High site fidelity does not equate to population genetic structure for common goldeneye and Barrow's goldeneye in North America - Brown, J. I.; Lavretsky, P.; Wilson, R. E.; Haughey, C. L.; Boyd, W. S.; Esler, D.; Talbot, S. L.; Sonsthagen, S. A. (JOURNAL OF AVIAN BIOLOGY, 2020)
Delineation of population structure provides valuable information for conservation and management of species, as levels of demographic and genetic connectivity not only affect population dynamics but also have important implications for adaptability and resiliency of populations and species. Here, we measure population genetic structure and connectivity across the ranges of two sister species of sea ducks: Barrow's goldeneye Bucephala islandica and common goldeneye B. clangula. We use two different marker types: 7-8 nuclear microsatellite loci assayed across 229 samples and 3678 double digest restriction-site associated DNA sequencing (ddRAD-seq) loci assayed across 61 samples. First, both datasets found no evidence of genetic structure within common or Barrow's goldeneye, including between North American and European samples of common goldeneye. These results are in contrast with previous mitochondrial DNA, band recovery and telemetry data which suggest that goldeneyes are structured across their range. We posit that the discordance between autosomal genetic markers and other data types suggests that males, possibly subadult males, may be maintaining genetic connectivity across each species' respective ranges. Next, although mate choice consequences resulting from inter-specific brood parasitism was hypothesized to cause some level of gene flow between goldeneye species, we only identified a single F1 hybrid with no further evidence of contemporary or historical gene flow. Despite ddRAD-seq demographic analyses which recovered an optimum evolutionary model of split-with-migration (i.e. secondary contact), estimates of gene flow were <<1 migrant per generation in both directions. Together, we conclude that either strong ecological barriers or assortative mating are likely playing a role in preventing further backcrossing. Finally, demographic analyses estimated a relatively deep divergence time between Barrow's goldeneye and common goldeneye of similar to 1.6 million years before present and suggests that the genomes of both species have been under similar evolutionary constraints.
Times Cited in Web of Science Core Collection: 4 Total Times Cited: 4 Cited Reference Count: 114
Keywords: sea ducks; waterfowl; SURVIVAL; DENSITY-DEPENDENCE; BRITISH-COLUMBIA; Bucephala; BUCEPHALA-CLANGULA; dispersal; DUCK ANAS-PLATYRHYNCHOS; FLOW; hybridization; MICROSATELLITE LOCI; MITOCHONDRIAL-DNA; NATAL PHILOPATRY; population genetic structure; population genomics

Waterfowl Production on Beaver Flowages in a Part of Northern New-York USA - Brown, M. K.; Parsons, G. R. (New York Fish and Game Journal, 1979)
Waterfowl were observed on 3 occasions at least a week apart during late May, June and early July in 1973 on selected beaver flowages in 4 ecological sections (Taconic, Central Adirondack, Adirondack Foothills and Mohawk) in Region 5S comprising Fulton, Hamilton, Saratoga, Warren and Washington Counties in New York. The flowages were classified as new active, old active or abandoned. The principal species were wood duck, black duck, hooded merganser and mallard. Frequencies in terms of number per flowage and number per acre for adults, broods and ducklings were derived as indices of waterfowl use and production. New active flowages were used to a greater degree than the other classifications. The contribution of beaver flowages to waterfowl production was greatest in the Taconic section. The use of such flowages may be sufficient in all sections of Region 5S to warrant a management program for beaver that would in turn benefit waterfowl. The relationship of such a program to beaver damage problems is also discussed.
Keywords: Breeding Season; Abundance, Distribution, and Trends; Habitat; Hooded Merganser; Lophodytes cucullatus

Nesting Biology of the White-Winged Scoter Melanitta-Fusca-Deglandi - Brown, P. W.; Brown, M. A. (Journal of Wildlife Management, 1981)
Nesting biology and productivity of white-winged scoters (M. fusca deglandi) were studied on islands in Redberry Lake, Saskatchewan, and Jessie Lake, Alberta [Canada], in 1975-1976. Males constituted 60% of the prenesting populations. Nest initiation peaked between June 8 and 21, and most nests were under dense shrubs at least 50 m from the nearest shoreline. The mean laying rate for 8 females was 1 egg every 34.4 h, and mean clutch size (146) was 9.17. The average incubation period for 22 clutches was 27.7 days, and 80% of all clutches hatched between July 17 and 31. Nesting success averaged 72%. Aggregate broods formed in late July and most hens deserted their broods between Aug. 10 and 23. Small, mixed-age broods were common after Aug. 21, and total number of ducklings declined markedly thereafter. Productivity was less than 1.0 ducklings per pair on both lakes in 1976.
Keywords: Breeding Season; Melanitta fusca; White-winged Scoter; Productivity

Growth and moult progression of White-winged Scoter ducklings - Brown, Patrick W.; Fredrickson, Leigh H. (Wildfowl, 1983)
Keywords: Breeding Season; Melanitta fusca; White-winged Scoter; Physiology

Food Habits of Breeding White-Winged Scoters - Brown, P. W.; Fredrickson, L. H. (Canadian Journal of Zoology, 1986)
Twenty-four adult and 10 duckling white-winged scoters were collected on four lakes in central Saskatchewan during the summers of 1977-1980. Hyalella azteca was the most important scoter food and made up 97% (aggregate percent dry weight) of the diet for 13 breeding females, 84% for 11 breeding males, and 100% for 10 ducklings. Hyalella azteca was consistently the most abundant food organism present in Eckman dredge samples taken at scoter feeding sites. Adults consumed H. azteca that were significantly larger than those consumed by ducklings. Both adults and ducklings fed primarily by diving at sites 1-3 m deep, but adults fed at deeper sites than ducklings. Timing of reproduction in white-winged scoters seems to be closely timed with increases in the biomass of abundance of Hyalella and possibly possibly other invertebrate foods.
Keywords: Breeding Season; Melanitta fusca; White-winged Scoter; Trophic Interactions

Time Budget and Incubation Behavior of Breeding White-Winged Scoters - Brown, P. W.; Fredrickson, L. H. (Wilson Bulletin, 1987)
We studied the behaviour and incubation constancy of breeding White-winged Scoters (Melanitta fusca deglandi) at Redberry Lake, Saskatchewan [Canada], during 1977-1980. Females spent 59.6% of the their time feeding during the prelaying period, 61.2% during laying, 60.7% during incubation recesses, and 37% during brood rearing. Prelaying and laying females consistently spent more time feeding than did their mates. Incubation constancy declined from 89.3% of daylight hours during the first third of incubation to 69.3% during the last third. Near the end of incubation, females were off the nest most often between 11:00 and 17:00. White-ringed Scoter females probably relay mainly on resources at the nesting area to meet the needs of reproduction.
Keywords: Behavior; Breeding Season; Melanitta fusca; White-winged Scoter

Body and Organ Weights and Carcass Composition of Breeding Female White-Winged Scoters - Brown, P. W.; Fredrickson, L. H. (Wildfowl, 1987)
Keywords: Breeding Season; Melanitta fusca; White-winged Scoter; Physiology; Energetics and Nutrition

White-Winged Scoter Melanitta-Fusca Populations and Nesting on Redberry Lake Saskatchewan Canada - Brown, P. W.; Fredrickson, L. H. (Canadian Field-Naturalist, 1989)
We studied the nesting ecology of White-winged Scoters (Melanitta fusca) on Redberry Lake, Sakatchewan (52.degree. 40'N, 107.degree. 10'W) in the summer of 1977 to 1981. Most scoters arrived in early May about 30 days before the period of peak nest initiation. About 44% of the female scoters observed soon after first arrival were paired, but 96% were paired by 31 May. Peak numbers of pairs varied little among years and ranged from 389 to 423 scoter pairs during the third week of May each year. About 78% of the peak population left the lake by 31 July when broods were common. Nest success averaged 72.3% for all years and the mean date of hatch was 23 July. Nests with complete concealment had higher sucess rates than nests located in sparser cover (P < 0.025). Duckling mortality was higher during the first week after hatch, but numbers continued to decline during early and mid-August. Annual productivity never exceeded 0.5 duckling/breeding pair.
Keywords: Breeding Season; Melanitta fusca; White-winged Scoter; Productivity; Survival

Longevity and Age of Maturity of White-Winged Scoters Melanitta-Fusca-Deglandi - Brown, P. W.; Houston, S. (Journal of Field Ornithology, 1982)
Keywords: Breeding Season; Melanitta fusca; White-winged Scoter; Survival

White-winged Scoter (Melanitta fusca) - Brown, Patrick W. and Leigh H. Fredrickson (The Birds of North America, 1997)
Keywords: Melanitta fusca; White-winged Scoter

Bird Mortality from Oil Slicks Off Eastern Canada February to April 1970 - Brown, R. G. B.; Gillespie, D. I.; Lock, A. R.; Pearce, P. A.; Watson, G. H. (Canadian Field-Naturalist, 1973)
Keywords: Sea Ducks - General; Nonbreeding Seasons; Contaminants

Embryotoxicity of Polycyclic Aromatic Hydrocarbons Pahs in Three Domestic Avian Species and of Pahs and Coplanar Polychlorinated Biphenyls Pcbs in the Common Eider - Brunstrom, B.; Broman, D.; Naf, C. (Environmental Pollution, 1990)
The embryotoxicity of an artificial mixture of 19 polycyclic aromatic hydrocarbons (PAHs) was tested by injection into the yolk sacs of eggs of four avian species: chicken Gallus domesticus, turkey Meleagris gallopavo, domestic duck Anas platyrhynchos and common eider Somateria mollisima. A dose of 2.0 mg kg egg-1 of the PAH mixture increased the mortality among the embryos of all four species. In the domestic duck, but not in the three other species, there was a significantly increased embryonic mortality at a dose of 0.2 mg kg-1 of this mixture. All 18 individual compounds in the mixture were tested for embryotoxicity in the chicken. The compound most toxic to chick embryos was benzo [k]fluoranthene. This substance also proved to be highly embroytoxic in the three other species. Previous studies have shown coplanar polychlorinated biphenyls (PCBs) to be much more embryotoxic in the chicken than in other avian species studies. In accordance with this, eider duck embryos proved to be considerably less sensitive to 3,3'4,4'-tetrachlorobiphenyl and 3,3',4,4',5-pentachlorobiphenyl than was previously found for chick embryos. For PAHs, however, chick embryos did not have a higher sensitivity than the other species tested.
Keywords: Breeding Season; Common Eider; Contaminants; Somateria mollissima

Quantifying Moonlight and Wind Effects on Flighted Waterfowl Capture Success During Night-Lighting - Buchanan, T.; Brook, R. W.; Purvis, M. P.; Davies, J. C. (Wildlife Society Bulletin, 2015)
Night-lighting is a common technique used to capture waterfowl, upland birds, and waterbirds. The method involves using bright artificial light and a steady loud noise to startle and confuse birds, allowing close approach and capture by hand or with a long-handled dip-net. Many researchers using this technique have noticed that moon phase (or relative brightness) and weather conditions can affect capture rates. Using 16 years (1996-2011) of night-lighting capture data collected during the Ontario Waterfowl Airboat Banding Program, Canada, the effects of moon phase and wind speed on capture rates for flighted waterfowl were quantified. Increasing moon brightness had a negative effect on capture rates for all species analyzed (mallard [Anas platyrhynchos], wood duck [Aix sponsa], blue-winged teal [Anas discors], green-winged teal [Anas crecca], ring-necked duck [Aythya collaris], hooded merganser [Lophodytes cucullatus], and American black duck [Anas rubripes]), with an increasing rate of decline in capture rates when the moon was >75% full (i.e., a bright night). Attempting waterfowl capture when the moon was >75% full led to 2-fold cost increase per bird captured over the average cost per bird captured. Increasing wind speed was positively correlated with capture rate for some species, but had no significant effect on capture rate for most species analyzed. Night-lighting capture of flighted waterfowl should be planned primarily during dark to moderately dark nights to maximize capture efficiency and reduce costs. (C) 2014 The Wildlife Society.
Buchanan, Tore Brook, Rodney W. Purvis, Matthew P. Davies, J. Chris
Keywords: Techniques; Hooded Merganser; Lophodytes cucullatus

Sequencing Dead Ducks - The Labrador Duck is Sister to Stellar's Eider and the Subfossil Chendytes lawi roots the dabbling duck clade - Buckner, J. C.; Ellingson, R.; Gold, D. A.; Jacobs, D. K. (INTEGRATIVE AND COMPARATIVE BIOLOGY, 2017)
Times Cited in Web of Science Core Collection: 0 Total Times Cited: 0 Cited Reference Count: 0

Mitogenomics supports an unexpected taxonomic relationship for the extinct diving duck Chendytes lawi and definitively places the extinct Labrador Duck - Buckner, J. C.; Ellingson, R.; Gold, D. A.; Jones, T. L.; Jacobs, D. K. (MOLECULAR PHYLOGENETICS AND EVOLUTION, 2018)
Chendytes lawi, an extinct flightless diving anseriform from coastal California, was traditionally classified as a sea duck, tribe Mergini, based on similarities in osteological characters. We recover and analyze mitochondrial genomes of C. lawi and five additional Mergini species, including the extinct Labrador Duck, Camptorhynchus labradorius. Despite its diving morphology, C. lawi is reconstructed as an ancient relictual lineage basal to the dabbling ducks (tribe Anatini), revealing an additional example of convergent evolution of characters related to feeding behavior among ducks. The Labrador Duck is sister to Steller's Eider which may provide insights into the evolution and ecology of this poorly known extinct species. Our results demonstrate that inclusion of full length mitogenomes, from taxonomically distributed ancient and modern sources can improve phylogeny reconstruction of groups previously assessed with shorter single-gene mitochondrial sequences.
Times Cited in Web of Science Core Collection: 10 Total Times Cited: 10 Cited Reference Count: 84
Keywords: Biodiversity; ANAS; Anatidae; Ancient DNA; ANSERIFORMES; AVES; California paleontology; COMPLETE MITOCHONDRIAL GENOME; CONVERGENCE; DNA; Duck evolution; EVOLUTION; Labrador duck; Mitochondrial genome; PHYLOGENETIC-RELATIONSHIPS; STELLERS EIDERS

Use of a new standardized habitat survey for assessing the habitat preferences and distribution of upland river birds - Buckton, Sebastian T.; Ormerod, Stephen J. (Bird Study, 1997)
Assessments of the habitat requirements of river birds are central to understanding their distribution and abundance. Here, we make an initial appraisal of the suitability for this purpose of a new standardized method of river habitat survey (RHS) developed by the Environment Agency (EA). We carried out RHS and recorded the presence of five common birds along 74 upland Welsh streams. RHS provided significant and meaningful correlates with bird distribution: Dippers Cinclus cinclus and Grey Wagtails Motacilla cinerea showed a significant preference for sites with tree-related features, while Common Sandpiper Actitis hypoleucos preferred streams with few trees but with more rough pasture and riparian wetlands. Dippers also showed a significant preference for streams with bridges and walls, often used as nesting or roosting sites. Mallards Anas platyrhynchos and Goosanders Mergus merganser both preferred sites with smoother flows, finer substrates and more emergent vegetation. For all species, multiple discriminant analysis (MDA) on RHS data predicted presence with a success rate of 50-81%. The distribution of Grey Wagtails and Dippers was best predicted by RHS variables from the channel, flow, bank and riparian zone, Common Sandpiper and Goosander distribution was predicted best by channel and flow characters, and that of Mallard by channel features alone. In three species (Dipper, Goosander and Mallard) stream chemistry (pH) improved predictive ability. We conclude that RHS, although designed initially for more general purposes, is a potentially important tool for describing and predicting river bird distribution. Future developments should include assessments of which RHS data best predict bird distribution across a wider array of river types and species. Incorporating other important influences on distribution, such as water chemistry, should both enhance predictive ability and allow further development to the role of river birds as ecological indicators.
Keywords: Breeding Season; Sea Ducks - General; Common merganser; Mergus merganser; Habitat

Carbon isotopic fractionation in eider adipose tissue varies with fatty acid structure: implications for trophic studies - Budge, S. M.; Wang, S. W.; Hollmen, T. E.; Wooller, M. J. (Journal of Experimental Biology, 2011)
Times Cited: 3 Budge, Suzanne M. Wang, Shiway W. Hollmen, Tuula E. Wooller, Matthew J. 3
Keywords: Spectacled Eider; Techniques; Trophic Interactions; somateria fischeri

Bills Favor Mining and Threaten Conservation of Brazilian Merganser (Mergus octosetaceus) at Serra da Canastra National Park, Minas Gerais, Brazil - Bueno, B. A. D.; Nunes, M. R.; Melo, C. (Natureza & Conservacao, 2012)
Times Cited: 1 de Andrade Bueno, Bruno Arantes Nunes, Marcela Riccomi Melo, Celine Melo, Celine/A-8874-2013 1
Keywords: Conservation; Brazilian Merganser; Mergus octosetaceus

The nesting of Steller's Eider in Norway - Bunyard, P. F. (Ibis, 1927)
Letter regarding a recent record. || ABSTRACT AUTHORS: W. W. Bowen
Keywords: Breeding Season; Polysticta stelleri; Steller's eider

Fall diets of red-breasted Merganser (Mergus serrator) and walleye (Sander vitreus) in Sandusky Bay and adjacent waters of Western Lake Erie - Bur, Michael T.; Stapanian, Martin A.; Bernhardt, Glen; Turner, Mark W. (American Midland Naturalist, 2008)
Although published studies indicate the contrary, there is concern among many sport anglers that migrating red-breasted mergansers (Mergus serrator) and other waterbirds pose a competitive threat to sport fish species such as walleye (Sander vitreus) in Lake Eric. We quantified the diet of autumn-migrant mergansers and walleye during 1998-2000 in Sandusky Bay and adjacent waters of western Lake Erie. We hypothesized that the diets of both predators would be similar in species composition, but because of different foraging ecologies their diets would differ markedly in size of prey consumed. In addition to predator samples, we used trawl data from the same general area as an index of prey availability. We found that mergansers fed almost exclusively on fish (nine species). Gizzard shad (Dorosoma cepedianum), emerald shiner (Notrapis atherinoides) and round goby (Neogobius melanostomus) were consumed in the greatest numbers, most frequently and comprised the greatest biomass. Walleye fed exclusively on fish: gizzard shad, alewife (Alosa psuedoharengus) and emerald shiner were consumed in the greatest numbers, most frequently and comprised the greatest biomass. Diet overlap between mergansers and walleye was 67% by weight and 66% by species frequency. Mean total lengths of gizzard shad, emerald shiner and round goby found in walleye stomachs exceeded those captured in trawls by 47%, on average. Mean total lengths of gizzard shad, emerald shiner and round goby were greater in walleye stomachs than in merganser stomachs. Mean total lengths of emerald shiner and round goby were less in merganser stomachs than in trawls. Our results suggest that although the diets of walleye and mergansers overlapped considerably, mergansers generally consumed smaller fish than walleye. Given the abundance and diversity of prey species available, and the transient nature of mergansers on Lake Eric during migration, we conclude that competition for food between these species is minimal.
Keywords: Nonbreeding Seasons; Trophic Interactions; Mergus serrator; Red-breasted merganser

Application of tracking and data-logging technology in research and conservation of seabirds - Burger, Alan E.; Shaffer, Scott A. (Auk, 2008)
Keywords: Sea Ducks - General; Techniques

Metals and radionuclides in birds and eggs from Amchitka and Kiska Islands in the Bering Sea/Pacific Ocean ecosystem - Burger, Joanna; Gochfeld, Michael (Environmental Monitoring and Assessment, 2007)
Metals and radionuclide levels in marine birds of the Aleutians are of interest because they are part of subsistence diets of the Aleut people, and can also serve as indicators of marine pollution. We examined geographic and species-specific variations in concentrations of radionuclides in birds and their eggs from Amchitka, the site of underground nuclear tests from 1965 to 1971, and Kiska Islands (a reference site) in the Aleutians, and the levels of lead, mercury and cadmium in eggs. In 2004 we collected common eiders (Somateria mollissima), tufted puffins (Fratercula cirrhata), pigeon guillemot (Cepphus columba) and glaucous-winged gulls (Larus glaucescens) from Amchitka and Kiska, and eggs from eiders and gulls from the two island. We also collected one runt bald eagle (Haliaeetus leucocephalus) chick from both Amchitka and Kiska Islands. For most species, the levels of radionuclide isotopes were below the minimum detectable activity levels (MDA). Out of 74 cesium-137 analyses, only one composite (gulls) was above the MDA, and out of 14 composites tested for plutonium (Pu-239, 240), only one exceeded the MDA (a guillemots). Three composites out of 14 tested had detectable uranium-238. In all cases, the levels were low and close to the MDAs, and were below those reported for other seabirds. There were significant interspecific differences in metal levels in eggs: gulls had significantly higher levels of cadmium and mercury than the eiders, and eiders had higher levels of lead than gulls. There were few significant differences as a function of island, but eiders had significantly higher levels of cadmium in eggs from Kiska, and gulls had significantly higher levels of mercury on Kiska. The levels of cadmium and mercury in eggs of eiders and gulls from this study were above the median for cadmium and mercury from studies in the literature. The levels of mercury in eggs are within the range known to affect avian predators, but seabirds seem less vulnerable to mercury than other birds. However, the levels of mercury are within the action levels for humans, suggesting some cause for concern if subsistence Aleuts eat a large quantity of eggs.
Keywords: Breeding Season; Common Eider; Contaminants; Somateria mollissima

Mercury and Other Metals in Feathers of Common Eider (Somateria mollissima) and Tufted Puffin (Fratercula cirrhata) from the Aleutian Chain of Alaska - Burger, Joanna; Gochfeld, Michael (Archives of Environmental Contamination and Toxicology, 2009)
We analyzed arsenic, cadmium, chromium, lead, manganese, mercury, and selenium in the feathers of common eiders (Somateria mollissima) and tufted puffins (Fratercula cirrhata) from Amchitka and Kiska islands (Aleutians). Between species, puffins had 10 times higher chromium (arithmetic mean = 1820 ppb), 7.5 times higher selenium (mean = 6600 ppb), and 3 times higher mercury (mean = 2540 ppb) than eiders. Eiders had significantly higher levels of manganese than puffins. Puffins are higher on the food chain than eiders, which is reflected in their generally higher levels of metals in their feathers. Interisland differences were generally small, and there were few significant differences as a function of the three nuclear test locations on Amchitka. The only sex-related difference was that female puffins had higher mercury than males (arithmetic mean of 3060 ppb vs. 2270 ppb). Mean levels of metals in the feathers of puffins and eiders from the Aleutians were low compared with comparable studies elsewhere, and the relatively low levels of metals do not indicate the potential for adverse behavioral or reproductive effects in the birds themselves, nor pose concern for other consumers, including subsistence hunters.
Keywords: Breeding Season; Common Eider; Contaminants; Somateria mollissima

Comparison of arsenic, cadmium, chromium, lead, manganese, mercury and selenium in feathers in bald eagle (Haliaeetus leucocephalus), and comparison with common eider (Somateria mollissima), glaucous-winged gull (Larus glaucescens), pigeon guillemot (Cepphus columba), and tufted puffin (Fratercula cirrhata) from the Aleutian Chain of Alaska - Burger, Joanna; Gochfeld, Michael (Environmental Monitoring and Assessment, 2009)
There is an abundance of field data for levels of metals from a range of places, but relatively few from the North Pacific Ocean and Bering Sea. In this paper we examine the levels of arsenic, cadmium, chromium, lead, manganese, mercury and selenium in feathers from common eiders (Somateria mollissima), glaucous-winged gulls (Larus glaucescens), pigeon guillemots (Cepphus columba), tufted puffins (Fratercula cirrhata) and bald eagles (Haliaeetus leucocephalus) from the Aleutian Chain of Alaska. Our primary objective was to test the hypothesis that there are no trophic levels relationships for arsenic, cadmium, chromium, lead, manganese, mercury and selenium among these five species of birds breeding in the marine environment of the Aleutians. There were significant interspecific differences in all metal levels. As predicted bald eagles had the highest levels of arsenic, chromium, lead, and manganese, but puffins had the highest levels of selenium, and pigeon guillemot had higher levels of mercury than eagles (although the differences were not significant). Common eiders, at the lowest trophic level had the lowest levels of some metals (chromium, mercury and selenium). However, eiders had higher levels than all other species (except eagles) for arsenic, cadmium, lead, and manganese. Levels of lead were higher in breast than in wing feathers of bald eagles. Except for lead, there were no significant differences in metal levels in feathers of bald eagles nesting on Adak and Amchitka Island; lead was higher on Adak than Amchitka. Eagle chicks tended to have lower levels of manganese than older eagles.
Keywords: Breeding Season; Common Eider; Contaminants; Somateria mollissima

Assessment of metals in down feathers of female common eiders and their eggs from the Aleutians: arsenic, cadmium, chromium, lead, manganese, mercury, and selenium - Burger, Joanna; Gochfeld, Michael; Jeitner, Christian; Snigaroff, Daniel; Snigaroff, Ronald; Stamm, Timothy; Volz, Conrad (Environmental Monitoring and Assessment, 2008)
Concentrations of arsenic, cadmium, chromium, lead, manganese, mercury and selenium were examined in the down feathers and eggs of female common eiders (Somateria mollissima) from Amchitka and Kiska Islands in the Aleutian Chain of Alaska to determine whether there were (1) differences between levels in feathers and eggs, (2) differences between the two islands, (3) positive correlations between metal levels in females and their eggs, and (4) whether there was more variation within or among clutches. Mean levels in eggs (dry weight) were as follows: arsenic (769 ppb, ng/g), cadmium (1.49 ppb), chromium (414 ppb), lead (306 ppb), manganese (1,470 ppb), mercury (431 ppb) and selenium (1,730 ppb). Levels of arsenic were higher in eggs, while chromium, lead, manganese, and mercury were higher in feathers; there were no differences for selenium. There were no significant interisland differences in female feather levels, except for manganese (eider feathers from Amchitka were four times higher than feathers from Kiska). Levels of manganese in eggs were also higher from Amchitka than Kiska, and eider eggs from Kiska had significantly higher levels of arsenic, but lower levels of selenium. There were no significant correlations between the levels of any metals in down feathers of females and in their eggs. The levels of mercury in eggs were below ecological benchmark levels, and were below human health risk levels. However, Aleuts can seasonally consume several meals of bird eggs a week, suggesting cause for concern for sensitive (pregnant) women.
Keywords: Breeding Season; Common Eider; Contaminants; Somateria mollissima

Radionuclides in marine fishes and birds from Amchitka and Kiska Islands in the Aleutians: Establishing a baseline - Burger, Joanna; Gochfeld, Michael; Kosson, David; Powers, Charles W.; Friedlander, Barry; Stabin, Michael; Favret, Derek; Jewett, Stephen; Snigaroff, Daniel; Snigaroff, Ronald; Stamm, Tim; Weston, James; et al. (Health Physics, 2007)
Amchitka Island (51 degrees N lat, 179 degrees E long) was the site of three underground nuclear tests from 1965-1971. There have been no substantive studies of radionuclides in marine fishes and birds in the area since the mid-1970's. In this study, levels of Co-60, Eu-52, Sr-90, Tc-99, I-129, Cs-137, and the actinides (Am-241, Pu-238, Pu-239,Pu-240, U-234, U-236, U-236, and U-238) were studied in ten marine fish species (including Pacific Cod Gadus macrocephalus and Pacific Halibut Hippoglossus stenolepis) and five marine bird species (including Glaucous-winged Gulls Larus glaucescens, Tufted Puffins Fratercula cirrhata, and Common Eider Ducks Somateria mollissima) from Amchitka. The same species were collected at a reference site, Kiska Island (52 degrees N lat; 177 degrees E long), about 130 km west of Amchitka. Each sample was a composite of edible muscle from five or more individual fish or birds of similar size (+/- 15%) from the same sampling station. The null hypotheses of no differences among species or between Amchitka and Kiska were tested. Most analytic results were below the minimum detectable activity (MDA), even when 1,000 g sizes and 72 h counting times were used. The only radionuclides detected above the MDA were Cs-137, Am-241, Pu-239,Pu-240, U-234, U-235, and U-238. There were significant differences in Cs-137 as a function of species, but not location, for top predatory fishes. Of the fishes, eight of ten species had Cs-137 values above the MDA for some samples; only one bird, Glaucous-winged Gull, had Cs-137 values above the MDA. The highest concentrations of Cs-137 were in Dolly Varden [Salvelinus manna. 0.780 (Bq kg(-1) wet weight)] and Pacific Cod (0.602 Bq kg(-1)). In aggregate for any actinides, 73 of 234 (31%) composites for fish were above the MDA, compared to only 3 of 98 (3 %) for birds. U-234 and U-238, radionuclides that are primarily natural in origin, were routinely detected in these biological samples, but there were no significant differences in mean concentrations between Amchitka and Kiska. The concentrations of all radionuclides examined at Amchitka are similar to those of other uncontaminated Northern Hemisphere sites, and are lower than those reported for fishes and birds from the Irish Sea in the vicinity of the Sellafield nuclear reprocessing facility, an area with known contamination.
Keywords: Common Eider; Contaminants; Somateria mollissima

Nesting Common Eider (Somateria mollissima) Population Quintuples in Northwest Greenland - Burnham, K. K.; Johnson, J. A.; Konkel, B.; Burnham, J. L. (Arctic, 2012)
Times Cited: 0 Burnham, Kurt K. Johnson, Jeff A. Konkel, Bridger Burnham, Jennifer L. 0
Keywords: Breeding Season; Abundance, Distribution, and Trends; Common eider; somateria mollissima

Mercury contamination of seabird and sea duck eggs from high Arctic Greenland - Burnham, K. K.; Meyer, F. K.; Burnham, J. L.; Chumchal, M.; Johnson, J. A. (POLAR BIOLOGY, 2021)
Mercury (Hg) levels in the environment have substantially increased over the past century leading to increased concentrations in many high trophic level predators, including Arctic seabirds. From the Canadian high Arctic, research on seabird eggs has documented some of the greatest concentrations of egg Hg anywhere in the Arctic. Farther east, in high Arctic Greenland, no similar data on Hg concentrations in eggs exist, making spatial comparisons unfeasible. To address this paucity of data, we collected whole eggs from Thick-billed Murre Uria lomvia (n = 11), Black-legged Kittiwake Rissa tridactyla (n = 9), and Common Eider Somateria mollissima (n = 12) in the high Arctic of northwest Greenland in the summer of 2014 and assessed their concentration of total Hg. Thick-billed Murre eggs had the highest mean total Hg concentrations (1.32 +/- 0.42 mg g(-1) dw) followed by kittiwakes (0.64 +/- 0.19) and eiders (0.23 +/- 0.10). When compared with murre and kittiwake egg samples collected in high Arctic Canada during the same time period, total Hg concentrations from northwest Greenland were higher, but not significantly. Based on what is known about lethal Hg concentrations in murre eggs, these results indicate that some murre eggs may be at risk for increased embryonic mortality and further monitoring is suggested to determine long-term trends in egg Hg concentrations.
Times Cited in Web of Science Core Collection: 0 Total Times Cited: 0 Cited Reference Count: 63
Keywords: Common Eider; BIRDS; TEMPORAL TRENDS; STABLE-ISOTOPES; BIOMAGNIFICATION; Black-legged Kittiwake; Egg; EXPOSURE; MARINE FOOD-WEB; Mercury; METHYLMERCURY; Northwest Greenland; ORGANOCHLORINES; Thick-billed Murre; TOXICITY; WEST

Birds of the Severn Estuary and Bristol Channel: Their current status and key environmental issues - Burton, N. H. K.; Musgrove, A. J.; Rehfisch, M. M.; Clark, N. A. (Marine Pollution Bulletin, 2010)
The Severn Estuary and Bristol Channel encompass a number of designated sites supporting populations of waterbirds and seabirds that are of national or international importance, including the Severn Estuary and Burry Inlet Special Protection Areas (SPAs)/Ramsar Sites and Carmarthen Bay, the UK's first marine SPA. Here, we provide an overview of the present numbers and trends of the waterbirds and seabirds using these sites, updating previous reviews undertaken prior to these designations. We further provide a summary of the main issues that have affected the status of the area's bird populations. Declines in the numbers of waders on the Severn Estuary and the southwest over the last two decades have been linked to climate change. The Sea Empress oil-spill impacted both breeding seabirds and the wintering common Scoters in Carmarthen Bay, though numbers of the latter recovered 3 years after the spill. At the Burry Inlet, Oystercatcher numbers have fallen over the last 25 years and considerable research has been undertaken into the conflict with cockle and mussel fisheries. A long-term study at Cardiff Bay, at the mouth of the Severn, revealed a significant impact on the survival of Redshanks following its impoundment and has helped to further understanding of responses of waterbirds to estuarine habitat loss. The potential impacts of the construction of a tidal power scheme on the Severn Estuary are also discussed. (C) 2009 Elsevier Ltd. All rights reserved.
Keywords: Abundance, Distribution, and Trends; Sea Ducks - General

Exploitation of others' vigilance by the Common Eider Somateria mollissima - Bustnes, Jan Ove (Wildfowl, 1993)
Individuals obtain advantages from group-living through reduced probability of predation (Hamilton 1971). In addition to reducing the perimeter exposed to predators, flocking behaviour also increases vigilance, and thereby reduces the chance of surprise attacks (Krebs & Davies 1986). In the Common Eider Somateria mollissima flocking behaviour during brood-rearing is very frequent. These groups are often called creches, and such behaviour has been explained as an adaptation for minimizing predation on the ducklings (Ahlen & Andersson 1970, Gorman & Milne 1972, Bedard & Munro 1976, Munro & Bedard 1977a,b, Bustnes & Erikstad 1991a). However, females, that do not care for young themselves, are often temporarily present in or near creches (Munro & Bedard 1977a, Schmutz et al. 1982, Bustnes & Erikstad 1991b). Adult Common Eider are exposed to dangers, such as harassment by kleptoparasitic gulls (Ingolfsson 1969) and, in some areas (e.g. northern Norway), predation from birds of prey such as White-tailed Eagles Haliaeetus albicilla (Norderhaug 1978). Females that care for ducklings spend 40 to 45% of a feeding bout watching for potential duckling predators (Bustnes & Erikstad 1991a). It would thus seem advantageous for a female without young to stay close to brood-caring females, thereby exploiting the high degree of vigilance that will enable them to feed more effectively (Bustnes & Erikstad 1991b). In order to test this hypothesis, I recorded time budgets of females, without young, that were feeding close to or away from creches.
Keywords: Behavior; Breeding Season; Common Eider; Somateria mollissima

Is parental care a constraint on the habitat use of common eider females? - Bustnes, Jan Ove (Condor, 1996)
The aim of this study was to investigate how parental care in Common Eider (Somateria mollissima) females affected their habitat selection. I compared the post-nesting behavior of brood-caring females and females without young. Females that cared for ducklings and females without young moved similar distances from the nesting colony to the feeding areas. However, throughout the brood rearing season, females without young undertook longer secondary movements than brood-caring females. The type of feeding habitat used and the feeding mode were similar among the different female categories, and all females that had attempted to nest foraged in the intertidal zone by dabbling. This study suggests that in a large sea duck like the Common Eider, with highly developed ducklings at hatching, parental care does not constrain habitat use very much compared to females without young.
Keywords: Behavior; Breeding Season; Common Eider; Somateria mollissima; Dispersal; Habitat

Selection of blue mussels, Mytilus edulis, by common eiders, Somateria mollissima, by size in relation to shell content - Bustnes, Jan Ove (Canadian Journal of Zoology, 1998)
The blue mussel, Mytilus edulis, is the most important food item for the common eider, Somateria mollissima, but the mussels eaten by eiders vary in length between both areas and seasons. The aim of this study was to experimentally test the hypothesis that common eiders try to minimize shell intake when selecting among mussels of different lengths. Two types of experiments were conducted using wild common eiders in captivity. Experiment 1 tested whether eiders could seek out the mussels with least relative shell content and highest flesh content from among mussels of an array of lengths. They selected the shortest mussels (<20 mm), which had the lowest shell content. In experiment 2, the eiders were given mussels of the same length class (26-31 mm), but with different shell morphology and shell mass, from the subtidal and upper intertidal zones. The birds only ate the subtidal-zone mussels with the lowest shell mass. The results of this study strongly indicate that reducing the amount of indigestible shell is an important factor for eiders selecting among mussels of different lengths.
Keywords: Common Eider; Somateria mollissima; Trophic Interactions

Reproductive Recovery of a Common Eider Somateria mollissima Population Following Reductions in Discharges of Polycyclic Aromatic Hydrocarbons (PAHs) - Bustnes, J. O. (Bulletin of Environmental Contamination and Toxicology, 2013)
Times Cited: 0 Bustnes, Jan O. 0
Keywords: contaminants; Breeding Season; Somateria mollissima; Population dynamics; Common eider; productivity

The diet of Steller's Eiders wintering in Varangerfjord, northern Norway - Bustnes, Jan O.; Asheim, Magne; Bjorn, Tor Harry; Gabrielsen, Heidi; Systad, Geir H. (Wilson Bulletin, 2000)
We examined the winter diet of Steller's Eiders (Polysticta stelleri) in Varangerfjord, northern Norway, by analyzing the esophagus content of 29 individuals (12 juveniles and 17 adults). A total of 8389 prey items of 31 species were identified: 13 species of gastropods (making up 68.4% of total number of items); 4 species of bivalves (18.5%); 12 species of crustaceans (13%); and 2 species of echinoderms (<0.1%). In terms of percentage aggregate wet weight 31.4% was gastropods, 22.6% was bivalves, and 41.4% was crustaceans. Juvenile eiders ate more crustaceans (x = 61% aggregate w.w.) than adults (x = 26%, P < 0.05), possibly because they were in poor body condition and may have had higher energy requirements than adults. Adults tended to eat more gastropods (x = 41% vs 22%) and Mytilus edulis (x = 27% vs 12%) than juveniles. There were only small differences between sexes. Most of the prey items were of species known to be associated with kelp plants, especially Laminaria hyperborea, suggesting that Steller's Eiders obtain a large proportion of their prey directly from the vegetation.
Keywords: Nonbreeding Seasons; Trophic Interactions; Polysticta stelleri; Steller's eider

The impact of climate sensitive factors on the exposure to organohalogenated contaminants in an aquatic bird exploiting both marine and freshwater habitats - Bustnes, J. O.; Bardsen, B. J.; Herzke, D.; Bangjord, G.; Bollinger, E.; Bourgeon, S.; Schulz, R.; Fritsch, C.; Eulaers, I. (SCIENCE OF THE TOTAL ENVIRONMENT, 2022)
To assess how climate-sensitive factors may affect the exposure to organochlorines (OCs) and perfluoroalkyl sub-stances (PFASs), we monitored concentrations in eggs of the common goldeneye (Bucephala clangula) over two decades (1999-2019) in central Norway. The goldeneye alternates between marine and freshwater habitats and is sensitive to climate variation, especially due to alterations in ice conditions which may affect feeding conditions. We assessed how biological factors such as diet (stable isotopes 813C and 815N), the onset of egg laying, and physical characteristics such as winter climate (North Atlantic Oscillation: NAOw) influenced exposure. We predicted compounds to show different temporal trends depending on whether they were still in production (i.e. some PFASs) or have been banned (i.e. legacy OCs and some PFASs). Therefore, we controlled for potential temporal trends in all analyses. There were declining trends for a- and y-hexachlorocyclohexane (HCH), oxychlordane, cis-chlordane, cis-nonachlor, p,p '-dichlorodiphenyl-trichloroethane (p.p '-DDT) and less persistent polychlorinated biphenyl (PCB) congeners (e.g. PCB101). In contrast, the dominant compounds, such as p,p '-dichlorodiphenyldichloroethylene (p,p '-DDE) and persistent PCB congeners, were stable, whereas hexachlorobenzene (HCB) increased over time. Most OCs were positively related to 815N, suggesting higher exposure in birds feeding at upper trophic levels. Chlordanes and HCB were positively associated with 813C, indicating traces of marine input for these compounds, whereas the relationships to most PCBs were negative. Among PFASs, perfluorooctanesulfonamide (PFOSA) and perfluorohexane sulfonic acid (PFHxS) declined. Most PFASs were positively associated with 813C, whereas there were no associations with 815N. Egg laying date was positively associ-ated to perfluoroheptanesulfonic acid (PFHpS), perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA), suggesting that some of the PFAS load originated from the wintering locations. Although NAOw had little impact on the exposure to organohalogenated contaminants, factors sensitive to climate change, especially diet, were associated with the exposure to OHCs in goldeneyes.
Times Cited in Web of Science Core Collection: 0 Total Times Cited: 0 Cited Reference Count: 86
Keywords: COMMON EIDERS; PERSISTENT ORGANIC POLLUTANTS; Climate; STABLE-ISOTOPES; Diet; EGGS; NORTHERN EUROPE; NUTRIENT-ALLOCATION; OCs; PERFLUOROALKYL SUBSTANCES; PFASs; POLYFLUOROALKYL SUBSTANCES; Sea ducks; Temporal trends; TERRESTRIAL RAPTOR

Ecosystem specific accumulation of organohalogenated compounds: A comparison between adjacent freshwater and terrestrial avian predators - Bustnes, J. O.; Bardsen, B. J.; Herzke, D.; Bangjord, G.; Bourgeon, S.; Fritsch, C.; Eulaers, I. (ENVIRONMENTAL RESEARCH, 2022)
Insight into processes determining the exposure of organohalogenated contaminants (OHCs) in wildlife might be gained from comparing predators in different ecosystems. This study compared two avian predator species with similar food chain lengths: the goldeneye duck (Bucephala clangula) and the tawny owl (Strix aluco) breeding in adjacent freshwater- and terrestrial ecosystems in central Norway. We measured lipophilic organochlorines (OCs) and protein-bound perfluorinated substances (PFASs) in eggs of the two species over 21 years (1999-2019). Across years, the proportional distribution of OCs (similar to 90% of the Sigma OHC load) relative to PFASs (similar to 10%) was similar in the two species. Moreover, Sigma OC concentrations were similar between the species, but PFAS compounds were 2-12 times higher in the goldeneyes than in tawny owls. OC-pesticides dominated in tawny owls (similar to 60% of Sigma SOC), whereas persistent polychlorinated biphenyl (PCBs) congeners were the main OC components in goldeneyes (similar to 70% of Sigma OC). The lipid-normalized concentrations of most OC-pesticides and the less persistent PCB101 declined significantly in both species. Hexachlorobenzene (HCB), p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE), and more persistent PCBs decreased in tawny owls, while they tended to increase in goldeneyes. The increase in HCB was particulary robust. Among the PFASs, contrasted temporal trends were found across the species for four out of 11 compounds: PFOS declined while most perfluorocarboxylic acids (PFCAs) increased in tawny owls. In contrast, most PFASs were stable in goldeneyes. Moreover, there was no annual covariance between the OHC exposure in the two species: i.e., high concentrations in one species in a given year did not translate into high concentrations in the other. Hence, the two avian predators in adjacent ecosystems seem to be subject to different processes determining the OHC exposure, probably related to variation in diet and climate, long-range transport of different contaminants, and emissions of pollution locally.
Times Cited in Web of Science Core Collection: 1 Total Times Cited: 1 Cited Reference Count: 58
Keywords: BIRDS; PERSISTENT ORGANIC POLLUTANTS; TEMPORAL TRENDS; ORGANOCHLORINES; EGGS; NUTRIENT-ALLOCATION; Bird of prey; CLIMATE; CONTAMINANTS; Duck; OC-pesticides; Owl; PCB; PERFLUORINATED COMPOUNDS; PFAS; REPRODUCTION

The Diets of Sympatric Wintering Populations of Common Eider Somateria-Mollissima and King Eider Somateria-Spectabilis in Northern Norway - Bustnes, J. O.; Erikstad, K. E. (Ornis Fennica, 1988)
A total of 2534 food items of 42 species (exclusive eggs of fish) were identified in the diet of Common Eiders Somateria mollissima (1650 items of 34 species) and King Eiders S. spectabilis (884 items of 35 species) from Troms in northern Norway in April/May. Both species had been feeding on much the same prey species but in quite different proportions. The diet of Common Eiders was dominated by Mytilus edulis (46.3% wet wt.), eggs of Cyclopterus lumpus (25.9%) and other molluscs, Modiolus modiolus (7.3%), Modiolaria discors (2.1%) and Arctica islandica (2.8%). King Eiders feed mainly on echinoderms, Ophiopholis aculeata (27.1%), Strongylocentrotus droebachiensis (22.7%) and Asterias rubens (15.1%). Other important King Eider food items were molluscs, Modiolaria discors (4.8%), Modiolus modiolus (3.6%) and Trophonopsis clathratus (4.3%). King Eiders had a broader diet than Common Eiders (average number of food species per individual 6.9 vs. 3.6), and the calculated diet overlap was 0.15. The differences in the diet observed is most likely a result of King Eiders feeding at greater depths than Common Eiders.
Keywords: Common Eider; Nonbreeding Seasons; Somateria mollissima; King Eider; Somateria spectabilis; Trophic Interactions

Size Selection of Common Mussels Mytilus-Edulis by Common Eiders Somateria-Mollissima Energy Maximization or Shell Weight Minimization - Bustnes, J. O.; Erikstad, K. E. (Canadian Journal of Zoology, 1990)
Prey size selection by common eiders, Somateria mollissima, preying on common mussels, Mytilus edulis, in northern Norway is described. The mean length (.+-. SD) of mussels preyed upon was 13.9 .+-. 5.7 mm (range 3.5-38.1 mm). The dry flesh weight as a percentage of the total dry weight ranged from 4.2 to 8.6% in different body-length categories and was greatest in the mussels most frequently fed upon. There was a close negative correlation between the size of mussels fed upon and the estimated total shell weight that birds had to ingest to obtain their daily requirement of food (rs = -0.86). A hypothesis is proposed that common eiders select mussels of certain size classes to minimize the daily shell weight intake.
Keywords: Common Eider; Somateria mollissima; Trophic Interactions

Effects of Patagial Tags on Laying Date and Egg Size in Common Eiders - Bustnes, J. O.; Erikstad, K. E. (Journal of Wildlife Management, 1990)
We examined the effects of patagial tags on common eiders (Somateria mollissima) by comparing laying date, clutch size, and egg size of the same females in 2 breeding seasons, before tagging (1987) and after the birds had carried tags for 1 year (1988). Similar data were obtained from unmarked birds used as controls in both years. Clutch size of tagged birds did not differ from control (P < 0.05), but tagged birds laid eggs later (P < 0.001) and produced smaller eggs (P < 0.05) in 1988 than in 1987. The egg size of control females was larger (P < 0.001) during 1988. We suggest that patagial tags affect a female's ability to accumulate body reserves before breeding by decreasing feeding time, increasing preening activity, and/or increasing energy costs of diving.
Keywords: Breeding Season; Common Eider; Somateria mollissima; Productivity; Techniques

Parental Care in the Common Eider Somateria-Mollissima Factors Affecting Abandonment and Adoption of Young - Bustnes, J. O.; Erikstad, K. E. (Canadian Journal of Zoology, 1991)
Parental care in common eiders (Somateria mollissima) was studied during three field seasons in northern Norway. Forty-two percent of the females were found to abandon their brood. Abandonment and tending of broods and creches were not obligate individual strategies, but changed between years. Females abandoning their young laid smaller clutches and had a lower body weight at hatching than brood- and creche-tending females, indicating that they were in poor body condition. This supports the hypothesis that abandoning the brood is a salvage strategy in which energetic stress limits females' ability to care for their young. Young of "abandoners" seemed to have a lower survival rate than young of "tenders," which suggests a reproductive cost of abandoning the young. Forty-seven percent of tagged ducklings were found with females other than their mother. Twenty-seven percent of the brood- and creche-tending females lost young to other females, but never more than one duckling. Adoptions of foreign ducklings, above the normal brood size of four, did not lead to greater parental effort, and duckling survival was similar among broods and creches of different sizes. This suggests that adoptions may be of neutral adaptive value. Two females often formed stable creches, but duckling survival was not sigificantly different from that in broods and creches with single females.
Keywords: Behavior; Breeding Season; Common Eider; Somateria mollissima

The Role of Failed Nesters and Brood Abandoning Females in the Creching System of the Common Eider Somateria-Mollissima - Bustnes, J. O.; Erikstad, K. E. (Ornis Scandinavica, 1991)
In Common Eiders, females other than the mother often protect young from predators. This study was designed to determine if failed nesters and females which loose their young shortly after hatching (brood abandoners) participate in such rearing activities. Brood caring females always reacted aggressively towards approaching gulls and stayed close to the young during disturbance. The behavior of failed nesters and brood abandoners towards broods and creches was similar. Their creche attendance was highly temporal and independent of the time since they had lost their eggs or hatched their young. They usually left the creches at the slightest disturbance, and during gull attacks failed nesters showed no reaction while a few brood abandoners tending creches reacted aggressively. Most of the creche attendance in nest-failing and brood abandoning females is presumably motivated by selfish interest, e.g. seeking safety from predators or kleptoparasites. The so-called "visiting" females or "aunts" in Eider creches should be divided into two categories: broody females showing protective behavior and females temporarily attending creches and showing no broodiness. Failed nesters and most of the brood abandoners belong to the latter category. Most of the females showing protective behaviour probably belong to the non-breeding cohort (young and/or non-breeding birds).
Keywords: Behavior; Breeding Season; Common Eider; Somateria mollissima

Site fidelity in breeding common eider Somateria mollissima females - Bustnes, Jan O.; Erikstad, Kjell E. (Ornis Fennica, 1993)
We studied nest-site and post-nesting feeding site fidelity in a population of Common Eiders Somateria mollissima in North Norway during five consecutive breeding seasons (1986-90). Twenty-five per cent of the females that nested successfully and none of the unsuccessful females returned to the same nest. Whether females nested at the same site was independent of nesting variables other than total clutch loss. Similarly, nest-site fidelity did not result in nesting variables different from those of females which changed their nest-site. In contrast, fidelity to post-nesting feeding sites was very high (92%). Females that showed post-nesting feeding site fidelity did not have a higher rate of nest-site fidelity than other birds in the population. We therefore contend that in Common Eiders fidelity to a specific nest-site is less important than fidelity to the post-nesting feeding site. Going to areas where the female knows that sufficient food can be found is very important for both the female and her brood. In comparison to other duck species with more specific nest-site requirements (cavity-nesting ducks), Common Eiders have a low return rate to previous nest-sites, and we suggest that this reflects a difference in the availability of suitable sites.
Keywords: Breeding Season; Common Eider; Somateria mollissima; Dispersal

Body condition and brood abandonment in Common Eiders breeding in the high Arctic - Bustnes, Jan O.; Erikstad, Kjell E.; Bjorn, Tor H. (Waterbirds, 2002)
Post-hatch brood amalgamation is common in many waterfowl species and especially prevalent in the Common Eider (Somateria mollissima). Studies in the temperate region have shown that brood abandonment is influenced both by female body condition and brood size. In this study we tested how these two factors influenced the probability of brood desertion in eiders breeding under harsh conditions in the high Arctic (78degreeN). We found that females in poor body condition were less likely to care for their young, but there was no effects of brood size. We speculate that the differences between southern and northern populations of eiders may be due to different environmental conditions.
Keywords: Behavior; Breeding Season; Common Eider; Somateria mollissima; Energetics and Nutrition

Anthropogenic influences on the infestation of intertidal gastropods by seabird trematode larvae on the southern Barents Sea coast - Bustnes, J. O.; Galaktionov, K. (Marine Biology (Berlin), 1999)
In this study we examined how the variation in the distribution of six species of seabird trematodes was influenced by human activities along the subarctic Barents Sea coast of northern Norway. This was done by comparing the prevalence of the parasites in two species of intermediate host (Littorina saxatilis and Littorina obtusata) on seashores near fishing industry complexes, fish farms and at control sites. In L. saxatilis there were higher prevalences at sites influenced by human activities for three out of five trematode species (Microphallus piriformes, M. similis, Cryptocotyle lingua) which have gulls (Larus spp.) as their predominant final hosts, while in L. obtusata, only M. similis was more common at sites with human activity. For M. pygmaeus, a trematode which has the common eider (Somateria mollissima) as its most predominant final host, the prevalence in L. saxatilis tended to be higher at sites with fishing industry, but differences were not significant. No such tendency was found in L. obtusata for this trematode. The overall prevalence in L. obtusata was lower than in L. saxatilis. This indicates that the vulnerability to trematode infection differs between the two snail species depending on the variation in the distribution patterns in the intertidal zone. Gulls tend to concentrate in areas near fishing industry and fish farms to feed on fish offal, which leads to an increase in the transmission between hosts, and to a higher level of parasite infection, locally.
Keywords: Common Eider; Somateria mollissima; Parasites

Evidence of a state-dependent trade-off between energy intake and parasite avoidance in Steller's eiders - Bustnes, Jan O.; Galaktionov, Kirill V. (Canadian Journal of Zoology, 2004)
We examined the hypothesis that Steller's eiders, Polysticta stelleri (Pallas, 1769), in good body condition avoided nutritious and abundant prey that were intermediate hosts of acanthocephalans, while birds in poor condition accepted the long-term costs of parasitism to minimize the short-term risk of starvation. We predicted that the intensity of the acanthocephalan Polymorphus phippsi (Kostylev, 1922) should be positively related to the intake of intermediate hosts and that the intake of such prey should be negatively related to body condition. All Steller's eiders were infected (2-1142 parasites/bird). Only the intake of the amphipod Gammarus oceanicus (Segerstrale, 1947), a known intermediate host of P. phippsi, was significantly related to parasite intensity. Juvenile Steller's eiders were in poorer condition than adults and fed more on amphipods (44% vs. 9% of total biomass). On the contrary, adults preferred isopods (26% of total biomass vs. 12% for juveniles), which were less abundant than littoral amphipods but were not intermediate hosts of P. phippsi. Moreover, in juveniles there was a negative relationship between body condition and the proportion of amphipods in the diet. Hence, juveniles in poor body condition consumed potentially infected prey while adults and juveniles in good condition avoided such prey. The cost of avoiding littoral amphipods was probably a lower energy return per unit feeding effort.
Keywords: Behavior; Nonbreeding Seasons; Energetics and Nutrition; Trophic Interactions; Parasites; Polysticta stelleri; Steller's eider

Sea ducks as predators on sea urchins in a northern kelp forest - Bustnes, Jan Ove; Lonne, Ole Jorgen (Ecology of fjords and coastal waters, 1995)
Keywords: Sea Ducks - General; Trophic Interactions

Temporal Dynamics of Circulating Persistent Organic Pollutants in a Fasting Seabird under Different Environmental Conditions - Bustnes, J. O.; Moe, B.; Hanssen, S. A.; Herzke, D.; Fenstad, A. A.; Nordstad, T.; Borga, K.; Gabrielsen, G. W. (Environmental Science & Technology, 2012)
Times Cited: 3 Bustnes, Jan Ove Moe, Borge Hanssen, Sveinn Are Herzke, Dorte Fenstad, Anette A. Nordstad, Tore Borga, Katrine Gabrielsen, Geir W. Hanssen, Sveinn Are/C-9989-2009 Hanssen, Sveinn Are/0000-0003-1792-435X 3
Keywords: contaminants; Breeding Season; Common eider; somateria mollissima

Strongly increasing blood concentrations of lipid-soluble organochlorines in high arctic common eiders during incubation fast - Bustnes, Jan Ove; Moe, Borge; Herzke, Dorte; Hanssen, Sveinn Are; Nordstad, Tore; Sagerup, Kjetil; Gabrielsen, Geir W.; Borga, Katrine (Chemosphere, 2010)
Female common eiders (Somateria mollissima) starve during the nesting stage and may loose 30-45% of their initial body mass, mostly through lipid mobilization. In this study, the effects of fasting on the blood concentrations of three lipid-soluble organochlorines (OCs: polychlorinated biphenyl [PCB]-153; 1-dichloro-2,2-bis (p-chlorophenyl) ethylene [p,p'-DDE]: and hexachlorobenzene [HCB]) were examined in eiders breeding in the high Arctic. Blood samples were taken from females (n = 47) at day 5 and day 20 of the incubation period. The mean wet weight concentrations of PCB-153 and p,p'-DDE increased strongly between day 5 and day 20 (3.6 and 8.2-fold, respectively), while HCB increased less (1.7-fold). There was a strong negative association between daily increase in PCB-153 and clutch size, and a weaker relationship for pp'-DDE, suggesting that maternal transfer to the eggs is a significant pathway of elimination of OCs in eiders. Moreover, poor body condition (body mass controlled for body size) late in the incubation period was associated with strong daily increase of both p,p'-DDE and PCB-153, which may suggest that the release of these compounds increases when lipid reserves become depleted. For HCB, the increase was mainly associated with increase in blood lipid concentrations, and weakly to the amount of burned lipids. The causes for the differences between the compounds are, however, poorly understood. Although the absolute levels of OCs in eiders were relatively low, their rapid build up during incubation is worrying as it coincides with poor body condition and weakened immune systems. (C) 2010 Elsevier Ltd. All rights reserved.
Keywords: Breeding Season; Common Eider; Contaminants; Somateria mollissima

Migration patterns, breeding and moulting locations of king eiders wintering in north-eastern Norway - Bustnes, Jan Ove; Mosbech, Anders; Sonne, Christian; Systad, Geir Helge (Polar Biology, 2010)
The Norwegian coast is a very important winter area for king eiders (Somateria spectabilis), but their origin has been unknown. We determined spring and autumn migration routes, timing of migration and potential breeding areas of king eiders wintering in north-eastern Norway using implanted satellite transmitters. Five males and five females were equipped with transmitters in February 2008, and location data were received from six birds. All birds departed within 10 days in mid April and flew to the Pechora Sea and Kara Sea in western Russia where they staged until mid June. Subsequently, four of five birds with active transmitters (two females and two males) moved east to potential breeding locations on the Gydan and Taymyr Peninsulas. In early July, the males moved west to moult at Kolguyev Island and in the Pechora Sea. The two females departed in mid July, one probably moulting between the gulfs of the Ob and Yenisei Rivers, after which it moved to the Pechora Sea. The other female probably moulted in the eastern Taymyr, thereafter moving to Novaya Zemlya. This female returned to the north-eastern coast of Norway 1 December, while the other female returned 2 January. For the males, the transmitters stopped in December/January when they were still in the Pechora/Kolguyev area. King eiders wintering in north-eastern Norway thus originate from the western half of Arctic Russia, and the Taymyr Peninsula is probably the dividing point between the eastern and western flyways.
Keywords: Breeding Season; Nonbreeding Seasons; Migration; King Eider; Somateria spectabilis; Population Delineation

Habitat use by wintering Steller's Eiders Polysticta stelleri in northern Norway - Bustnes, Jan O.; Systad, Geir H. (Ardea, 2001)
Habitat use of Steller's Eiders Polysticta stelleri was studied in Varangerfjord, northern Norway, during three winter periods (November, January and April) in 1996/97. We partitioned habitats based on water depth and benthic conditions, and compared the benthic characteristics in known feeding areas to nearby areas avoided by Steller's Eiders. On average 88% of the birds were in natural habitats, outside of harbours. Mean water depth at feeding areas varied from 3.7 m in November to 2.5 m in April. Overall 89% of eiders foraged by diving at locations where water depths were less than 5 m. Steller's Eiders foraged in areas with underwater vegetation, predominantly in kelp beds. Two factors were positively associated (P < 0.05) with the probability that an area was used by Steller's Eiders: the proportion of the area covered by the kelp species Laminaria hyperborea and the vegetation density. Shallowly flooded kelp beds are the prime habitat for Steller's Eiders in Varangerfjord, and protection of these habitats is probably of great importance for preserving the species in the area.
Keywords: Nonbreeding Seasons; Habitat; Polysticta stelleri; Steller's eider

Comparative feeding ecology of Steller's Eider and Long-tailed Ducks in winter - Bustnes, Jan Ove; Systad, Geir Helge (Waterbirds, 2001)
We examined the flexibility in feeding ecology of Steller's Eider (Polysticta stelleri) by comparing its diet to the taxonomically relatively close Long-tailed Duck (Clangula hyemalis) during two winter periods (early and late) when the two species occurred together. Steller's Eider generally fed on the same type of prey in early and late winter, with a dietary overlap of 43% between the two periods (57% among shelled prey). The mean number of prey species per bird was 7.8 in both early winter and late winter. In contrast, the Long-tailed Duck changed completely from feeding on benthic invertebrates in early winter to spawning Capelin (Mallotus villosus) in late winter. The dietary overlap between the two bird species was 38% in early winter. In early winter, the mean number of prey species was 5.5 in the Long-tailed Duck, and not significantly different from the Steller's Eider. Steller's Eider seemed to be restricted to small prey, both compared to availability of sizes and also to the prey size taken by the Long-tailed Duck. Thus the worldwide rare Steller's Eider seems to be a specialist with limited ability to exploit different food resources, while the numerous Long-tailed Duck is an opportunistic generalist. Low flexibility in feeding ecology indicates that winter habitats for Steller's Eider may be limited, and protection of these areas would probably benefit the species.
Keywords: Nonbreeding Seasons; Clangula hyemalis; Long-tailed Duck; Trophic Interactions; Polysticta stelleri; Steller's eider

Changing distribution of flocking sea ducks as non-regenerating food resources are depleted - Bustnes, J. O.; Systad, G. H.; Ydenberg, R. C. (Marine Ecology Progress Series, 2013)
Times Cited: 0 Bustnes, Jan O. Systad, Geir H. Ydenberg, Ronald C. 0
Keywords: Nonbreeding Seasons; Trophic Interactions; somateria mollissima; COmmon eider

Genetic variability among long-tailed ducks wintering in the Baltic Sea - Butkauskas, D.; Sruoga, A.; Svazas, S.; Paulauskas, A. (Journal of Ornithology, 2006)
Keywords: Nonbreeding Seasons; Clangula hyemalis; Long-tailed Duck; Population Delineation

Moulting sites of sea ducks and other marine birds in Frederick Sound, southeast Alaska - Butler, Robert W. (Canadian Field-Naturalist, 1998)
A total of 5920 moulting sea ducks were found at four sites characterized by shallow water foraging areas around islands and at entrances to glacial inlets.
Keywords: Abundance, Distribution, and Trends; Melanitta fusca; Nonbreeding Seasons; White-winged Scoter; Melanitta perspicillata; Surf Scoter; Molt; Habitat

Handling Stress of Female Common Eiders During Avian Cholera Outbreaks - Buttler, E. Isabel; Gilchrist, H. Grant; Descamps, Sebastien; Forbes, Mark R.; Soos, Catherine (Journal of Wildlife Management, 2011)
Researchers often consider the importance of minimizing holding time during research activities; however, the long-term costs of such handling stress is rarely measured explicitly. As part of an ongoing study of common eiders (Somateria mollissima) at a breeding colony in East Bay, Southampton Island, Nunavut, we recorded duration of restraint for females captured during avian cholera epizootics (2007 and 2008) and monitored female fates (breeding probability, onset of laying, and survival) relative to holding time. Probability of death increased with holding time in 2007 from an estimated 0.05 for females held 20 min to 0.33 for females held for 150 min. In 2008, we responded by limiting holding time to <90 min and mortality was no longer positively correlated with holding time, although total mortality was greater due to increased severity of avian cholera. In both years, longer restraint durations delayed onset of egg-laying after capture by 0.5 days for each 10 min of additional restraint but did not prevent breeding. This delay of nest initiation did not enhance survival probability. Our results show that prolonged holding time can exacerbate mortality during epizootics and emphasize the importance of minimizing restraint time in wild birds, especially in the presence of diseases. (C) 2011 The Wildlife Society.
Keywords: Breeding Season; Common Eider; Somateria mollissima; Techniques

Spring migration and subsistence hunting of king and common eiders at Holman, Northwest Territories, 1996-98 - Byers, Tim; Dickson, D. Lynne (Arctic, 2001)
A subsistence hunt for eiders by Inuvialuit of Holman, Northwest Territories, was observed over three spring harvest seasons from 1996 to 1998 to determine rates of crippling loss and to assess the sustainability of the harvest. King eiders (Somateria spectabilis) are the dominant waterfowl species harvested. The number of king eiders estimated to migrate past Holman in spring varied from 40 696+-4461 (95% confidence interval) in 1996 to 70 018+-14 356 in 1998, averaging 53 000 per year. Common eiders (Somateria mollissima v-nigra) were much less abundant, varying from 2728+-631 to 6017+-770 birds, averaging 4400 annually. Peak numbers of king eiders moved through the study area in 1-8 days during the second to third week of June in all years, and common eiders peaked in 1-8 days during the first to second week of June. Strong winds may have hindered migration for a few days. Crippling loss rates during the hunt were low (3-9%) in the first two years of the study, but increased to 13-20% in the early open-water spring of 1998, when hunters were forced to shoot over open water rather than shorefast ice. On the basis of these estimates and harvest data from the Inuvialuit Harvest Study, we determined that Holman hunters removed 3.7-6.9% of the king eider subpopulation and less than 1% of the common eiders over the three-year study period. The present level of harvest of eiders available to Holman hunters is likely sustainable. However, more information on natural mortality and recruitment rates, particularly for king eiders, is needed to confirm this.
Keywords: Conservation; Common Eider; Nonbreeding Seasons; Migration; Somateria mollissima; King Eider; Somateria spectabilis

Identifying inter-dive intervals in time-activity budget studies of diving ducks - Byrkjedal, Ingvar (Wildlife Biology, 1997)
In order to identify inter-dive intervals in diving ducks, i.e. the time spent regaining breath between consecutive feeding dives, the position of the tail, carpal joints and head was recorded in different behavioural categories for eight species on the southwestern coast of Norway in March. Inter-dive intervals are part of the feeding behaviour and are easily confused with the behavioural categories of swimming and loafing. During inter-dive intervals the ducks adopt a more or less hunch-backed position, preparing for the next dive. In this position the tail touches the water surface and the head is held in a more forward position than during loafing and swimming. Some species expose carpal joints in inter-dive intervals, while most of the wings are covered by the flank feathers during non-feeding behaviour. Logistic regressions showed that a near perfect classification was obtained from the position of the wings alone in common eider Somateria mallissima, velvet scoter Melanitta fusca, and long-tailed duck Clangula hyemalis. An almost equally good classification was obtained for the two last mentioned on the position of the tail, for scaup Aythya marila on the position of the head, and for red-breasted merganser Mergus merganser on the position of the head and the stretching of the neck. Less reliable classifications were obtained for goldeneye Bucephala clangula and tufted duck Aythya fuligula, whereas in common scoter Melanitta nigra none of the variables fulfilled the criteria for entering a logistic regression function.
Keywords: Behavior; Sea Ducks - General

The role of Velvet Scoters Melanitta fusca for pursuit-diving seabirds in winter - Byrkjedal, Ingvar (Ornis Norvegica, 2000)
While digging in the bottom substrate for food Velvet Scoters expose worms which are utilized by wintering Red-necked Grebes Podiceps griseigena, causing the grebes to form feeding associations with individual scoters. Several other pursuit-diving seabird species wintering on the coast of Jaeren, SW Norway, are here reported associating with Velvet Scoters. Of 14 seabird species, four species (Red-necked Grebe, Razorbill Alca torda, Red-throated Diver Gavia stellata and Slavonian Grebe Podiceps auritus) regularly formed feeding associations with Velvet Scoters (association frequencies ranging from 38% of the individuals in Red-necked to 9% in Slavonian Grebes), six species did so more casually (less than 2.5% of the observed individuals of Great Northern Diver Gavia immer, Great Crested Grebe Podiceps cristatus, Shag Phalacrocorax aristotelis, Red-breasted Merganser Mergus serrator, Common Guillemot Uria aalge, and Little Auk Plotus alle), while four species were not recorded associating with Velvet Scoters (Black-throated Diver Gavia arctica, Great Cormorant Phalacrocorax carbo, Goosander Mergus merganser, and Black Guillemot Cepphus grylle). Velvet Scoters were highly preferred association partners compared to other species of diving ducks. Association frequencies decreased towards April from a maximum in November. No clear relationship was found between association and the general prey type of the pursuit-diving species involved, but large and small species associated less often with Velvet Scoters than medium-sized species, probably reflecting an effect of optimal prey size.
Keywords: Behavior; Melanitta fusca; Nonbreeding Seasons; White-winged Scoter; Trophic Interactions; Common merganser; Mergus merganser; Mergus serrator; Red-breasted merganser

Feeding associations between red-necked grebes Podiceps griseigena and velvet scoters Melanitta fusca in winter - Byrkjedal, Ingvar; Eldoy, Steinar; Grundetjern, Svein; Loyning, Mass K. (Ibis, 1997)
Red-necked Grebes Podiceps griseigena wintering along the coast of Jaeren, southwest Norway were found to feed either solitarily or in close association with Velvet Scoters Melanitta fusca feeding on bottom prey (mainly echinoderms) dug out from the sandy substrate. By scuba diving at spots where both species were feeding, we found that stirring the sand caused polychaete worms to emerge from the substrate. Bottom samples showed that these worms (on average gt 1000 per m-2) vastly outnumbered other animal taxa living in the substrate and that polychaetes were probably the most likely prey of grebes associated with scoters. Food competition between the two species and/or kleptoparasitism by the grebes were probably not involved (no food-stealing attempts by the grebes toward scoters handling prey brought to the surface, no aggression by scoters toward grebes and no effect of the grebes on the time budget of the scoters). Red-necked Grebes associating with scoters were mainly first-year birds, and the frequency of association decreased from a maximum of nearly 60% of the grebes in November to c. 5% before spring departure in April. Grebes feeding solitarily hunted in a manner resembling divers (Gavia), and they brought fish to the surface significantly more often than grebes feeding with scoters. Solitary grebes spent less time feeding and more time preening and swimming than did grebes associating with scoters. The association appears to be a way naive birds could easily obtain prey. Skills needed to dive for more nutritious but agile fish are probably gradually acquired through the winter as more of the grebes adopt solitary feeding.
Keywords: Melanitta fusca; Nonbreeding Seasons; White-winged Scoter; Trophic Interactions

Physical condition of an animal, using as an example the common elder, Somateria mollissima - Cabanac, Arnaud J. (Canadian Field-Naturalist, 2003)
An index of the physical condition of an animal should describe its endogenous available energy. The welfare of the animal depends on its ability to spend its stored energy (lipid and protein) in order to survive the environmental and behavioural challenge at the particular time of its capture. I propose a new index to predict the survival chance of the subject. The new index of physical condition takes into account the available endogenous energy reserves and the known needs of the species at that particular time of year. I further illustrate this new method of estimating the physical condition by running a trial with Common Eiders, Somateria mollissima.
Keywords: Common Eider; Somateria mollissima; Energetics and Nutrition; Techniques

Temperature and heart rate as stress indicators of handled common eider - Cabanac, A. J.; Guillemette, M. (Physiology and Behavior, 2001)
Three eider ducks were handled every 4 min for 16 min to measure their cloacal temperature. This simple handling triggered a rise in their core temperatures from 41.5+-0.6degreeC at minute 0 to 43.5+-0.5degreeC at minute 16. This increase in body temperature occurred with no obvious motor load from the eiders, but was facilitated by peripheral vasoconstriction and, moreover, was blocked significantly by salicylate, suggesting that the increase in temperature was due to fever. After 10 days of similar handling, the mean fever-like responses displayed by the ducks was significantly lower than their responses of day one, showing a habituation to the emotional stimulation. The eider's heart rate was measured continuously before, during and for a 10-min session following a 1-min handling period. Results showed that the eiders displayed a tachycardia during handling and for 2-3 min posthandling. Such tachycardia is another sign of emotion in animals (Am J Psychol 39 (1927) 106). Our study showed therefore that eider ducks are prone to emotions and, when emotionally stressed, will display a fever-like response and a tachycardia. Our results on ducks are similar to responses obtained from studies on more terrestrial birds in similar conditions (e.g., chicken (Physiol Behav 69 (2000) 541)), but are in opposition to the bradycardia and the observed decreases in temperature (Hvalradets Skr 22 (1940) 1; Acta Physiol Scand 46 (1959) 231) of birds forcibly submerged.
Keywords: Common Eider; Somateria mollissima; Physiology

Diet of cormorants, mergansers, and kingfishers in northeastern North America - Cairns, David K. (Canadian Technical Report of Fisheries and Aquatic Sciences, 1998)
Cormorant, merganser, and kingfisher diets in northeastern North America are reviewed. Double-crested cormorants (Phalacrocorax auritus) breed and forage primarily along the coast, but may invade fresh water during spring runs of anadromous fish. Diets include a substantial fraction of Atlantic salmon (Salmo salar) during smolt exodus in rivers whose runs are supplemented by stocking. At other times birds feed on a variety of marine and estuarine species. Great cormorants (P. carbo) occupy marine habitats, and chiefly eat marine bottom fish. Common mergansers (Mergus merganser) eat juvenile salmon and other freshwater fish during spring and summer, but tend to move toward river mouths and estuaries in late summer. Red-breasted merganser's (M. serrator) have a largely coastal distribution, where they feed on estuarine, diadromous, and some salmonid species. Hooded merganser (Lophodytes cucullatus) diet in the region is poorly known, but probably includes a variety of fish and invertebrates. Belted kingfishers (Ceryle alcyon) live mostly along rivers, where they eat salmonids and other freshwater and diadromous fishes. Mean representation of commercial and recreational prey species is 44% for double-crested cormorants (outside the Atlantic salmon smolt run), 31 % for great cormorants, 43% for common mergansers, 3% for red-breasted mergansers, and 34% for belted kingfishers. Despite large sample sizes (total N > 6,982), reported diets only approximately reflect actual food ingested. Major sources of bias include differential digestion rates, erroneous inclusion of prey from prey stomachs, incomplete spatial and temporal coverage, and over-representation of samples from salmon rivers.
Keywords: Breeding Season; Nonbreeding Seasons; Trophic Interactions; Common merganser; Mergus merganser; Mergus serrator; Red-breasted merganser

Surveys of waterbirds in the Darkhad Depression, Mongolia, during summer and autumn - Call, M. N.; Schummer, M. L.; Smith, C. J.; Dovchin, B.; Tumur, B.; Byambaa, B.; Jal, T.; Watters, R. J. (WILDFOWL, 2019)
The Darkhad Depression provides one of the most extensive concentrations of waterbird breeding, moulting, and migration stopover site habitat in Mongolia. To our knowledge, this is the first large-spatial scale survey completed for waterbirds in the region. Surveys were conducted at 60 wetlands and a portion of a river (total area = 5,873 ha) in summer (15-19 July), and at 36 wetlands (5,285 ha, including 27 wetlands from the summer) in autumn 2018 (6-10 October). Thirty-seven species were detected (13 with juveniles) during the summer and 23 species in autumn. The frequency of occurrence of species among wetlands and densities of waterbirds among occupied wetlands (birds/ha) were calculated for summer. These estimates were scaled to the total wetland area in the region, for estimating the proportion of the flyway population occurring in the Darkhad Depression for each species. Six species were on the IUCN Red List (IUCN 2018) or in the Mongolian Red Book (Shiirevdamba el al. 2016): Falcated Duck Anas falcaia, Common Pochard Aythya ferina, Common Crane Grus grus, Northern Lapwing Vanellus vanellus, Eurasian Curlew Numenhis arquata, and Horned Grebe Podiceps auritus. In summer, Common Goldeneye Bucephala clangula used the greatest percentage of wetlands included in the survey (57.4%) and Tufted Duck Aythya fuligula had the greatest mean density among occupied wetlands (6.66 +/- 5.69 s.e. birds/ha). Most individuals appeared to be moulting adults. Greatest juvenile:adult ratios were for Eared Grebes Podiceps nigricollis (1.3), Ruddy Shelduck Tadorna ferruginea (1.4), and Whooper Swans Cygnus minis (1.1). In autumn, Common Goldeneye (n = 1,375), dabbling ducks (Anas sp.; n = 2,206), and Whooper Swans (n = 1,065) were the most common waterbirds observed, and 88% of all waterbirds counted occurred on just three wetlands. The Darkhad Depression appears to be important for waterbirds from the Central and East Asian Flyways, and our surveys suggest it likely supports > 1% of Common Goldeneye, Tufted Duck, Bar-headed Goose Anser indicirs, and Ruddy Shelduck populations of these Flyways. To develop a greater understanding of waterbird reproduction and seasonal use, as well as threats to waterbirds in the region, we suggest that standardised surveys should be undertaken during spring through to autumn in future years.
Times Cited in Web of Science Core Collection: 1 Total Times Cited: 1 Cited Reference Count: 25

Organochlorine contaminants in the country food diet of the Belcher Island Inuit, Northwest Territories, Canada - Cameron, Marjorie; Weis, I. Michael (Arctic, 1993)
An initial assessment of the country food diet at the Belcher Islands' community of Sanikiluaq, Northwest Territories (Canada) was made by interviewing 16 families during May-July 1989. Estimates of consumption per day were established over a two-week period for 10 of these families. This information was utilized along with previously published harvest data for the community to estimate country food consumption in grams/day and kg/year. Beluga (Delphinapterus leucas), ringed seal, (Phoca hispida), arctic charr (Salvelinus alpinus), common eider (Somateria mollissima) and Canada goose (Branta canadensis) were found to be important components in the diet during this period. Results of analysis for organochlorine contaminants reveal that ringed seal fat and beluga muktuk (skin and fat layer) samples have the highest concentration of DDE and total PCBs among the country food species. Average DDE and total PCB values were 1504.6 mu-g/kg and 1283.4 mu-g/kg respectively in ringed seal fat and 184.3 mu-g/kg and 144.7 C(9/kg respectively in beluga muktuk. Comparison of contaminants in seal fat indicates concentrations approximately two times higher in samples from the Belcher Islands than from sites in the Canadian Western Arctic, but lower than concentrations reported from various European sites. The daily consumption estimates in grams/day were used along with organic contaminant analysis data to calculate the estimated intake levels of 0.22 mu-g/kg body weight/day of total DDT and 0.15 mu-g/kg body weight/day of total PCBs during the study period. Although limited in sample site, studies such as this provide a framework from which to establish future consumption guidelines more applicable to arctic systems and native diets.
Keywords: Breeding Season; Common Eider; Contaminants; Somateria mollissima

The Canvasback Common Goldeneye and Bufflehead in Arctic Alaska USA Aythya-Valisineria Bucephala-Clangula Bucephala-Albeola Occurrence - Campbell, J. M. (Condor, 1969)
Keywords: Breeding Season; Abundance, Distribution, and Trends; Bucephala clangula; Common Goldeneye; Bucephala albeola; Bufflehead

Patterns of Distribution and Behavior of Flocks of Sea Ducks Wintering at Leith and Musselburgh Scotland - Campbell, L. H. (Biological Conservation, 1978)
The numbers, distribution and behavior of flocks of seaducks in the Firth of Forth off Edinburgh [UK] are described for 6 winters. Flocks of goldeneye and scaup were concentrated near sewer outfalls where they fed on invertebrates benefiting from the sewage and on items (grain) in the effluent. Eiders were found around beds of mussels and other bivalves. For goldeneye and scaup, feeding on items in the effuent was of secondary importance to feeding on sewer-enriched populations of invertebrates. While these species showed a close link with sewers, eiders and other marine seaduck species [long-tailed duck, common and velvet scoter] were at most only tenuously linked.
Keywords: Abundance, Distribution, and Trends; Sea Ducks - General; Nonbreeding Seasons

The Impact of Changes in Sewage Treatment on Sea Ducks Wintering in the Firth of Forth Scotland Uk - Campbell, L. H. (Biological Conservation, 1984)
Changes in the numbers and distribution of seaducks wintering in the Firth of Forth off Edinburgh following the introduction of sewage treatment are described. Numbers of scaup [Aythya marila] and goldeneye [Bucephala clangula] were considerably reduced and feeding flocks were only recorded at outfalls where sewage continued to be discharged in large quantities. Although food items borne in the sewage were important in determining local distribution patterns, it was unclear whether these or abundant invertebrates were the most important factor attracting seaducks to this area. As a result of an environmentally desirable improvement scheme the UK has lost an internationally important concentration of wildfowl.
Keywords: Conservation; Abundance, Distribution, and Trends; Sea Ducks - General; Nonbreeding Seasons

Mass mortality of common eiders (Somateria mollissima) in the Dutch Wadden Sea, winter 1999/2000: Starvation in a commercially exploited wetland of international importance - Camphuysen, C. J.; Berrevoets, C. M.; Cremers, H. J. W. M.; Dekinga, A.; Dekker, R.; Ens, B. J.; van der Have, T. M.; Kats, R. K. H.; Kuiken, T.; Leopold, M. F.; Van der Meer, J.; Piersma, T. (Biological Conservation, 2002)
Mass mortality of common eiders (Somateria mollissima) was observed in winter 1999/2000 in the Dutch Wadden Sea. Approximately 21,000 common eiders died. Dissected birds were severely emaciated and 94% were infected with the acanthocephalan parasite Profilicollis botulus. Green shore crabs (Carcinus maenas), intermediate hosts of the parasite, were slightly more 'available' than in other years, but parasite infections in the eiders were close to normal. Few eiders were oiled (5%), there were no toxicological, bacteriological, or virological explanations for the observed mortality. In the Wadden Sea, a wetland of international importance, mussel (Mytilus edulis) cultures occur in sublittoral areas, while mechanical cockle (Cerastoderma edule) fisheries are licensed annually after evaluation of available resources. The wintering eiders in 1999/2000 required c. 3.1 million kg ash-free dry mass, while information on mussel and cockle stocks (irrespective of accessibility and profitability) suggested a resource 4.7X the requirement of common eiders only. Food shortage is suggested to have caused the observed mortality, involving both principal (mussels and cockles) and secondary (Spisula) prey. Winter census reports showed shifts in wintering distribution of common eiders in the 1990s, indicating the utilisation of Spisula in the North Sea in poor food years in the Wadden Sea. Following particularly intense fisheries in summer 1999, attempts to feed on Spisula in winter 1999/2000 failed. It is hypothesised that overfishing of mussels and cockles in the Wadden Sea in the early 1990s resulted in structurally reduced food resources, contractions of the foraging area of common eiders, and increased use of secondary prey in the North Sea.
Keywords: Common Eider; Nonbreeding Seasons; Somateria mollissima; Survival; Trophic Interactions

Beached seabirds in The Netherlands: 26 years of study (1965-1991) - Camphuysen, Kees C. J. (Limosa, 1993)
National beached bird surveys in February has been conducted annually in The Netherlands since 1965, with the exception of 1974. Between 1965 and 1978, the surveys were organized by The Netherlands' Youth organisation for Nature studies (NJN). Since 1979, the working group beached bird surveys (NSO) was responsible. Slight differences in methodology between the two schemes have made that the oil rates were different (generally slightly lower since 1979). Volunteers were asked to search for corpses at the high water mark. During 1965-78, the main attempt was to cover as many kilometres as possible, regardless where. Since 1979, 6 subregions (fig. 1) were "sampled" (at least 10% surveyed was considered a reliable sample). The usual output of the national surveys, a "national" density (N/km) was considered reliable, particularly because some of the subregions were not visited every year (tab. 1). A re-analysis of the data was performed din order to assess densities in each of the subregions and to provide baseline data for a future monitoring programme for beached birds in The Netherlands. Proportions oiled were calculated using all birds in a survey, to avoid small samples (national index): oil rates were calculated only when samples continued at least 10 corpse of a species or group. Trends in oil rates were tested using Spearman's Rank Correlation Coefficient for 1965-78 and for 1979-91 separately (tab. 2). Correlations between oil rate and density, and between an index of winter severity (IJnsen index) and density were tested using linear regression analysis, differences in species composition were assessed using the G-test (Sokal and Rohlf (1981). Of 531 divers found dead, 8.1% remained unidentified. Red-throated divers predominated (75.6%, N = 488). Ca. 90% of the divers were oiled, while densities were slightly lower in recent years than previously (fig. 2). Great Crested Grebes were the most numerous grebes (84.6%, N = 1929), followed by Red-necked Grebes (9.0%). Massive mortality was recorded in most cold and all severe winters (fig. 3), when oil rates were comparatively low. Fulmars were found in small numbers in most years (N = 473), but an increase was found in recent years (fig. 4, appendix 1, 2). Mass strandings in 1981 (95), 1984 (54), and 1988 (83) included 91.7, 90.2 and 67.2% with oil on the feathers. Gannets were found in small numbers, and generally, over 75% were oiled. Several oil incidents involving Eiders and scoters were recorded (fig. 5, 6). In Eider, oil rates declined, while other mortality factors became more prominent. Particularly so in the 1990s, when acute food shortages due to overfishing of shellfish in the Wadden Sea led to starvation and mass mortality. Oil was the most important cause of death in scoters (tab. 2). Scaup, Goldeneye, Goosander and Red-breasted Merganser were the most common species in a group named "other sea-duck". Severe winter conditions can force these birds to leave the IJsselmeer and Wadden Sea to enter the coastal marine environment and mass mortality occurred particularly in cold and severe winters (tab. 3). Other waterfowl and wader also were mainly encountered in beached bird surveys in cold winters (appendix 1, 2). Relatively few were oiled, and this proportion declined (tab. 2). Herring, Common, Black-headed and Great Black-backed were the commonest of the Larus-gulls. Some 50% of these gulls were oiled and the proportion declined slightly, but not significantly (fig. 7, tab. 2). Slightly higher numbers were found in cold winters. Of Kittiwakes, a common species only in the early 1980s (fig. 8), the majority were oiled. Wrecks were recorded during 1981-84, with oil rates above average. The Guillemot was the most numerous oiled bird on Dutch beaches in the 1980s and early 1990s. A sudden increase in numbers was found from 1981 onwards (fig. 9), remarkably few were found in 1987. Oil rates were always high (tab. 2). As in the next species, very few were found in the 1970. Also the Razorbill was found in lares numbers in the early 1980s, but number fell after 1984 (fig. 10). A wreck was recorded in 1990. Very high numbers were oiled (tab. 2). The value of national surveys is discussed. Important features to be derived from these data are: (1) winter mortality, particularly amongst species not normally occurring in Dutch coastal waters (grebes, seaduck, waterfowl, waders), (2) local oil incidents, (3) a decline in the oil rate in several of the coastal species, (4) very large proportions oiled in pelagic species and (5) mass strandings of pelagic species in the 1980s. The auk 'wrecks' are discussed in more detail. Patterns found in The Netherlands were in fact found all along the North Sea, including very small numbers in 1987 (and 1992). The availability of food in winter is probably the key factor, leading to changes in winter distribution. The oil-induced mortality in our waters, clearly shows that pollution of the North Sea by oil is still at an unacceptable level.
Keywords: Sea Ducks - General; Nonbreeding Seasons; Contaminants

Seabirds in the North Sea demobilized and killed by polyisobutylene (C4H8)n (PIB) - Camphuysen, Kees C. J.; Barreveld, Hein; Dahlmann, Gerhard; Van Franeker, Jan Andries (Marine Pollution Bulletin, 1999)
This paper reports on a mass stranding of seabirds in the North Sea in December 1998. Hundreds of birds were washed ashore alive in Zeeland (SW Netherlands), covered in a whitish, sticky substance, and were transported to a rehabilitation centre. About 10 days later, more (dead) casualties washed ashore further to the north on Texel and along the mainland coast, again covered in a glue-like substance. Common guillemots Uria aalge, northern fulmars Fulmarus glacialis and common scoters Melanitta nigra were the most numerous birds affected in this incident. Both strandings were temporarily (10 days) and geographically separated (ca. 120 km apart), but were apparently caused by a single source of pollution. The meteorology at the time was consistent with the course of a single incident. At least 1100 seabirds were affected by this substance, soon identified as polyisobutylene (C4H8)n. PIB is known as a non-toxic, non-aggressive substance. Volunteers cleaning the birds in the rehabilitation centre reported serious discomfort and dizziness and the soft parts of the PIB-affected birds found dead (bill, eye, throat, feet, webs) appeared to dissolve in a few days time. Both effects cannot be attributed to PIB, and are therefore unexplained. Although the dumping of PIB in the marine environment is not explicitly prohibited under MARPOL, the effects on wildlife observed are enough to plead for counter-measures.
Keywords: Nonbreeding Seasons; Contaminants; Black Scoter; Melanitta nigra

The Food and Feeding of Common Eiders in the St-Lawrence Estuary Canada USA in Summer - Cantin, M.; Bedard, J.; Milne, H. (Canadian Journal of Zoology, 1974)
Keywords: Breeding Season; Common Eider; Somateria mollissima; Trophic Interactions

Ineffectiveness of light emitting diodes as underwater deterrents for Long-tailed Ducks Clangula hyemalis - Cantlay, J. C.; Bond, A. L.; Wells-Berlin, A. M.; Crawford, R.; Martin, G. R.; Rouxel, Y.; Peregoy, S.; McGrew, K. A.; Portugal, S. J. (GLOBAL ECOLOGY AND CONSERVATION, 2020)
Gillnet bycatch accounts for over 400,000 bird mortalities worldwide every year, affecting a wide variety of species, especially those birds that dive when foraging. Technological solutions to improve gillnet visibility or deter birds from approaching nets, such as LED lights, are essential for aiding diving birds to perceive nets as a hazard. Designing such solutions requires obtaining visual and behavioural ecology information from species to assess their ability to see the warning devices, and to examine their behavioural responses to them. Seaducks, particularly Long-tailed Ducks Clangula hyemalis, have high bycatch mortality rates. We examined the visual fields of four Long-tailed Ducks to understand their three-dimensional view around the head. The visual field characteristics of this species indicate a reliance on visual guidance for foraging associated with their capture of varied, mobile prey in their generalist diet. We subsequently conducted dive tank trials to test the effectiveness of 12 different LED treatments as visual deterrents to the underwater foraging behaviour of 8 Long-tailed Ducks. During each trial, ducks were offered food rewards from a specific underwater location in a dive tank, having the choice of whether to take the food or not. At the same time, they were exposed to either one LED light or the control (no light) to determine whether the presence of each light affected the foraging success rate of dives compared to the control. Exposure of ducks to all 13 treatment combinations was randomised over the trial period. White lights with an increasing flash rate were shown to have a significant positive effect on foraging success, and likely acted as a visual attractant, rather than as a deterrent. No light treatment significantly reduced the foraging success of ducks. LED lights did not inhibit the feeding of Long-tailed Ducks. Such lights may be ineffective as underwater visual deterrents when deployed on gillnets, while white flashing lights may make foraging sites more attractive to Long-tailed Ducks. (C) 2020 The Authors. Published by Elsevier B.V.
Times Cited in Web of Science Core Collection: 9 Total Times Cited: 9 Cited Reference Count: 54
Keywords: ECOLOGY; SEABIRDS; BEHAVIORAL-RESPONSES; EYE STRUCTURE; Foraging; GILLNET FISHERIES; LED lights; PENGUIN; Seaduck bycatch; SPHENISCUS-HUMBOLDTI; TURTLE BYCATCH; VISION; Visual deterrents; Visual fields; VISUAL-FIELDS

Anatidae in eastern China during the non-breeding season: Geographical distributions and protection status - Cao, Lei; Zhang, Yong; Barter, Mark; Lei, Gang (Biological Conservation, 2010)
Eastern China's Anatidae are globally important, occurring in large numbers and exhibiting very high diversity; however populations have declined greatly since the 1950s due to habitat loss and degradation, and poaching. To meet the urgent need for up-to-date conservation information, we conducted extensive surveys of the region's inland and coastal wetlands to collect data on current Anatidae numbers, distributions and key sites. This paper provides information on the non-breeding distributions of 27 species and how these have changed during the last 30 years, and discusses the protection status afforded to Anatidae and their habitats. About 80% of eastern China's Anatidae occur at inland wetlands, predominantly within the Yangtze River floodplain. Current distributions of most species are different to those of the late-1970s; range contraction, range shift and northward expansion have occurred. Approximately 45% of the total Anatidae population, and high proportions of five globally threatened species populations, were located within National Nature Reserves: coverage could be increased to ca. 65% by inclusion of additional important Anatidae sites within the National Reserve system. However, a number of important issues, such as management skilling and control of land use within reserves, need to be addressed if National Nature Reserves are to provide satisfactory protection for Anatidae. it is also highly desirable that the China National List of Protected Animals include all the relevant Anatidae species on the IUCN Red List to provide a high level of protection for globally threatened species. (C) 2009 Elsevier Ltd. All rights reserved.
Keywords: Abundance, Distribution, and Trends; Sea Ducks - General; Nonbreeding Seasons; Bucephala clangula; Common Goldeneye

Environmental pollutants in the Swedish marine ecosystem, with special emphasis on polybrominated diphenyl ethers (PBDE) - Carlsson, Pernilla; Herzke, Dorte; Wedborg, Margareta; Gabrielsen, Geir Wing (Chemosphere, 2011)
Levels of polybrominated diphenyl ethers (PBDEs), polybrominated biphenyls (PBBs), polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane (DDT) and perfluorinated organic compounds (PFCs) were analysed in whole herring (Clupea harengus) and sprat (Sprattus sprattus), eggs from common eider (Somateria mollissima) and eggs and livers from herring gull (Larus argentatus) from the Swedish west coast. The contaminant values obtained were compared with published values from the Arctic marine ecosystem. Tetra- and penta-brominated PBDEs were detected at low levels in herring, sprat and common eider (Sigma PBDE 0.3-2.0 ng g(-1) ww), while the levels were higher in the herring gull samples (Sigma PBDE 1.3-29.9 ng g(-1) ww). Hexa-decaBDEs were also found in samples from herring gulls. Eggs from herring gulls from the sub-Arctic contained four times more PBDE than the Swedish herring gulls eggs. Fish samples from the Arctic had two times higher levels of PBDEs and DDTs than similar samples from Sweden. The higher levels of contaminants in fish and seabirds from the Arctic reflect differences in transport processes, feeding ecology (reflected by trophic levels) and metabolism. PBDEs contributed to <10% of the total contaminant load in all investigated samples. The relative contribution of DDTs was higher in fish and bird samples from the Arctic when compared to Swedish samples, e.g. 65% in glaucous gull livers compared to 10% in herring gull livers. This study shows that even though the Swedish west coast is more urban than the Arctic, higher pollutants levels are found in seabird species from the Arctic. (C) 2010 Elsevier Ltd. All rights reserved.
Keywords: Breeding Season; Common Eider; Contaminants; Somateria mollissima

Maritime mammals: terrestrial mammals as consumers in marine intertidal communities - Carlton, J. T.; Hodder, J. (Marine Ecology Progress Series, 2003)
Carlton, JT Hodder, J

Species Age and Sex Identification of Nearctic Goldeneyes from Wings - Carney, S. M. (Journal of Wildlife Management, 1983)
Wings from Barrow's (Bucephala islandica) and common goldeneyes (B. clangula) were evaluated for species, sex and age differences. On Barrow's goldeneyes, the black bases of most greater secondary coverts (GSC) are visible, the white or gray-white on lesser secondary coverts (LSC) is restricted to feather edges, and usually the outer vanes of fewer than 7 secondaries are white. On common goldeneyes, the black bases of GSC are hidden by the middle coverts, several LSC are white or gray-white, and outer vanes of 7 or more secondaries are white. After-hatching-year (AHY) males of each species are sufficiently distinctive to be easily identified. AHY females of both species have a broad black band across the tips of the GSC. GSC of hatching-year (HY) birds of both species have white or variably dark-spotted tips (not banded) that are often slightly frayed. The sexes of HY birds appear similar, but 95% may be identified on the basis of wing length. Wings of HY male Barrow's goldeneyes are .gtoreq. 218 mm; HY female wings are .ltoreq. 217 mm. Wings of HY male common goldeneyes are .gtoreq. 213 mm; HY female wings are .ltoreq. 212 mm.
Keywords: Bucephala clangula; Common Goldeneye; Techniques; Barrow's Goldeneye; Bucephala islandica

Population trends and habitat use of harlequin ducks in Rhode island - Caron, Christine M.; Paton, Peter W. C. (Journal of Field Ornithology, 2007)
To assess population trends of Harlequin Ducks (Histrionicus histrionicus) in Rhode Island (U.S.A.), we analyzed Christmas Bird Counts and other historical surveys and also conducted surveys during the winter of 2005-2006. We estimated sex and age ratios, evaluated the effects of tidal regime and time of day on survey precision, and quantified habitat use. The population in Rhode Island experienced logistic growth from 1976 to 2004, with approximately 150 birds now wintering at three primary sites in the state. We estimated that the current ratio of males to females in the region was 1.6:1 (62% males) and that 13% of males were first-winter birds. Most Harlequin Ducks were observed in rocky habitats within 50 m of the shore or offshore islands. We detected the greatest numbers of birds, with the least amount of variation, during morning surveys at low tide, suggesting that this may be the most appropriate time for population monitoring. Increases in the Rhode Island population and male-biased sex ratios may indicate a local population recovery resulting from a hunting ban initiated in 1990. Although most Harlequin Ducks in eastern North America winter in Maine, the population in Rhode Island represents one of the largest in the southern part of their range.
Keywords: Abundance, Distribution, and Trends; Nonbreeding Seasons; Harlequin duck; Histrionicus histrionicus; Habitat

The Goosander in Relation to Salmon Fisheries - Carter, S.; Evans, P. (Ibis, 1988)
Keywords: Conservation; Trophic Interactions; Common merganser; Mergus merganser

Distribution and Population Status of Harlequin Ducks in Idaho - Cassirer, E. F.; Groves, C. R.; Wallen, R. L. (Wilson Bulletin, 1991)
Keywords: Breeding Season; Abundance, Distribution, and Trends; Harlequin duck; Histrionicus histrionicus

Cavity nesting by Harlequin Ducks in the Pacific Northwest - Cassirer, E. Frances; Schirato, Greg; Sharpe, Fred; Groves, Craig R.; Anderson, Rusty N. (Wilson Bulletin, 1993)
Keywords: Breeding Season; Harlequin duck; Histrionicus histrionicus; Habitat

Changes in abundance and at-sea distribution of seabirds in the Bay of Biscay prior to, and following the "Erika"oil spill - Castege, Iker; Hemery, Georges; Roux, Nicole; d'Elbee, Jean; Lalanne, Yann; D'Amico, Frank; Mouches, Claude (Aquatic Living Resources, 2004)
We investigated the impact of the "Erika" oil spill in the Bay of Biscay (France) on seabird populations. Relative abundance and spatial distribution at sea between 1980-1999 and 2000-2002 periods were compared. This study took place in a standardized monitoring at sea carried out with Coast Guard vessels following the line transect method. This work rests on 107 551 standardized counts of one minute before "Erika" and 23 449 after the oil spill. There was not a simple correlation between the number of individuals found oiled and the numerical variation of the populations at sea during the two years following the accident. The guillemot Uria aalge, the most frequently collected species in the north of the Bay of Biscay, showed no decrease in at sea abundance during the two years following the pollution. Conversely, some species found in small numbers on the coast (e.g. divers Gavia sp., razorbill Alca torda, common scoter Melanitta nigra) decreased significantly at sea (20 to 80%). Overall, marine bird populations declined significantly in the northern sector of the Bay of Biscay (48degree32' to 46degree58' north) and increased in the southern sector (45degree13' to 43degree15' north), whereas decreases and increases occurred in the central sector (46degree57' to 45degree14' north). Changes in the spatial distribution of the species after the "Erika" oil spill occurred through disappearance or retraction (Bay of Vilaine, Houat-Hoedic archipelago), or through displacement and reinforcement (Gouf of Capbreton). Overall, this suggests a redistribution of the populations within the Bay of Biscay, depending on the level of injuries to the ecosystems caused by the pollution.
Keywords: Abundance, Distribution, and Trends; Contaminants; Black Scoter; Melanitta nigra

The importance of Prespa National Park for breeding and wintering birds - Catsadorakis, G. (Hydrobiologia, 1997)
The breeding avifauna of Prespa National Park is of national and international importance both due to its high richness and the internationally important populations of rare species. The latter include the Dalmatian (Pelecanus crispus) and Great White (Pelecanus onocrotalus) pelicans and the Pygmy Cormorant (Phalacrocorax pygmaeus). Populations of national interest include Cormorant (Phalacrocorax carbo), Greylag Goose (Anser anser), Goosander (Mergus merganser), Great White Egret (Egretta alba) and six other species of ardeids. Among the 261 bird species observed in the area of ca 250 km2 since the late 60s, 164 breed and 41 are very rarely observed. Passage migrants and winter visitors include 91 species. Twelve breeding species became extinct in the National Park during the last 25 years and others are endangered. Raptors and aquatic birds suffered more due to habitat and land use alterations brought about by the construction of an irrigation scheme. Eighty-one species observed in the area are listed as in need of special protection in Annex I of the 79/409 EEC Directive and 32 of them breed. Lake Mikri Prespa is of virtually no importance for wintering waterfowl since it is frozen every winter, but the Greek part of Lake Megali Prespa, which never freezes, concentrates among other species the 20% and 35% respectively of the Great Crested Grebes and Tufted Ducks wintering in Greece.
Keywords: Breeding Season; Abundance, Distribution, and Trends; Sea Ducks - General; Common merganser; Mergus merganser

Distribution of wintering Common Eider Somateria mollissima in the Dutch Wadden Sea in relation to available food stocks - Cervencl, A.; Troost, K.; Dijkman, E.; de Jong, M.; Smit, C. J.; Leopold, M. F.; Ens, B. J. (Marine Biology, 2015)
The number of Eiders Somateria mollissima wintering in the Dutch Wadden Sea has declined rapidly during the last two decades. Changes in the available food stocks are assumed to be an important cause of this trend. In order to extend the knowledge of the importance of particular food sources to wintering Eiders, data on distribution of Eiders obtained from aerial counts were spatially related to routinely collected monitoring data of shellfish. Based on previous diet studies, we hypothesized that the distribution of Eiders in the Dutch Wadden Sea is related to the presence of Mytilus edulis stocks and that M. edulis from the sublittoral areas, especially the ones from mussel culture plots will have the strongest effect on Eider distribution. Boosted regression tree models were applied to quantify the relative importance of different potential prey items on the distribution of wintering Eiders. Indeed, Eiders were found to prefer sites with high densities of medium- and large-sized M. edulis, especially from mussel culture plots. Other bivalve species seemed to serve as alternative prey, since sites with a relatively high abundance of these species increased in importance, when less M. edulis was available on culture plots. The contribution of cultured M. edulis to the diet of Eiders decreased during the course of the winter seasons, indicating that harvesting of M. edulis from the culture plots might reduce this high-quality food source at the end of the winter, forcing the Eiders to switch to less profitable prey.
Cervencl, Anja Troost, Karin Dijkman, Elze de Jong, Martin Smit, Cor J. Leopold, Mardik F. Ens, Bruno J.
Keywords: Common Eider; Somateria mollissima; Habitat; Abundance, Distribution, & Trends; Nonbreeding season

PCBs, dioxins and furans in hooded merganser (Lophodytes cucullatus), common merganser (Mergus merganser) and mink (Mustela vison) collected along the St. Maurice River near La Tuque, Quebec - Champoux, L. (Environmental Pollution, 1996)
A pulp and paper mill located in La Tuque on the St. Maurice River, Quebec, and using the kraft bleaching process was historically the largest pulp and paper industry point source of chlorinated dibenzo-p-dioxins and dibenzofurans in Quebec. A study was undertaken to document the bioaccumulation of PCBs, dioxins and furans in piscivorous birds and mammals in this area. Hooded and Common Merganser eggs were collected in nest boxes along the St. Maurice River and Common Merganser fledglings were collected at two sites on the river. Wild minks were trapped along the St. Maurice River and in a control area upstream. Analysis of pooled merganser eggs showed contamination with dioxins, furans and PCBs. Liver samples of fledglings were contaminated with 2,3,7,8-tetrachlorodibenzofuran at the downstream site. Analysis of mink livers showed a significant higher contamination with dioxins and furans in some downstream samples compared with the upstream samples.
Keywords: Breeding Season; Contaminants; Common merganser; Mergus merganser; Hooded Merganser; Lophodytes cucullatus

Distribution Abundance and Fluctuations in Populations of Marine Birds of the Mingan Archipelago Gulf of St-Lawrence Quebec Canada - Chapdelaine, G.; Bourget, A. (Naturaliste Canadien (Quebec), 1981)
Eleven spp. of marine birds breed in the Mingan archipelago along the north shore of the Gulf of St. Lawrence. The family Laridae accounts for 97.4% of the total population [great black-backed gull (Larus marinus), herring gull (L. argentatus), ring-billed gull (Larus delawarensis), black-legged kittiwake (Rissa tridactyla), common tern (Sterna hirundo) arctic tern (S. paradisaea)], the Alcidae 1.5% [razorbill auk (Alca torda), black guillemot (Cepphus grylle), Atlantic puffin (Fratercula arctica)] and the Anatidae 1.1% [common eider (Somateria mollissima)]. Double-crested cormorant (Phalacrocorax auritus) was not a nesting species in 1978, but was considered as such in 1980. Common and arctic tern populations represent one of the most important concentrations of these birds in the Gulf of St. Lawrence. Larids have increased considerably since 1925 while alcids and common eiders have diminished since 1965. The birds are found mainly in the western part of the archipelago, where 71% of the breeding birds are found. Factors influencing bird distribution and population changes in the Mingan Islands are discussed.
Keywords: Breeding Season; Abundance, Distribution, and Trends; Common Eider; Somateria mollissima

Thirteenth Census of Seabird Populations in the Sanctuaries of the North Shore of the Gulf of St. Lawrence 1982-1988 - Chapdelaine, G.; Brousseau, P. (Canadian Field-Naturalist, 1991)
The 1988 census revealed an increase in all families of birds present in the sanctuaries. Common Eiders increased tremendously between 1982 and 1988. The vigorous enforcement program carried out by Parks Canada in Betchouane Bird Sanctuary and by the Canadian Wildlife Service in the Iles Sainte-Marie Bird Sanctuary may explain this spectacular comeback. The high rate of yearly increase of this species supports an immigration hypothesis. Although the gull population also grew, their rate of increase was lower those that of other species. Alcids, which represent 58% of the nesting birds, continued to increase, as they have done since 1977. Two factors may account for the improvement: a better conservation program, of which enforcement and education are the two main components, and the exploitation of large predatory fish competitors by fisheries, which made more small prey fish (Capelin and sand lace) available for seabirds. However, the abundant Capelin stocks have now become attractive to the fisheries, and their imminent exploitation may augur a leaner future for the alcids.
Keywords: Abundance, Distribution, and Trends; Common Eider; Sea Ducks - General

Evidence of recent population increases in common eiders breeding in Labrador - Chaulk, Keith; Robertson, Gregory J.; Collins, Brian T.; Montevecchi, William A.; Turner, Bruce (Journal of Wildlife Management, 2005)
Keywords: Breeding Season; Abundance, Distribution, and Trends; Common Eider; Somateria mollissima

Aspects of common eider nesting ecology in Labrador - Chaulk, Keith; Robertson, Gregory J.; Montevecchi, William A.; Ryan, Pierre C. (Arctic, 2005)
The status, distribution, and nesting ecology of common eiders (Somateria mollissima) breeding in Labrador are not well known. This study is an initial effort to improve understanding of the nesting ecology of eiders on the Labrador coast, a zone of intergradation between the northern (S. m. borealis) and American (S. in. dresseri) subspecies of common eider. During 1998 and 1999, 187 islands were surveyed for nesting eiders at four sites (from north to south: Nain, Hopedale, Makkovik, St. Peter's Bay) along 750 km of the coast. Nest initiation dates (calculated by candling eggs) ranged over a four- to five-week period and were positively associated with latitude: the earliest mean initiation date (5 June) was in St. Peter's Bay in the south and the latest (27 June) at Nain in the north. Mean clutch size ranged from 3.5 to 4.2 and varied by area and year; eiders nesting in Nain had the smallest clutches. In 1999, the highest nest density (49.8 nests/ha) was observed in Nain and the lowest (3.9 nests/ha) in Makkovik. In some cases, we used boat surveys to assess eider presence and absence and found it to be a reliable method; this search technique could be beneficial to researchers working in remote locations where operational costs are high.
Keywords: Breeding Season; Abundance, Distribution, and Trends; Common Eider; Somateria mollissima; Productivity

Suspected Long-Term Population Increases in Common Eiders, Somateria mollissima, on the Mid-Labrador Coast, 1980, 1994, and 2006 - Chaulk, Keith G. (Canadian Field-Naturalist, 2009)
Aerial surveys for adult male Common Eiders, Somateria mollissima, were flown on the Labrador coast during June 2006. This information was then compared with aerial counts of adult male Common Eiders collected in 1980 and 1994. For each survey year, data were grouped and paired by coastal block and were analyzed for population trends. Overall, the observed counts of adult male Common Eiders increased by 244% between 1980 and 2006. Much of this increase seemed to occur in the southern region of the study area.
Keywords: Breeding Season; Abundance, Distribution, and Trends; Common Eider; Somateria mollissima

Does spring ice cover influence nest initiation date and clutch size in common eiders? - Chaulk, K. G.; Mahoney, M. L. (Polar Biology, 2012)
Times Cited: 5 Chaulk, Keith G. Mahoney, Matthew L. 5
Keywords: Breeding Season; Common eider; somateria mollissima; productivity

Regional and annual variability in common elder nesting ecology in Labrador - Chaulk, Keith G.; Robertson, Gregory J.; Montevecchi, William A. (Polar Research, 2004)
Nesting densities are often used to estimate breeding population size and with other measures of reproductive performance can be useful indicators of population status. These aspects of breeding biology often show considerable spatial and temporal variation. Between 2000 and 2003, we surveyed nesting common ciders (Somateria mollissima) on 172 islands in three archipelagos (Nain, Hopedale, Rigolet) on the Labrador coast. Rigolet was the largest archipelago (2834 km2) followed by Nain then Hopedale, and island density varied inversely with archipelago size. Overall means were: nest density 52.0 +/- 141.9 (SD) nests/ha; nest initiation 12 June 12 days; clutch size 3.7 +/- 1.2 eggs/nest; egg volume 98.8 +/- 10.4 cm3; and clutch volume 392.3 +/- 135.0 cm3. Rigolet had the highest average egg volumes and nest densities, the highest single island nest density of 1053 nests/ha, and the earliest average nest initiation date. We found significant differences in nest densities among archipelagos and across years; significant archipelago and year interactions were detected for nest initiation date and clutch size. Significant differences were found among individual islands for all response variables except egg volume. For egg volume, within-archipelago island differences were not significant, but between-archipelago differences were significant. Thus egg volume may be a useful diagnostic to identify population affiliation.
Keywords: Breeding Season; Common Eider; Somateria mollissima; Productivity

Extinction, colonization, and distribution patterns of common eider populations nesting in a naturally fragmented landscape - Chaulk, K. G.; Robertson, G. J.; Montevecchi, W. A. (Canadian Journal of Zoology, 2006)
Spatial distribution, patchy environments, and population turnover have many fundamental implications for conservation ecology. Common eider (Somateria mollissima L., 1758) population processes were investigated in Labrador, Canada, between 1998 and 2003. We predicted that local colonies would exhibit population turnover, that extinction would be negatively related to colony and patch size, that colonization would be negatively related to island isolation, and that intraspecific incidence-abundance relationships would be positive. We found that small colonies were prone to extinction, but patch size was not a significant predictor of extinction, nor was colonization related to isolation. The overall observed annual extinction and colonization rates were 0.11 +/- 0.02 and 0.41 +/- 0.06, respectively, and showed variation across archipelagos. At two spatial scales we found that mean colony size was a positive predictor of island occupancy (incidence), and these relationships were maintained across years. Our findings show that common eider colonies in Labrador are dynamic and have greater turnover rates than previously expected in a species that is considered highly philopatric. Our findings support the notion that highly mobile organisms such as migratory birds can exhibit characteristics associated with metapopulation processes.
Keywords: Breeding Season; Common Eider; Somateria mollissima; Dispersal; Population Delineation

Landscape features and sea ice influence nesting common eider abundance and dispersion - Chaulk, Keith G.; Robertson, Gregory J.; Montevecchi, William A. (Canadian Journal of Zoology, 2007)
Factors that influence individual and colony spacing are still not well understood in many organisms. Common ciders (Somateria mollissima (L. 1758)) nest on coastal islands and forage in intertidal and shallow subtidal waters. We considered several biotic and abiotic factors, their interactions, and how these might influence the distribution of eider colonies at several spatial scales in Labrador, Canada. At the island level, nest abundance was not related to intertidal prey density. At the 104 km(2) grid scale, eider nest abundance and the coefficient of dispersion (CD; the variance to mean ratio of colony size or grid cell, where CD indicates population dispersion) were negatively related to the number of islands. Spring ice cover was positively related to the number of islands but was negatively related to eider nest abundance and to CD. Ice cover - abundance and ice cover - CD were significant at two spatial scales (104 and 455 km(2), respectively), but other relationships were weaker at the larger spatial scale. We hypothesize that during the spring, archipelagos with many islands trap ice, providing terrestrial predators access to nesting islands by acting as bridges and that increased predation reduces habitat quality causing nesting ciders to disperse. Our findings suggest that ciders respond to landscape features, including ice cover, a feature that is being influenced by climate change.
Keywords: Breeding Season; Common Eider; Somateria mollissima; Habitat

The timing of waterfowl arrival and dispersion during spring migration in Labrador - Chaulk, Keith G.; Turner, Bruce (Northeastern Naturalist, 2007)
Weekly aerial surveys were conducted in central Labrador during the spring staging period (27 April to 29 May, 2000), and the relative abundance of waterfowl was documented. Anas rupribes (American Black Duck) and Bucephala clangula (Common Goldeneye) were among the first species to arrive, while peak waterfowl diversity occurred on the latest survey date. Overall, Branta canadensis (Canada Geese) were the most abundant species, followed by American Black Duck and Anas crecca (Green-winged Teal). As expected, the relative abundance of these species varied by date and region. By the time of the last survey on 29 May, average flock size had decreased for most species, most likely corresponding with the start of breeding and nest initiation. Our findings could be useful as baseline information for future studies of climate change, may have implications for the management of the aboriginal spring hunt, and also might be used to mitigate the effects of military flying activity.
Keywords: Nonbreeding Seasons; Migration; Bucephala clangula; Common Goldeneye

Sex-biased kleptoparasitism of Hooded Mergansers by Ring-billed Gulls - Chavez-Ramirez, Felipe (Wilson Bulletin, 1995)
Keywords: Trophic Interactions; Hooded Merganser; Lophodytes cucullatus

Genetic identification of eggs purportedly from the extinct Labrador Duck (Camptorhynchus labradorius) - Chilton, Glen; Sorenson, Michael D. (Auk, 2007)
Material extracted from inside the shells of nine purported Labrador Duck (Camptorhynchus labradorius) eggs was subjected to DNA extraction and polymerase chain reaction (PCR) amplification. For each egg, partial sequences of one to three mitochondrial genes (12S, ND2, and control region) were compared with sequences derived from a Labrador Duck specimen and representatives of several other waterfowl species. Sequences from six eggs were consistent with those of the Red-breasted Merganser (Mergus serrator), whereas the sequences from one egg was most consistent with that of the Common Eider (Somateria mollissima). The remaining two eggs yielded sequences consistent with that of the Mallard (Anas platyrhynchos) or a domestic duck. Regrettably, none of the eggs provided additional information about the breeding grounds of the extinct Labrador Duck. To our knowledge, this is the first report of DNA extraction and amplification from old eggshells of birds.
Keywords: Breeding Season; Common Eider; Somateria mollissima; Techniques; Mergus serrator; Red-breasted merganser

Three trematodes from the harlequin duck - Ching, Hilda Lei (Canadian Jour Zool, 1961)
Three trematodes from the digestive tract of two harlequin ducks, Histrionicus histrionicus pacificus were collected at Friday Harbour, Washington. They are Paramonostomum histrionici, n. sp. (Notocotylidae), and two micro-phallids, Pseudospelotrema japonicum Yamaguti, 1939 (new locality record) and Spelotrema pygmaeum (Levinsen, 1881) Jagerskiold, 1901 (new host and locality record). || ABSTRACT AUTHORS: Author
Keywords: Nonbreeding Seasons; Harlequin duck; Histrionicus histrionicus; Parasites

Profilicollis-Botulus Van Cleave 1916 from Diving Ducks and Shore Crabs of British Columbia Canada - Ching, H. L. (Journal of Parasitology, 1989)
Adults of Profilicollis botulus were found in 6 species of diving ducks in British Columbia including 3 new hosts: common goldeneye, Bucephala clangula (L.); Barrow's goldeneye, B. islandica (Gmelin); and greater scaup, Aythya marila (L.). The identification of the species was verified by the examination of co-types and specimens from eider ducks, Somateria mollissima (L.), from Scotland [UK] and oldsquaw, Clangula hyemalis (L.), from New Brunswick. Cystacanths from the hairy shore crab, Hemigrapsus oregonensis (Dana), were similar in morphology to those from Carcinus maenas (L.) from Scotland.
Keywords: Nonbreeding Seasons; Bucephala clangula; Common Goldeneye; Parasites; Barrow's Goldeneye; Bucephala islandica

Avian botulism type E in waterbirds of Lake Michigan, 2010-2013 - Chipault, J. G.; White, C. L.; Blehert, D. S.; Jennings, S. K.; Strom, S. M. (Journal of Great Lakes Research, 2015)
During 2010 to 2013, waterbird mortality surveillance programs used a shared protocol for shoreline walking surveys performed June to November at three areas in northern Lake Michigan. In 2010 and 2012, 1244 total carcasses (0.8 dead bird/km walked) and 2399 total carcasses (1.2 dead birds/km walked), respectively, were detected. Fewer carcasses were detected in 2011 (353 total carcasses, 0.2 dead bird/km walked) and 2013 (451 total carcasses, 0.3 dead bird/km walked). During 3 years, peak detection of carcasses occurred in October and involved primarily migratory diving and fish-eating birds, including long-tailed ducks (Clangula hyemalis; 2010), common loons (Gavia immer; 2012), and red-breasted mergansers (Mergus serrator; 2013). In 2011, peak detection of carcasses occurred in August and consisted primarily of summer residents such as gulls (Larus spp.) and double-crested cormorants (Phalacrocorax auritus). A subset of fresh carcasses was collected throughout each year of the study and tested for botulinum neurotoxin type E (BoNT/E). Sixty-one percent of carcasses (57/94) and 10 of 11 species collected throughout the sampling season tested positive for BoNT/E, suggesting avian botulism type E was a major cause of death for both resident and migratory birds in Lake Michigan. The variety of avian species affected by botulism type E throughout the summer and fall during all 4 years of coordinated surveillance also suggests multiple routes for bird exposure to BoNT/E in Lake Michigan. Published by Elsevier B.V. on behalf of International Association for Great Lakes Research.
Chipault, Jennifer G. White, C. LeAnn Blehert, David S. Jennings, Susan K. Strom, Sean M.
Keywords: Melanitta fusca; White-winged Scoter; Clangula hyemalis; Long-tailed Duck; Disease; Mergus serrator; Nonbreeding season; Red-breasted Merganser

Status of the common eider breeding in the municipality of Avanersuaq (Thule), north-west Greenland - Christensen, Kim Diget; Falk, Knud (Polar Research, 2001)
Late in the summers of 1997 and 1998 surveys of common eider (Somateria mollissima) colonies were conducted throughout Avanersuaq Municipality in north-west Greenland. Although old information from eider colonies was available, these surveys provided the first thorough census of almost all colonies in the district, thereby improving the baseline data for assessing future population changes. The surveys were based on nest counts, and all but two colonies in the district were counted. In total, 3800 nests were counted, and an educated guess for the total common eider population in Avanersuaq Municipality, including the two inaccessible colonies, would be around 5000 pairs. Average clutch size was 3.74, similar to or higher than in other areas of Greenland and high Arctic Canada, suggesting favourable conditions for eiders in the survey area. Comparison with older data suggests that the breeding population in Avanersuaq is stable. This observation contrasts with the declines observed in other parts of Greenland. Further studies into possible population-specific migration routes and wintering areas as well as the direct and indirect effects of the intensive winter hunting in south-west Greenland are warranted.
Keywords: Breeding Season; Abundance, Distribution, and Trends; Common Eider; Somateria mollissima

Effects of cohort and individual variation in duckling body condition on survival and recruitment in the Common Eider Somateria mollissima - Christensen, Thomas Kjaer (Journal of Avian Biology, 1999)
The relationship between juvenile body condition and pre-reproductive survival and recruitment of female Common Eiders was analysed in three duckling cohorts marked in the Stavns Fjord colony, Denmark during 1991-1993, based on recoveries of females in the colony in 1996. Mean duckling condition differed significantly between the three cohorts, but recruitment was not affected by this difference, c. 18% having recruited from each cohort in the third year after ringing. Compared to mean cohort condition, in all years a positive relationship existed between individual duckling condition and recruitment, irrespective of duckling size at capture. The present results suggest that survival and recruitment of female eiders were related to the relative body condition attained as ducklings within cohorts rather than related to the absolute condition attained by separate cohorts.
Keywords: Breeding Season; Common Eider; Somateria mollissima; Survival; Energetics and Nutrition

Female pre-nesting foraging and male vigilance in Common Eider Somateria mollissima - Christensen, Thomas Kjaer (Bird Study, 2000)
Foraging activity and behaviour of paired female Common Eider from arrival to laying at Saltholm, Denmark, was studied during the spring of 1994 and 1995 to assess the importance of female resource accumulation just prior to egg-laying. Ovary development was studied in paired females collected in 1995, 1996 and 1998. Male activity and behaviour were recorded in 1996 in order to assess the importance of mate-guarding in optimizing female resource acquisition. From arrival at the colony in late March until laying in mid-April, female Eiders allocated on average 62% of the daylight hours to foraging by dabbling in inshore waters (<1 m water depth). In offshore waters (1-4 m depth) foraging by diving averaged 74% of the daylight hours. Paired males foraged an average of 17% of the day time in the inshore habitat, and closely attended their females during this time. The males actively defended their females in encounters with other pairs and from single males. Defence events involving encounters with single males increased significantly from 9.2 times per hour to 17.5 times per hour by the time of laying. The frequency of interruption to female foraging did not change significantly as a result of the more frequent encounters towards the time of laying, being 4.0 times per hour before early April and 5.8 times per hour at the time of laying. Female ovary weights showed a significant increase from early April, indicating that resources obtained locally were allocated to egg production. The increase in encounters with single males suggests that extra-pair copulation may be a secondary reproductive strategy in male Eiders at the time their females start to incubate. The present results emphasize the importance of pre-nesting foraging for female Eiders in maximizing the nutrient intake in preparation for reproduction, and the importance of the behaviour of attendant males in protecting female foraging from interruptions from other males.
Keywords: Behavior; Breeding Season; Common Eider; Somateria mollissima; Energetics and Nutrition

Effects of duckling body condition on hunting vulnerability in juvenile and immature common eiders Somateria mollissima - Christensen, Thomas Kjaer (Wildlife Biology, 2001)
Condition related pre-breeding hunting vulnerability in the common eider Somateria mollissima, i.e. the relationship between body condition attained as a duckling and the probability of being shot, was analysed from recoveries of hunter-retrieved birds ringed in the Stavns Fjord colony in Denmark during 1991-1995. Mean duckling cohort condition showed significant variation between years, but the proportions of birds retrieved during the first three seasons were similar (4.9%+-1.4 SD). The proportion of birds retrieved by hunters declined from 3.9% in the first year to 0.64% and 0.38% in the second and third year, respectively. A condition bias was found in first-year retrieved birds in the cohorts with the highest and poorest mean condition, but not in the cohorts of intermediate condition. In accordance with a priori predictions regarding condition related non-hunting mortality during the period between marking and the opening of the hunting season, the direction of the bias was negative (hunters retrieved poor individuals compared to cohort mean) in the cohort of high mean condition, and positive (hunters retrieved good individuals compared to cohort mean) in the cohort of poor mean condition. Despite significant variation in cohort condition, the duckling condition of individuals retrieved during their first season from the cohorts of high and poor mean condition was comparable. The condition of first-year retrieved birds was not significantly different from the condition of birds retrieved during their second and third year, when all years were pooled. As there is a significant positive relationship within cohorts between duckling condition and recruitment of (female) eiders, the present results suggest, 1) that hunting vulnerability in the eider is related to a specific (poor) level of body condition attained prior to fledging, and 2) that hunting tends to remove the poorest individuals present at the time when the hunting season opens.
Keywords: Conservation; Breeding Season; Common Eider; Nonbreeding Seasons; Somateria mollissima; Survival; Energetics and Nutrition

Factors affecting the bag size of the common eider Somateria mollissima in Denmark, 1980-2000 - Christensen, Thomas Kjer (Wildlife Biology, 2005)
Based on data compiled from the official Danish Bag Record and from the annual wing surveys of waterfowl, analyses of long-term trends in the bag of common eiders Somateria mollissima were performed for the period 1958-2000, while more detailed analyses of factors affecting bag size were made for the period 1980-1999. The bag size increased from ca 100,000 in the late 1950s to ca 140,000 in the 1970s and 1980s. During the 1990s, the bag size decreased to ca 83,000 in parallel with a decrease in the number of eiders wintering in Danish waters and in parallel with a significant decrease in the number of eider hunters. Assessed from both national and regional developments in bag size, hunter numbers and numbers of eiders bagged per hunter during 1980-1999, there were no indications that bag size was related to the number of wintering eiders. Stepwise multiple regression on data from 1983-1999 showed that the number of eider hunters significantly explained 71.3% of the variation in bag size, and the annual juvenile:adult female ratio in October significantly explained 10.6% of the variation. Marked decreases in the number of eider hunters during the mid-1980s and between the hunting seasons of 1992/93 and 1993/94 coincide with public debates and introductions of legislative restrictions on waterfowl hunting in Denmark. My results stress the importance of detailed analyses of factors contributing to variation in the bag size of waterfowl before accepting an apparent correlation between bag size and population size.
Keywords: Conservation; Common Eider; Nonbreeding Seasons; Somateria mollissima

Condition dependent strategies of egg size variation in the Common EiderSomateria mollissima - Christensen, T. K.; Balsby, T. J. S. (PLOS ONE, 2020)
We analysed intraclutch egg-size variation over the laying sequence in relation to clutch size, and the relation between clutch size and female body condition, in the Common EiderSomateria mollissimaduring an 8-year period. The aim was to assess if eiders adjusted egg size within the laying sequence depending on clutch sizes in response to body condition, as such an adjustment could have adaptive implications on reproductive success through a size advantage for the hatchlings. The analyses were performed on a population level; and then at the individual level using data from recaptured females that changed clutch size between years. Based on 1,099 clutches from 812 individual females, population clutch size averaged 4.13 eggs (range: 1-6), with 4- and 5-egg clutchesconstitutingc.70% of all clutches, taking turns in being the most represented clutch size. Clutch size was positively related to female pre-laying body condition at both the population and individual levels. Egg size varied significantly within and between clutch sizes and changes were significantly related to the laying sequence. First eggs were significantly larger in 4-egg clutches and second eggs marginally smaller than in 5-egg clutches, a pattern also found among individual females changing clutch size between years. The relationship between female pre-laying body condition and clutch size, and the intraclutch egg-size pattern indicate that both clutch size and egg size are actively adapted to the pre-breeding body condition of the female. As egg size potentially optimise reproductive success through a size advantage in hatchlings, the observed pattern of intraclutch egg-size variation suggests that female eiders possesses a finely tuned conditional dependent mechanism that may optimize reproductive output in years were females are in suboptimal body condition for breeding.
Times Cited in Web of Science Core Collection: 0 Total Times Cited: 0 Cited Reference Count: 69
Keywords: CONSEQUENCES; CLUTCH-SIZE; BROOD PARASITISM; EIDER; FEMALE AGE; HATCHING SYNCHRONY; INTRACLUTCH VARIATION; LAYING DATE; OFFSPRING SURVIVAL; PARENTAL CARE

Outbreak of Pasteurellosis among wintering and breeding common eiders Somateria mollissima in Denmark - Christensen, Thomas K.; Bregnaballe, Thomas; Andersen, Thomas H.; Dietz, Hans Henrik (Wildlife Biology, 1997)
In 1996, an epizootic occurred among wintering and breeding common eiders Somateria mollissima in southwest Kattegat, Denmark, causing the death of at least 900 birds during late winter, and of a total of 3,146 females in five local breeding colonies, corresponding to 35-95% of the females present within the single colonies. The cause of death was related to a bacterial infection by Pasteurella multocida isolated from all examined eiders collected on wintering and breeding grounds. This is the first documented incidence of pasteurellosis in Scandinavia. Based on knowledge of the phenology and winter distribution of eiders, the temporal occurrence of the disease suggests that apparently healthy birds acted as carriers of the disease bringing it from the wintering grounds to the breeding colonies.
Keywords: Breeding Season; Common Eider; Nonbreeding Seasons; Somateria mollissima; Survival; Disease

Changes in age and sex ratios amongst samples of hunter-shot wings from common duck species in Denmark 1982-2010 - Christensen, T. K.; Fox, A. D. (European Journal of Wildlife Research, 2014)
There are almost no long-term demographic monitoring programmes of commoner waterbird species, yet such data are fundamental to our understanding of drivers of population change. In the present study, we present annual age and sex ratios in samples of shot duck wings forwarded on a voluntary basis by hunters throughout Denmark from 1982 to 2010 for eight common quarry species. Wigeon, Shoveler, Pintail and Goldeneye showed statistically significant declines in the proportions of young birds in the samples, but only Wigeon showed a statistically significant decline in the proportion of females in the adult sample over this period. Amongst Wigeon, the proportions of first winter birds and females were lower amongst the sample shot over decoys compared with those shot without decoys, suggesting these two shooting methods differentially select for young birds and females. However, the slopes of declines in these proportions shot with and without decoys over time did not differ. We found no correlations between North Atlantic Oscillation index values and the proportions of young for any of the species or between May and June temperatures on the breeding areas of Wigeon and the proportions of young in samples derived the following winter. With the exception of Wigeon, little is known about how well the shot duck wing samples reflect the true ratios in the populations, and unravelling the error and bias associated with these samples remains a high future research priority. If long-term declines in age and sex ratio in the wing surveys reflect true trends in the Wigeon population as a whole, we have strong grounds for concern for this population, and effort should be invested in increased demographic surveillance to better understand the causes of these changes. We need improved methods to derive unbiased measures of annual breeding of our common duck species if we are to be better able to understand the population dynamics of these stocks and be effective in their management. In the meantime, the Danish wing survey represents a unique time series of reproductive success for many common migratory duck species and must be maintained and further exploited.
Christensen, Thomas K. Fox, Anthony D.
Keywords: Bucephala clangula; Common Goldeneye; Population Dynamics

Managing hunted populations through sex-specific season lengths: a case of the Common Eider in the Baltic-Wadden Sea flyway population - Christensen, T. K.; Hounisen, J. P. (European Journal of Wildlife Research, 2014)
Management of harvested wildlife populations aims to protect species from overexploitation and ultimately extinction, by regulating exploitation towards achievable sustainable levels. However, assessments of impact and sustainability of implemented management actions on a population level are scarce. This study assesses effects of changes in hunting season length imposed on the Baltic-Wadden Sea Common Eider Somateria mollissima population, including differential restriction on hunting of the sexes. The potential impact of these changes on the population was assessed by simple demographic matrix projections. Since the early 1990s, this population has declined at ca. 6.3 % per annum, and the male/female ratio among shot birds has fallen from 3:2 to about 3:1. Concerns in Denmark regarding the conservation status and sustainability of contemporary levels of exploitation resulted in shortening the open season by 44 and 46 days for females and 13 and 15 days for males from the hunting seasons 2004/2005 and 2011/2012 onwards, respectively. These reduced the kill of adult females by 82 %, adult males by 31 %, juvenile females by 58 % and juvenile males by 55 %. The observed reduction in the kill of adult females following both changes in 2004/2005 and 2011/2012 matched the expected changes based on the seasonal distribution of sexes in the bag prior to the change. Post 2004/2005 hunters killed more adult males, but shot markedly fewer juvenile birds than expected. Demographic modelling of the female population showed that the effects of the reduced hunting would correspond to an increase in the annual population growth rate from the previous -6.3 to -3.6 % (post 2004) and -1.6 % (post 2011). The model also predicted that a full ban on hunting female eiders (adults and juveniles) would lead to a positive population growth rate of 0.7 %. Taking into account the conservative model estimates and natural variations in annual breeding success, the implemented changes in sex-specific regulation of hunting may potentially be an effective management tool to halt the decline of the Baltic-Wadden Sea eider population, potentially rendering such levels of hunting sustainable under prevailing conditions.
Christensen, Thomas Kjaer Hounisen, Jens Peder
Keywords: Conservation; Common Eider; Somateria mollissima; Population Dynamics; Population Model; Survival; Nonbreeding season

Epidemic-like outbreak of disease due to zooparasites. among the common eiders. S. mollissima.on the Island of Bornholm - Christiansen, M. (Dansk Ornithol Foren Tidsskr, 1948)
A disease outbreak in Aug.-Sept., 1947, was caused by Polymorphus boschadis, one of the Acanthocephala, which were attached in masses in the small intestines. Three birds had lesions in the kidneys caused by coccidia. Later reports indicate no serious reduction of the eider colony. || ABSTRACT AUTHORS: O. J. Murie
Keywords: Common Eider; Somateria mollissima; Disease

Renal coccidiosis in wild anseriform birds. E. somateriae n. sp. in the common eider - Christiansen, M. (Nordisk Veterinaermed, 1952)
E. truncata was found in goslings of the grey goose (Anser anser) from 2 separate nesting places. Oocysts resembling E. truncata but much smaller were found in kidneys of 4 young swans (Cygnus olor). 20 out of 21 common eiders (Somateria mollisima) were found to have 2 kinds of oocysts. One appeared to be a small variant of E. truncata; the other is descr. as E. somateriae. || ABSTRACT AUTHORS: A. G. Karlson
Keywords: Breeding Season; Common Eider; Somateria mollissima; Parasites

Non-linear effect of sea ice: Spectacled Eider survival declines at both extremes of the ice spectrum - Christie, K. S.; Hollmen, T. E.; Flint, P.; Douglas, D. (ECOLOGY AND EVOLUTION, 2018)
Understanding the relationship between environmental factors and vital rates is an important step in predicting a species' response to environmental change. Species associated with sea ice are of particular concern because sea ice is projected to decrease rapidly in polar environments with continued levels of greenhouse gas emissions. The relationship between sea ice and the vital rates of the Spectacled Eider, a threatened species that breeds in Alaska and Russia and winters in the Bering Sea, appears to be complex. While severe ice can impede foraging for benthic prey, ice also suppresses wave action and provides a platform on which eiders roost, thereby reducing thermoregulation costs. We analyzed a 23-year mark-recapture dataset for Spectacled Eiders nesting on Kigigak Island in western Alaska, and tested survival models containing different ice and weather-related covariates. We found that much of the variation in eider survival could be explained by the number of days per year with >95% sea ice concentration at the Bering Sea core wintering area. Furthermore, the data supported a quadratic relationship with sea ice rather than a linear one, indicating that intermediate sea ice concentrations were optimal for survival. We then used matrix population models to project population trajectories using General Circulation Model (GCM) outputs of daily sea ice cover. GCMs projected reduced sea ice at the wintering area by year 2100 under a moderated emissions scenario (RCP 4.5) and nearly ice-free conditions under an unabated emissions scenario (RCP 8.5). Under RCP 4.5, stochastic models projected an increase in population size until 2069 coincident with moderate ice conditions, followed by a decline in population size as ice conditions shifted from intermediate to mostly ice-free. Under RCP 8.5, eider abundance increased until 2040 and then decreased to near extirpation toward the end of the century as the Bering Sea became ice-free. Considerable uncertainty around parameter estimates for survival in years with minimal sea ice contributed to variation in stochastic projections of future population size, and this uncertainty could be reduced with additional survival data from low-ice winters.
Times Cited in Web of Science Core Collection: 3 Total Times Cited: 3 Cited Reference Count: 67
Keywords: survival; Somateria fischeri; Spectacled Eider; BIRDS; CONSEQUENCES; CLIMATE-CHANGE; PATTERNS; Bering Sea; BIOMASS; DYNAMICS; IMPACTS; mark-recapture; MASS; PROTECTED AREAS; sea ice; SHIFTS

Unusual Harlequin Duck, Histrionicus histrionicus, nest site discovered in central Labrador - Chubbs, Tony E.; Mactavish, Bruce; Oram, Keith; Trimper, Perry G.; Knox, Kathy; Goudie, R. Ian (Canadian Field-Naturalist, 2001)
During telemetry monitoring of adult Harlequin Ducks, Histrionicus histrionicus, in 1999, a female was radio-tracked to her nest site. The nest site, only the third recorded in Labrador, was unusual, as it was located 108 m from the nearest river, in open spruce-lichen boreal forest.
Keywords: Breeding Season; Harlequin duck; Histrionicus histrionicus; Habitat

Site characteristics of a repetitively used Harlequin Duck, Histrionicus histrionicus, nest in northern Labrador - Chubbs, Tony E.; Mactavish, Bruce; Trimper, Perry G. (Canadian Field-Naturalist, 2000)
As part of field investigation for the Voisey's Bay Mine Mill Environmental Assessment in 1995, baseline studies on Harlequin Ducks, Histrionicus histrionicus, were initiated around the proposed site on Labrador's north coast. During ground brood surveys in 1997, a Harlequin Duck nest was discovered. This was the second Harlequin Duck nest ever found in Labrador. The exact same site was used again in 1998 indicating favorable nesting habitat and repetitive nest-site use for Harlequin Ducks in Labrador. This finding contributes to our meager knowledge of the species breeding habits in Labrador and has implications on future research.
Keywords: Breeding Season; Harlequin duck; Histrionicus histrionicus; Habitat

Tracking Seasonal Movements of Adult Male Harlequin Ducks from Central Labrador Using Satellite Telemetry - Chubbs, Tony E.; Trimper, Perry G.; Humphries, Gary W.; Thomas, Peter W.; Elson, Leanne T.; Laing, Dawn K. (Waterbirds, 2008)
Satellite telemetry was used to determine the migration patterns between breeding, staging, and molting areas of adult. male Harlequin Ducks (Histrionicus histrionicus) breeding in central Labrador during 2001 (N = 5) and 2002 (N = 6). Male Harlequin Ducks remained near their capture locations for an average of 19-20 d. Males spent an average of 18 and 34 d on the Labrador coast in 2001 and 2002, respectively, and moved along the coast between several important staging areas prior to migration to Greenland. Male Harlequin Ducks may be completing a pre-basic molt prior to migrating to Greenland. Seven males migrated from the Labrador coast to three distinct molting areas in Greenland. All transmitters, expired by September preventing a confirmation of whether these males wintered in Greenland. The absence of hand sightings during winter in eastern Canada, especially Maine, indicates that some Harlequin Ducks breeding in central Labrador may also winter in eastern Greenland.
Keywords: Breeding Season; Nonbreeding Seasons; Harlequin duck; Histrionicus histrionicus; Population Delineation

Rescue Operations for Oiled Sea Birds - Clark, R. B.; Croxall, J. P. (Marine Pollution Bulletin, 1972)
Keywords: Sea Ducks - General; Contaminants

Spring phenology and timing of breeding in short-distance migrant birds: phenotypic responses and offspring recruitment patterns in common goldeneyes - Clark, R. G.; Poysa, H.; Runko, P.; Paasivaara, A. (Journal of Avian Biology, 2014)
Understanding how organisms adjust breeding dates to exploit resources that affect fitness can provide insights into impacts of climate change on avian demography. For instance, mismatches have been reported in long-distance migrant bird species when environmental cues experienced during spring migration are decoupled from conditions on breeding grounds. Short-distance migrant bird species that store reproductive nutrients prior to breeding may avoid or buffer adverse phenological effects. Furthermore, reduced short-term reproductive success could be offset by higher future recruitment of surviving offspring. We evaluated whether recruitment of locally-hatched female offspring was related to hatching date alone or strength of mismatched breeding date for 405 individually-marked adult female common goldeneyes Bucephala clangula (a short-distance migrant) and their ducklings from a site in central Finland where ice-out date has advanced by approximate to 2 weeks over 24 yr. Path analyses revealed that older, early-nesting females with good body condition and larger broods recruited the most female offspring. Offspring recruitment decreased strongly among females that bred late relative to other females in the population each year; the extent of mismatched breeding date, i.e. hatching date scaled to annual ice-out date, was less influential. Overall, most females advanced breeding dates when ice-out occurred earlier in spring, but some females exhibited greater flexibility in response to ice-out conditions than did others. In general, directional selection favoured early breeding over a wide range of ice-out dates. Our results seem most consistent with a hypothesis that some short-distance migrant species like goldeneyes have the capacity to track and respond appropriately to changing environmental conditions prior to onset of breeding.
Clark, Robert G. Poysa, Hannu Runko, Pentti Paasivaara, Antti
Keywords: Behavior; Breeding Season; Bucephala clangula; Common Goldeneye; Productivity

Seaduck engineers in the Arctic Archipelago: nesting eiders deliver marine nutrients and transform the chemistry of island soils, plants, and ponds - Clyde, N.; Hargan, K. E.; Forbes, M. R.; Iverson, S. A.; Blais, J. M.; Smol, J. P.; Bump, J. K.; Gilchrist, H. G. (OECOLOGIA, 2021)
Seabirds are thought to provide ecological services such as the movement of nutrients between marine and terrestrial ecosystems, which may be especially critical to productivity and diversity in nutrient-poor environments. Most Arctic ecosystems are unaffected by local human impacts and are naturally nutrient poor and especially sensitive to warming. Here, we assessed the effects of nesting common eider ducks (Somateria mollissima) on soil, vegetation, and pond sediments on island archipelagoes in Hudson Strait between Nunavut and Quebec, Canada. Soil, moss, and pond sediments were significantly higher in nitrogen on islands with large numbers of nesting eiders compared to sites with no nesting birds. The highest concentrations of nitrogen in soils and moss occurred at the margins of ponds on eider islands, which correspond to the areas of highest eider use. delta N-15 and delta S-34 values in soils, moss, and sediments indicated substantial marine-derived organic matter inputs at the higher nutrient sites. We propose that by foraging on coastal marine benthic invertebrates and returning to islands to nest, eider ducks bio-transport and concentrate marine-derived nutrients to their colony islands, fertilizing Arctic island ecosystems in the process. As common eiders nest on thousands of low to mid-latitude islands throughout the circumpolar Arctic, these nutrient inputs likely dramatically affect biota and ecosystem functioning throughout the tundra biome.
Times Cited in Web of Science Core Collection: 5 Total Times Cited: 5 Cited Reference Count: 40
Keywords: Arctic; Bio-vectors; Islands; Nutrient subsidies; Seaduck; Stable isotopes

Species limits within the genus Melanitta, the scoters - Collinson, Martin; Parkin, David T.; Knox, Alan G.; Songster, George; Helbig, Andreas J. (British Birds, 2006)
As part of its reassessment of the taxonomy of birds on the British List, the BOURC Taxonomic Sub-committee has assessed all six recognised taxa of scoters Melanitta against its previously published Species Guidelines (Helbig et al. 2002). We consider that, on the basis of evidence currently available, at least five species should be recognised: Common Scoter M. nigra, Black Scoter M. americana, Velvet Scoter M. fusca,White-winged Scoter M. deglandi and Surf Scoter M. perspicitiata. The taxonomic status of the Asian subspecies of White-winged Scoter (stejnegeri) is uncertain, owing to insufficient information on several aspects of its morphology and behaviour. Provisionally, we suggest that it is best treated as conspecific with M. deglandi.
Keywords: Taxonomy; Melanitta fusca; White-winged Scoter; Melanitta perspicillata; Surf Scoter; Black Scoter; Melanitta nigra

Deterring coastal birds from roosting on oyster culture gear in eastern New Brunswick, Canada - Comeau, L. A.; St-Onge, P.; Pernet, F.; Lanteigne, L. (Aquacultural Engineering, 2009)
An ornithological survey was conducted along the eastern coastline of New Brunswick Canada where,, oysters are cultivated in suspension using PVC bags and wire-mesh cages. Thirteen bird species and a variety of unidentified shorebirds were observed roosting on the floating oyster gear. The double-crested cormorant (Phalacrocorax auritus) was the most common species observed (47.6% of all counts) closely, followed by herring gulls (Larus argentatus) and common terns (Sterna hirundo) at 18.7% and 13.0%, respectively. Birds were densely aggregated where few cages or bags had been deployed. A gear-type effect was also detected: birds were more abundant on floating cages (mean = 47.9/100 m(2) of exposed area, S.E. = 5.8) than on floating bags (mean = 32.8/100 m(2), S.E. = 1.9). The survey was followed by two experiments designed to test the effects of gear modifications on bird abundance and diversity. For bags, results indicated that shallow immersion (similar to 6 cm below surface) and floater instability were effective deterrents to P. auritus, reducing its abundance by a 37-fold factor. For wire-mesh cages, a dented triangular structure mounted on top of floaters was a harassing physical barrier to roosting behaviour, consequently reducing bird abundances to null (or near null) values. Crown Copyright (C) 2008 Published by Elsevier B.V. All rights reserved.
Keywords: Sea Ducks - General

Modeling probability of waterfowl encounters from satellite imagery of habitat in the central Canadian arctic - Conkin, J. A.; Alisauskas, R. T. (Journal of Wildlife Management, 2013)
Times Cited: 0 Conkin, John A. Alisauskas, Ray T. 0
Keywords: Breeding Season; Abundance, Distribution, and Trends; Sea Ducks; habitat

The breeding biology and management of the northern eider (Somateria mollissima borealis) in the Cape Dorset Area, Northwest Territories - Cooch, F. G. (Wildlife Manage Bull [Ottawa] Ser Ii, 1965)
The first northern eiders arrived in early May, with the peak of migration occurring in late May and early June. The first migrants were males, but sex ratios equalized in early June. Little courtship was noted at first, but it became fairly common in early June. Pre-nesting flights started in mid-June, and egg laying on June 19, 1955, and on June 23, 1956. Most nest sites were inspected and prepared at least 2 days before the laying of the 1st egg. More than 90% of the sites contained old down. Site tenacity is shown to occur in northern eiders. The average clutch size on the study area in 1955 was 3.7 eggs and in 1956, 3.83 eggs. Predation and other losses accounted for 25% of all eggs laid in 1955 and 15% in 1956. Renesting reduced the effect of complete nest destruction. However, second clutches were approximately half as large as 1st ones. Nearly all nesting down is deposited before the laying of the last egg. Incubation frequently starts before the last egg is laid, and lasts 28 to 29 days. Males desert nesting females soon after the laying of the last egg. The female rarely leaves the nest after the midpoint of incubation. Ducklings are able to leave the nest soon after hatching. On the West Foxe Islands, most ducklings remain on the lakes for 2 or 3 days; elsewhere they proceed directly to the sea. A post-hatch migration to mainland tidal pools occurs within a week of hatching. Ducklings, escorted by relatively few females, stay in those areas for nearly a month. The fledging period is thought to be 60 days. Autumn migration from Cape Dorset area is gradual. Some birds remain in the area throughout the winter. || ABSTRACT AUTHORS: Author
Keywords: Breeding Season; Common Eider; Somateria mollissima; Productivity

Molt and the basic plumage of male harlequin ducks - Cooke, Fred; Robertson, Gregory J.; Goudie, R. Ian; Boyd, W. Sean (Condor, 1997)
Using observations on 28 individually marked male Harlequin Ducks from mid-June until late November, we describe plumage changes which occur as individuals proceed from the alternate plumage through basic to the return of the new alternate plumage. We also describe the timing of these events, at the individual and population level. Conspicuous white tertial feathers which become visible early in the period of the basic plumage present a challenge to existing theories to explain the function of the drab basic plumage. We hypothesize that these feathers act as a badge of quality and are used as a sexual signal to other birds. Intra-sexual competition among males to assess the quality of rival males prior to subsequent pair formation is a proposed function of this feather badge.
Keywords: Behavior; Nonbreeding Seasons; Harlequin duck; Histrionicus histrionicus; Molt

Survival, emigration, and winter population structure of Harlequin Ducks - Cooke, Fred; Robertson, Gregory J.; Smith, Cyndi M.; Goudie, R. Ian; Boyd, W. Sean (Condor, 2000)
A population of individually marked Harlequin Ducks (Histrionicus histrionicus) at White Rock, British Columbia, Canada was examined to measure the degree of population differentiation among birds which pair during the winter months. This required an understanding of the patterns of emigration among wintering sites in different segments of the population. Some juveniles arrived at the wintering grounds accompanied by their mothers, thus initially arriving into the same winter population as their parents. Young males were more likely than young females to disperse during the first two years of life. Adult males had higher local survival than adult females during the summer months, probably because of the greater mortality risks to nesting females. During the nonbreeding seasons, local survival was the same in both sexes. Paired males had a local survival of more than 90%, suggesting both high survival and strong philopatry. Unpaired males had a lower local survival rate, suggesting they have higher mortality and/or emigration rates. Young females had the same local survival rate as adult females, suggesting that they did not disperse during the winter. These winter philopatry patterns are similar to the general pattern of breeding philopatry in waterfowl, with females showing stronger philopatry than males, and paired adults stronger philopatry than unpaired and young birds. The dispersal of young males makes local population differentiation unlikely in this species.
Keywords: Nonbreeding Seasons; Harlequin duck; Histrionicus histrionicus; Dispersal; Population Dynamics; Survival; Population Delineation

Linkages between sea-ice coverage, pelagic-benthic coupling, and the distribution of spectacled eiders: Observations in March 2008, 2009 and 2010, northern Bering Sea - Cooper, L. W.; Sexson, M. G.; Grebmeier, J. M.; Gradinger, R.; Mordy, C. W.; Lovvorn, J. R. (Deep-Sea Research Part Ii-Topical Studies in Oceanography, 2013)
Icebreaker-based sampling in the northern Bering Sea south of St. Lawrence Island in March of 2008, 2009, and 2010 has provided new data on overall ecosystem function early in the annual productive cycle. While water-column chlorophyll concentrations (<25 mg m(-2) integrated over the whole water column) are two orders of magnitude lower than observed during the spring bloom in May, sea-ice algal inventories of chlorophyll are high (up to 1 g m(-3) in the bottom 2-cm of sea-ice). Vertical fluxes of chlorophyll as measured in sediment traps were between 0.3 and 3.7 mg m(-2) d(-1) and were consistent with the recent deposition (days' to weeks' time scale) of chlorophyll to the surface sediments (0-25 mg m(-2) present at 0-1 cm). Sediment oxygen respiration rates were lower than previous measurements that followed the spring bloom, but were highest in areas of known high benthic biomass. Early spring release of sedimentary ammonium occurs, particularly southeast of St. Lawrence Island, leading to bottom-water ammonium concentrations of >5 mu M. These data, together with other physical, biological, and nutrient data, are presented here in conjunction with observed sea-ice dynamics and the distribution of an apex predator, the Spectacled Eider (Somateria fischeri). Sea-ice dynamics in addition to benthic food availability, as determined by sedimentation processes, play a role in the distribution of spectacled eiders, which cannot always access the greatest biomass of their preferred bivalve prey. Overall, the data and observations indicate that the northern Bering Sea is biologically active in late winter, but with strong atmospheric and hydrographic controls. These controls pre-determine nutrient and chlorophyll distributions, water-column mixing, as well as pelagic-benthic coupling. (C) 2013 Elsevier Ltd. All rights reserved.
ISI Document Delivery No.: 244BH Times Cited: 2 Cited Reference Count: 42 Cooper, L. W. Sexson, M. G. Grebmeier, J. M. Gradinger, R. Mordy, C. W. Lovvorn, J. R. Grebmeier, Jacqueline/L-9805-2013 North Pacific Research Board; Office of Polar Programs of the National Science Foundation [ARC-0732767, ARC-0732430, ARC-082290]; Joint Institute for the Study of the Atmosphere and Ocean (JISAO) under NOAA [NA17RJ1232] The field sampling would not have been possible without strong support from the commanding officers, crew and officers of both the USCGC Healy on the 2008 and 2009 cruises, and during the apparently final science mission of the USCGC Polar Sea in 2010. Shipboard support for water column collections and data management was provided by Steve Roberts, Tom Bolmer, Matt Durham, Ben Gire, Sigrid Salo, Peter Proctor, Mark Bradford, John Allison, and Scott Hiller. Also at sea, we thank Markus Janout, Boris Sirenko, Craig Casemodel, Deanna Wheeler, Rebecca Neumann, Sarah Story, Joe Bump, Perry Pungowiyi, Gay Sheffield, Marisa Guarinello, Regan Simpson, Krista Hoff, Maria Ceballos, Linton Beaven, Cynthia Yeung, Laura Gemery, Nathalie Morata, Jared Weems, Brenna McConnell, Marjorie Brooks, Steve Fenske, Dawn Sechler, Martin Schuster, and Edward Davis for their help in collecting the data presented here. Alynne Bayard and Aariel Rowan provided GIS expertise with drafting some of the figures and Dana Biasatti made the oxygen isotope determinations. We thank two anonymous reviewers and guest editor Mike Lomas for their efforts in reviewing earlier versions of the manuscript. Financial support was provided in part by the North Pacific Research Board. The Office of Polar Programs of the National Science Foundation also supported this work, through ARC-0732767 to RG, ARC-0732430 to CM, and ARC-082290 to L.C. and J.G. The spectacled eider telemetry efforts were supported by the Bureau of Ocean Energy Management, the Bureau of Land Management, the National Fish and Wildlife Foundation, the US Fish and Wildlife Service, ConocoPhillips-Alaska, Inc., the Columbus Zoo and Aquarium, the Mesker Park Zoo & Botanic Garden, and the Point Defiance Zoo 82 Aquarium. Use of trade names is for descriptive purposes only and does not imply endorsement by the US Geological Survey or the US Government. This study was also in part funded by the Joint Institute for the Study of the Atmosphere and Ocean (JISAO) under NOAA Cooperative Agreement no. NA17RJ1232. This work is Contribution 3854 to NOAA's Pacific Environmental Laboratory, 2041 to JISAO, EcoFOCI-0786 to NOAA's Fisheries-Oceanography Coordinated Investigations, and Contribution 87 to the BEST-BSIERP program. 2 PERGAMON-ELSEVIER SCIENCE LTD OXFORD DEEP-SEA RES PT II
Keywords: Somateria fischeri; Spectacled Eider; Nonbreeding Seasons; Trophic Interactions; Habitat

The voice of the velvet scoter, Melanitta fusca (L.), a hitherto unsolved riddle - Corfixsen, R. O. Y. (Dansk Orni Thol Foren Tidsskr, 1947)
Observing flocks of males in the winter of 1946-47 off the coast of s. Zealand, the author recorded the call motes as "longong-longong" (o pronounced as i in bird), and another call "tititititi" which was believed not to come from the wing beats. || ABSTRACT AUTHORS: O. J. Murie
Keywords: Behavior; Melanitta fusca; Nonbreeding Seasons; White-winged Scoter

Nest Boxes Facilitate Local-Scale Conservation of Common Goldeneye (Bucephala clangula) and Bufflehead (Bucephala albeola) in Alberta, Canada - Corrigan, R. M.; Scrimgeour, G. J.; Paszkowski, C. (Avian Conservation and Ecology, 2011)
Times Cited: 2 Corrigan, Robert M. Scrimgeour, Garry J. Paszkowski, Cynthia 2
Keywords: Conservation; Breeding Season; Bucephala clangula; Common Goldeneye; Habitat; Bucephala albeola; Bufflehead

Population Assessment and Habitat Use of Brown Trout Following Severe Overwinter Predation from Common Mergansers in a Western New York Stream - Corser, K.; Wilcox, D. A. (NORTHEASTERN NATURALIST, 2019)
Heavy predation by Mergus merganser (Common Merganser) during severe winters of 2013-2014 and 2014-2015 resulted in substantial reductions of wild Salmo trutta (Brown Trout) in open-water, groundwater-fed reaches of Oatka Creek in western New York State. New York State Department of Environmental Conservation considered the need for habitat manipulation to reduce the severity of future overwinter-predation by mergansers in Oatka Creek Park (OCP) but lacked data to make an informed decision. Thus, this study sought to estimate population abundance, density, and year-class distribution of Brown Trout; quantify the availability of cover and habitat; and identify habitat features used by Brown Trout in OCP. We recorded data for 100 Brown Trout (101-512 mm TL) during spring 2016, autumn 2016, winter 2017, and spring 2017. Despite the absence of mergansers in ensuing warmer winters, trout population indices decreased as the study continued, likely affected by high streamflow during sampling events. Year-class distributions typical of a small stream, however, suggest that the population is recovering. Velocity refuges and structural cover were the primary factors determining habitat selection. Large woody debris was the most favored cover type by all Brown Trout; however, boulders were also important, especially during low streamflow. Large trout (>300 mm) showed a strong preference for deepwater habitats with slow currents and high densities of woody debris and boulders, while small trout (<200 mm) preferred shallower complex habitats with slow currents, course substrates, and high cover densities. Quality trout habitat and instream cover is abundant throughout OCP, but the abundance of highly complex overwinter habitats capable of providing protection from mergansers may be limited. Adding complex structural cover to areas favored by smaller trout (<300 mm) could increase habitat complexity and likely reduce the severity of future overwinter predation.
Times Cited in Web of Science Core Collection: 0 Total Times Cited: 0 Cited Reference Count: 36
Keywords: BEHAVIOR; COVER; FISH; HATCHERY; JUVENILE ATLANTIC SALMON; MERGUS-MERGANSER; RESPONSES; SALAR; WILD; WINTER HABITAT

A winter survey of sawbill ducks and cormorants on the River Deveron, north east Scotland - Cosgrove, P. J. (Scottish Birds, 1997)
During January 1996 a winter survey of sawbill ducks and Cormorants was carried out on the main stem of the River Deveron, in north east Scotland. A total of 91 Goosanders were counted representing approximately one bird per 1km of river. Nearly half of the birds were adult males and the rest females or yearlings. Goosanders were most abundant in the lower to middle reaches of the river. No Red-breasted Mergansers were detected on the river. There were 15 Cormorants on the river representing approximately one bird per 6 km of river, although birds were only recorded in the lower to middle sections of the river. The figure of 91 Goosanders shows that the River Deveron is a nationally important wintering site, holding at least 1% of the estimated population in Great Britain. However the national population has been estimated in the absence of comprehensive river surveys and so the national figures need to be reassessed to take account of all Goosander habitats. Both Goosanders and Cormorants have been culled under licence in relatively high numbers on the Deveron in recent years. The impact of culling on the bird and fish populations are considered and the necessity of culling is questioned.
Keywords: Abundance, Distribution, and Trends; Nonbreeding Seasons; Common merganser; Mergus merganser

Canoe and walking surveys of wintering Goosanders, Red-Breasted Mergansers, Great Cormorants and Common Goldeneyes on the River Spey, 1994-2003 - Cosgrove, P. J.; Butler, J. R. A.; Laughton, R. L. (Scottish Birds, 2004)
Winter surveys of Goosanders, Red-breasted Mergansers, Great Cormorants and Common Goldeneyes on the main stem of the River Spey were carried out in December 2002 and February 2003 using a novel survey methodology based on canoe counts. The River Spey holds nationally important wintering populations of Goosanders and Common Golden eyes, but not Red-breasted Mergansers or Great Cormorants. These data were compared with historical survey data, which demonstrated that wintering Goosander densities have remained stable on the River Spey between 1994 and 2003. Recommendations are made for future survey methods of Goosanders, Red-breasted Mergansers, Great Cormorants and Common Goldeneyes on the River Spey.
Keywords: Abundance, Distribution, and Trends; Nonbreeding Seasons; Bucephala clangula; Common Goldeneye; Common merganser; Mergus merganser

Food habits of North American diving ducks - Cottam, Clarence (U S Dept Agric Tech Bull, 1939)
To return to a satisfactory abundance the duck population, which has decreased alarmingly in recent years, owing in part to drought, reclamation, and overshooting, it is necessary effectively to apply principles of conservation and restoration. To do this, a knowledge of the food requirements of the species is requisite. This bulletin treats of the food habits of the 22 N. American diving ducks (exclusive of mergansers), which may be roughly segregated as inland divers and sea ducks. It is based both on field studies and on the analyses in the Food Habits Laboratory of the Biol. Survey of the stomach contents (including both gizzard and gullet) of 6,665 adults and 141 juveniles. For each species there is a summary of distribution, habits, and status, along with detailed data on food preferences. Food percentages were computed by the volumetric method. The inland divers include the redhead, ringneck, canvasback, greater and lesser scaups, ruddy duck, and the masked duck. With the exception of the greater scaup, which consumes nearly equal proportions of plant and animal food, all are predominantly vegetarians, feeding on tubers, underground rootstalks, seeds, and green vegetative fibers of many aquatic and marsh plants. The sea ducks include the American and Barrow's goldeneyes, bufflehead, old squaw, and harlequin duck; the eiders[long dash]Steller's northern, American, Pacific, king, and spectacled[long dash]and the scoters[long dash]white-winged, surf, and American. All of these are predominantly animal feeders. For the inland divers, few plants appear to be of outstanding value as food. Most important are the submerged pondweeds (Najadaceae), wild celery (Vallisneria spiralis), musk grass (Characeae), watershield (Brasenia schreberi), wild rice (Zizania aquatica), bulrushes (Scirpus), and smartweeds (Polygonum). The most important animal foods are mollusks and insects[long dash]particularly caddis fly and midge larvae, water bugs, and water beetles. A section of the bulletin treats of methods of propagating desirable duck foods. For the sea ducks, mollusks (mostly pelecypods, especially Mytilus edulis) were the most important food for 8 species, crustaceans for 4, and insects for 2. Fishes are acceptable to all the spp. treated but were consumed in small numbers, and the kinds taken are rarely of commercial or sporting importance. Within limits, availability is the most important factor governing food selection. When an acceptable food is found the adults often make their entire meal on a single or a related group of species. The young of most spp. fed principally upon animal foods, mainly insects, crustaceans, and small mollusks, although some juveniles showed a decided, though indiscriminate, preference for vegetable material. || ABSTRACT AUTHORS: C. Cottam
Keywords: Sea Ducks - General; Trophic Interactions

Third Census of Seabird Populations of the Gaspe Peninsula, Quebec, 2002 - Cotter, Richard; Rail, Jean-Francois (Canadian Field-Naturalist, 2007)
In the tradition of the quinquennial census of seabirds in the Migratory Bird Sanctuaries along Quebec's North Shore. which began in 1925, this paper presents the results of the first three seabird censuses of the Gaspe Peninsula conducted in 1979. 1989, and 2002, with an emphasis on the third census and on changes in seabird populations that occurred between the second and third censuses. In 1979 the population of seabirds was estimated at 134 163 birds, and this increased 72% to 23 1 186 birds in 1989. The upward trend in population continued in the 1990s but less sharply. The 2002 census recorded 279 276 birds, a 21% increase over the second census. The seabird community of the Gaspe Peninsula comprises 14 species. In each of the three censuses, three species accounted for over 75% of the total seabird population: Northern Gannet, Black-legged Kittiwake, and Common Murre. Between 1989 and 2002, Common Eider, Northern Gannet, Great Cormorant, Ring-billed Gull, Razorbill, and Black Guillemot increased in numbers. whereas Herring Gull, Black-legged Kittiwake. and Common Tern all suffered declines. Populations for Double-crested Cormorant, Great Black-backed Gull, and Common Murre all remained stable. Very small populations (<25 birds) of Leach's Storm-Petrel and Atlantic Puffin have been recorded during the censuses at only one location, Bonaventure Island. In the 2002 census there were no petrels observed, neither of adults nor of active burrows.
Keywords: Abundance, Distribution, and Trends; Sea Ducks - General; Common eider

A long-term study of the population dynamics of Common Eiders Somateria mollissima: why do several parameters fluctuate markedly? - Coulson, John C. (Bird Study, 2010)
Capsule The population dynamics of an Eider population has been studied from 1958 to 2006 to evaluate the causes of changes in abundance and breeding potential.Aims To evaluate the changes in clutch size, survival rate of adult ducks, the extent of non-breeding, and recruitment to the breeding population of Common Eiders nesting on Coquet Island, Northumberland.Methods Survival rates, recruitment and size of the population have been determined by an annual mark-recapture study, while the numbers of nests and clutch size have been directly recorded each year.Results There was marked annual variation in the number of ducks alive, their mortality rates, extent of non-breeding, clutch size and recruitment of adult ducks. Overall, the annual survival rate and clutch size decreased, and numbers of adult ducks, and presumably the population, peaked on two occasions.Conclusions No density-dependent effects were identified and the size of the population was mainly determined by changes in the adult survival rates. Because of non-breeding, nest counts were an unreliable measure of the population size. It is suggested that food shortage is the main factor that has produced the long-term changes in the population and there is an indication that adverse conditions for Eiders have extended over much of northern Europe in recent years. Identification of why the duckling survival rates were so low and whether these can be increased offers the most likely means of active conservation of this species and would involve management of feeding sites rather than breeding areas.
Keywords: Breeding Season; Common Eider; Somateria mollissima; Productivity; Population Dynamics; Survival

Age-related and Annual Variation in Mortality Rates of Adult Female Common Eiders (Somateria mollissima) - Coulson, J. C. (Waterbirds, 2013)
Times Cited: 0 Coulson, John C. 0
Keywords: survival; common eider; Breeding Season; Nonbreeding Seasons; Somateria mollissima

The invertebrate fauna of High Arctic seabird nests: the microarthropod community inhabiting nests on Spitsbergen, Svalbard - Coulson, S. J.; Moe, B.; Monson, F.; Gabrielsen, G. W. (Polar Biology, 2009)
The invertebrate fauna of the nests of three seabird species, black-legged kittiwakes (Rissa tridactyla), common eider (Somateria mollissima) and glaucous gull (Larus hyperboreus), were sampled in Kongsfjorden, Spitsbergen, Svalbard. The invertebrate community was species poor, consisting predominantly of the flea, Mioctenopsylla arctica arctica (Insecta: Siphonaptera), but with six species of oribatid mite (Acari: Oribatida), Diapterobates notatus, Oribatula tibialis, Ameronothrus lineatus, Hermannia reticulata, Trichoribates trimaculatus and Ceratoppia bipilis, plus an occasional mesostigmatid mite. No Collembola or ticks (Acari: Ixodidae) were observed. With the exception of M. arctica arctica, the fauna of seabird nests consisted of opportunistic microarthropod species rather than specialised nest-dwelling or bird parasitic species. Species diversity of soil oribatid mites was greater in nests of the common eider than compared to nests of the black-legged kittiwake, which may be related to the ground nesting behaviour of the common eiders. No rare or unusual microarthropod species for Svalbard were found in the seabird nests. The contentions that nests may facilitate microarthropod colonisation of High Arctic regions via bird phoresy by providing a high-quality habitat at the point of arrival, or that there might be a specialised microarthropod fauna exploiting this habitat, were not supported in this study. These are amongst the first data on the microarthropod community of seabird nests in the High Arctic.
Keywords: Breeding Season; Common Eider; Somateria mollissima

Immune parameters in different age classes of captive male Steller's eiders (Polysticta stelleri) - Counihan, K. L.; Hollmen, T. E. (DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY, 2018)
The immune system is important for host defense against antigens, but little is known about Steller's eider (Polysticta stelleri) immunology. This study compared hematological parameters, serum protein levels, lymphocyte proliferation, heat shock protein levels and oxidative damage in four different age classes of captive male Steller's eiders. The hatch year cohort had significantly higher total white blood cell and lymphocyte counts. The second year cohort had significantly higher albumin, alpha globulins and lymphocyte proliferation, and significantly lower beta globulin levels. The 9 year old males had a significantly higher IgY:IgY(Delta Fc) ratio. The oldest eiders in the study, 14 + year old males, had significantly higher serum IgY, pre-albumin and glutathione reductase activity, and the lowest lymphocyte proliferation. This study provided a baseline of immune parameters in captive male Steller's eiders, and the results suggested the parameters were influenced by age-related changes. (C) 2018 Elsevier Ltd. All rights reserved.
Times Cited in Web of Science Core Collection: 2 Total Times Cited: 2 Cited Reference Count: 28
Keywords: Oxidative damage; BIRDS; Steller's eider; Age; DUCK; HEALTH; IMMUNOGLOBULINS; Immunology; IMMUNOSENESCENCE; PHYSIOLOGY; PROTEINS; STRESS; SYSTEM; TRANSTHYRETIN

The influence of year, laying date, egg fertility and incubation, individual hen, hen age and mass and clutch size on maternal immunoglobulin Y concentration in captive Steller's and spectacled eider egg yolk - Counihan, K. L.; Maniscalco, J. M.; Bozza, M.; Hendon, J. M.; Hollmen, T. E. (Developmental and Comparative Immunology, 2015)
Steller's eiders and spectacled eiders are sea duck species whose populations have declined significantly and infectious diseases could influence offspring survival. Therefore, the maternal transfer of immunoglobulin Y (IgY) into yolk was investigated in captive Steller's and spectacled eiders during the 2007-2013 breeding seasons. This project had two objectives: establish baseline IgY levels in Steller's and spectacled eider yolk under controlled captive conditions and evaluate the effect of year, laying date, egg fertility, egg incubation duration, individual hen, hen age and mass, and laying order to determine which variables influenced IgY levels. Average IgY concentrations were 0.03-0.48 mg ml(-1) in Steller's eider yolk and 0.10-0.51 mg ml(-1) in spectacled eider yolk. The year and individual hen influenced IgY concentration in Steller's and spectacled eider yolk. The laying date was negatively correlated with egg IgY levels for most Steller's eider hens, but laying order was positively correlated with egg IgY concentration for spectacled eiders. (C) 2015 Elsevier Ltd. All rights reserved.
Counihan, Katrina L. Maniscalco, John M. Bozza, Maryann Hendon, Jill M. Hollmen, Tuula E.
Keywords: Breeding Season; Somateria fischeri; Spectacled Eider; Physiology; Polysticta stelleri; Steller’s Eider

Phylogenetic and pathogenic characterization of novel adenoviruses isolated from long-tailed ducks (Clangula hyemalis) - Counihan, K. L.; Skerratt, L. F.; Franson, J. C.; Hollmen, T. E. (Virology, 2015)
Novel adenoviruses were isolated from a long-tailed duck (Clangula hyemalis) mortality event near Prudhoe Bay, Alaska in 2000. The long-tailed duck adenovirus genome was approximately 27 kb. A 907 bp hexon gene segment was used to design primers specific for the long-tailed duck adenovirus. Nineteen isolates were phylogenetically characterized based on portions of their hexon gene and 12 were most closely related to Goose adenovirus A. The remaining 7 shared no hexon sequences with any known adenoviruses. Experimental infections of mallards with a long-tailed duck reference adenovirus caused mild lymphoid infiltration of the intestine and paint brush hemorrhages of the mucosa and dilation of the intestine. This study shows novel adenoviruses from long-tailed ducks are diverse and provides further evidence that they should be considered in cases of morbidity and mortality in sea ducks. Conserved and specific primers have been developed that will help screen sea ducks for adenoviral infections. (C) 2015 Elsevier Inc. All rights reserved.
Counihan, Katrina L. Skerratt, Lee F. Franson, J. Christian Hollmen, Tuula E.
Keywords: Clangula hyemalis; Long-tailed Duck; Disease

Differential Progression of Lymphoma in Two Captive Steller's Eiders (Polysticta stelleri) - Counihan, K. L.; Tuomi, P. A.; Hollmen, T. E. (JOURNAL OF AVIAN MEDICINE AND SURGERY, 2020)
This report details 2 different presentations of lymphoma in captive Steller's eiders (Polysticta stelleri). A female Steller's eider, at least 10 years old, developed lameness and lethargy. A complete blood cell count (CBC) revealed a severely elevated total white blood cell (WBC) count with a lymphocytosis. A subsequent liver biopsy confirmed a diagnosis of lymphoma and lymphocytic leukemia. The female Steller's eider was euthanatized 11 days after presentation. On necropsy, neoplastic lymphoid infiltrates were present in multiple tissues, primarily in the skin and subcutis. The results of a CBC from an apparently healthy male Steller's eider, at least 14 years old, also indicated this bird had an increased WBC count with a lymphocytosis. Serum submitted for protein electrophoresis indicated that this bird had a monoclonal gammopathy. Lymphocytes isolated from the male Steller's eider had low levels of proliferation in response to mitogens. The bird survived nearly 2 years without treatment, and the WBC count continued to increase during this time. The male Steller's eider maintained good body condition and exhibited normal behavior throughout the course of the disease until a sudden decline just prior to death. Lymphoma was diagnosed based on histopathology results. Infiltrates of atypical lymphocytes were observed in the bone marrow, proventriculus, ventriculus, heart, and eyes.
Times Cited in Web of Science Core Collection: 1 Total Times Cited: 1 Cited Reference Count: 10
Keywords: Polysticta stelleri; Steller's eider; avian; cataracts; gammopathy; lymphocytosis; lymphoma; lymphoproliferation

Factors affecting the pairing chronologies of three species of Mergansers in southwest British Columbia - Coupe, Malcolm; Cooke, Fred (Waterbirds, 1999)
Most Northern Hemisphere ducks form pairs on the wintering grounds, and timing of pairing varies considerably among species and populations. Hypotheses to explain variation in pairing chronology utilize sex-specific cost-benefit frameworks. These hypotheses have not been adequately tested, largely because of inadequate sample size of pairing chronologies, especially within the tribe Mergini. Wintering Common (Mergus merganser), Hooded (Lophodytes cucullatus), and Red-breasted mergansers (M. serratus) were observed at several sites in southwest British Columbia to determine pairing chronology. Courtship displays of Hooded Mergansers occurred significantly earlier than those of Red-breasted Mergansers. Hooded Mergansers began to pair in mid-November, Red-breasted Mergansers in early February, and Common Mergansers in late February. We tested the prediction that the largest species of ducks pair earliest. This could occur if females derive energetic benefits as a result of pairing, and females of larger species begin to accumulate endogenous nutrients earlier. It could also occur if pairing exerts an energetic cost on males, such that males of smaller species are more prone to winter mortality as a result of fluctuations in energy demand. The much earlier pairing of the smallest species (Hooded Mergansers) is inconsistent with either scenario. We suggest that between-species differences in pairing chronology may be better explained by the constraints imposed by sexual segregation during winter.
Keywords: Behavior; Nonbreeding Seasons; Common merganser; Mergus merganser; Mergus serrator; Red-breasted merganser; Hooded Merganser; Lophodytes cucullatus

Comparing waterfowl densities detected through helicopter and airplane sea duck surveys in Labrador, Canada - Cox, A. R.; Gilliland, S. G.; Reed, E. T.; Roy, C. (AVIAN CONSERVATION AND ECOLOGY, 2022)
Sea ducks are inadequately monitored because traditional waterfowl surveys omit most of their breeding range and may be conducted too early for these species which typically nest late in the season. The gap in monitoring is particularly concerning for scoters (genus Melanitta) because the limited available data suggest that the abundance across the three species of scoters in North America has declined since the 1980s. We conducted trial sea duck surveys in central Labrador, Newfoundland, and Labrador, Canada, using both helicopter plot and fixed-wing line-transect surveys (10-19 June and 17-19 June 2009, respectively) to assess the feasibility of conducting specialized surveys for late-nesting waterfowl during the scoter breeding season. We present the results of the fixed-wing line-transect component, which we analyzed in a distance-sampling hierarchical framework to calculate and correct for imperfect detection. We found that the breeding density of Black (Melanitta americana), Surf (Melanitta perspicillata), and White-winged (Melanitta deglandi) Scoters combined was 0.15 (90% credible interval: 0.12-0.18) indicating breeding pairs per km', one of the highest breeding densities of any waterfowl species in the area at this time. Estimates of waterfowl density approximately doubled for all species after accounting for detection because observers only detected between 20% to 40% of all groups depending on the species or genus. Though there was a slight male bias in the sex ratios, groups observed were two individuals (i.e., a breeding pair), suggesting that timing the survey in mid-June captured the breeding window for sea ducks. Despite correcting for detection, breeding densities estimated by the fixed-wing transect component of the survey remained substantially lower than those estimated from the previously published helicopter component, suggesting there were differences in availability bias between the two survey platforms.
Times Cited in Web of Science Core Collection: 0 Total Times Cited: 0 Cited Reference Count: 33
Keywords: scoter; ABUNDANCE; SIZE; SCOTERS; sea duck; AERIAL; distance detection; waterfowl survey

Red-breasted Merganser (Mergus serrator) - Craik, Shawn, John Pearce and Rodger D. Titman (The Birds of North America, 2015)
Keywords: Mergus serrator; Red-breasted Merganser

Potential Impacts of Storm Surges and Sea-level Rise on Nesting Habitat of Red-breasted Mergansers (Mergus serrator) on Barrier Islands in New Brunswick, Canada - Craik, S. R.; Hanson, A. R.; Titman, R. D.; Mahoney, M. L.; Tremblay, E. (Waterbirds, 2015)
Predicted sea-level rise and increases in the frequency and magnitude of storm surges are potential threats to waterbird nests and associated breeding habitat on low-lying landforms, such as barrier islands. Sea-level rise in Northumberland Strait of eastern Canada, predicted to rise by at least 0.50-0.60 m by 2100, could permanently flood large tracts of barrier island habitat. Potential impacts of higher sea levels on breeding habitat of Red-breasted Mergansers (Mergus serrator) were studied on three barrier islands at Kouchibouguac National Park, New Brunswick, Canada. Objectives of the study were to: 1) identify the range of dates for which nests (n = 189) were active and thus vulnerable to flooding; 2) determine elevation and distance to water for each nest; 3) examine whether birds selected nest sites that were relatively elevated and far from water; and 4) estimate the proportion of nests that could be flooded under four plausible sea-level rise and storm surge scenarios. Peak nesting occurred during mid-June to mid-July. Red-breasted Mergansers generally sought elevated regions with beach grasses for nest placement. Nearly 50% of nests were < 2 m above mean sea level. Nest elevations were greater than a conservative estimate of sea-level rise of 0.60 m. However, = 50% of these nests are predicted to be flooded during a high spring tide if sea levels are 0.60 m greater, and these impacts would be exacerbated when phased with a storm surge. A predicted surge of 2.55 m above mean sea level would inundate 90% of nests on the islands. Results indicate that predicted sea-level rise for Northumberland Strait over the next century threatens the habitat and survival of waterbird nests on barrier islands, particularly if there is little accretion to the islands during this period. Accordingly, rates of sediment accretion or erosion on the Tern Islands should be monitored closely as sea levels continue to rise.
Craik, Shawn R. Hanson, Alan R. Titman, Rodger D. Mahoney, Matthew L. Tremblay, Eric
Keywords: Conservation; Breeding Season; Habitat; Mergus serrator; Red-breasted Merganser

Wing and Body Molts of Male Red-Breasted Mergansers in the Gulf of St. Lawrence, Canada - Craik, Shawn R.; Savard, Jean-Pierre L.; Titman, Rodger D. (Condor, 2009)
Little is known of the chronology of wing molt and the intensity of body molt among flightless Red-breasted Mergansers (Mergus serrator) in North America. We examined molt of 39 postbreeding males collected at Anticosti Island, Quebec, Canada, from July to September 2005 and 2006. We estimated that birds were flightless for 30-33 days. Nearly 75% of males initiated the flightless period between 20 July and 3 August, and >90% were flightless from 8 to 25 August. Subadult males became flightless slightly earlier ((x) over bar = 28 July; n = 7) than adult males (a = 1 August; n = 28). Most of the head and neck attained the cryptic alternate plumage before remiges were lost, consistent with observations at a neat-by breeding site in eastern New Brunswick, where >75% of adult males were undergoing prealternate molt on the head region by late June. Molt intensities declined on the side, collar, and back and increased on the belly and tail throughout the period of flightlessness. Greater coverts generally molted in synchrony with new flight feathers, and most median and lesser coverts initiated replacement within 10 days of loss of remiges. This study provides evidence that the prealternate molt functions effectively to replace bright upperpart feathers with cryptic plumage prior to the flightless period. We suggest that the staggered pattern of molt among feather regions may minimize nutritional and energetic demands associated with feather replacement and changes in plumage insulation among flightless male Red-breasted Mergansers in the upper Gulf of St. Lawrence.
Keywords: Nonbreeding Seasons; Molt; Mergus serrator; Red-breasted merganser

Foraging Ecology of Flightless Male Red-breasted Mergansers in the Gulf of St. Lawrence, Canada - Craik, S. R.; Savard, J. P. L.; Richardson, M. J.; Titman, R. D. (Waterbirds, 2011)
Times Cited: 2 Craik, Shawn R. Savard, Jean-Pierre L. Richardson, Michael J. Titman, Rodger D. 2
Keywords: Nonbreeding Seasons; Trophic Interactions; Mergus serrator; Red-breasted merganser; molt

Movements and Habitat Use by Red-Breasted Merganser Broods in Eastern New Brunswick - Craik, Shawn R.; Titman, Rodger D. (Wilson Journal of Ornithology, 2008)
Red-breasted Mergansers (Mergus serrator) commonly breed in estuaries, but little is known about their brood-rearing in coastal environments. We measured daily movements and habitat use of radio-marked (n = 17) female Red-breasted Mergansers with broods originating from coastal barrier islands at Kouchibouguac National Park, New Brunswick, Canada from 2002 to 2004. primary brood movements from nest sites to initial rearing areas were often extensive, averaging 3.5 km (it = 15), since many brood,; crossed Saint-Louis Lagoon to continental rearing sites. Broods remained mobile throughout the rearing period and there was little difference in daily movements between age class I (days 1-10 post nest exodus), Class II (days 11-20), and class III (> 20 days) broods. Broods frequented shallow ((x) over bar = 51 cm, 95% CI: 44-58 cm, n = 191 locations), nearshore ((x) over bar = 47 in, 95% CI: 33-60 n = 157 locations) waters that often supported submergent eel grass (Zostera marina). Broods selected estuarine intertidal regions in Saint-Louis and Kouchibouguac lagoons, as well as wetlands at the mouths of tidal streams. Few broods Were found in tidal river and marine habitats. Continental estuarine intertidal, tidal stream, and saltmarsh habitats were preferred by age class I broods whereas estuarine intertidal and subtidal habitats were preferred by age classes II and III. This study highlights the importance Of estuarine habitats in lagoons and tidal streams for brood-rearing Red-breasted Mergansers in eastern New Brunswick.
Keywords: Breeding Season; Dispersal; Habitat; Mergus serrator; Red-breasted merganser

Nesting Ecology of Red-breasted Mergansers in a Common Tern Colony in Eastern New Brunswick - Craik, Shawn R.; Titman, Rodger D. (Waterbirds, 2009)
Nest-site selection and nest success for Red-breasted Mergansers (Mergus senator) breeding on a barrier island complex (Tern Islands) with >10,000 Common Terns (Sterna hirundo) in eastern New Brunswick, Canada, were studied in 2005 and 2006. Concealment was the most important feature for nest placement as 153 of 156 nests were in dense stands of Marram Grass (Ammophila breviligulata), and overhead concealment, vegetation density and vegetation height were all greater at nests than at random locations. Apparent. success for all nests was 57% and was similar between years. Few nests were depreciated (N = 3), but abandonment was responsible for 95% of nest losses and was most common early in the season. Nest success was <45% for nests initiated before 25 May but >75% for nests initiated after 10 June. Nest. abandonment was influenced by intraspecific nest parasitism and investigator activity. Red-breasted Mergansers selected nest sites adaptively on Tern Islands because: 1) nests were more concealed than random sites; 2) avian predation at nests in the Common Tern colony was lower than at nests on nearby islands without terns; 3) nests were not exposed to mammalian predators; and 4) nest success and nest densities were high.
Keywords: Breeding Season; Productivity; Habitat; Mergus serrator; Red-breasted merganser

Host traits and lifetime fitness costs of being parasitized in red-breasted mergansers - Craik, S. R.; Titman, R. D.; Calvert, A. M.; Robertson, G. J.; Mallory, M. L.; Gutowsky, S. E. (FACETS, 2021)
The addition of eggs to a nest by a conspecific is known for approximately 250 bird species. Understanding the evolution of conspecific brood parasitism (CBP) requires assessment of fitness consequences to the egg recipient (host). We addressed host traits and the effects of CBP on future reproduction (i.e., annual survival) and hatching success of hosts by following the nesting of 206 red-breasted mergansers (Mergus serrator) for a colony in which an average of 41% of nests was parasitized annually. Each host was tracked for >= 2 seasons and up to seven seasons. The proportion of a host's nesting attempts that was parasitized averaged 43% and varied considerably across individuals (range 0%-100%). Probability of parasitism, however, was not repeatable across a host's nests. Rather, rates of CBP throughout a host's lifetime increased with earlier dates of nest initiation. CBP had no effect on annual survival of a host. Hatching success throughout a host's lifetime declined with a greater number of foreign eggs added to the individual's nests. This study revealed that there may be measurable costs of CBP to lifetime reproductive success in red-breasted mergansers, although our observations suggest that costs to hosts are limited to the most heavily parasitized clutches.
Times Cited in Web of Science Core Collection: 0 Total Times Cited: 0 Cited Reference Count: 85
Keywords: conspecific brood parasitism; INTRASPECIFIC NEST PARASITISM; Mergus serrator; SURVIVAL; SELECTION; SIZE; BUCEPHALA-CLANGULA; alternative reproductive strategies; annual survival; date of nest initiation; hatching success; HIGH-RATES; INCUBATION; red-breasted merganser; REPRODUCTIVE SUCCESS; WOOD DUCKS

Costs and response to conspecific brood parasitism by colonial red-breasted mergansers - Craik, S. R.; Titman, R. D.; Savard, J. P. L.; Kaouass, M.; Thimot, N.; Elliott, K. H.; Tremblay, E. (JOURNAL OF ETHOLOGY, 2018)
Costs of conspecific brood parasitism (CBP) are expected to be influenced by a species' life history traits. Precocial birds lay large clutches, and clutches that have been enlarged by CBP can affect host fitness through a longer incubation period, displaced eggs, and lower hatching success. We examined costs and response to CBP by hosts in a population of colonial red-breasted mergansers (Mergus serrator; n=400 nests over 8years) within which 29% of parasitized clutches were enlarged considerably (15 eggs). Length of the incubation period did not increase with clutch size. The mean number of eggs displaced from a parasitized nest during incubation (2.8) was 2xgreater than at an unparasitized nest (1.4). Hatching success declined by 2% for each additional egg in the nest. Thus, for a nest with15 eggs, one or more fewer host eggs hatch relative to an unparasitized nest with the same number of host eggs, assuming equal probability of success for all eggs. Hosts were 40% more likely to desert nests receiving 2 or 6 experimental eggs relative to unparasitized control nests, although it is unknown whether hens deserting a nest renested elsewhere. Our study indicates that costs of CBP to hosts during nesting may be limited to those red-breasted mergansers incubating the largest clutches (15 eggs), and it raises questions about the adaptive significance of deserting a parasitized clutch.
Times Cited in Web of Science Core Collection: 5 Total Times Cited: 5 Cited Reference Count: 41
Keywords: BIRDS; INTRASPECIFIC NEST PARASITISM; Mergus serrator; Red-breasted merganser; DUCKS; ECOLOGY; EVOLUTION; EGGS; Breeding behavior; Colonial nesting; Conspecific brood parasitism; Fitness costs; FREQUENCY; HOST; RECOGNITION

Does blood sampling during incubation induce nest desertion in the female Common Eider Somateria mollissima? - Criscuolo, Francois (Marine Ornithology, 2001)
The Common Eider Somateria mollissima is an appropriate species with which to study the physiology of fasting during reproduction, and particularly to follow how individual females incubate in natural conditions. However, it usually relies on invasive techniques including bird capture and blood sampling. Consequently, disturbance of birds can induce unusual behaviour and lead to nest desertion and spurious results. This note describes the effect of capture and blood sampling on incubating female eiders from Spitzbergen. Female eiders were either caught and bled or simply flushed from their nests. We found that nest desertion was linked with treatment and with the date of incubation. Birds were more likely to desert their nests when handled at the beginning of incubation. By contrast, no effect of disturbance (without capture) was detected. We suggest that capture of incubating eiders should be avoided during the critical initial incubation period.
Keywords: Breeding Season; Common Eider; Somateria mollissima; Techniques

Corticosterone alone does not trigger a short term behavioural shift in incubating female common eiders Somateria mollissima, but does modify long term reproductive success - Criscuolo, Francois; Chastel, Olivier; Bertile, Fabrice; Gabrielsen, Geir Wing; Le Maho, Yvon; Raclot, Thierry (Journal of Avian Biology, 2005)
The trade-off between reproductive effort and adult survival in birds is modulated by several factors. Corticosterone and prolactin have additive effects on reproductive behaviour by stimulating foraging and parental behaviours, respectively. When incubation is associated with fasting, nest desertion is supposed to be activated by an unknown refeeding signal when body condition becomes critically deteriorated. The concomitant rise in corticosterone levels has been suggested to be the triggering factor. We tested the role of corticosterone on reproductive success by observing the effect of corticosterone implants on reproductive success and on plasma prolactin concentration in female common eiders Somateria mollissima. Implanted females showed a significant increase in corticosterone and a decrease in prolactin levels. Despite their enhanced daily body mass loss, females did not abandon incubation nor did they start to refeed in the four days following implantation. These data show that the experimentally induced rise in plasma corticosterone concentration alone does not trigger nest desertion. However, after 25 days of incubation, implanted females displayed a higher rate of egg loss, suggesting lower nest attentiveness towards the end of incubation. We suggest that the short-term effects of corticosterone may be dependent on the energy state of the bird. However, the late-induced change in reproductive success is indirectly linked to corticosterone, and we suggest that either a prolactin decrease, or a depletion in protein body reserves, may participate in the long-term adjustment of incubation behaviour in female eiders.
Keywords: Breeding Season; Common Eider; Somateria mollissima; Productivity; Physiology

Factors affecting plasma concentrations of prolactin in the common eider Somateria mollissima - Criscuolo, Francois; Chastel, Olivier; Gabrielsen, Geir Wing; Lacroix, Andre; Le Maho, Yvon (General and Comparative Endocrinology, 2002)
In the common eider only the females incubate while they fast for 25 days. Thus, since they rely entirely on their body reserves for successful incubation, they can be defined as capital incubators. To assess the potential effects of their initial body mass, the incubation duration, and depletion in body reserves on prolactinemia, blood samples of eiders were analyzed during the breeding cycle and an experimental manipulation of the duration of incubation. Levels of circulating prolactin increased at the onset of incubation and then reached a high and stable level during incubation before increasing sharply before hatching. The prolactin level decreased significantly upon hatching. Captive females deprived from their eggs exhibited a rapid decrease in prolactinemia, suggesting that egg stimuli are necessary to prolactin secretion. Aunts, i.e., helper females caring for conspecific young, presented prolactin levels higher than nonbreeding captive females but not significantly different from those of females at hatching. Plasma prolactin at hatch was directly related to body mass loss. Birds with shortened incubation have higher body masses and showed higher levels of prolactinemia at hatching than the control group, in accordance with the idea that circulant prolactin at hatching is linked to body condition. Females which underwent an extended incubation (and started to eat again) displayed a low body mass and a high prolactinemia. These data therefore suggest that refeeding, albeit increasing the risk of predation, enhances prolactin secretion and allows the bird to continue incubation despite that it has reached a poor body condition.
Keywords: Breeding Season; Common Eider; Somateria mollissima; Physiology

Body mass regulation during incubation in female common eiders Somateria mollissima - Criscuolo, Francois; Gabrielsen, Geir W.; Gendner, Jean-Paul; Le Maho, Yvon (Journal of Avian Biology, 2002)
We investigated changes in incubation behaviour induced by body fuel depletion in incubating female common eiders, which, in contrast to pelagic seabirds, fast despite being close to marine food sources. In the Svalbard Archipelago, electronic scales were placed under eider nests and the incubation of six birds was prolonged by using wax-filled eggs. Based on changes in the rate of body mass loss in normally incubating females and in ten captive birds that did not incubate, body reserves neared depletion on average four days after hatching. During prolonged incubation, females took more frequent and longer recesses. Nest attentiveness consequently decreased, but was still high. In contrast to recesses during normal incubation, during which body mass of the birds decreased, mass remained constant during the recesses of prolonged incubation. The body stores of female eiders seemed to enable them to complete incubation with a limited safety margin. A further drop in body mass is avoided when a critical body mass is reached, because birds then start feeding enough to maintain mass while continuing incubation. Presumably, a similar mechanism will enable eiders to continue incubation when body reserves are prematurely depleted before hatching.
Keywords: Behavior; Breeding Season; Common Eider; Somateria mollissima; Energetics and Nutrition

An automatic weighing system application in a study of the Common Eider Somateria mollissima breeding biology - Criscuolo, Francois; Gabrielsen, Geir Wing; Gendner, Jean-Paul; Yvon, Le Maho (Alauda, 2000)
Keywords: Breeding Season; Common Eider; Somateria mollissima; Techniques

Recess behaviour of the incubating Common Eider Somateria mollissima - Criscuolo, Francois; Gauthier-Clerc, Michel; Gabrielsen, Geir Wing; Maho, Yvon Le (Polar Biology, 2000)
Female eiders show the highest incubation constancy among ducks. However, detailed data on their behaviour during the short recesses were not available. In this study, activities during recesses were observed in a colony of female eiders breeding in the high arctic to define what the principal purposes of these temporary nest desertions are. Incubating eiders do not feed during their recess periods. Drinking salt or fresh water or eating snow (28.7%) and preening (38.0%) were the two main activities observed. After snow melting, the time spent drinking decreased (14.3%) while the time spent preening was unchanged (38.1%). Moreover, despite the fact that females started to fly longer distances to reach fresh water sources, the recess duration did not change significantly (401.5 vs 431.0 s). Since recess during incubation increases the risk of breeding failure, drinking presumably has an important survival value for female eiders. In this context, our data suggest that searching for fresh water at a greater distance is favoured despite the higher energetic cost for a fasting bird.
Keywords: Behavior; Breeding Season; Common Eider; Somateria mollissima

Brood patch temperature during provocation of incubating common eiders in Ny-Alesund, Svalbard - Criscuolo, Francois; Gauthier-Clerc, Michel; Le Maho, Yvon; Gabrielsen, Geir W. (Polar Research, 2001)
In this short note we describe the behaviour and body temperature changes of three incubating female common eiders (Somateria mollissima) during provocation made by humans approaching the nest. The study site was near the settlement of Ny-Alesund, Svalbard. Temperature transmitters were implanted subcutaneously at the brood patch and data recorded using a VHF receiver. We found that the female eiders in the experiment exhibited a passive defence response ("freezing"), accompanied by a significant drop in brood patch temperature (0.6 degreeC) during provocation; this temperature drop lasted for 5 minutes. These results accord with other studies of the physiological changes which accompany the passive defence response in birds and other animals.
Keywords: Behavior; Breeding Season; Common Eider; Somateria mollissima; Physiology

Sleep changes during long-term fasting in the incubating female Common Eider Somateria mollissima - Criscuolo, Francois; Gauthier-Clerc, Michel; Le Maho, Yvon; Zorn, Thierry; Gabrielsen, Geir Wing (Ardea, 2001)
In the present study we have made observations of eye closure duration of Common Eider Somateria mollissima in the field, to determine the amount of time devoted to sleep during the incubation period, both in breeding and non-breeding females. Breeding females started to incubate with a higher level of vigilance than non-breeding females, and increased progressively the duration of sleep over the course of incubation. At the end of the incubation period, breeding females reached a sleep time comparable to that of the non-breeding females. The data are in accordance with the hypothesis that sleep time could be modified in relation to the deterioration of body condition. Accordingly, we suggest that sleep might play a key role in saving energy when the birds experience a prolonged negative energy balance. Consequently, since female eiders can be threatened by terrestrial predators during incubation, they would therefore have to found a compromise between energy conservation while sleeping and maintenance of a threshold vigilance. Incubating female eiders could thus face conflicting priorities during incubation: that is sleeping to save energy and wakefulness for predator detection.
Keywords: Behavior; Breeding Season; Common Eider; Somateria mollissima

Do T3 levels in incubating eiders reflect the cost of incubation among clutch sizes? - Criscuolo, Francois; Raclot, Thierry; Le Maho, Yvon; Gabrielsen, Geir Wing (Physiological and Biochemical Zoology, 2003)
Complete development of avian eggs requires external heat, inducing in most species an energetic cost of incubation for the parents. Triiodothyronine (T3) has been implicated in the control of the metabolic rate and is decreased during fasting in most bird species. This raises the question of the regulation of T3 during reproduction when incubation (thus heat production) is associated with fasting (and energy sparing). In this study, plasma concentrations of T3 were studied for different clutch sizes in incubating, as well as in nonincubating, fasting female eiders. Our results show that the T3 levels decrease during fasting in nonincubating birds, whereas they were maintained during the incubation fast. T3 levels increased in female eiders at hatching. The plasma T3 level did not vary among natural clutch sizes in eiders but did so when manipulated. T3 levels increased when eggs were added (to a maximum of six eggs, i.e., the biggest natural clutch size) or removed (to two eggs, i.e., the smallest natural clutch size). Our results suggest that (1) high T3 levels during incubation may participate to a threshold of heat production and incubation metabolic rate in eiders despite the fact that they are fasting; (2) since T3 is associated with the energy expenditure in birds, incubating an enlarged or reduced clutch size may lead to a higher energetic cost of incubation in eiders; and (3) the energy demand of the ducklings at hatching is probably important, as the female T3 concentrations are then at their highest levels. Thus, any modification of the natural clutch size leads to a rise in the T3 level of the incubating female, suggesting an additional cost of incubation. Knowing that there is no variation of T3 levels among natural clutch sizes, this study suggests that a female eider produces a number of eggs corresponding to the energy she can invest in incubation.
Keywords: Breeding Season; Common Eider; Somateria mollissima; Physiology

A comparison of auditory brainstem responses across diving bird species - Crowell, S. E.; Wells-Berlin, A. M.; Carr, C. E.; Olsen, G. H.; Therrien, R. E.; Yannuzzi, S. E.; Ketten, D. R. (Journal of Comparative Physiology a-Neuroethology Sensory Neural and Behavioral Physiology, 2015)
There is little biological data available for diving birds because many live in hard-to-study, remote habitats. Only one species of diving bird, the black-footed penguin (Spheniscus demersus), has been studied in respect to auditory capabilities (Wever et al., Proc Natl Acad Sci USA 63:676-680, 1969). We, therefore, measured in-air auditory threshold in ten species of diving birds, using the auditory brainstem response (ABR). The average audiogram obtained for each species followed the U-shape typical of birds and many other animals. All species tested shared a common region of the greatest sensitivity, from 1000 to 3000 Hz, although audiograms differed significantly across species. Thresholds of all duck species tested were more similar to each other than to the two non-duck species tested. The red-throated loon (Gavia stellata) and northern gannet (Morus bassanus) exhibited the highest thresholds while the lowest thresholds belonged to the duck species, specifically the lesser scaup (Aythya affinis) and ruddy duck (Oxyura jamaicensis). Vocalization parameters were also measured for each species, and showed that with the exception of the common eider (Somateria mollisima), the peak frequency, i.e., frequency at the greatest intensity, of all species' vocalizations measured here fell between 1000 and 3000 Hz, matching the bandwidth of the most sensitive hearing range.
Crowell, Sara E. Wells-Berlin, Alicia M. Carr, Catherine E. Olsen, Glenn H. Therrien, Ronald E. Yannuzzi, Sally E. Ketten, Darlene R.
Keywords: Common Eider; Melanitta fusca; White-winged Scoter; Melanitta perspicillata; Surf Scoter; Histrionicus histrionicus; Clangula hyemalis; Long-tailed Duck; Somateria mollissima; Physiology; Black Scoter; Melanitta americana; Harlequin Duck

Eastern Canada Flocks: images and manually annotated bird positions - Cruz, M.; Gonzalez-Villa, J.; Lefebvre, J.; Gilliland, S.; St-Pierre, F.; English, M.; Lepage, C. (ECOLOGY, 2021)
The Eastern Canada (ECA) Flocks data set consists of manually annotated images from the Common Eider (COEI, Somateria mollissima) Winter Survey and the Greater Snow Geese (GSGO, Anser caerulescens atlanticus) Spring Survey. The images were taken in eastern Canada using fixed-wing aircraft and manually annotated with ImageJ's Cell counter plugins. We selected and annotated the ECA Flocks images in order to test the precision of the CountEm flock size estimation method. ECA Flocks includes 179 COEI and 99 GSGO single flock images. We cut each image manually to a rectangle that excluded large parts of the image with no birds. Both versions (original and cut) of each image are available in the data set. We manually annotated 637,555 (124,309 COEI and 514,235 GSGO) bird positions in the cut images from both surveys. Each bird has an associated "Type," which refers to species and/or sex. Sex identification was only possible for adult common eiders, because females and immature males are brown birds, whereas adult males have mainly white plumage. In the COEI images 64,484 males and 58,029 females, as well as 1,796 birds of other species, were identified. In the GSGO images 504,891 Snow Geese and 9,344 birds of other species were labeled. A .csv file including all annotated bird positions and types is available for each image. The COEI and GSGO photos of the ECA Flocks data set were taken in the years 2006 and 2018 and 2016-2018, respectively. We selected these photos in order to include images with different quality and resolution. COEI and GSGO flock sizes range from 6 to 4,154 and from 43 to 36,241 respectively. There is high variability in light conditions, backgrounds, and number and spatial arrangement of birds across the images. The data set is therefore potentially useful to test the precision of methods for analyzing imagery to estimate the abundance of animals by directly detecting, identifying, and counting individuals. We release these data into the public domain under a Creative Commons Zero license waiver. When you use the data in your publication, cite this data paper. Should ECA Flocks be a major part of the data analyzed in your study, you should consider inviting the ECA Flocks originators as collaborators. If you plan to use the ECA Flocks data set, we request that you contact the ECA Flocks core team to learn whether updates are available, and whether similar analyses are already ongoing.
Times Cited in Web of Science Core Collection: 1 Total Times Cited: 1 Cited Reference Count: 0
Keywords: common eider; Eastern Canada; computer vision; ecology; flock size; greater snow goose; image analysis; population size; segmentation; stereology; wildlife management

Food habits of diving ducks the in the Great Lakes after the zebra mussel invasion - Custer, Christine M.; Custer, Thomas W. (Journal of Field Ornithology, 1996)
Zebra mussels (Dreissena polymorpha) invaded the Great Lakes in the mid-1980s and quickly reached high densities. The objective of this study was to determine current consumption of zebra mussels by waterfowl in the Great Lakes region. Feeding Lesser Scaups (Aythya affinis), Greater Scaups (A. marila), Canvasbacks (A. valisineria), Redheads (A. americana), Buffleheads (Bucephala albeola) and Common Goldeneyes (B. clangula) were collected in western Lake Erie and in Lake St. Clair between fall and spring, 1992-1993 to determine food habits. All 10 Redheads, 97% of Lesser Scaups, 83% of Goldeneyes, 60% of Buffleheads and 9% of Canvasbacks contained one or more zebra mussels in their upper gastrointestinal tracts. The aggregate percent of zebra mussels in the diet of Lesser Scaups was higher in Lake Erie (98.6%) than in Lake St. Clair (54.4%). Zebra mussels (aggregate percent) dominated the diet of Common Goldeneyes (79.2%) but not in Buffleheads (23.5%), Redheads (21 %) or Canvasbacks (9%). Lesser Scaups from Lake Erie fed on larger zebra mussels ( hivin x = 10.7 +- 0.66 mm SE) than did Lesser Scaups from Lake St. Clair ( hivin x = 4.4 +- 0.22 mm). Lesser Scaups, Buffleheads and Common Goldeneyes from Lake Erie consumed zebra mussels of similar size.
Keywords: Nonbreeding Seasons; Bucephala clangula; Common Goldeneye; Trophic Interactions; Bucephala albeola; Bufflehead

Organochlorine trace element contamination in wintering migrating diving ducks in the southern Great Lakes, USA, since the zebra mussel invasion - Custer, Christine M.; Custer, Thomas W. (Environmental Toxicology and Chemistry, 2000)
Because of the potential for increased trophic transfer of contaminants by zebra mussels (Dreissena sp.) to higher trophic levels, we collected four species of waterfowl (n=65 ducks) from four locations in Lake Erie, Lake St. Clair, and Lake Michigan, USA, between 1991 and 1993 for organochlorine contaminant and trace element analyses. Geometric mean concentrations of total polychlorinated biphenyls (PCBs) and p,p'-dichlorodiphenyldichloroethylene (DDE) were 1.35 and 0.15 mug/g wet weight in lesser scaup (Aythya affinis) carcasses and were below known effect levels. Total PCBs in 80% of carcasses, however, were above the U.S. Food and Drug Administration's threshold of 3.0 mug/g lipid weight for consumption of poultry. With the exception of selenium, trace elements were also at background or no-effect levels. Selenium concentrations in livers of 95% of lesser scaup, 90% of bufflehead (Bucephala albeola), and 72% of common goldeneye (Bucephala clangula) were in the elevated (>10 mug/g dry wt) or potentially harmful range (>33 mug/g dry wt). The effects of these high selenium concentrations are unknown but should be investigated further based on reproductive effects observed in field and laboratory studies of dabbling ducks and because lesser scaup populations are declining. Concentrations of total PCBs in dreissenid mussels in western Lake Erie were 10 times higher than in the upper Mississippi River but were similar to concentrations in other industrialized rivers in Europe and the United States. Metal concentrations were similar to other industrialized sites where zebra mussels have been sampled.
Keywords: Nonbreeding Seasons; Bucephala clangula; Common Goldeneye; Contaminants; Bucephala albeola; Bufflehead

Dioxins and congener-specific polychlorinated biphenyls in three avian species from the Wisconsin River, Wisconsin - Custer, T. W.; Custer, C. M.; Hines, R. K. (Environmental Pollution, 2002)
Sediments from the Wisconsin River, WI, USA are contaminated with 2,3,7,8-tetrachloro-p-dioxin (TCDD) and polychlorinated biphenyls (PCBs). Wet weight concentrations of TCDD and PCBs in eggs were at background levels and highest in the piscivorous hooded merganser (Lophodytes cucullatus; geometric mean = 7 pg/g TCDD and 0.92 mug/g PCBs) and lowest in the omnivorous wood duck (Aix sponsa) (< 1 pg/g and 0.07 mug/g); concentrations in eggs of the insectivorous tree swallow (Tachycineta bicolor) were intermediate (< 1 pg/g and 0.33 mug/g). Positive accumulation rates of TCDD (8-19 pg/day) and PCBs (0.4-0.7 mug/day) in tree swallow nestlings suggest that the Wisconsin River is the source of these contaminants for tree swallow nestlings. The lower representation of trichlorobiphenyls and tetrachorobiphenyls in hooded merganser eggs compared to wood duck or tree swallow eggs suggests that the hooded merganser or its diet has a greater ability to metabolize lower-numbered PCB congeners than wood ducks or tree swallows.
Keywords: Breeding Season; Contaminants; Hooded Merganser; Lophodytes cucullatus

Contributions of feather microstructure to eider down insulation properties - D'Alba, L.; Carlsen, T. H.; Asgeirsson, A.; Shawkey, M. D.; Jonsson, J. E. (JOURNAL OF AVIAN BIOLOGY, 2017)
Insulation is an essential component of nest structure that helps provide incubation requirements for birds. Many species of waterfowl breed in high latitudes where rapid heat loss can necessitate a high energetic input from parents and use down feathers to line their nests. Common eider Somateria mollissima nest down has exceptional insulating properties but the microstructural mechanisms behind the feather properties have not been thoroughly examined. Here, we hypothesized that insulating properties of nest down are correlated to down feather (plumule) microstructure. We tested the thermal efficiency (fill power) and cohesion of plumules from nests of two Icelandic colonies of wild common eiders and compared them to properties of plumules of wild greylag goose Anser anser. We then used electron microscopy to examine the morphological basis of feather insulating properties. We found that greylag goose down has higher fill power (i.e. traps more air) but much lower cohesion (i.e. less prone to stick together) compared to common eider down. These differences were related to interspecific variation in feather microstructure. Down cohesion increased with the number of barbule microstructures (prongs) that create strong points of contact among feathers. Eider down feathers also had longer barbules than greylag goose down feathers, likely increasing their air-trapping capacity. Feather properties of these two species might reflect the demands of their contrasting evolutionary history. In greylag goose, a temperate, terrestrial species, plumule microstructure may optimize heat trapping. In common eiders, a diving duck that nests in arctic and subarctic waters, plumule structure may have evolved to maximize cohesion over thermal insulation, which would both reduce buoyancy during their foraging dives and enable nest down to withstand strong arctic winds.
Times Cited in Web of Science Core Collection: 10 Total Times Cited: 11 Cited Reference Count: 47
Keywords: FIBER; NEST SHELTER

The role of nest site and structure in incubation performance in the Common Eider - D'Alba, L.; Monaghan, P.; Nager, R. (Journal of Ornithology, 2006)
Keywords: Breeding Season; Common Eider; Somateria mollissima; Productivity; Habitat

Thermal benefits of nest shelter for incubating female eiders - D'Alba, L.; Monaghan, P.; Nager, R. G. (Journal of Thermal Biology, 2009)
1. In species that actively maintain optimal conditions for offspring development, the quality of the breeding site may have a substantial effect on reproductive effort and breeding success. Here, we studied the effect of nest shelter on reproductive costs for incubating female common eiders (Somateria mollissima) nesting in an arctic environment using both a correlative and an experimental approach.2. The correlative data showed that females that nested in naturally well-sheltered nests experienced milder temperatures, laid larger clutches, provided a more favourable thermal environment for their eggs and had a higher hatching success than those at exposed nest-sites.3. We added artificial shelters to exposed nest-sites and compared them to unmanipulated exposed nest-sites to examine the effect of nest shelter in females of similar quality. Costs of nesting in exposed sites were greater as evidenced by the reduced female mass loss and more favourable thermal conditions for the eggs at artificially sheltered nest-sites relative to exposed nest-sites. However, there was no difference in hatchings success between artificially sheltered and exposed nest-sites.4. This study shows even small changes in the climatic conditions at the nest-site can have substantial consequences for reproductive effort, but the association between nest-site quality and breeding success in eiders is due to better quality individuals occupying better nest-sites. (C) 2008 Elsevier Ltd. All rights reserved.
Keywords: Breeding Season; Common Eider; Somateria mollissima; Productivity; Habitat

Advances in laying date and increasing population size suggest positive responses to climate change in Common Eiders Somateria mollissima in Iceland - D'Alba, Liliana; Monaghan, Pat; Nager, Ruedi G. (Ibis, 2010)
Models of climate change predict that its effects on animal populations will not always be negative, but most studies indicate negative associations between changes in climate and the phenology of animal migration and reproduction. For some populations, however, climate change may render particular environments more favourable, with positive effects on population growth. We used a 30-year population dataset on over 2000 Common Eiders Somateria mollissima at a colony in southwest Iceland to examine the response of this species to climate fluctuations. Eiders are strongly dependent on suitable climatic conditions for successful reproduction and survival. Temperatures in southwest Iceland, in both winter and summer, have generally increased over the past 30 years but have shown considerable fluctuation. We show that females laid earlier following mild winters and that year-to-year variation in the number of nests was related to the temperature during the breeding season 2 years previously. Milder summers could have positive effects on breeding success and offspring survival, producing an increase in nest numbers 2 years later when most Eiders recruit into the breeding population. In this part of their range, Eiders could benefit from a general warming of the climate.
Keywords: Breeding Season; Abundance, Distribution, and Trends; Common Eider; Somateria mollissima; Productivity

State dependent effects of elevated hormone: Nest site quality, corticosterone levels and reproductive performance in the common eider - D'Alba, L.; Spencer, K. A.; Nager, R. G.; Monaghan, P. (General and Comparative Endocrinology, 2011)
Nest shelter in incubating birds is of major importance in providing protection against unfavourable conditions such as harshness of the environment and exposure to predators. We examined the link between nest shelter, baseline corticosterone (CORT) levels and hatching success in common eiders (Somateria mollissima) incubating at nest sites with different levels of shelter. Since more sheltered nest sites could be occupied by better-quality females, we also used an experimental manipulation of nest shelter to separate the effects of the physical attributes of the nest site from those of individual quality. We compared birds with naturally sheltered nests, exposed nests and exposed nests provided with artificial nest shelters and measured clutch size, body condition, CORT levels at the end of incubation and hatching success. If nest shelter reduces CORT levels, we predicted that CORT levels would be highest at the least sheltered sites, and that the provision of artificial shelter would reduce CORT levels. We found that nest shelter was not related to CORT levels in incubating eiders. Nest shelter, however, affected body condition, with females at exposed sites losing more body mass during incubation than females at naturally and artificially sheltered nests. Interestingly however, in those birds nesting at the exposed sites, with and without artificial shelter, those with the highest CORT levels had the lowest hatching success. This relationship was not evident in females nesting at naturally sheltered sites. These results suggest that the level of nest shelter does not directly affect CORT levels in females. Instead, we suggest that the relationship between CORT levels and hatching success is state-dependent. Exposed sites are occupied by individuals that laid smaller clutches, and hence are likely to be of lower quality, and the negative effects of elevated CORT on hatching success are more pronounced in these females. Published by Elsevier Inc.
Keywords: Breeding Season; Common Eider; Somateria mollissima; Physiology; Energetics and Nutrition; Habitat

Lipids and stable isotopes in common eider, black-legged kittiwake and northern fulmar: A trophic study from an Arctic fjord - Dahl, T. M.; Falk-Petersen, S.; Gabrielsen, G. W.; Sargent, J. R.; Hop, H.; Millar, R. M. (Marine Ecology Progress Series, 2003)
Lipid class and fatty acid compositions were determined in common eider (Somateria mollissima), black-legged kittiwake (Rissa tridactyla) and northern fulmar (Fulmarus glacialis) from Kongsfjorden, Spitsbergen. Muscle and liver were sampled in all species, while fat tissue was sampled in eiders and fulmars. Triacylglycerols (TAG) dominated the lipid class compositions of all tissues, and the major fatty acids found in TAG were: 18:1n9, 16:0, 18:0, 20:5n3 and 16:1n7 for eider; 16:0, 18:1n9, 18:0, 20:1n9 and 16:1n7 for kittiwake; 18:1n9, 16:0, 20:1n9, 22:1n11, and 18:0 for fulmar. To attain information on prey composition, fatty acid signature analysis was performed on muscle fatty acid profiles of the bird species, together with fatty acid data from potential prey species. This study of lipids combined with stable isotopes supports the following findings: (1) Common eiders are strongly linked to the benthic food chain, through both fatty acid compositions (high levels of 20:4n6) and stable isotope values (high levels of delta13C). (2) Black-legged kittiwakes and northern fulmars are linked to the pelagic food chain, through both fatty acid compositions (high levels of 20:1n9 and 22:1n11) and stable isotope values (low levels of delta13C). The high level of 20:1 and 22:1 moieties also indicates the importance of Calanus in the Arctic pelagic food chain supporting fulmar and kittiwake. (3) The levels delta15N show that of the 3 species, the fulmar occupies the highest trophic level, followed by kittiwake and common eider.
Keywords: Breeding Season; Common Eider; Somateria mollissima; Trophic Interactions

Hydroxylated and methoxylated polybrominated diphenyl ethers in long-tailed ducks (Clangula hyemalis) and their main food, Baltic blue mussels (Mytilus trossulus x Mytilus edulis) - Dahlberg, A. K.; Chen, V. L.; Larsson, K.; Bergman, A.; Asplund, L. (Chemosphere, 2016)
Long-tailed ducks (Clangula hyemalis) that breed in northern Europe and western Siberia and commonly winter in the Baltic Sea, are threatened by a significant population decrease. The ducks are, by primarily feeding on Baltic blue mussels (Mytilus trossulus x Mytilus edulis) while wintering in the Baltic Sea, potentially subjected to high levels of toxic hydroxylated polybrominated diphenyl ethers (OH-PBDEs). To assess long-tailed ducks exposure to polybrominated phenols (PBPs), polybrominated anisoles (PBAs), hydroxylated polybrominated diphenyl ethers (OH-PBDEs), their methylated counterparts (MeO-PBDEs) and polybrominated diphenyl ethers (PBDEs), livers of ten long-tailed ducks wintering in the Baltic Sea were analysed. Pattern and levels of analytes in long-tailed ducks (liver) and blue mussels sampled in March and May at nine sites in the Baltic Sea were compared. The geometric mean concentration (ng/g l.w.) in livers of long-tailed ducks and Baltic blue mussels were: Sigma(2)PBPs: 0.57 and 48; Sigma 2PBAs: 0.83 and 11; Sigma 7OH-PBDEs: 6.1 and 45; Sigma 7MeO-PBDEs: 3.8 and 69; Sigma 7PBDEs: 8.0 and 7.2, respectively. Based on an estimated daily intake of 450 g fresh blue mussel meat, long-tailed ducks daily dietary intake of brominated substances while foraging in the Baltic Sea in March-May was estimated to; 390 ng Sigma(2)PBPs, 90 ng Sigma 2PBAs, 370 ng Sigma 7OH-PBDEs, 590 ng Sigma 7MeO-PBDEs and 59 ng Sigma 7PBDEs. The low levels of PBPs, PBAs, OH-PBDEs and MeO-PBDEs in the long-tailed duck livers compared to blue mussel, despite a continuous daily intake, suggest that these compounds are poorly retained in long-tailed ducks. (C) 2015 The Authors. Published by Elsevier Ltd.
Dahlberg, Anna-Karin Chen, Vivian Lindberg Larsson, Kjell Bergman, Ake Asplund, Lillemor
Keywords: Clangula hyemalis; Long-tailed Duck; Contaminants; Trophic Interactions; Nonbreeding season

Recovery discrepancies of OH-PBDEs and polybromophenols in human plasma and cat serum versus herring and long-tailed duck plasma - Dahlberg, A. K.; Norrgran, J.; Hovander, L.; Bergman, A.; Asplund, L. (Chemosphere, 2014)
Hydroxylated polybrominated diphenyl ethers (OH-PBDEs) have been identified as metabolites of polybrominated diphenyl ethers (PBDEs) and/or as natural products. The OH-PBDEs and polybromophenols have come into focus over the last decade due to their abundance in biota and their potential adverse health effects. The present recovery study aims to validate a commonly used method (published by Hovander et al. 2000) for OH-PBDE analysis in human plasma. Further, the authors intended to determine the method's applicability to serum/plasma matrices from other species than humans. The investigated matrices were human plasma, cat serum, herring- and long-tailed duck plasma. The recovery study included nine OH-PBDEs, four polybromophenols and three methoxylated PBDEs (MeO-PBDEs). Five replicates of each matrix were spiked with these compounds at two dose levels; a low dose (0.5 ng) and a high dose (5 ng) and were cleaned up according to the Hovander method. The recovery of OH-PBDEs and polybromophenols in human plasma and cat serum were high and reproducible at both dose levels whereas the recovery for herring and long-tailed duck plasma were low and insufficient with great variability amongst OH-PBDE congeners at both dose levels. Our data show that the method can be fully applied to matrices like human plasma and cat serum but not for herring and long-tailed duck plasma without further method development. Hence care needs to be taken when applying the method onto other blood matrices without validation since the present study have demonstrated that the recoveries may differ amongst OH-PBDE congeners and specie. (C) 2013 Published by Elsevier Ltd.
Dahlberg, Anna-Karin Norrgran, Jessica Hovander, Lotta Bergman, Ake Asplund, Lillemor
Keywords: Clangula hyemalis; Long-tailed Duck; Contaminants; Techniques

Female Goldeneye Ducks (Bucephala clangula) Do Not Discriminate among Male Precopulatory Display Patterns - Dane, B.; Harris, R.; Reed, J. M. (Plos One, 2013)
Times Cited: 0 Dane, Benjamin Harris, Rebecca Reed, J. Michael 0
Keywords: Behavior; Bucephala clangula; Common Goldeneye

Abundance and Productivity of Ducks on Boreal Lakes in Northern Sweden - Danell, K.; Sjoberg, K. (Annales Zoologici Fennici, 1979)
The numbers of duck pairs and broods present within a 56 km2 study area, predominantly pine and spruce forest, in the coastal region of northern Sweden were estimated during 1977. The study area contained 95 relatively small, shallow lakes, covering 3.6% of the total area. In May, 3 counts showed a total of 108 duck pairs, and 91 broods were recorded during July. The duck species observed were: mallard (Anas platyrhynchos), teal (A. crecca), wigeon (A. penelope), pochard (Aythya ferina), tufted duck (A. fuligula), velvet scoter (Melanitta fusca), goldeneye (Bucephala clagula), smew (Mergus albellus), red-breasted merganser (M. serrator) and goosander (M. merganser). The mean values for the whole survey period were 2.2 pairs and 1.9 broods/km of lake shoreline, or 54 pairs and 46 broods/100 h of the entire area covered by lakes.
Keywords: Breeding Season; Abundance, Distribution, and Trends; Sea Ducks - General

The role of the mussel (Mytilus edulis L.) and mussel culture in the Dutch Wadden Sea - Dankers, Norbert; Zuidema, Duurt R. (Estuaries, 1995)
Mussel populations (Mytilus edulis) in the Dutch Wadden Sea (intertidal mussel beds, subtidal beds and culture plots), the culture methods, the extent of mussel culture, and the ecology of the mussel are described. Mussels filter suspended matter from the water column and deposit it as feces and pseudofeces. Mussel beds consume large amounts of phytoplankton and speed up the cycle of production and breakdown of organic matter. There are indications that the consumption of phytoplankton can lead to food shortage for several animal groups. Mussels serve as an important food source for a wide range of organisms (e.g., starfish, eider ducks, and oystercatchers). Because mussel culture increased the mussel biomass in the Dutch Wadden Sea, the impact also increased. The most obvious impact of the culture is the dredging of seed mussels. Overexploitation of intertidal mussel and cockle beds and bad spatfall of both mussels and cockles since 1988 had a negative impact on bird populations. The extent of positive and negative aspects of mussel culture depends on natural and human influences. The negative aspects may (partly) be overcome by appropriate measures.
Keywords: Sea Ducks - General; Trophic Interactions

Capturing and Marking Spectacled Eiders in Alaska - Dau, C. P. (Bird-Banding, 1976)
Keywords: Breeding Season; Somateria fischeri; Spectacled Eider; Techniques

Clutch Sizes of the Spectacled Eider on the Yukon Kuskokwim Delta Alaska USA - Dau, C. P. (Wildfowl, 1976)
Keywords: Breeding Season; Somateria fischeri; Spectacled Eider; Productivity

Observations on Helminth Parasites of the Spectacled Eider Somateria-Fischeri in Alaska USA - Dau, C. P. (Canadian Journal of Zoology, 1978)
Data concerning the occurrence of species diversity of helminth parasites in a sample of 11 spectacled eiders from the Yukon-Kuskokwim Delta, Alaska [USA] are presented. Differences in helminth species diversity and intensity of infections were encountered between adult males and females. Adult males and young of the year were host to the greatest variety of species and in most cases total helminths. Helminth parasitism in the spectacled eider may be a compounding factor in the mortality of young birds after departure from the nesting grounds. [Helminths found were Lateraporus teres, Fimbriaria fasciolaris, Diorchis inflata, Sobolevicanthus sp., Hymenolepis echinorostrae, H. formosa, H. yukonensis, Corynosoma strumosum, C. tunitae, Filicollis anatis and an unidentified cestode and an acanthocephalan.].
Keywords: Breeding Season; Somateria fischeri; Spectacled Eider; Parasites

Distribution of recoveries of Steller's Eiders banded on the lower Alaska Peninsula, Alaska - Dau, Christian P.; Flint, Paul L.; Petersen, Margaret R. (Journal of Field Ornithology, 2000)
Molting adult Steller's Eiders (Polysticta stelleri) were banded at Izembek Lagoon (1961-1998) and Nelson Lagoon (1995-1997) along the lower Alaska Peninsula to determine breeding distribution and movements. Of 52,985 Steller's Eiders banded, 347 were recovered. The overall low recovery rate may not be indicative of harvest levels but may be due to low reporting rates of bands. Almost all recoveries during summer were from Russia and recovery rates did not differ between sexes. We found no evidence that Steller's Eiders molting in specific locations were more likely to be recovered in specific geographic locations in Russia. Our recoveries suggest that Steller's Eiders molting along the Alaska Peninsula were from Russian breeding sites and from remnant breeding populations in Alaska.
Keywords: Abundance, Distribution, and Trends; Molt; Population Delineation; Polysticta stelleri; Steller's eider

Seasonal movements and distribution of the Spectacled Eider - Dau, C. P.; Kistchinski, S. A. (Wildfowl, 1977)
Observations show that the nesting patterns of the Spectacled Eider, Somateria fischeri are similar on their Alaskan and Siberian nesting areas. Adult males are the first to leave the nesting grounds, doing so during the incubation period. Subadult males are rarely encountered on the nesting grounds and but few subadult females. Seasonal movements to and from the nesting grounds are poorly known. Published and unpublished data on the distribution in fall and winter are summarized and interpreted in conjunction with information on the dynamics of the Bering Sea ice pack as revealed by Satellite photographs.
Keywords: Behavior; Breeding Season; Somateria fischeri; Spectacled Eider; Abundance, Distribution, and Trends; Nonbreeding Seasons

A census of waterbirds on large fishponds in the northern Ukraine - Davydenkol, I. (Journal of Ornithology, 2006)
Keywords: Abundance, Distribution, and Trends; Sea Ducks - General

Seabirds in the northern Gulf of Alaska and adjacent waters, October to May - Day, Robert H. (Western Birds, 2006)
I studied the distribution and abundance of seabirds in the northern Gulf of Alaska and adjacent waters during 16 research cruises from October to May 1997-2001. 1 recorded 58 species of seabirds on transects, plus one off the transects. The avifauna was dominated numerically by tubenoses (50% of all birds) and alcids (29%), with much smaller numbers of lands (3%), shorebirds (phalaropes; 3%), waterfowl (2%), cormorants (1%), and loons (< 1%). Five species each composed >= 5%, and collectively composed 74%, of the wintering avifauna: the Common Murre (Uria aalge; 21%), Northern Fulmar (Fulmarus glacialis; 19%), Fork-tailed Storm-Petrel (Oceanodroma furcata; 16%), Sooty Shearwater (Puffinus griseus; 11%), and Black-legged Kittiwake (Rissa tridactyla; 7%). Another nine species collectively composed similar to 19% of all birds, whereas the other 44 species collectively composed similar to 7% of all birds. I recorded from 10 to 37 species per cruise; both the number of species and total density of all birds combined decreased from October to March, then increased rapidly in April and (especially) May.
Keywords: Abundance, Distribution, and Trends; Sea Ducks - General

Effects of the Exxon Valdez oil spill on habitat use by birds in Prince William Sound, Alaska - Day, Robert H.; Murphy, Stephen M.; Wiens, John A.; Hayward, Gregory D.; Harner, E. James; Smith, Louise N. (Ecological Applications, 1997)
Oil spills may affect species through direct effects on population size and structure and direct and indirect (toxicological) effects on reproduction. Spill effects on the habitats these organisms occupy have received less attention, but they are no less important. For 2.5 yr following the Exxon Valdez oil spill in Prince William Sound, Alaska, we studied the use of oil-affected habitats by 42 species of marine-oriented birds. On 11 survey cruises, we surveyed bays that had received different levels of initial oiling. We related the abundance of individual species in the bays to the oiling gradient, using regression models that included habitat measures to control for variations among the sites in features other than oiling level. We defined a spill-induced impact as a statistically significant relationship between the abundance of a species and values along the oiling gradient, after accounting for the effects of variations in habitat features. We used among-year comparisons of regressions between oiling levels and abundance, controlled for season, to assess recovery. We concluded that recovery from a spill-induced impact had occurred when we no longer could detect a significant relationship between a species' abundance and oiling levels. Overall, 23 (55%) of the 42 species exhibited no initial negative impacts on their use of oil-affected habitats. Of the 19 species that did exhibit negative impacts, 13 (68%) showed evidence of recovery within 2.5 yr (the final survey in 1991). Six species (Homed Grebe, Red-necked Grebe, Barrow's Goldeneye, Bufflehead, Mew Gull, and Northwestern Crow) showed no clear evidence of recovery by our final survey. The proportion of species recorded on individual surveys that exhibited negative impacts at that time declined over the study, from 54% on the first survey after the spill in 1989 to 10% in late 1991. A principal components analysis revealed extensive ecological overlap between species that were negatively impacted in their use of oil-affected habitats and those that were not. The six species that had not recovered by late 1991 tended to be intertidal feeders and residents, but these traits also characterized some species that did not exhibit initial impacts and some species that subsequently recovered from impacts. We detected no obvious ecological differences between species that suffered spill impacts on habitat use and those that apparently were not affected, or between impacted species that later recovered in their use of habitats and species that had not yet recovered. These results indicate that the Exxon Valdez oil spill had clear initial negative impacts on habitat use by nearly half of the species examined, suggesting substantial initial effects on habitat suitability for these species. These impacts persisted for lt 2.5 yr for most affected species. This rate of recovery in habitat use parallels the rapid recovery (usually lt 2 yr) documented for other oil-affected communities (e.g., intertidal invertebrates, fishes, and birds) that have been studied in Alaska and elsewhere.
Keywords: Sea Ducks - General; Nonbreeding Seasons; Contaminants; Habitat

Effects of a Hazing-Light System on Migration and Collision Avoidance of Eiders at an Artificial Oil-Production Island, Arctic Alaska - Day, R. H.; Prichard, A. K.; Rose, J. R.; Streever, B.; Swem, T. (ARCTIC, 2017)
During migration, Common and King Eiders (Somateria mollissima and S. spectabilis) cross the Beaufort and Chukchi Seas of Arctic Alaska. Because they may become attracted to lights, eiders are susceptible to collision with structures, including offshore oil facilities. We used ornithological radar in 2001 - 04 to characterize the behavior of eiders migrating past Northstar Island, an oil-production island near Prudhoe Bay, Alaska, and to assess the effects of a hazing-light system on migrating eiders. "Eider" radar targets exhibited pulsed, irregular periods of movement; movement rates were higher when sea ice was present, without precipitation, and during tailwinds and crosswinds but were not affected by lights. Velocities (ground speeds) were higher when ice was present and with strong tailwinds. They were lower at night when the lights were on, but higher during the day when the lights were on. Radar targets exhibited little variation in flight behavior as they passed the island; the proportion of non-directional behavior was larger when ice was present, with tailwinds, with weak winds, and near the full moon when it was not visible. Lights had no effect on flight behavior. Birds tended to exhibit more course changes as they approached the island, greater angular changes when they changed course, and larger net increases in passing distance as a result of those course changes when the lights were on; however, none of these differences were statistically significant. Overall, the hazing lights at Northstar did not disrupt the birds' migratory movements but resulted in increased avoidance of the island.
Times Cited in Web of Science Core Collection: 1 Total Times Cited: 1 Cited Reference Count: 44
Keywords: migration; BIRDS; BEAUFORT SEA; SEABIRDS; Alaska; behavior; COAST; collision; eider; light attraction; MOLLISSIMA; POINT-BARROW; risk; Somateria; SPRING MIGRATION; SUMMER; WATERBIRD MIGRATION; YUKON

Environmental effects on the fall migration of eiders at Barrow, Alaska - Day, Robert H.; Rose, John R.; Prichard, Alexander K.; Blaha, Richard J.; Cooper, Brian A. (Marine Ornithology, 2004)
We studied the effects of environmental factors on the migration of Common and King Eiders (Somateria mollissima and S. spectabilis) past Barrow, Alaska, during fall migration in 1997 and 2000 with ornithological radar and visual observations. Among-day variation in movement rates was high, with birds apparently flying at any time if migratory conditions were favorable. Movement rates were significantly higher during good visibility than poor visibility, higher during tailwinds than crosswinds and headwinds, higher during strong crosswinds than weak ones and higher during weak headwinds than strong ones. Eider groundspeed velocities averaged 83.5 +/- 0.3 km/h and were significantly higher with good visibility and strong winds, higher with good visibility at night than with poor visibility at night, higher with crosswinds and tailwinds than with headwinds, higher with weak headwinds than with strong ones and higher with strong tailwinds and crosswinds than with weak ones. Eiders flew slightly south of northwest (310 degrees). Flight directions differed significantly by time of day and visibility, but the differences are not biologically significant. Essentially all migrating ciders passing Barrow flew through a 3-km-wide zone centered on the base of Barrow Spit. Eider flocks averaged 110.4 +/- 7.1 birds and were largest during crosswinds and smallest during tailwinds. Eiders had a mean flight altitude of 12.1 +/- 0.8 m above ground or sea level (agl/asl); night altitudes were significantly lower during headwinds than during crosswinds and tailwinds. Wind direction and strength had the greatest effect on eider migration past Barrow, in that strong tailwinds and crosswinds significantly increased movement rates, velocities (if crosswinds or tailwinds), flock sizes and flight altitudes. Monitoring of eider migration should be modified to increase the accuracy and precision of population estimates by using a stratified systematic sampling scheme based on weather conditions and by sampling at night.
Keywords: Common Eider; Nonbreeding Seasons; Migration; Somateria mollissima; King Eider; Somateria spectabilis

Effects of Gas Flaring on the Behavior of Night-Migrating Birds at an Artificial Oil-Production Island, Arctic Alaska - Day, R. H.; Rose, J. R.; Prichard, A. K.; Streever, B. (Arctic, 2015)
We studied movement rates and the general flight behavior of bird flocks seen on radar and recorded visually at Northstar Island, Arctic Alaska, from 13 to 27 September 2002. Most of this period (13-19 and 21-27 September) had no gas-flaring events, but a major gas-flaring event occurred on the night of 20 September. Movement rates of targets on radar and of bird flocks recorded visually in the first similar to 50%-60% of the night were much lower during the non-flaring period than during the night of flaring, whereas rates in the last similar to 40%-50% of the night were similar in all periods. The general flight behavior of birds also differed significantly, with higher percentages of both radar targets and bird flocks exhibiting straight-line (directional) flight behaviors during the non-flaring periods and higher percentages of radar targets and bird flocks exhibiting non-straight-line (erratic and circling) flight behaviors during the gas-flaring period. During the night of gas flaring, the bright illumination appeared to have an effect only after sunset, when flocks of birds circled the island after being drawn in from what appeared to be a substantial distance from the island. On both radar and visual sampling, the number of bird flocks approaching the island declined over the evening, and the attractiveness of the light from flaring appeared to decline. The visibility of the moon appeared to have little effect on the behavior of birds. Because illumination from extensive gas-flaring is such a strong attractant to migrating birds and because most bird flocks fly at low altitudes over the water, flaring booms on coastal and offshore oil-production platforms in Arctic Alaska should be positioned higher than the mean flight altitudes of migrating birds to reduce the chances of incineration.
Day, Robert H. Rose, John R. Prichard, Alexander K. Streever, Bill
Keywords: Conservation; Behavior; Common Eider; Clangula hyemalis; Long-tailed Duck; Migration; Somateria mollissima; King Eider; Somateria spectabilis; Nonbreeding season

Wintering waterbirds in the province of Belluno: Years 1989-1996 - De Faveri, Adriano; Zenatello, Marco (Societa Veneziana di Scienze Naturali Lavori, 1997)
Wintering waterbirds were counted in the main wetlands of the province of Belluno (NE Italy) during years 1989-1996. Among the less common species, extreme interest for local wetlands comes from wintering individuals of Podiceps nigricollis, Phalacrocorax carbo, Bucephala clangula, Mergus merganser and Larus minutus.
Keywords: Abundance, Distribution, and Trends; Sea Ducks - General; Nonbreeding Seasons; Common merganser; Mergus merganser

The Dutch Wadden Sea: A changed ecosystem - De Jonge, V. N.; Essink, K.; Boddeke, R. (Hydrobiologia, 1993)
Since 1600 the surface area of the Dutch Wadden Sea decreased considerably by successive reclamations of saltmarshes. In 1932 the Zuiderzee (3200 km-2) was closed off from the Wadden Sea causing in the remaining part an increase in tidal range and current velocities. In 1969 the Lauwerszee (91 km-2) was closed off and turned into a freshwater lake as well. Man's use of the Wadden Sea changed simultaneously. Dredging in harbours and shipping routes, and extraction of sand and shells became common practice. Extraction of sand increased manifold between 1960 and 1985. These activities did contribute to the turbidity of the Wadden Sea water. Discharge of nitrogen and phosphorus compounds into the western Wadden Sea increased also manifold since 1950, causing an increase in phytoplankton production, duration of phytoplankton blooms, and intertidal macrozoobenthic biomass. Loads of metals and organochlorine contaminants entering the Wadden Sea were hard to estimate. Fisheries changed drastically since the 1930's. Fishing for 'Zuiderzee' herring came to an end shortly after closing off the Zuiderzee. The anchovy fishery ceased in the 1960's; that for flounder in 1983. Undersized brown shrimps were fished until 1971. Selective shrimptrawls and sorting devices with flushing seawater were introduced to reduce mortality among young flatfish and shrimps. Oysters became extinct in the 1960's due to over-exploitation of the natural beds. Production of mussels increased more than ten times between 1950 and 1961 due to 'culturing'; catches of cockles increased slowly between 1955 and 1984. Whelks were fished until 1970. The most important changes in the biotic system of the Wadden Sea, increased production of microalgae and intertidal macrozoobenthos, can be attributed to increased nutrient loads. Eutrophication provided ample food supply for mussels which are harvested mainly by man and eider duck, and may have caused also increased growth in juvenile plaice. Increased turbidity may have impaired life conditions for adult dab, and have prevented also recovery of sublittoral eelgrass beds after their disappearance in the 1930's due to the 'wasting disease'. Increased turbidity in the Wadden Sea is probably caused by closing off the Zuiderzee (1932), a significant increase of dredge spoil disposal near Hoek van Holland between 1970 and 1983, and a more than 10-fold increase of mussel culturing in the Wadden Sea since 1950. Stocks of several bird species breeding in the Wadden Sea area suffered great losses in the early 1960's due to a pesticide accident. Most of the breeding populations have recovered. PCB's caused a reproduction failure among harbour seals in the 1970's. Since 1980 official Dutch policy aims at multiple use of the Wadden Sea, with emphasis on protection and restoration of the natural environment. The 3rd Water Management Plan (1989) aims at a development of the Wadden Sea ecosystem towards the situation of ca. 1930, i.e. without undoing present sea dikes and reclaimed polders. Management of the Dutch Wadden Sea will therefore have to focus mainly on reduction of eutrophication, pollution and turbidity. Some management options are discussed.
Keywords: Common Eider; Nonbreeding Seasons; Somateria mollissima; Habitat

Bird observations in Severnaya Zemlya, Siberia - De Korte, J.; Volkov, A. E.; Gavrilo, M. V. (Arctic, 1995)
Field work in different parts of Severnaya Zemlya in 1985, 1991,1992 and 1993 and aerial surveys in 1994 revealed a limited bird fauna with a total of 17 breeding species. The most numerous breeding birds are cliff-nesting seabirds, comprising little auk (Alle alle), 10 000-80 000 pairs; kittiwake (Rissa tridactyla), 5000-10 000; black guillemot (Cepphus grylle), 1000-5000; ivory gull (Pagophila eburnea), 1000-2000; and glaucous gull (Larus hyperboreus), 500-1000. They breed all over the archipelago, usually in rather small mixed- or single-species colonies. Arctic tern (Sterna paradisaea) 100-500, and herring gull (Larus argentatus) 1-10, breed as solitary pairs or with a few pairs together. Of tundra birds, only brent goose (Branta bernicla), purple sandpiper (Calidris maritima) and snow bunting (Plectrophenax nivalis) are found breeding on most of the major islands. The other tundra species-red-throated diver (Gavia stellata), king eider (Somateria spectabilis), sanderling (Calidris alba), Arctic skua (Stercorarius parasiticus), long-tailed skua (Stercorarius longicaudus), snowy owl (Nyctea scandiaca) and Lapland bunting (Calcarius lapponicus)-breed in small numbers and in limited areas, often not every year. Of the even fewer mammal species, reindeer (Rangifer tarandus) occurs occasionally, while Arctic fox (Alopex lagopus) and collared lemming (Dicrostonyx torquatus) are locally common in some years.
Keywords: Breeding Season; Abundance, Distribution, and Trends; Sea Ducks - General; King Eider

Resource selection and space use by sea ducks during the non-breeding season: Implications for habitat conservation planning in urbanized estuaries - De la Cruz, S. E. W.; Eadie, J. M.; Miles, A. K.; Yee, J.; Spragens, K. A.; Palm, E. C.; Takekawa, J. Y. (Biological Conservation, 2014)
Wide-ranging marine birds rely on multiple habitats for wintering, breeding, and migrating, and their conservation may be dependent on protecting networks of key areas. Urbanized estuaries are critical wintering and stopover areas for many declining sea ducks in North America; however, conservation measures within estuaries are difficult to establish given lack of knowledge about habitat use by these species and the variety of competing human interests. We applied hierarchical modeling to evaluate resource selection of sea ducks (surf scoters, Melanitta perspicillata) wintering in San Francisco Bay, California, USA, a large and highly urbanized estuary. We also examined their distribution, home range, and movements with respect to key habitat features and regions within the estuary. Herring roe was the strongest predictor of bird locations; however, eelgrass, water depth and salinity were also highly-ranked, with sea ducks using deeper areas of higher salinity associated with herring roe and eelgrass presence during mid-winter. Sea ducks were also strongly associated with ferry routes, suggesting these areas may contain resources that are too important to avoid and emphasizing the need to better understand water traffic effects. Movements and home range size differed between males and females in early winter but became more similar in late winter. Birds traveled farther and used several sub-bays in early winter compared to mid-winter when herring roe availability peaked in the Central Bay. Our findings identified key environmental variables, highlighted core use areas, and documented critical periods for consideration when developing conservation plans for sea ducks in urbanized estuaries. Published by Elsevier Ltd.
De la Cruz, Susan E. W. Eadie, John M. Miles, A. Keith Yee, Julie Spragens, Kyle A. Palm, Eric C. Takekawa, John Y.
Keywords: Melanitta perspicillata; Surf Scoter; Habitat; Nonbreeding season

Post-release survival of surf scoters following an oil spill: An experimental approach to evaluating rehabilitation success - De la Cruz, S. E. W.; Takekawa, J. Y.; Spragens, K. A.; Yee, J.; Golightly, R. T.; Massey, G.; Henkel, L. A.; Larsen, R. S.; Ziccardi, M. (Marine Pollution Bulletin, 2013)
Times Cited: 0 De la Cruz, Susan E. W. Takekawa, John Y. Spragens, Kyle A. Yee, Julie Golightly, Richard T. Massey, Greg Henkel, Laird A. Larsen, R. Scott Ziccardi, Michael 0
Keywords: survival; Nonbreeding Seasons; Melanitta perspicillata; Contaminants; Surf scoter; techniques

Spring migration routes and chronology of surf scoters (Melanitta perspicillata): a synthesis of Pacific coast studies - De La Cruz, S. E. W.; Takekawa, J. Y.; Wilson, M. T.; Nysewander, D. R.; Evenson, J. R.; Esler, D.; Boyd, W. S.; Ward, D. H. (Canadian Journal of Zoology, 2009)
Understanding interconnectivity among wintering, stopover, and breeding areas of migratory birds is pivotal to discerning how events occurring in each might have a cross-seasonal effect on another. Such information can guide the location and timing of conservation efforts. Thus, we examined spring migration routes, chronology, and stopover use of 85 surf scoters (Melanitta perspicillata (L., 1758)) marked with satellite transmitters at four Pacific Flyway wintering sites: San Quintin Bay, Baja California; San Francisco Bay, California; Puget Sound, Washington; and Strait of Georgia, British Columbia. Eighty-three percent of marked scoters followed two main routes to the breeding area: a Southern Inland route involving staging in Puget Sound and Strait of Georgia and protracted inland migration, or a Northern Coastal route characterized by short movements along the Pacific coast of British Columbia and southeast Alaska with inland migration initiating from Lynn Canal and surrounding areas. Route choice was related to nesting site latitude in the Canadian Northern Boreal Forest. Data from birds tracked over 2 years indicated strong migration route fidelity, but altered chronology and stopover locations between years. Departure date varied by wintering site, but arrival and apparent settling dates were synchronous, suggesting individuals adjusted migration timing to meet an optimized reproductive schedule.
Keywords: Breeding Season; Nonbreeding Seasons; Melanitta perspicillata; Surf Scoter; Migration; Dispersal; SDJV funded; Population Delineation

Toxoplasma and Intestinal Parasites in Birds in the Netherlands - De Roever-Bonnet, H. (Journal of Parasitology, 1971)
Keywords: Black Scoter; Melanitta nigra; Parasites

Habitat use by brood-rearing waterfowl in subarctic Quebec - Decarie, Robert; Morneau, Francois; Lambert, Daniel; Carriere, Suzanne; Savard, Jean-Pierre L. (Arctic, 1995)
Aerial surveys of waterfowl were conducted in subarctic Quebec in 1989 and 1990 on randomly selected 100 km-2 plots. We used logistic regression for modelling relationships between the presence of waterfowl broods and habitat characteristics. For each species, models of habitat use were generated with one data set and tested with two others. We also compared the frequency distributions of broods of each species in different habitat types. Correct-classification rates of models varied between 0.53 and 0.77. Sensitivity of models generally increased when applied to validation data sets. Models showed that green-winged teals (Anas crecca) avoided lakes gt 501 ha and used vegetated lakes, ponds and fens or bogs more than predicted by their availability. Black scoters (Melanitta nigra) and surf scoters (M. perspicillata) were found mostly on small lakes ( lt 10 ha) and medium lakes (10- 100 ha). Black scoters were associated with the presence of ponds and lakes with sedge and grass, whereas surf scoters were not. The presence of scaup (Aythia spp.) broods was associated with the presence of vegetation. Green-winged teals were observed more often on bogs than were either scoters or scaups. Black scoters were observed more often on ponds and less often on medium-sized lakes than surf scoters and scaups. The latter differed in their use of lakes lt 10 ha: surf scoters, like black scoters, mostly used unvegetated lakes, while scaups and green-winged teals mostly used vegetated lakes. The accuracy and precision of logistic models may be enhanced by additional habitat variables, careful selection of sample-cell size and further investigation of the breeding biology of the surveyed species.
Keywords: Breeding Season; Melanitta perspicillata; Surf Scoter; Habitat; Black Scoter; Melanitta nigra

Status of Scoters Melanitta sp in the Belgian Entre-Sambre-et-Meuse - Deflorenne, Philippe; Derouaux, Antoine (Aves, 2010)
The Velvet Scoter Melanitta fusca and the Common Scoter Melanitta nigra are rarely, but regularly seen in Wallonia. They are almost never seen in Brussels. Essentially they are limited to the river Meuse and to some large lakes. In particular, the lakes of les Barrages de l'Eau d'Heure (BEH), which offer an abundant source of crayfish and molluscs, are a regular overwintering site for the Velvet Scoter. Although one Common Scoter has been observed overwintering among Velvet Scoters at BEH, this species is normally a bird of passage in Wallonia. It is found on more sites than the Velvet Scoter, including much smaller lakes (for example in the Entre-Sambre-et-Meuse, Roly, Virelles ...)
Keywords: Abundance, Distribution, and Trends; Melanitta fusca; Nonbreeding Seasons; White-winged Scoter; Black Scoter; Melanitta nigra

Degenerative joint disease in captive waterfowl - Degernes, L. A.; Lynch, P. S.; Shivaprasad, H. L. (Avian Pathology, 2011)
A retrospective study was conducted to evaluate degenerative joint disease (DJD) in captive waterfowl that died or were euthanized at Fresno's Chaffee Zoo in Fresno, California, USA from 2001 to 2005. Of these, 16 out of 33 birds (48%) had DJD in one or both stifle (femoral-tibiotarsal joint; n = 13), hock (tibiotarsal-tarsometatarsal joint; n = 4), or toe joints (n = 2), based on gross, histologic and/or radiographic confirmation. No joint disease was observed in any wings, nor were any infectious pathogens isolated from affected joints. Sixteen species of waterfowl were included (n = 1 to 5 per species), with an average age at death of 12.1 years and 11.3 years for waterfowl with, and without DJD, respectively. Neither age nor sex was associated with the presence of joint disease. Waterfowl housed in the Rainforest exhibit were more likely to be diagnosed with DJD compared with waterfowl housed in the duck pond exhibit, possibly due to the rough-textured concrete surfaces in the Rainforest exhibit. Further research involving a larger number of zoological collections and birds is necessary to gain a better understanding of risk factors in captive waterfowl.
Keywords: Sea Ducks - General; Disease

Spatial distribution, population dynamics and productivity of Spisula subtruncata: implications for Spisula fisheries in seaduck wintering areas - Degraer, Steven; Meire, Patrick; Vincx, Magda (Marine Biology (Berlin), 2007)
Bivalves are important in shallow marine habitats, not at least being the major food resource for seaducks such as the common scoter (Melanitta nigra), thousands of which are wintering on the Western Coastal Banks, near the Belgian-French border (North Sea). Next to this ecological importance, fishable stocks of one of these bivalves, Spisula subtruncata, occur in the area. This study aimed at investigating S. subtruncata's spatial distribution, population dynamics and productivity and its implications for a sustainable Spisula fishery in seaduck wintering areas. The spatial distribution of S. subtruncata was studied in 1994 and 1997 in two areas of the Belgian Western Coastal Banks. The population dynamics and production were investigated by monthly sampling of two stations between April 1995 and April 1996 and a seasonal sampling between April 1996 and April 1998. Spisula subtruncata had a patchy distribution in the deeper (6 m), fine sandy (200 +/- 20 mu m) sediments of the Abra alba community, mainly found in the western most part of the Western Coastal Banks. In August 1995, an overwhelming and successful recruitment was observed in this area: local densities were as high as 150,000 ind m(-2). Minor, non-successful recruitments were detected in August 1996 and 1997. Due to space limitation, high densities of S. subtruncata are hypothesized to be responsible for the occurrence of aberrant shapes as observed from August 1996 onwards. Growth was described by a seasonally oscillating version of the von Bertalanffy growth function (VBGF): a growth stop was observed from late autumn till early spring. The VBGF parameters K (growth constant) and L-infinity (asymptotic length) were estimated at 0.7-0.9 and 31-33 mm. A combination of length and individual biomass increment showed: (1) a faster length increment of smaller individuals during the second growing period (catching-up phenomenon), (2) a constant length combined with a decreasing individual biomass during the suboptimal winter periods (except for the first winter, when the individual biomass slightly increased), (3) a positive relationship between the individual biomass decrease and the seawater temperature during the winter periods, and (4) a strong increase of the individual biomass in early spring (April 1997 and 1998) because of gametogenesis, followed by a decrease because of spawning (August 1997). The extremely high total production of the 1995 year class in the tidal gully (Potje) during the study period was estimated at approximately 1,500 g ash-free dry weight (ADW) m(-2) or 600 g ADW m(-2) on average per year. Shellfisheries for S. subtruncata within seaduck wintering areas, such as the Western Coastal Banks, should be carefully deliberated since (1) an important food resource for the seaducks will decrease, (2) the ecologically most diverse and rich macrobenthic A. alba community will be heavily affected, and (3) the recovery of Spisula populations after depletion is expected to be erratic.
Keywords: Nonbreeding Seasons; Trophic Interactions; Black Scoter; Melanitta nigra

The macrozoobenthos of an important wintering area of the common scoter (Melanitta nigra) - Degraer, Steven; Vincx, Magda; Meire, Patrick; Offringa, Henk (Journal of the Marine Biological Association of the United Kingdom, 1999)
In October 1994, 39 macrobenthic samples, divided between two areas, were taken on the western Belgian Coastal Banks. The two areas could not be clearly divided, concerning their macrobenthic communities. Multivariate techniques revealed five coherent communities, linked with typical sedimentological factors: (1) the Barnea candida community in a very compact muddy sediment (median 14 mum); (2) a second community characterized by the presence of spat of Mytilus edulis, with a medium sandy sediment (median 456 mum); (3) the Lanice conchilega community inhabiting a fine sandy sediment (median 211 mum); (4) the Nephtys cirrosa-Echinocardium cordatum community in a coarser fine sandy sediment (median 242 mum); and (5), closely related to the latter, the N. cirrosa community also occurring in a fine sandy sediment (median 224 mum). Only the L. conchilega community belongs to the diverse transition zone. The other four communities seem to be part of the heterogeneous, species-poor coastal zone associations. No open sea communities have been detected in the area. On the western Coastal Banks only the L. conchilega community, because of the high numbers of Abra alba, Tellina fabula, and Spisula subtruncata, can be interesting as feeding grounds for the common scoter (Melanitta nigra (Aves: Mergini)). Comparison of the spatial distribution of the wintering common scoters and the L. conchilega community revealed no direct similarity. The factors possibly causing this dissimilarity have been discussed.
Keywords: Nonbreeding Seasons; Trophic Interactions; Habitat; Black Scoter; Melanitta nigra

Boat disturbance effects on moulting common eiders Somateria mollissima - Dehnhard, N.; Skei, J.; Christensen-Dalsgaard, S.; May, R.; Halley, D.; Ringsby, T. H.; Lorentsen, S. H. (MARINE BIOLOGY, 2019)
Ship and boat traffic are increasing sources of disturbance to marine wildlife. During moult, sea ducks are flightless and rely on productive and shallow feeding areas. However, this period coincides with the peak of the recreational boating season. This is the first study to investigate the escape behaviour of moulting common eiders (Somateria mollissima) to the approach of small boats. We quantified flight initiation distances (flock-to-boat distance at which an energy-demanding escape occurred), displacement distances (distance between the pre- and post-disturbance position of the flock) and the time it took flocks to return to pre-disturbance (foraging- or resting-) behaviour. Moulting common eiders showed average flight initiation distances of 177 m and displacement distances of 771 m. Displacement distances decreased with flock size, under higher wind speeds and when previous foraging habitat was shallower. Time-to-return to pre-disturbance behaviour decreased with flock size but increased with wind speed and accessibility of foraging habitat at the previous location. Most (75%) of flocks returned to pre-disturbance behaviour within 10 min after the disturbance, while three flocks kept disturbed even 45 min after the approach. Finally, flocks encountered less accessible (deeper) habitats after disturbance than before. Our results suggest that approaching boats imply considerable disturbance effects for moulting common eiders through increased locomotion costs, displacement from accessible foraging habitat and/or time lost for foraging or resting. We provide valuable information for policy makers and marine spatial planning and highlight the need for awareness among recreational boat drivers on their impact on wildlife.
Times Cited in Web of Science Core Collection: 7 Total Times Cited: 7 Cited Reference Count: 56
Keywords: SELECTION; BEHAVIOR; GROUP-SIZE; IMPACT; MANAGEMENT; POLYSTICTA-STELLERI; PREDATION RISK; SPP.; STRATEGIES; TOURISM

Hematozoa of hatch-year common mergansers from Michigan - DeJong, Randall J.; Reimink, Ronald L.; Blankespoor, Harvey D. (Journal of Wildlife Diseases, 2001)
Fifty-five hatch-year common mergansers (Mergus merganser) were sampled for hematozoa from Douglas Lake (Michigan, USA) on 17 July 1995. Forty-one (75%) were infected with hematozoa. Haemoproteus greineri and Leucocytozoon simondi were common, infecting 28 (51 %) and 26 (47%) common mergansers, respectively. Plasmodium circumflexum infected two (4%) birds. The common merganser is a new host record for H. greineri and P. circumflexum. Intensity data indicate possible negative interspecific interaction between H. greineri and L. simondi.
Keywords: Breeding Season; Common merganser; Mergus merganser; Parasites

Predation behaviour of the Common Goosander Mergus merganser in low water levels - Delcourt, Johann (Aves, 2010)
This article describes the predation behaviour of the Common Goosander, observed on the river Ourthe during periods of low water levels. Even though it is catalogued as a diving duck, the bird can, starting from the "head under water" posture typical of the species, adopt a mode of search and pursuit of its prey which does not require diving. The "head under water" posture has been noted previously in the specialist literature, but it has never before been so precisely described. The fishing behaviour in very low water levels was never mentioned. We report here observations carried out in September 2009 and June 2010 on the site of the Grosses-Battes in Basse-Ourthe (Angleur). These observations show that some summering individuals prefer riffle zone close to the dam as feeding site at times of low water level, even though many deeper zones are accessible in the vicinity.
Keywords: Behavior; Breeding Season; Common merganser; Mergus merganser

Change in Density of Duck Nest Cavities at Forests in the North Central United States - Denton, J. C.; Roy, C. L.; Soulliere, G. J.; Potter, B. A. (Journal of Fish and Wildlife Management, 2012)
Times Cited: 0 Denton, John C. Roy, Charlotte L. Soulliere, Gregory J. Potter, Bradly A. 0
Keywords: Breeding Season; Bucephala clangula; Common Goldeneye; Bucephala albeola; habitat; bufflehead