaatinen, K.; Ost, M. (American Naturalist, 2013)
Times Cited: 1 Jaatinen, Kim Ost, Markus Ost, Markus/C-7376-2008; Jaatinen, Kim/A-3221-2011 1
Keywords: Behavior; Breeding Season; Somateria mollissima; Common eider

Differential responses to related hosts by nesting and non-nesting parasites in a brood-parasitic duck - Jaatinen, K.; Ost, M.; Gienapp, P.; Merila, J. (Molecular Ecology, 2011)
Times Cited: 4 Jaatinen, Kim Ost, Markus Gienapp, Phillip Merila, Juha Jaatinen, Kim/A-3221-2011; Merila, Juha/A-4061-2008; Ost, Markus/C-7376-2008; Gienapp, Phillip/A-2261-2014 Merila, Juha/0000-0001-9614-0072; Gienapp, Phillip/0000-0002-9368-8769 4
Keywords: Behavior; Breeding Season; Barrow's Goldeneye; Bucephala islandica

Facultative Sex Allocation and Sex-Specific Offspring Survival in Barrow's Goldeneyes - Jaatinen, K.; Ost, M.; Gienapp, P.; Merila, J. (Ethology, 2013)
Times Cited: 0 Jaatinen, Kim Ost, Markus Gienapp, Phillip Merila, Juha Ost, Markus/C-7376-2008; Jaatinen, Kim/A-3221-2011; Merila, Juha/A-4061-2008; Gienapp, Phillip/A-2261-2014 Merila, Juha/0000-0001-9614-0072; Gienapp, Phillip/0000-0002-9368-8769 0
Keywords: Behavior; Breeding Season; Survival; Barrow's Goldeneye; Bucephala islandica

State-dependent capital and income breeding: a novel approach to evaluating individual strategies with stable isotopes - Jaatinen, K.; Ost, M.; Hobson, K. A. (Frontiers in Zoology, 2016)
Background: Species-specific strategies for financing the costs of reproduction are well understood, forming a continuum ranging from high to low reliance on stored nutrients. Animals relying mostly on stored reserves are termed 'capital breeders', whereas 'income breeders' rely mostly on concurrent intake when financing the costs of reproduction. The role and adaptive value of individual variation in these strategies remain elusive. Life-history theory posits that capital breeding should be favoured when offspring reproductive value peaks, typically occurring early in the season, and that current income should increasingly be used with progressing season. Because resource limitation may hamper flexible resource allocation, a corollary prediction is that only good-condition individuals may show the expected seasonal shift in resource use. To test this prediction, we examined stable isotopes (delta C-13 and delta N-15) in blood and lipid-free egg yolk of breeding eider females (Somateria mollissima) from the Baltic Sea to assess the role of individual variation in the use of proteins from local diet vs. stored reserves. Results: We show for the first time that individuals from a single population differ in their utilization of stored reserves and concurrent intake to finance the costs of reproduction. Consistent with our prediction, heavy females predominantly used stored reserves for producing egg yolks early in the season, increasingly relying on local feeding with later onset of breeding, whereas light females showed no seasonal change in allocation strategy. Conclusions: Stable isotope profiling at the individual level is a powerful tool for monitoring relative changes in investment strategies through time, showing promise as an early warning indicator of ecological change in food webs.
Jaatinen, Kim Ost, Markus Hobson, Keith A.
Keywords: Breeding Season; Common Eider; Somateria mollissima; Energetics and Nutrition

Adult predation risk drives shifts in parental care strategies: a long-term study - Jaatinen, Kim; Ost, Markus; Lehikoinen, Aleksi (Journal of Animal Ecology, 2011)
P>1. Grouping provides antipredatory benefits, and therefore aggregation tendencies increase under heightened predation risk. In socially breeding groups, however, conflicts over reproductive shares or safety tend to disintegrate groups. Group formation thereby involves a balance between the antipredatory benefits of aggregation and the destabilizing effect of reproductive conflict.2. We study the grouping behaviour of a facultatively social precocial sea duck with uniparental female care, the eider (Somateria mollissima Linnaeus). Females tend their young solitarily or in groups of 2-5 females. Here, we focus on the effect predation on adults has on group-formation decisions of brood-caring females.3. By modifying an existing bidding game over care, we model the effects of predation risk on the width of the window of selfishness, which delimits the reproductive sharing allowing cooperation within brood-rearing coalitions, and generate predictions about the relative frequencies of solitary versus cooperative parental care modes. Furthermore, we model the dilution effect as a function of female group size and predation risk.4. The window of selfishness widens with increasing predation risk, and the dilution of predation risk increases with both female group size and increasing predation risk, yielding the following predictions: (i) cooperative brood care becomes more prevalent and, conversely, solitary brood care less prevalent under heightened predation risk and (ii) group sizes increase concomitantly.5. We tested these predictions using 13 years of data on female grouping decisions and annual predation rates, while controlling for the potentially confounding effect of female body condition.6. Our data supported both predictions, where heightened predation risk of nesting females, but not changes in their condition, increased the relative frequency of cooperative brood care. Increased female nesting mortality also resulted in larger groups of cooperative females.7. The predation risk of incubating females has long-term implications for later parental care decisions. We discuss the potential consequences of predation-induced shifts in group size on per capita fitness and population-wide productivity.
Keywords: Behavior; Breeding Season; Common Eider; Somateria mollissima

Clutch desertion in Barrow's goldeneyes (Bucephala islandica) - effects of non-natal eggs, the environment and host female characteristics - Jaatinen, Kim; Ost, Markus; Waldeck, Peter; Andersson, Malte (Annales Zoologici Fennici, 2009)
Addition of eggs to nests of conspecifics is a common avian alternative breeding strategy, called conspecific brood parasitism. The consequences of this breeding strategy on recipient breeding success have seldom been quantified, while taking into account environmental factors and host female characteristics. We study the occurrence of nest parasitism and, using an information theoretic approach, the most important factors responsible for nest desertion in female Barrow's goldeneyes (Bucephala islandica). Nest parasitism is common in the study populationpopulation, and 58% of the nests contained non-natal eggs, representing 20% of all eggs. A prime factor explaining nest desertion was the number of non-natal eggs. There were also significant effects of year and own clutch size. By contrast, ambient temperature and female laying date did not influence nest desertion. These results provide one of the first demonstrations that non-natal eggs can have substantial negative effects also in precocial species.
Keywords: Behavior; Breeding Season; Barrow's Goldeneye; Bucephala islandica

Brain size-related breeding strategies in a seabird - Jaatinen, K.; Ouml;st, M. (Oecologia, 2016)
The optimal compromise between decision speed and accuracy may depend on cognitive ability, associated with the degree of encephalization: larger brain size may select for accurate but slow decision-making, beneficial under challenging conditions but costly under benign ones. How this brain size-dependent selection pressure shapes avian breeding phenology and reproductive performance remains largely unexplored. We predicted that (1) large-brained individuals have a delayed breeding schedule due to thorough nest-site selection and/or prolonged resource acquisition, (2) good condition facilitates early breeding independent of relative brain size, and (3) large brain size accrues benefits mainly to individuals challenged by environmental or intrinsic constraints. To test these predictions, we examined how the relative head volume of female eiders (Somateria mollissima) of variable body condition correlated with their breeding schedule, hatching success and offspring quality. The results were consistent with our predictions. First, large head size was associated with a progressively later onset of breeding with increasing breeding dispersal distance. Second, increasing body condition advanced the timing of breeding, but this effect was significantly weaker in large-brained females. Third, larger head volume was associated with increased hatching success mainly among late breeders and those in poor body condition, and duckling body condition was positively related to maternal head volume, but only in poor-condition mothers. Our study is, to our knowledge, the first to demonstrate the presence of brain size-related differences in reproductive strategies within a single natural population.
Jaatinen, Kim Ost, Markus
Keywords: Behavior; Breeding Season; Common Eider; Somateria mollissima

Context dependency of baseline glucocorticoids as indicators of individual quality in a capital breeder - Jaatinen, K.; Seltmann, M. W.; Hollmen, T.; Atkinson, S.; Mashburn, K.; Ost, M. (General and Comparative Endocrinology, 2013)
Times Cited: 0 Jaatinen, Kim Seltmann, Martin W. Hollmen, Tuula Atkinson, Shannon Mashburn, Kendall Ost, Markus Ost, Markus/C-7376-2008 0
Keywords: Breeding Season; Somateria mollissima; Physiology; Techniques; Common eider

Context-dependent stress responses and their connections to fitness in a landscape of fear - Jaatinen, K.; Seltmann, M. W.; Ost, M. (Journal of Zoology, 2014)
The acute glucocorticoid stress response is presumed to facilitate escape from life-threatening situations such as predation and thus it is assumed to be linked to fitness. However, the fitness effects of glucocorticoid reactivity remain controversial, as these effects may be context-dependent. Individuals differing in their emphasis on current versus future reproduction may differ in their risk-taking under threat of predation; this variation in risk-taking may be mediated by variations in stress reactivity. We set out to test whether predation risk (island- and year-specific proportion of depredated nests) modified the relationships between stress responsiveness and current reproductive investment (clutch weight) and between stress responsiveness and reproductive success (viable proportion of the clutch) in the long-lived female eider Somateria mollissima. This study system shows large spatial and annual fluctuations in predation risk, indexed by the annual island-specific proportion of depredated nests. The capture stress-related corticosterone output was attenuated with increasing clutch weight under low predation pressure but elevated under severe predation pressure, and females in well-concealed nests had lower stress responsiveness. The viable proportion of the clutch decreased with increasing corticosterone reactivity under low to moderate predation pressure, but slightly increased under severe predation pressure. The acute stress response may thus mediate adaptive plasticity; dampened stress reactivity may ensure successful reproduction under low predation threat or in nest sites reducing detection by visual predators, whereas preparing for potential attacks may be favoured under elevated predation risk.
Jaatinen, K. Seltmann, M. W. Ost, M.
Keywords: Behavior; Breeding Season; Common Eider; Somateria mollissima; Physiology

Little Blue Herons and Snowy Egrets use Red-breasted Mergansers as "beaters" - Jackson, Jerome A.; Davis, William E., Jr. (Oriole, 2004)
Keywords: Behavior; Mergus serrator; Red-breasted merganser

The Uropygial Gland Wax from the Common Scoter Melanitta-Nigra - Jacob, J.; Zeman, A. (Zeitschrift fuer Naturforschung Teil B Anorganische Chemie Organische Chemie Biochemie Biophysik Biologie, 1972)
Keywords: Physiology; Black Scoter; Melanitta nigra

Winter surveys of water birds in Wallonia and in the centre of Brabant: 1995/96 - Jacob, Jean-Paul; Loly, Pierre (Aves, 1996)
Winter surveys of water birds in Wallonia and in the centre of Brabant : 1995/96 During a winter that was harder than preceding ones, the general abundance of water birds reached particularly high levels, especially in January and February. This was due principally to the arrival of a series of species in numbers unprecedented in recent decades. The main species were divers like the great crested grebe and the little grebe, cormorants, goosanders, pochards and tufted ducks. Although very small in absolute terms, the presence of other species was higher than usual in Wallonia and in Brussels (whooper swan, wigeon, goldeneye etc.). On the other hand, numbers of mallards and moorhens were again rather low.
Keywords: Abundance, Distribution, and Trends; Sea Ducks - General; Nonbreeding Seasons

Results of the winter censuses of waterbirds in Wallonie and Brussels area (Belgium) between 1998-1999 and 2003-2004 - Jacob, Jean-Paul; Loly, Pierre; Kinet, Thierry (Aves, 2004)
Winter censuses of waterbirds from 1998-99 to 2003-2004 in Wallonia and in the Brussels area were conducted during rather mild winters, with limited cold spells occurring notably early in 2003 (when arrivals of Wigeons, Mallards, Goosanders. Cormorants and Tufted duck were noted). The results per winter and per region are shown in table 7a-f (see Fig.2 for the regions); they are summarized in table 8. Totals for January censuses are 22.317 to 28.603 indigenous anatidae and: an increasing number of birds of introduced species (1.768 in January 2004, amounting to 6,4 % of the totals for this family). Laridae numbered about 60.000 ex, and the other species from 10 to 13.000 individuals, mainly Cormorants. Moorhens and Coots. Observed numbers generally remain within recent variations except for record numbers of Whooper swans and Teals in 2002, of Moorhens in 2000 and of species that clearly increase such as Cormorant. Great White Egret, Canada Goose, Mute Swan and Gadwall. Results of Gulls censused at resting places in 2000 (table 11) confirm the decrease of the Herring Gull. small numbers of wintering Lesser black-backed ked Gulls as well as the occurrence of a few Yellow-legged and Pontic Gulls.
Keywords: Abundance, Distribution, and Trends; Sea Ducks - General; Nonbreeding Seasons; Common merganser

Polar bears are inefficient predators of seabird eggs - Jagielski, P. M.; Dey, C. J.; Gilchrist, H. G.; Richardson, E. S.; Love, O. P.; Semeniuk, C. A. D. (ROYAL SOCIETY OPEN SCIENCE, 2021)
Climate-mediated sea-ice loss is disrupting the foraging ecology of polar bears (Ursus maritimus) across much of their range. As a result, there have been increased reports of polar bears foraging on seabird eggs across parts of their range. Given that polar bears have evolved to hunt seals on ice, they may not be efficient predators of seabird eggs. We investigated polar bears' foraging performance on common eider (Somateria mollissima) eggs on Mitivik Island, Nunavut, Canada to test whether bear decision-making heuristics are consistent with expectations of optimal foraging theory. Using aerial-drones, we recorded multiple foraging bouts over 11 days, and found that as clutches were depleted to completion, bears did not exhibit foraging behaviours matched to resource density. As the season progressed, bears visited fewer nests overall, but marginally increased their visitation to nests that were already empty. Bears did not display different movement modes related to nest density, but became less selective in their choice of clutches to consume. Lastly, bears that capitalized on visual cues of flushing eider hens significantly increased the number of clutches they consumed; however, they did not use this strategy consistently or universally. The foraging behaviours exhibited by polar bears in this study suggest they are inefficient predators of seabird eggs, particularly in the context of matching behaviours to resource density.
Times Cited in Web of Science Core Collection: 9 Total Times Cited: 9 Cited Reference Count: 90
Keywords: CONSEQUENCES; CLIMATE-CHANGE; ECOLOGY; BODY CONDITION; EVOLUTION; FOOD; common eiders; alternative food resources; CONSUMPTION; foraging performance; ICE CONDITIONS; INFORMATION; optimal foraging theory; polar bears; seabird eggs; VISUAL CUES

Polar bear foraging on common eider eggs: estimating the energetic consequences of a climate-mediated behavioural shift - Jagielski, P. M.; Dey, C. J.; Gilchrist, H. G.; Richardson, E. S.; Semeniuk, C. A. D. (ANIMAL BEHAVIOUR, 2021)
Climate-mediated phenological shifts can cause species to lose access to their primary prey while increasing opportunities for alternative-prey encounters. Species that are able to capitalize on alternative resources could potentially profit from prey-switching should the benefits of procuring these alternative resources outweigh their acquisition costs. Polar bears, Ursus maritimus, use sea ice as a platform to hunt seals, and individuals inhabiting the southern-most extent of their range rely on accumulated fat reserves to sustain themselves during the increasingly lengthy ice-free season. In response to declining access to their primary prey through documented sea ice loss, some polar bears are foraging on the eggs of birds in lieu of hunting opportunities on ice, as their onshore arrival is increasingly overlapping with birds' breeding schedules. To gain a better understanding of the energetic consequences of this behaviour, we used aerial drones to record polar bears foraging on sea duck eggs (common eider, Somateria mollissima) on Mitivik Island, Nunavut, Canada. Using these data, we examined variation in individual polar bear foraging behaviours and estimated the energetic benefits and costs associated with foraging on common eider eggs. Because of low costs associated with nest searching and consumption, the energetic cost of foraging remained relatively constant throughout the 2-week observation period. However, we found that as the common eider breeding season progressed, polar bears consumed eggs at a lower rate as they depleted the nesting colony and spent proportionally more time searching for nests. Collectively, this foraging pattern led to an overall declining trend in the net energy gained from egg consumption. Foraging on common eider eggs during increasingly lengthy ice-free seasons is apparently beneficial for polar bears, but only during a limited window of opportunity. By coupling energetic estimates with detailed behavioural data collected through aerial videography, this study provides a quantification of both the benefits and costs of egg consumption for polar bears. (C) 2020 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.
Times Cited in Web of Science Core Collection: 10 Total Times Cited: 11 Cited Reference Count: 101
Keywords: common eider; Somateria mollissima; Ursus maritimus; RINGED SEALS; ECOLOGY; BODY CONDITION; REPRODUCTIVE SUCCESS; foraging; MARITIMUS SUMMER DIETS; PREDATOR; ICE CONDITIONS; East Bay Migratory Bird Sanctuary; eggs; energetic benefit-cost; HUDSON-BAY; Mitivik Island; MODEL SELECTION; PHOCA-HISPIDA; polar bear; terrestrial resource

Endogenous reserve dynamics of northern common eiders wintering in Greenland - Jamieson, Sarah E.; Gilchrist, H. Grant; Merkel, Flemming R.; Diamond, Antony W.; Falk, Knud (Polar Biology, 2006)
Endogenous reserves influence both survival and reproduction of many waterfowl species, but little is known about reserve levels of most species during the nonbreeding season, particularly those wintering at high latitudes. We investigated whether age, sex, and season were related to carcass composition of northern common eiders (Somateria mollissima borealis) wintering in southwest Greenland during 1999-2002. Adults carried more lipid and protein than juveniles during all winters. Among both age classes, males and females had similar fat levels but males carried slightly more protein. There was no dramatic seasonal variation in lipid or protein content. This suggests that during the period of this study, these eiders did not experience large-scale nutritional shortfalls. As predicted, Greenlandic eiders carried more lipid reserves than eider populations wintering in more temperate environments. Contrary to prediction, there was little relation between reserve levels and photoperiod, ambient temperature, or hunting disturbance intensity. Our results suggest that both sexes are equally capable of dealing with nutritional deficits, and that juvenile birds are more prone to nutritional stress as evidenced by their consistently poorer body condition.
Keywords: Common Eider; Nonbreeding Seasons; Somateria mollissima; Energetics and Nutrition

An evaluation of methods used to estimate carcass composition of common eiders Somateria mollissima - Jamieson, Sarah E.; Gilchrist, H. Grant; Merkel, Flemming R.; Falk, Knud; Diamond, Antony W. (Wildlife Biology, 2006)
To examine how endogenous reserves may influence avian life history, it is often necessary to quantify carcass composition. However, proximate analyses are expensive, time-consuming and difficult to perform under field conditions. Consequently, carcass composition is often estimated from easily measured data. We evaluate methods of estimating carcass composition of the common eider duck Somateria mollissima. We measured, dissected and completed proximate analyses of 92 ciders. Predictive models were derived using multiple regressions of 70 birds, while the remaining 22 were used as an independent test of the models. Each model's accuracy was evaluated by comparing estimates against known values of protein and lipids, using root mean square error (RMSE). Abdominal and leg fat pad mass were highly correlated with total lipid (r = 0.92), and body mass was highly correlated with total protein (r = 0.80). Models that used body mass, fat depots and/or muscle group data were the most accurate (lipids adjusted R-2 = 0.93, RMSE = 14.60; protein adjusted R-2 = 0.74, RMSE = 11.14). By using these equations it is possible, using dissection data, to accurately estimate carcass composition of eiders. If dissection data are not available, one can still estimate carcass composition using equations that require only morphometrics although in our lipid analysis such equations had relatively low accuracy (lipids adjusted R-2 = 0.54, RMSE = 32.74).
Keywords: Common Eider; Nonbreeding Seasons; Somateria mollissima; Energetics and Nutrition; Techniques

Autumn and winter diet of Long-tailed Duck in the Belcher Islands, Nunavut, Canada - Jamieson, Sarah E.; Robertson, Gregory J.; Gilchrist, H. Grant (Waterbirds, 2001)
We examined the diet of Long-tailed Ducks (Clangula hyemalis) in the autumn and winter of 1998-99 in the Belcher Islands, Nunavut, Canada. Collections were made in early November before sea ice had formed and in February and March, the time of maximum ice cover. Eight birds collected in the autumn and 19 collected in the winter had food items in the proventriculus/esophagus. For birds collected in the fall, 89% (aggregate wet mass) of the diet consisted of the amphipod Calliopius laeviusculus. The remainder consisted of other smaller amphipods (5%) and sandlance (sandeels, Ammodytes sp.; 6%). In winter, Long-tailed Duck diet consisted of the amphipod Ischyrocerus anquipes (69%), fish eggs (probably sandlance; 24%), sandlance (1%) and other amphipods (5%). Long-tailed Duck foraging at the landfast ice floe edge along coasts fed mostly on fish and fish eggs, while those in polynyas among islands fed on amphipods. Consuming soft-bodied prey with high energy densities is likely to allow Long-tailed Ducks to successfully winter in the predominately ice-covered Hudson Bay.
Keywords: Nonbreeding Seasons; Clangula hyemalis; Long-tailed Duck; Trophic Interactions

Eneolithic pile dwellers captured waterfowl in winter: Analysis of avian bone remains from two pile dwellings in Ljubljansko barje (Slovenia) - Janzekovic, F.; Klenovsek, T.; Mlikovsky, J.; Toskan, B.; Veluscek, A. (INTERNATIONAL JOURNAL OF OSTEOARCHAEOLOGY, 2021)
This study presents the results of an ornitho-archaeological analysis of avian bones from Stare gmajne and Blatna Brezovica, two Eneolithic pile dwelling sites in the area of Ljubljansko barje, Slovenia. Avian bone remains, together with remnants of huts, tools, mammal bones and bones of other vertebrates, represent the material remnant of a pile dwelling culture from the second half of the fourth millennium BC. A total of 2091 avian bones or fragments thereof were excavated. The avifauna includes 682 taxonomically identified remains (NISP), assigned to 15 bird taxa. Taxonomically, species from the Anatidae group predominate (68.7% of NISP), mainly Bucephala clangula (40.3% of NISP). Also abundant is Fulica atra (26.2% NISP) from the family Rallidae. In the ecological context, species inhabiting aquatic or marshy habitats prevail. Representatives of three ecomorphological groups of waterbirds were found: diving birds (Podiceps sp., Phalacrocorax carbo, Aythya fuligula, B. clangula and Mergus sp.), waterbirds (Cygnus sp., Anser sp., Anas sp. and F. atra) and the marsh species group (Ardea cinerea). The absence of medullary bone and the abundance of wintering species in the area are consistent with the hypothesis that the birds were captured during the winter season. Taphonomic evidence (burned bones) suggests that the studied assemblages were human food waste. The abundance of avian bone remains supports the hypothesis that the native peoples were skilled hunters of aquatic birds.
Times Cited in Web of Science Core Collection: 1 Total Times Cited: 1 Cited Reference Count: 51
Keywords: archaeozoology; bird bones; Eneolithic; palaeoecology; pile dwellings; taphonomy

Behavioural responses of non-breeding waterbirds to marine traffic in the near-shore environment - Jarrett, D.; Calladine, J.; Cook, Ascp; Upton, A.; Williams, J.; Williams, S.; Wilson, J. M.; Wilson, M. W.; Woodward, I.; Humphreys, E. M. (BIRD STUDY, 2021)
Capsule Recording of behavioural responses to ferry traffic for 11 target species showed that Red-throated Diver Gavia stellata, Slavonian Grebe Podiceps auratus, and Black-throated Diver Gavia arctica were most likely to react to passing vessels. Aim To provide information on how responses to marine traffic vary between waterbird species to inform marine spatial planning and environmental impact assessments in the near-shore environment. Methods We recorded behavioural responses to ferry traffic for 11 target species in near-shore waters: Common Eider Somateria mollissima, Goldeneye Bucephala clangula, Long-tailed Duck Clangula hyemalis, Velvet Scoter Melanitta fusca, Red-breasted Merganser Mergus serrator, Black-throated Diver, Great Northern Diver Gavia immer, Red-throated Diver, European Shag Gulosus aristotelis, Slavonian Grebe and Black Guillemot Cepphus grylle. Responses were analysed using generalized linear models and mixed models. Results Red-throated Diver, Black-throated Diver and Slavonian Grebe were the most likely species to exhibit a response to passing vessels. While Red-throated Divers and Slavonian Grebes were highly likely to flush, Black-throated Divers and Great Northern Divers rarely took flight, instead favouring swim or dive responses. In rougher sea conditions birds were more likely to take flight, and the propensity to respond declined across the wintering period. Conclusions This research provides comparative evidence on the behavioural responses of waterbirds to marine traffic. The results support previous studies which highlighted the high sensitivity of diver species to disturbance and provide new evidence that Slavonian Grebe may also be a high sensitivity species.
Times Cited in Web of Science Core Collection: 0 Total Times Cited: 0 Cited Reference Count: 58
Keywords: CONSEQUENCES; VULNERABILITY; SEABIRDS; IMPACTS; POPULATIONS; HABITUATION; HUMAN DISTURBANCE; OFFSHORE WIND FARMS; OYSTERCATCHERS HAEMATOPUS-OSTRALEGUS; WAVE

The impact of sea ice conditions on breeding decisions is modulated by body condition in an arctic partial capital breeder - Jean-Gagnon, F.; Legagneux, P.; Gilchrist, G.; Belanger, S.; Love, O.; Bety, J. (OECOLOGIA, 2018)
Determining how environmental conditions interact with individual intrinsic properties is important for unravelling the underlying mechanisms that drive variation in reproductive decisions among migratory species. We investigated the influence of sea ice conditions and body condition at arrival on the breeding propensity, i.e. the decision to reproduce or not within a single breeding season, and timing of laying in migrating common eiders (Somateria mollissima) breeding in the Arctic. Using Radarsat satellite images acquired from 2002 to 2013, we estimated the proportion of open water in the intertidal zone in early summer to track the availability of potential foraging areas for pre-breeding females. Timing of ice-breakup varied by up to 20 days across years and showed strong relationship with both breeding propensity and the timing of laying of eiders: fewer pre-breeding individuals were resighted nesting in the colony and laying was also delayed in years with late ice-breakup. Interestingly, the effect of sea ice dynamics on reproduction was modulated by the state of individuals at arrival on the breeding grounds: females arriving in low condition were more affected by a late ice-breakup. Open water accessibility in early summer, a likely proxy of food availability, is thus crucial for reproductive decisions in a (partial) capital breeder. Our predictive capacity in determining how Arctic-breeding seabirds respond to changes in environmental conditions will require incorporating such cross-seasonal cumulative effects.
Times Cited in Web of Science Core Collection: 27 Total Times Cited: 27 Cited Reference Count: 81
Keywords: CLUTCH SIZE; POPULATION-DYNAMICS; SOMATERIA-MOLLISSIMA; Common eider; CONDITION-DEPENDENT MODEL; TRADE-OFFS; HUDSON-BAY; Breeding propensity; INDIVIDUAL QUALITY; Individual state; REPRODUCTIVE CONSEQUENCES; Reproductive decisions; Sea ice; SEASONAL DECLINE; SNOW GEESE

Assessing the recovery of lakes in southeastern Canada from the effects of acidic deposition - Jeffries, Dean S.; Clair, Thomas A.; Couture, Suzanne; Dillon, Peter J.; Dupont, Jacques; Keller, Wendel; McNicol, Donald K.; Turner, Michael A.; Vet, Robert; Weeber, Russell (Ambio, 2003)
Reductions in North American sulfur dioxide (SO2) emissions promoted expectations that aquatic ecosystems in southeastern Canada would soon recover from acidification. Only lakes located near smelters that have dramatically reduced emissions approach this expectation. Lakes in the Atlantic provinces, Quebec and Ontario affected only by long-range sources show a general decline in sulfate (SO42-) concentrations, but with a relatively smaller compensating increase in pH or alkalinity. Several factors may contribute to the constrained (or most likely delayed) acidity response: declining base cation concentrations, drought-induced mobilization of SO42-, damaged internal alkalinity generation mechanisms, and perhaps increasing nitrate or organic anion levels. Monitoring to detect biological recovery in southeastern Canada is extremely limited, but where it occurs, there is little evidence of recovery outside of the Sudbury/Killarney area. Both the occurrence of Atlantic salmon in Nova Scotia rivers and the breeding success of Common Loons in Ontario lakes are in fact declining although factors beyond acidification also play a role. Chemical and biological models predict that much greater SO2 emission reductions than those presently required by legislation will be needed to promote widespread chemical and latterly, biological recovery. It may be unrealistic to expect that pre-industrial chemical and biological conditions can ever be reestablished in many lakes of southeastern Canada.
Keywords: Sea Ducks - General; Contaminants; Common merganser

Foraging by a Red-Tailed Hawk along a wetland edge: How large a duck can be captured? - Jehl, Joseph R., Jr. (Wilson Bulletin, 2004)
A Red-tailed Hawk (Buteo jamaicensis; estimated mass 1,000-1,200 g) failed to kill a Red-breasted Merganser (Mergus serrator; estimated mass 1,150 g) that it captured in shallow water (<25 cm), but evidently dispatched a starving Red-necked Grebe (Podiceps grisegena; mass 645-660 g). These observations are pertinent to estimating the upper mass limit for successful foraging in water.
Keywords: Trophic Interactions; Mergus serrator; Red-breasted merganser

Rehabilitation of Oiled Birds a Physiological Evaluation of Four Cleaning Agents - Jenssen, B. M.; Ekker, M. (Marine Pollution Bulletin, 1989)
The development of more efficient detergents for cleaning oiled birds is important in order to improve on existing methods. In the present study we tested the properties of four different cleaning agents to remove oil from the plumage and to restore the water repellent and insulative properties of the feathers of domestic ducks (Anas platyrhynchos) and of common eiders (Somateria mollissima). By using more efficient detergents, the cleaning time was reduced by approximately 50%. Our results also show that these detergents are efficient in restoring the insulative properties of the cleaned plumage. The study also showed that the water repellent properties of the plumage were not re-established before the plumage was dry, and that cleaning oiled birds using cold water resulted in hypothermia.
Keywords: Common Eider; Contaminants; Somateria mollissima; Techniques

Dose Dependent Effects of Plumage-Oiling on Thermoregulation of Common Eiders Somateria-Mollissima Residing in Water - Jenssen, B. M.; Ekker, M. (Polar Research, 1991)
Thermoregulatory effects which occur during the first hours after plumage-oiling were studied under laboratory conditions by measuring the metabolic heat production of Common Eiders (Somateria mollissima) which were resting in water for up to three hours. The ducks were exposed to 10-70 mL Statfjord A crude oil while residing in water inside a respiration chamber at 5.5.degree. C. The study demonstrated a dose-and time-dependent effect of plumage oiling on metabolic heat production during the first three hours after contact with the oil. The results indicate that the immediate, short-term effects following initial contact with oil at sea are lesser in scale than those which occur after the birds have preened the oil into a greater part of their plumage. After plumage contamination with 70 mL crude oil, the rate of heat loss exceeded the thermoregulatory heat production capacity and the Eiders became hypothermic within 70 minutes after contamination.
Keywords: Common Eider; Contaminants; Somateria mollissima; Energetics and Nutrition

Effects of Plumage Contamination with Crude Oil Dispersant Mixtures on Thermoregulation in Common Eiders and Mallards - Jenssen, B. M.; Ekker, M. (Archives of Environmental Contamination and Toxicology, 1991)
Thermoregulatory effects of plumage-oiling with Statfjord A crude oil (SACO), or of SACO mixed with the dispersants Finasol OSR-5 or OSR-12 were studied by measuring the rate of metabolic heat production of common eiders (Somateria mollissima) and mallards (Anas platyrhynchos) residing in water (6.57%C). The study suggests that oil-dispersant mixtures are more potent than the crude oil alone, and that common eiders are more sensitive to crude oil-dispersant mixtures than are mallards. The species differences is probably due to specific differences in plumage structure, i.e., birds possessing an air-filled plumage, with high insulative properties, are probably more vulnerable than species with a plumage which does not offer so much resistance to heat loss. The level of heat production of contaminated mallards was higher on the day following contamination compared to the metabolic rate recorded two-three hours after contamination, presumably because the birds preened the pollutants further into their plumage, enhancing its wettability. Because exposure to very small volumes of chemically treated oil may cause a significant decrease in plumage-insulation, birds should be prevented from coming into contact with chemically treated oilslicks.
Keywords: Common Eider; Contaminants; Somateria mollissima; Energetics and Nutrition

Thermoregulation in Winter-Acclimatized Common Eiders Somateria-Mollissima in Air and Water - Jenssen, B. M.; Ekker, M.; Bech, C. (Canadian Journal of Zoology, 1989)
Metabolic heat production, body temperature, and skin temperatures of the back and breast were measured and the thermal conductance, and thus insulation, estimated in winter-acclimatized common eiders (Somateria mollissima) exposed to air and water. When exposed to low air temperatures, the plumage was responsible for most of the insulation. When exposed to water, the insulation in the plumage was reduced. This decrease was, however, compensated through increased peripheral vasoconstriction. A low total thermal conductance lowers the energetic costs of existence in cold environments. This reduces the nutritional demands, and may be an adaptation to living in polar and subpolar regions where temperatures are low and where the short day length during winter may reduce the time available for feeding.
Keywords: Common Eider; Somateria mollissima; Energetics and Nutrition

Observations of Molting Eider and Breeding Common Eider Somateria-Mollissima at Nordaustlandet Svalbard Norway in 1979 - Jepsen, P. U. (Polar Research, 1984)
A survey on the common eider S. mollissima in wing feacher molt and females with young was carried out in connection with Norsk Polarinstitutt's expedition to Svalbard in July and Aug. 1979. A total of 3450 molting eider were found on a water area of approximately 2500 km2; 18% of these were flightless. Females dominated in the population with about 82%. Of the breeding population, 109 females with 336 young were found. The average ratio of female to young has been calculated at 1:3.08. This ratio in relation to other studies of eider productivity is discussed briefly.
Keywords: Breeding Season; Abundance, Distribution, and Trends; Common Eider; Nonbreeding Seasons; Molt; Somateria mollissima

Mass Stranding of Marine Birds Caused by a Surfactant-Producing Red Tide - Jessup, David A.; Miller, Melissa A.; Ryan, John P.; Nevins, Hannah M.; Kerkering, Heather A.; Mekebri, Abdou; Crane, David B.; Johnson, Tyler A.; Kudela, Raphael M. (PLoS One, 2009)
In November-December 2007 a widespread seabird mortality event occurred in Monterey Bay, California, USA, coincident with a massive red tide caused by the dinoflagellate Akashiwo sanguinea. Affected birds had a slimy yellow-green material on their feathers, which were saturated with water, and they were severely hypothermic. We determined that foam containing surfactant-like proteins, derived from organic matter of the red tide, coated their feathers and neutralized natural water repellency and insulation. No evidence of exposure to petroleum or other oils or biotoxins were found. This is the first documented case of its kind, but previous similar events may have gone undetected. The frequency and amplitude of red tides have increased in Monterey Bay since 2004, suggesting that impacts on wintering marine birds may continue or increase.
Keywords: Nonbreeding Seasons; Melanitta perspicillata; Surf Scoter; Survival

Habitat Selection of Scaly-sided Merganser under Multiple Area Scales in Water Systems of Poyang Lake, China - Jin, Z. Y.; Qin, S. M. (PAKISTAN JOURNAL OF ZOOLOGY, 2020)
Habitat selection of the Endangered Scaly-sided Merganser Mergus squamatus was studied in four rivers of Poyang Lake, Jiangxi Province, China at landscape and micro-habitat scales, from November 2017 to March 2018 and November 2018 to March 2019. At landscape scale, the main foraging habitats of this species include woodlands and farmlands. The largest proportion of woodland in the habitats was 88.70%. Proportion of shoals in foraging habitats at 500-m, 1000-m, 1500-m and 5000-m scales were larger than that in control plots, indicating that the presence of shoals is an important factor determining habitat selection of this bird. At micro-habitat scale, water flow speed (P=0.044), and distance to road (P=0.018) and village (P=0.001) were significantly greater than in control plots. Principal component analysis showed that safety factors (vegetation cover on both banks, distance to a mine factory and river width) were the three most important habitat factors, indicating that Scaly-sided Merganser had high requirements for shelter and safety. Twenty two species offish belonging to eight families and three orders were identified in foraging areas of the Scaly-sided Merganser. We could identify only six fish species eaten by the merganser viz., Carassius auratus, Misgurnus anguillicaudatus, Noemacheilus fasciolatus, Silurus asotus, Tachysurus fulvidraco and Siniperca chuatsi, which were relatively common and present in all the four rivers, indicating that this bird was an opportunist predator. It is important to reduce human activities and protect woodland and aquatic environments because Scaly-sided Merganser have high requirements for safety and water conditions under both landscape and micro-habitat scales.
Times Cited in Web of Science Core Collection: 2 Total Times Cited: 2 Cited Reference Count: 29
Keywords: Scaly-sided Merganser; WINTER; Habitat selection; Mergus squamatus; MERGUS-SQUAMATUS; Multiple scales

Oil Pollution and Sea Birds in Denmark 1935-1968 - Joensen, A. H. (Danish Review of Game Biology, 1972)
Keywords: Sea Ducks - General; Contaminants

Studies on Oil Pollution and Sea Birds in Denmark 1968-1971 - Joensen, A. H. (Danish Review of Game Biology, 1972)
Keywords: Sea Ducks - General; Contaminants

Molt Migration and Wing Feather Molt of Sea Ducks in Denmark - Joensen, A. H. (Danish Review of Game Biology, 1973)
Keywords: Sea Ducks - General; Nonbreeding Seasons; Molt; Migration

Oil Pollution and Sea Birds in Denmark 1971-1976 - Joensen, A. H.; Hansen, E. B. (Danish Review of Game Biology, 1977)
The main topics discussed are: general collection of information on oil pollution incidents; reports on 2 disasters in 1972; questionnaire surveys to diving-duck hunters; surveys of beached birds; geographical and seasonal distribution of seabird mortality; species affected by oil pollution; and trends in seabird mortality during 1968-1976.
Keywords: Sea Ducks - General; Contaminants

On the Molting Migration of the Goldeneye Bucephala and the Common Scoter Melanitta-Nigra in Estonia - Jogi, A. (Ornithologische Mitteilungen, 1971)
Keywords: Nonbreeding Seasons; Molt; Migration; Bucephala clangula; Common Goldeneye; Black Scoter; Melanitta nigra

Change in waterfowl nest cavity density in a New Brunswick floodplain forest - Johnsen, Eric P.; Dilworth, Tim G.; Kehoe, Pat (Ecoscience, 1994)
A study of waterfowl nest cavities conducted in the Saint John River valley in 1963-1964 by Prince recorded a density of 5.5 suitable nesting cavities/ha, which is the highest reported to date in North America. Since that study, the area's timber characteristics have been altered via Dutch elm disease and timber harvest. We investigated whether these factors caused a reduction in the number of cavities available to cavity-nesting waterfowl by conducting an inventory of the forest composition and recording density and use of cavities. Plots studied in 1963 and 1964 by Prince were used to be comparable. Total basal area for each sample plot was significantly reduced with a mean decrease of 51%. For the two most important cavity tree species, this represented a reduction from 80 to 0.7 m-2/ha for American elm (Ulmus americana L.) and from 103.6 to 51.9 m-2/ha for silver maple (Acer saccharinum L.). The number of cavities/ha for the four sample plots ranged from 0 to 2.5 with a mean of 1.0. Sixteen of 50 "suitable" cavities were unused by animals and only six were used by waterfowl.
Keywords: Breeding Season; Bucephala clangula; Common Goldeneye; Habitat

Hybridization in the Anatidae and its taxonomic implications - Johnsgard, Paul A. (Condor, 1960)
A summary of published and unpublished records of interspecific hybridization in the waterfowl family Anatidae indicate that the tribes and genera that have been proposed by J. Delacour and E. Mayr are substantiated by hybrid evidence. Wide interspecific hybrid fertility necessitates broad generic limits in the Anatidae. Frequency of intertribal hydridization in the perching duck tribe (Cairinini) indicates that this tribe should be placed between the shelduck tribe (Tadornini) and the surface-feeding ducks (Anatini), rather than between the diving ducks (Aythyini) and the sea ducks (Mergini) where the perching ducks are presently placed. || ABSTRACT AUTHORS: P. A. Johnsgard
Keywords: Taxonomy; Sea Ducks - General

Classification and evolutionary relationships of the sea ducks - Johnsgard, Paul A. (Condor, 1960)
Anatomical and behavioral variations among the sea ducks (Mergini) of the avian family Anatidae are discussed with reference to the probable taxonomic validity of this tribe as it was erected by J. Delacour and E. Mayr (Wilson Bull. 57: 3-15. 1945). Evidence for recent suggestions that the eider group be removed from the tribe is analyzed and rejected on both anatomical and behavioral grounds. However, the generic separation of the Steller's eider (Polysticta stelleri) from the typical eiders (Somateria) is upheld. It is concluded that the tribe has its closest evolutionary affinities with the pochard group (Aythyini) rather than with the dabbling ducks (Anatini) or the perching ducks (Cairinini). ABSTRACT AUTHORS: P. A. Johnsgard
Keywords: Taxonomy; Sea Ducks - General

The sexual behavior and systematic position of the Hooded Merganser - Johnsgard, Paul A. (Wilson Bull, 1961)
The courtship and copulatory behavior patterns of the Hooded Merganser are discribed, and homologies are pointed out with other Mergus species and with Bucephala. Some of its courtship displays and precopulatory behavior has typical Mergus elements and others show affinities with Bucephala. The Hooded Merganser provides a connecting link between Bucephala and Mergus. || ABSTRACT AUTHORS: W. Porter
Keywords: Taxonomy; Behavior; Hooded Merganser; Lophodytes cucullatus

Comparative behavior and relationships of the eiders - Johnsgard, Paul A. (Condor, 1964)
Pair-forming and copulatory displays of the 4 spp. of eiders (Anatidae) are described and illustrated, based on observations of captive and wild specimens. Behavioral differences indicate that 2 genera (Polysticta and Somateria) of eiders should be recognized, and that Lampronetta should be considered a synonym of Somateria. Racial differences in the displays of Somateria mollissima mollissima and S. m. v. nigra are explained on the basis of sympatry between the latter and S. fischeri, producing selection for display divergence that has not affected S. m. mollissima. Similarities in the behavior patterns of the eiders and scoters suggest that the eiders are directly related to the scoters and other sea ducks (Mergini), probably through such intermediate forms as Camptorhynchus, Clangula, and Histrionicus, for which the behavior patterns are largely or entirely unknown. || ABSTRACT AUTHORS: P. A. Johnsgard
Keywords: Taxonomy; Behavior; Sea Ducks - General

Aerial monitoring of marine waterfowl in the Alaskan Beaufort Sea - Johnson, Stephen R.; Noel, Lynn E.; Gazey, William J.; Hawkes, Virgil C. (Environmental Monitoring and Assessment, 2005)
The purpose of this study was to design and test a monitoring protocol for marine waterfowl in the central Alaskan Beaufort Sea. The study provides an important case-study of how a long-term monitoring program may be affected by unanticipated human disturbances.Because of its overwhelming and widespread abundance, relatively sedentary behavior, ease in counting, and the extensive historical database, the long-tailed duck (Clangula hyemalis) was selected as the focal species. Two null hypotheses were formulated concerning potential changes in the numbers and distribution of long-tailed ducks in relation to disturbance in an industrial study area, compared to a reference study area located about 50 km to the east.A 9-year historical database (1977-1984, 1989) of long-tailed duck densities and other important data recorded during systematic aerial surveys was analyzed retrospectively using multiple regression techniques. The retrospective analyses determined which of several predictor variables recorded were significantly related to long-tailed duck density. Separate analyses were conducted for two periods: (1) the overall period when long-tailed ducks were present in the lagoon study areas, and (2) the shorter adult male molt period. The results of the two analyses indicated that 57% and 68%, respectively, of the total variation in long-tailed duck density during the two periods could be explained by variables recorded during the surveys. Predictor variables representing habitat, day of the year, time of day, amount of ice, and wave height recorded on-transect during surveys were most closely associated with long-tailed duck density. Measurement error during the surveys, and influences outside the study area such as nesting success in tundra habitats and mortality during migration and in over-wintering areas likely also had strong influences on the results, but these factors were not measurable in our study.Based on results of the retrospective analyses, a long-term monitoring protocol consisting of a program of systematic aerial surveys and an analyses of variance and covariance (ANOVA and ANCOVA) statistical procedure was designed and initially tested in 1990 and 1991. This 2-year testing phase resulted in several revisions to the monitoring protocol. Refinements were made to the original sampling procedures, to the survey schedule, and to the recommended statistical analysis procedures. Results of the ANOVA and ANCOVA indicated that there was no evidence of a change in long-tailed duck densities that could be attributable to disturbance (from any source) in the industrial study area relative to a reference area with no industrial development. Other analyses indicated that the sampling and analysis procedures would be adequate to detect long-term trends in long-tailed duck density and localized disturbance effects, but that the monitoring program should be continued well beyond two years to detect statistically significant changes. As a result, additional aerial surveys of both study areas were conducted again during 1999-2001.Results of the revised ANOVA and ANCOVA of the 1990-1991 and 1999-2001 survey data indicated that the density of long-tailed ducks had significantly declined in coastal lagoons along the central Alaskan Beaufort Sea coast during the study period. In addition, disturbances throughout the barrier island-lagoon systems used by these ducks, including both the industrial and the reference study areas, had significantly increased over the same period. However, because unanticipated disturbances from a variety of anthropogenic sources, and not just industry sources, increased in both study areas, the reference study area was not an effective statistical control. As a result, the decline in long-tailed duck density in both study areas was not attributable to industry-related activities. Although the monitoring protocol described here is an effective method to detect statistically significant changes in long-tailed duck distribution and abundance in the nearshore Alaskan Beaufort Sea, many more years of sampling would be necessary to attribute observed changes to industry-related disturbances.
Keywords: Conservation; Breeding Season; Abundance, Distribution, and Trends; Nonbreeding Seasons; Clangula hyemalis; Long-tailed Duck; Habitat

Water Bird Migration near the Yukon and Alaskan Coast of the Beaufort Sea 2. Molt Migration of Sea Ducks in Summer - Johnson, S. R.; Richardsn, W. J. (Arctic, 1982)
Westward molt migrations of seaducks were studied in the summers of 1972 and 1975 (northern Yukon) and 1977-1978 (west of Prudhoe Bay, Alaska [USA]). Methods used were visual observations from the coast, aerial surveys and (in 1975) DEW [distant early warning] radar. Many male oldsquaws (Clangula hyemalis) fly west near the north coast of Alaska in early July. Most seem to travel only a short distance; tens of thousands subsequently molt in various lagoons along northern Alaska. Few of the male eiders (Somateria spp.) that leave the Beaufort Sea in summer travel west along the coast past the 2 study areas. Instead, the main route may be seaward of the barrier islands until the eiders approach Point Barrow. In late June and July, several thousand male surf scoters (Melanitta perspicillata) fly west near the Yukon and Alaskan coast to molting areas in lagoons. This flight, unlike molt migrations of most scoters, is not directed toward the wintering areas.
Keywords: Sea Ducks - General; Nonbreeding Seasons; Melanitta perspicillata; Surf Scoter; Molt; Clangula hyemalis; Long-tailed Duck; Migration

Late-summer abundance and distribution of marine birds in Kasegaluk Lagoon, Chukchi Sea, Alaska - Johnson, Stephen R.; Wiggins, David A.; Wainwright, Peter F. (Arctic, 1993)
Oil and gas drilling programs in the Alaska Chukchi Sea were carried out on leases offshore from Kasegaluk Lagoon in 1989-91, and further exploration and development activities in this area are likely in future years. We conducted aerial surveys between late July and early September 1989-91 to determine the distribution and abundance of marine birds in the Kasegaluk Lagoon area. We hypothesized that Kasegaluk Lagoon supported an avifauna similar to that found in other lagoon systems in arctic Alaska. In fact, the richness and diversity of bird species using Kasegaluk Lagoon were greater than in lagoon systems in the Beaufort Sea. Brant (Branta bernicla) was the most abundant species in Kasegaluk Lagoon compared to lagoons in the Beaufort Sea, where the Oldsquaw (Clangula hyemalis) is the dominant species. Several other species or species groups, such as Glaucous Gull (Larus hyperboreus), Arctic Tern (Sterna paradisaea), small shorebirds (mainly Calidris and Phalaropus), and Lesser Snow Goose (Chen caerulescens) were also relatively abundant in Kasegaluk Lagoon.
Keywords: Abundance, Distribution, and Trends; Nonbreeding Seasons; Clangula hyemalis; Long-tailed Duck

Macroalgae composition alters occupancy o multiple bird guilds in rocky intertidal communities - Johnston, E. M.; Klemmer, A. J.; Blomberg, E. J.; Baron, A.; Watson, V. K.; Tudor, L.; Welch, L. J.; Olsen, B. J. (MARINE ECOLOGY PROGRESS SERIES, 2021)
In the north Atlantic, rocky intertidal shores with diverse macroalgal assemblages are common. Despite this, the effect of macroalgae on bird use of these habitats is not well understood. We used a single-season, single-species occupancy framework to investigate the influence of the macroalgal assemblage on 3 bird guilds and 2 single-species groups: shorebirds (waders), scavengers, divers, common eider Somateria mollissima non-parenting adults, and common eider broods. In particular, we considered whether bird occupancy is more strongly determined by the taxonomic composition of the macroalgal assemblage or by structural characteristics of the collective assemblage. We conducted avian point counts and intertidal habitat surveys at 75 sites along the Maine (USA) coast in 2016 and 2017. Macroalgae increased the probability of site occupancy for 1 guild and 2 single-species groups. Most notably, we found that shorebird occupancy had a positive relationship with the spatial extent and mat depth of Ascophyllum nodosum, indicating a preference for more homogeneous and deeper macroalgal assemblages dominated by this common, tall-canopied taxon. In contrast, common eider presence had a positive relationship with the spatial extent of 2 categories of shorter-canopied macroalgae that are less dominant members of the macroalgal assemblage. Both shorebirds and eiders were less likely to occur in areas with steeper intertidal slopes, which provide less potential habitat during low tides. Overall, our results suggest that macroalgae composition and availability influences bird occupancy in rocky intertidal habitats, but more mechanistic studies (e.g. behavioral) are needed to understand the exact role macroalgae play in coastal bird ecology.
Times Cited in Web of Science Core Collection: 2 Total Times Cited: 2 Cited Reference Count: 75
Keywords: Somateria mollissima; COMMON EIDERS; Common eider; HABITAT USE; BAY; MODEL SELECTION; Ascophyllum nodosum; ASCOPHYLLUM-NODOSUM; BLACK-BACKED GULLS; Fucus vesiculosus; FUNDY; HERRING-GULLS; Intertidal ecology; Macroalgae; MIGRATING SHOREBIRDS; SEMIPALMATED SANDPIPERS; Shorebirds; Single-species occupancy; Waders

Avian influenza virus screening in wild waterfowl in Norway, 2005 - Jonassen, Christine Monceyron; Handeland, Kjell (Avian Diseases, 2007)
The prevalence of influenza A virus infection, and the distribution of different subtypes of the virus, were studied in 604 geese and ducks shot during ordinary hunting 2005. The study was based upon molecular screening of cloacal swabs taken by the hunters. The sampling included the following species: greylag (Anser anser), mallard (Anas platyrhynchos), wigeon (Anas penelope), teal (Anas crecca), goosander (Mergus merganser), tufted duck (Aythya fuligula), common scoter (Melanitta nigra), goldeneye (Bucephala clangula), and red-breasted merganser (Mergus serrator).The samples found to be positive in the initial pan-influenza A virus reverse transcription-polymerase chain reaction (RT-PCR) were further subtyped by using a specific H5 RT-PCR and full-length RT-PCRs for the hemagglutinin (HA) and neuraminidase genes.None of the greylag samples (0/185) were positive for influenza A virus, whereas 19.1% of the ducks (80/419) were positive. The prevalences of influenza A virus in the different duck species were as follows: mallard, 20.4% (58/284); wigeon, 12.5% (8/64); teal, 30.9% (13/42); goosander, 0% (0/5); tufted duck, 0% (0/4); common scoter, 14.3% (1/7); goldeneye, 0% (0/11); and red-breasted merganser, 0% (0/2). H5N1 subtype was found in one mallard and H5N2 subtype in another mallard and one teal. Sequencing of the HA gene identified all three viruses as low-pathogenic strains, closely related to low-pathogenic H5 influenza A viruses evidenced in recent years in Sweden and the Netherlands. The other subtypes identified included H1N1, H2, H3N2, H3N8, H6N1, H6N2, H6N8, H8N4, H9N2, H11N9, and H12 in mallards; H3N2, H6N2, H6N8, and H9N2 in teals; and H6N2 in wigeons and common secret.
Keywords: Sea Ducks - General; Nonbreeding Seasons; Disease

The Lake Myvatn Ecosystem Iceland - Jonasson, P. M. (Oikos, 1979)
Lake Myvatn lies at 63.degree.35'N and 17.degree.00'W and at 278 m above sea level in northern Iceland. The climate is more continental than maritime. But in some years the proximity to the Arctic Circle causes the climate to be cold, wet and foggy. Lake Myvatn has 2 basins: the north basin and the south basin. Volcanic activity since 1975 has caused a land rise of 34 cm at the northeast coast of the north basin. Water enters the lake mainly from cold and warm springs along the east shore (range 5.2-23.1.degree. C) and is discharged, to the west, into the River Laxa. The drainage basin is at least 1000 km2. Retention time in the north basin was 14 days and in south basin, 24 days. Temperature records reveal large variations in response to climatic factors. Air temperatures correlate well with water temperature. The annual amplitude of water temperature was 18.degree. C with a daily amplitude of 3.degree. C in south basin. Wind-induced water level fluctuations are 0.7 m in the north basin and 0.4 m in the south basin. Average ice-cover is 190 days yr-1. Resuspension is high and varies with depth. It was 3 times higher in the north than the south basin. The resuspension provides renewal of nutrients from the bottom, but P seems limiting during calm periods with high demands. N-fixation ensures sufficient N. The N:P ratio in the outlet is 8:1. An inverse thermocline develops in winter and O2 is depleted from the bottom water, but oxygenated conditions are re-established in Feb.-March due to production of benthic diatoms. Phytoplankton gross production was 118 g C m-2 yr-1 in the south basin but only 75 in the north basin. Seasonal succession was unimodal. High production due to Anabaena flos-aquae coincided with high radiation, high temperature and time of ice-break. Production was low at other seasons despite considerable biomass of diatoms and chrysophyceans. Net production in the south basin was calculated to 600 kcal m-2 yr-1. A net production of benthic diatoms amounted to 2220 kcal m-2 yr-1. A dim-light adapted Cladophora aegagropila forms massive phytobenthos in the south basin with 50 g ash-free dry weight m-2. Calculated production was 500 kcal m-2 yr-1. Macro- and epiphytes are important in the north-basin. A living substratum of Cladophora and macrophytes stabilizes the sediment and acts as a sieve for resuspended organic matter. A close relation was found between substrate type and zoobenthos abundance and production. In the south basin, with mud and Cladophora, chironomids dominate numerically (average of total zoobenthos 75,500 individuals m-2) and in terms of production (200 kcal m-2 yr-1). In the north basin, with diatoms, average values are 9750 m-2 and 32 kcal m-2 yr-1. Benthic Crustacea produce approximately 10 kcal m-2 yr-1 in both basins. Zooplankton produced on an average 43 and 15 kcal m-2 yr-1 in the south and north basin, respectively. Fish production, calculated from catch data, was 3 kcal m-2 yr-1 and ducks produced 0.5 kcal m-2 yr-1. Thus energy flow is mainly channeled through phyto- and zoobenthos.
Keywords: Sea Ducks - General; Habitat

Winter Feeding Ecology of Scaup and Common Goldeneye Bucephala-Clangula in Michigan USA - Jones, J. J.; Drobney, R. D. (Journal of Wildlife Management, 1986)
The feeding ecology of wintering greater scaup (Aythya marila), lesser scaup (A. affinis), and common goldeneye (Bucephala clangula) was studied on the Detroit River in southeast Michigan during 1980-81. Aquatic oligochaetes, wildcelery (Vallisneria americana), and pondweeds (Potamogeton spp.) were the principal foods consumed by all 3 species. Ducks foraged almost exclusively at sites with water depths .ltoreq. 2 m. Macroinvertebrate densities were greater (P < 0.05) at shallow depths (2 m) than at deep depths (4.5 m), indicating that the use of feeding sites by waterfowl was influenced by food availability and foraging efficiency. Consequently, shallow areas are critical to diving ducks on the Detroit River, particularly during periods of harsh winter weather.
Keywords: Nonbreeding Seasons; Bucephala clangula; Common Goldeneye; Trophic Interactions

Mass mortality of marine birds in the Northeast Pacific caused by Akashiwo sanguinea - Jones, T.; Parrish, J. K.; Punt, A. E.; Trainer, V. L.; Kudela, R.; Lang, J.; Brancato, M. S.; Odell, A.; Hickey, B. (MARINE ECOLOGY PROGRESS SERIES, 2017)
Harmful algal blooms (HABs) are dense concentrations of phytoplankton that can have deleterious effects on marine life. We documented two of the largest marine bird mortality events ever definitively ascribed to a single HAB, the cause of which was death resulting from plumage fouling by surfactant-like proteins produced by the dinoflagellate Akashiwo sanguinea. The two mortality events were observed along the coast of Washington State in September and October 2009, collectively representing an estimated deposition of 10 500 carcasses, of which the majority were surf scoters, white-winged scoters and common murres. Each mortality event was coincident in space and time with observed bloom landfall, with each event preceded by a similar chain of environmental conditions. Prior to each event, the presence of A. sanguinea and upwelling-favourable conditions likely led to bloom proliferation. In both cases, this period was followed by conditions that transported the senescent bloom into the nearshore environment, whereupon subsequent wave action lysed A. sanguinea cells, creating foam that contained surfactant- like compounds. This sequence of conditions, exacerbated by the presence of aggregations of marine birds in wing moult, appear to be the necessary requirements for marine bird mortality of this scale due to foam-induced plumage fouling. This mechanism of HAB-induced mortality may become more prevalent in the California Current System given the apparent increasing occurrence of HABs and the broad environmental tolerances exhibited by A. sanguinea.
Times Cited in Web of Science Core Collection: 22 Total Times Cited: 22 Cited Reference Count: 93
Keywords: Citizen science; CLIMATE-CHANGE; COAST; PHYTOPLANKTON; BAY; Beached birds; CALIFORNIA CURRENT SYSTEM; Common murres; Dinoflagellates; DOMOIC ACID; GYMNODINIUM-SANGUINEUM; Harmful algal bloom; HARMFUL ALGAL BLOOMS; MOLT; RED TIDE; Scoters

Observations of Mergansers in the Zaan District - Jonker, K. (Maandblad de Pieper, 1972)
Keywords: Common merganser; Mergus merganser

Toxicity and irreversible binding of two DDT metabolites-3-methylsulfonyl-DDE and o,p'-DDD-in adrenal interrenal cells in birds - Jonsson, C. J.; Lund, B. O.; Brunstrom, B.; Brandt, I. (Environmental Toxicology and Chemistry, 1994)
The toxicity and the metabolism-dependent irreversible binding of the lipophilic DDT metabolites 3-methylsulfonyl-DDE (MeSO-2-DDE) and o,p'-DDD in the adrenal gland of the chicken were examined. As determined by histopathology, vacuolar degeneration and pycnosis of adrenal interrenal cells occurred 4 d after injection of a single dose of either compound (0.25 mmol/kg; 80- 100 mg/kg body weight) to 6-d-old chicken. In addition, o, p'-DDD, but not MeSO-2-DDE, induced fatty degeneration of the liver. According to autoradiography, irreversibly bound radioactivity was present in the interrenal cells after injection of the 14C-labeled compounds into the air sacs of eggs. Both DDT metabolites were also irreversibly bound to protein after incubation with adrenal 300 g supernatant in vitro, with apparent K-m values of 2.0 and 8.3 mu-M for MeSO-2-DDE and o, p'-DDD, respectively. The irreversible binding in vitro was inhibited by metyrapone, SKF 525A, and carbon monoxide, suggesting a cytochrome P450-dependent metabolic activation to reactive intermediates. Addition of glutathione to the incubations reduced the irreversible binding of MeSO-2-(14C)DDE significantly, whereas the irreversible binding of o,p'-(14C)DDD remained unchanged. The results indicate that MeSO-2-DDE and o, p'-DDD are adrenocorticolytic following an adrenal P450-dependent metabolic activation in the chicken. Experiments with embryonated eggs from common eider and domestic duck demonstrated that MeSO-2-DDE and o, p'-DDD are also metabolically activated and irreversibly bound to adrenal tissue in embryos of these species.
Keywords: Breeding Season; Common Eider; Contaminants; Somateria mollissima; Physiology

Sex ratios of Eurasian wigeon, mallard and common eider in Iceland - Jonsson, Jon Einar (Natturufraedingurinn, 2010)
Sex ratios of Eurasian wigeon, mallard and common eider in Iceland Sex ratios often are uneven in birds, especially northern hemisphere ducks. During winter, the male:female ratio is closest to 1:1 in southern parts of the range, whereas it tends to become progressively more skewed towards males with increasing latitudes. This has been explained by two hypotheses: (1) males prefer to winter near the breeding grounds but are socially dominant to females and force them to winter further south; (2) females may migrate further south because they are smaller and less tolerant of cold weather. Here, the sex ratios of three residential, Icelandic duck populations (Eurasian Wigeon Anas penelope, Mallard A. platyrhynchos and Common Eider Somateria mollissima) were evaluated and compared with data from Western Europe. The sex ratio of Icelandic Eurasian Wigeon was even (1:1), in contrast to male skewness in Great Britain and Western Europe. The sex ratio of Icelandic Mallards averaged 58% males. The sex ratio of European Mallards was correlated with mean average temperature in January with the highest male skewness in the coldest areas. The sex ratios of Icelandic Common Eider were similar to those of other European populations (55-60% males). Winter sex ratios of these species were similar to those of breeding birds, which indicates that the sexes do not segregate in residential duck populations in Iceland. The distance to the mainland probably explains why these populations are residential in Iceland. However, all three species pair relatively early, which in turn precludes males from excluding females from preferred wintering areas for longer than 1-2 months. Residential populations of Icelandic ducks, all of which pair early in winter, may have taken the first evolutionary steps towards speciation similar to the "Island waterfowl" in the Southern Hemisphere.
Keywords: Common Eider; Nonbreeding Seasons; Somateria mollissima; Population Dynamics