Liver Antioxidants in Relation to Beak Morphology, Gizzard Size and Diet in the Common Eider Somateria mollissima - Moller, A. P.; Laursen, K.; Karadas, F. (ANTIOXIDANTS, 2019)
Antioxidants in the liver are particularly abundant in capital breeders that rely on stored resources for egg production. Capital breeders like eider (hereafter common eider) Somateria mollissima have disproportionately large livers with low levels of coenzyme Q(10) when compared to other bird species. Concentrations of total carotenoids and vitamin E in the livers of eiders were smaller than predicted for similarly sized bird species. Eiders with high body condition estimated as body mass relative to skeletal body size had high levels of total carotenoids and low levels of coenzyme Q(10). The concentration of total carotenoids per gram of liver increased with age, and vitamin E and total carotenoids accumulated during the winter onwards from February to peak at the start of incubation in April. Total vitamin E, total carotenoids, and coenzyme Q(10) per gram of liver decreased with increasing beak volume. The size of the empty gizzard increased with increasing liver mass but decreased with total carotenoids and coenzyme Q(10). The main components of the diet were blue mussels Mytilus edulis (40%), draft whelk Nassarius reticulatus (27%), and periwinkle Littorina littorea (10%). The concentration of vitamin E increased with the number of razor clams Ensis sp. and draft whelks in the gizzard and the concentration of total carotenoids increased with the number of beach crabs Carcinus maenas. These observations are consistent with the hypothesis that eiders are limited in their levels of antioxidants through food limitation. Furthermore, they imply that diet and morphological characters involved in food acquisition and processing are important determinants of the level of antioxidants in the liver.
Times Cited in Web of Science Core Collection: 5 Total Times Cited: 5 Cited Reference Count: 43
Keywords: EGGS; alpha-tocopherol; antioxidants; CAROTENOID STATUS; carotenoids; coenzyme Q(10); COENZYME-Q; eiders; IMMUNITY; LIPID-PEROXIDATION; retinol; TISSUES; VITAMIN-E; YOLK

Niche Overlap and Habitat Use by Sympatric Duck Broods in Eastern Washington USA - Monda, M. J.; Ratti, J. T. (Journal of Wildlife Management, 1988)
We evaluated niche overlap and habitat use among duck broods on Turnbull National Wildlife Refuge (Turnbull NWR). During summer of 1983 and 1984, 485 brood observations were recorded in 46 days. Data were gathered on 320 feeding broods of 9 species along 12 niche dimensions. Mean niche overlap values ranged from 0.62 to 0.94 for 36 possible species pairs. The greatest niche separation occurred on hatching date and feeding depth dimensions. Gadwall (Anas strepera) and teal (A. discors and A. cyanoptera) broods were ecologically very similar. Both had sharp mid-season hatching peaks and feed over dense beds of submerged macrophytes. Five species of diving duck broods tended to feed in deeper water and over areas with sparse submerged macrophytes. Among diving ducks, bufflehead (Bucephala albeola) broods were ecologically distinct, feeding over sparse vegetation often far from land. Mallard (A. platyrhynchos) broods were ecologically isolated from other dabbling ducks. They fed in shallow water within stands of emergent vegetation. The niche for ring-necked duck (Aythya collaris) broods was most similar to dabbling ducks, but also showed similarities with other divers. [Other species discussed include Aythya valisineria, A. affinis, A. americana and Oxyura jamaicensis].
Keywords: Breeding Season; Habitat; Bucephala albeola; Bufflehead

The 1978 Epornitic of Avian Cholera on the Chesapeake Bay USA - Montgomery, R. D.; Stein, G. Jr; Stotts, V. D.; Settle, F. H. (Avian Diseases, 1979)
In an outbreak of avian cholera (Pasteurella multocida infection) in wildfowl on and around Chesapeake Bay during March and April of 1978, 31,295 carcasses were retrieved from Maryland and Virginia [USA]. Although other birds were involved, mortality was heaviest among diving ducks (90% of the total), and especially oldsquaw ducks (80% of the total). This is the second outbreak involving primarily diving ducks to be reported from this area of the Atlantic Flyway. It mimics in many respects the epornitic that occurred in 1970. Although mortality was heavy then, this occurrence appears much more severe and could be the largest recorded outbreak of avian cholera in North America.
Keywords: Nonbreeding Seasons; Clangula hyemalis; Long-tailed Duck; Disease

Eiders, nutrients and eagles: Bottom-up and top-down population dynamics in a marine bird - Morelli, F.; Laursen, K.; Svitok, M.; Benedetti, Y.; Moller, A. P. (JOURNAL OF ANIMAL ECOLOGY, 2021)
1. The main objective of this long-term study (1978-2016) was to find the underlying factors behind the declining trends of eider Somateria mollissima in the Baltic/Wadden Sea. 2. Specifically, we aimed at quantifying the bottom-up effect of nutrients, through mussel stocks, on reproduction and abundance of eider, and the top-down effects caused by white-tailed eagle Haliaeetus albicilla predation. 3. Bottom-up effects increase marine primary productivity with subsequent effects on food availability for a major mussel predator. Top-down effects may also regulate eider populations because during incubation female eiders are vulnerable to predation by eagles. 4. Our structural equation modelling explained a large percentage of the variance in eider abundance. We conclude that the Baltic/Wadden Sea eider population was regulated directly by white-tailed sea eagle predation on incubating females and indirectly by the amount of nutrients in seawater affecting both mussel stocks and the breeding success of eiders, reflecting density dependence. 5. These findings may explain the decreasing trend in the Baltic/Wadden Sea eider population during the last decades as an additive effect of top-down and bottom-up factors, and likely as an interaction between them.
Times Cited in Web of Science Core Collection: 9 Total Times Cited: 9 Cited Reference Count: 94
Keywords: Somateria mollissima; COMMON EIDER; SOMATERIA-MOLLISSIMA; SIZE; SPRING MIGRATION; LIFE-HISTORY; WADDEN SEA; LONG-TERM; WINTER; fertilizer; BODY RESERVES; bottom-up effects; breeding success; Haliaeetus albicilla; marine environments; mussel stocks; nutrients

The broader isotopic niche of Long-tailed Duck Clangula hyemalis implies a higher risk of ingesting plastic and non-plastic debris than for other diving seabirds - Morkunas, J.; Biveinyt, V.; Balciunas, A.; Morkune, R. (MARINE POLLUTION BULLETIN, 2021)
This study presents the first data relating to debris ingestion by diving seabirds wintering in the south-eastern Baltic Sea, sets baselines for further studies and presents the first global record of plastic ingestion in Longtailed Duck (Clangula hyemalis). Three of the six studied seabird species, and 2.1% of all 524 examined individuals collected from fishery bycatch, had ingested marine debris. Frequency of ingestion of Long-tailed Duck, Common Murre (Uria aalge) and Red-throated Loon (Gavia stellata) were 5.0%, 4.5% and 3.0% debris respectively, dominated by plastic objects. Providing detailed information about the studied individuals and the debris, this initiates discussion about diving birds' sensitivity to marine debris - it may depend on the feeding preferences of the birds, expressed as isotopic niches in this paper.
Times Cited in Web of Science Core Collection: 5 Total Times Cited: 5 Cited Reference Count: 66
Keywords: BIRDS; COMMUNITIES; Long-tailed Duck; STABLE-ISOTOPES; ACCUMULATION; SEA; Seabirds; Red-throated Loon; Velvet Scoter; Common Murre; Debris; Isotopic niche; LITTER; MARINE DEBRIS; MICROPLASTICS; Plastics; POLLUTION; WATERS

Seabird bycatch in a Baltic coastal gillnet fishery is orders of magnitude larger than official reports - Morkunas, J.; Oppel, S.; Bruzas, M.; Rouxel, Y.; Morkune, R.; Mitchell, D. (AVIAN CONSERVATION AND ECOLOGY, 2022)
Bycatch, or the incidental capture of non-target species in fisheries, has been identified as one of the major threats affecting seabird populations worldwide. In the Baltic Sea, a globally important area for wintering seabirds, bycatch in gillnets represents an important cause of human-induced mortality for seabird species whose populations have declined significantly in recent decades. Although countries are required by European law to report official bycatch data, a lack of data on bycatch in small-scale fisheries impedes an assessment of the contribution of bycatch to declines of seabird populations. This study presents data on the total seabird bycatch in the small-scale coastal fishery for an entire country, Lithuania, in the southeastern Baltic Sea, during the 2015-2020 winter period. An average of 19.3% of the total fishing effort in net-meter days (15.5% of fishing days) were observed each winter season, resulting in observations of 909 bycaught birds from 15 species. Two species composed two-thirds of the total bycatch, Long-tailed Duck (Clangula hyemalis; 42.1%) and Velvet Scoter (Melanitta fusca; 35.4%). Bycatch composition varied with depth, with the majority of bycatch occurring in nets set at depths = 10 m. Adult males dominated the bycatch of benthivorous sea ducks, whereas adult females composed the majority of piscivorous birds caught. Low numbers of juveniles in the bycatch may indicate different wintering sites for young birds. We estimate that between 1500 and 3000 seabirds were bycaught annually in the Lithuanian small-scale coastal fishery in the 2015-2020 period. Because this number is orders of magnitude larger than the bycatch officially reported by the Lithuanian authorities (six birds), our study highlights deficiencies in the country's current bycatch reporting. In contrast to official statistics based on inadequate data, the unintended capture of seabirds in gillnets remains high, despite financial investments to minimize the impact of fisheries on biodiversity.
Times Cited in Web of Science Core Collection: 0 Total Times Cited: 0 Cited Reference Count: 56
Keywords: sea ducks; seabirds; Baltic Sea; THREATS; bycatch composition; gillnets; small-scale fishery; SURF

Triple stable isotope analysis to estimate the diet of the Velvet Scoter ( Melanitta fusca) in the Bantic Sea - Morkune, R.; Lesutiene, J.; Morkunas, J.; Bariseviciute, R. (PEERJ, 2018)
This study quantifies contributions of different food sources in the winter diet of the Velvet Scoter (Melanitta fusca) in coastal waters of the Lithuanian Baltic Sea using nonlethal avian sampling. We highlight the application of stable sulphur isotope ratios as complementary to stable carbon and nitrogen isotope analysis in order to discriminate sandy bottom macrozoobenthos organisms as potential food sources for the Velvet Scoter. Selection of the most relevant trophic enrichment factors and Monte Carlo simulations in order to choose the best fitted model were undertaken. The stable isotope mixing model revealed the main contributions of a group of bivalves, Mya arenaria and Cerastoderma glaucum, to be 46-54%, and while the crustacean, Saduria entomon, comprised 26-35% of the diet.
Times Cited in Web of Science Core Collection: 5 Total Times Cited: 5 Cited Reference Count: 51
Keywords: FOOD-WEB; MODELS; FEATHERS; BLOOD; FISHERIES; Carbon; DEPTH; DISCRIMINATION FACTORS; Gut content; MATTER; Mixing models; Monte Carlo simulations; Nitrogen; PLANKTON; QUANTITATIVE APPROACH; Soft bottom macrozoobenthos; Sulphur; Trophic enrichment factors

Abundance and Distribution of Harlequin Ducks in the Hudson and James Bay Area, Quebec - Morneau, Francois; Robert, Michel; Savard, Jean-Pierre L.; Lamothe, Pierre; Laperle, Marcel; D'Astous, Natalie; Brodeur, Serge; Decarie, Robert (Waterbirds, 2008)
As part of the Hydro-Quebec Grande-Baleine (Great Whale) hydroelectric project feasibility studies, Harlequin Duck (Histrionicus histrionicus) surveys were conducted in 1996 and 1991 in the eastern Hudson Bay and James Bay drainage basins. A total of 142 and 420 Harlequin Ducks were Counted ill 1991 and 1992, respectively, of which 142 (199 1) and 356 (1992) Were found in the area surveyed both years. Most individuals were in pairs and the overall sex-ratio did not deviate significantly from 1:1. The highest numbers of Harlequin Ducks counted over the two),cars were found oil the Little Whale River, Des Loups-Marins Lake, and Nastapoka, A l'Eau Claire and Boutin Rivers. Highest pair densities were observed in June 1992 oil rivers located in tundra and forest tundra i.e., the lower Little Whale, A l'Eau Claire and Nastapoka Rivers, and near D'Iberville Lake. In 1992, pair densities varied between 0.003 and 0.093 pair/km, depending oil the watershed, and followed a latitudinal gradient. Two broods were located in 1991 and three were found during a preliminary survey conducted in 1989. Broods were located on Boutin, Nastapoka, and Great Whale Rivers, as well as along the Hudson Bay coast. The difference in the number of Harlequin Ducks found in June 1991 and 1992 may have been related to weather and methodological factors. Considering the vastness of northern Quebec and the limited area Surveyed during this study, we Suggest that Harlequin Ducks breeding in northern Quebec may well number in the thousands, and represent a very high proportion of the Greenland molting and wintering populations.
Keywords: Breeding Season; Abundance, Distribution, and Trends; Harlequin duck; Histrionicus histrionicus

Thiamine deficiency impairs common eider (Somateria mollissima) reproduction in the field - Morner, T.; Hansson, T.; Carlsson, L.; Berg, A. L.; Munoz, Y. R.; Gustavsson, H.; Mattsson, R.; Balk, L. (SCIENTIFIC REPORTS, 2017)
The Baltic Sea population of the common eider (Somateria mollissima) has declined dramatically during the last two decades. Recently, widespread episodic thiamine (vitamin B1) deficiency has been demonstrated in feral birds and suggested to contribute significantly to declining populations. Here we show that the decline of the common eider population in the Baltic Sea is paralleled by high mortality of the pulli a few days after hatch, owing to thiamine deficiency and probably also thereby associated abnormal behaviour resulting in high gull predation. An experiment with artificially incubated common eider eggs collected in the field revealed that thiamine treatment of pulli had a therapeutic effect on the thiamine status of the brain and prevented death. The mortality was 53% in untreated specimens, whereas it was only 7% in thiamine treated specimens. Inability to dive was also linked to brain damage typical for thiamine deficiency. Our results demonstrate how thiamine deficiency causes a range of symptoms in the common eider pulli, as well as massive die-offs a few days after hatch, which probably are the major explanation of the recent dramatic population declines.
Times Cited in Web of Science Core Collection: 13 Total Times Cited: 13 Cited Reference Count: 48
Keywords: WILD BIRDS; 2 EXPERIMENTAL-MODELS; BRAIN; DEPENDENT ENZYMES; ENCEPHALOPATHY; GLUTAMATE; MEMORY; SEX-RATIO

The Role of Predators in Shaping Urban Bird Populations. 3. Are Predators a Barrier to the Synurbization of Prey Species in Russia's Cities? - Morozov, N. S. (BIOLOGY BULLETIN, 2022)
Cities in which the synurbization of some important predators began simultaneously with, or earlier than, the synurbization of prey species are a precious tool for studying the specificity of predator-prey interactions in urban landscapes. The city of Moscow is an excellent example. The following bird species can be considered synurbic in the city: Tadorna ferruginea (introduced), Bucephala clangula (a successfully introduced species, but the breeding population has declined dramatically since 2010), Anas platyrhynchos (reintroduced), Accipiter gentilis, Falco subbuteo, F. tinnunculus, Corvus cornix, Turdus pilaris, Parus major, and Cyanistes caeruleus. Accipiter nisus, Gallinula chloropus, Asio otus, Motacilla alba, Lanius collurio, Sturnus vulgaris, Hippolais icterina, Sylvia atricapilla, Muscicapa striata, Erithacus rubecula, Luscinia luscinia, Turdus philomelos, T. merula, Fringilla coelebs, Carduelis chloris, and C. carduelis are also successful inhabitants of the city, although their maximum breeding densities in urban green spaces are not obviously higher than those in rural/natural landscapes. A huge and dense population of Corvus cornix, an important nest predator, was formed in Moscow during the 1960s and early 1970s. The urban population of Accipiter gentilis varying during the last decades around 35-40 pairs yearly developed between the late 1970s and early 1990s. Currently, some areas within the city support comparatively diverse predator assemblages. For example, the 1.7-km(2) initial area of the Lomonosov Moscow State University at Vorob'evy Gory contains at least 18 predatory species of mammals and birds in the breeding season, including Falco peregrinus, F. subbuteo, F. tinnunculus, Accipiter nisus, Asio otus, Garrulus glandarius, etc. At the same time, some important predators, like most mustelids, are lacking or rare in Moscow. The order and approximate timing of the establishment of urban populations of different species indicate that a number of avian prey species have reached or been able to maintain high breeding densities in urban green spaces simultaneously with and/or after the synurbization of important predators. In several prey species studied at some localities of the city over the last decades, the proportion of depredated nests was, on average, relatively moderate for a given species (in Turdus philomelos) or sufficiently low (in Parus major, Cyanistes caeruleus, and Turdus pilaris). In general, these conclusions are supported by published data on the same or other prey species from some other cities located in the European part of Russia (Kaliningrad, Ryazan, Voronezh). Even in the presence of numerous predators, urban environments are more or less successfully occupied by substantial numbers of avian prey species from distant taxa and different ecological groups. These include many open-nesters whose clutches and nestlings are highly vulnerable to such predators as corvids and owls. To conclude, a negative answer, although with some reservations, must be given to the question: are predators a difficult barrier for the synurbization of avian prey species?
Times Cited in Web of Science Core Collection: 0 Total Times Cited: 0 Cited Reference Count: 200
Keywords: species interactions; predation; ANSERIFORMES; Russia; ANAS-PLATYRHYNCHOS; ANATIDAE POPULATION; CANIS-FAMILIARIS; CORNIX; DORMICE GLIRIDAE; Moscow; nest predation; NESTING BIRDS; NUMBERS DYNAMICS; predation paradox; predator-prey relationships; SPARROW PASSER-DOMESTICUS; synurbic species; urban ecology; urbanization

THE ROLE OF PREDATORS IN SHAPING URBAN BIRD POPULATIONS. 3. ARE PREDATORS A BARRIER FOR THE SYNURBIZATION OF PREY SPECIES IN RUSSIA'S CITIES? - Morozov, N. S. (ZOOLOGICHESKY ZHURNAL, 2022)
Cities in which the synurbization of some important predators began simultaneously with or earlier than the synurbization of prey species are a precious tool for studying the specificity of predator-prey interactions in urban landscapes. The city of Moscow is an excellent example. The following bird species can be considered synurbic in the city: Tadorna ferruginea (introduced), Bucephala clangula (a successfully introduced species, but the breeding population has declined dramatically since 2010), Anas platyrhynchos (reintroduced), Accipiter gentilis, Falco subbuteo, F. tinnunculus, Corvus cornix, Turdus pilaris, Parus major, and Cyanistes caeruleus. Accipiter nisus, Gallinula chloropus, Asio otus, Motacilla alba, Lanius collurio, Sturnus vulgaris, Hippolais icterina, Sylvia atricapilla, Muscicapa striata, Erithacus rubecula, Luscinia luscinia, Turdus philomelos, T. merula, Fringilla coelebs, Carduelis chloris, and C. carduelis are also successful inhabitants of the city, although their maximum breeding densities in urban green spaces are not obviously higher than those in rural/natural landscapes. A huge and dense population of Corvus cornix, an important nest predator, was formed in the Moscow City during the 1960's and early 1970's. The urban population of Accipiter gentilis varying during the last decades around 35-40 pairs yearly was developed between the late 1970's and early 1990's. Currently, some areas within the city support comparatively diverse predator assemblages. For example, the 1.7-km2 initial area of the Lomonosov Moscow State University at Vorobyovy Gory contains at least 18 predatory species of mammals and birds in the breeding season, including Falco peregrinus, F. subbuteo, F. tinnunculus, Accipiter nisus, Asio otus, Garrulus glandarius, etc. At the same time, some important predators like most mustelids are lacking or rare in Moscow. The order and approximate timing of the establishment of urban populations of different species indicate that a number of avian prey species have reached or been able to support high breeding densities in urban green spaces simultaneously with and/or after the synurbization of important predators. In several prey species studied at some localities of the city over the last decades, the proportion of depredated nests was, on average, relatively moderate for a given species (in Turdus philomelos) or sufficiently low (in Parus major, Cyanistes caeruleus, Turdus pilaris). In general, these conclusions are supported by published data on the same or other prey species from some other cities located in the European part of Russia (Kaliningrad, Ryazan', Voronezh). Even in the presence of numerous predators, urban environments are more or less successfully occupied by substantial numbers of avian prey species from distant taxa and different ecological groups. Among them, there are many open-nesters which clutches and nestlings are highly vulnerable to such predators as corvids and owls. To conclude, a negative answer, although with some reservations, must be given to the question: are predators a difficult barrier for the synurbization of avian prey species?
Times Cited in Web of Science Core Collection: 2 Total Times Cited: 2 Cited Reference Count: 203
Keywords: species interactions; predation; ANSERIFORMES; Russia; ANAS-PLATYRHYNCHOS; ANATIDAE POPULATION; CANIS-FAMILIARIS; CORNIX; DORMICE GLIRIDAE; Moscow; nest predation; NESTING BIRDS; NUMBERS DYNAMICS; predation paradox; predator-prey relationships; SPARROW PASSER-DOMESTICUS; synurbic species; urban ecology; urbanization

Anti-parasite treatment results in decreased estimated survival with increasing lead (Pb) levels in the common eider Somateria mollissima - Morrill, A.; Provencher, J. F.; Gilchrist, H. G.; Mallory, M. L.; Forbes, M. R. (PROCEEDINGS OF THE ROYAL SOCIETY B-BIOLOGICAL SCIENCES, 2019)
Field experiments where parasites are removed through treatment and contaminant levels in host tissues are recorded can provide insight into the combined effects of parasitism and contaminants in wild populations. In 2013 and 2014, we treated northern common eider ducks (Somateria mollissima) arriving at a breeding colony with either a broad-spectrum antihelminthic (PANACUR (R)) or distilled water, and measured their blood lead (Pb) levels. Breeding propensity and clutch sizes were inversely related to Pb in both treatment groups. In comparison, a negative effect of Pb on resight probability the following year was observed only in the anti-parasitic treatment (APT) group. These contrasting patterns suggest a long-term benefit to survival of intestinal parasitism in eiders experiencing Pb exposure. The arrival date of hens explained some, but not all, of the effects of Pb. We weigh the merits of different hypotheses in explaining our results, including protective bioaccumulation of Pb by parasites, condition-linked thresholds to costly reproduction and the direct effects of APT on eider health. We conclude that variation in helminth parasitism influences survival in this migratory bird in counterintuitive ways.
Times Cited in Web of Science Core Collection: 7 Total Times Cited: 7 Cited Reference Count: 71
Keywords: contaminants; Somateria mollissima; Arctic; BODY CONDITION; BREEDING SUCCESS; INDIVIDUAL OPTIMIZATION; AGE; ARRIVAL DATE; COMMERCIAL TURKEYS; FENBENDAZOLE; IMMUNE FUNCTION; PANACUR (R); parasites; Pb; REPRODUCTIVE EFFORT

Some Aspects of the Breeding Biology of the Hooded Merganser - Morse, T. E.; Jakabosky, J. L.; McCrow, V. P. (Journal of Wildlife Management, 1969)
Keywords: Breeding Season; Hooded Merganser; Lophodytes cucullatus

Distribution, abundance and reaction to aerial surveys of post-breeding king eiders (Somateria spectabilis) in western Greenland - Mosbech, Anders; Boertmann, David (Arctic, 1999)
Moulting and post-breeding king eiders in western Greenland were surveyed in late August and early September of 1993, 1994, and 1995. We counted all eiders observed during fixed-winged aircraft flights along coastlines and offshore transects. The coastline in the survey area is roughly 13 400 km long, and our flightlines totaled approximately 16 500 km. The areas optimal for the birds were covered fully several times; in less suitable areas, only a fraction of the coastline was covered. Using the largest count for coastlines covered more than once, we counted a total of 22 980 king eiders. Large numbers of king eiders were observed at a number of remote localities on the west coast of Disko Island and in southern Upernavik. At localities considered to have frequent human disturbance, few birds were observed. Highest densities were found along coasts with sandy or muddy areas at the shorelines. Overall we estimate that 30000 to 40000 king eiders reside in the coastal zone of western Greenland in late August. Even allowing for a high turnover rate, as different individuals may occupy the moulting areas during the extended period from July to October, this figure can account for only half of a 1950s estimate that 200 000 males and immatures were moulting in western Greenland.
Keywords: Abundance, Distribution, and Trends; Nonbreeding Seasons; Molt; King Eider; Somateria spectabilis

Year-round movements of Northern Common Eiders Somateria mollissima borealis breeding in Arctic Canada and West Greenland followed by satellite telemetry - Mosbech, Anders; Gilchrist, Grant; Merkel, Flemming; Sonne, Christian; Flagstad, Annette; Nyegaard, Helene (Ardea, 2006)
We implanted satellite transmitters to track Northern Common Eiders Somateria mollissima borealis from breeding grounds in West Greenland and eastern Arctic Canada, and from their wintering grounds in SW Greenland. We compared distances moved, timing, duration, and patterns of movement between migration flyways and between spring and autumn migration. Common Eiders used two wintering areas linked by three routes. Eiders tracked from a NW Greenland breeding colony (n = 10) migrated south along the coast to winter exclusively in west and southwest Greenland. Breeders from Arctic Canada wintered in two distinct areas with a tendency to segregate by sex. Some eastern Canadian Arctic Eiders from a colony near Southampton Island, migrated through Hudson Strait along the Labrador and Newfoundland coasts, to winter in Atlantic Canada. However, 60% (n = 25) originating from this colony crossed the Davis Strait to winter in SW Greenland, returning in spring to breed in Canada, linking the two north-south flyways. Seven of 8 Eiders implanted in SW Greenland in winter crossed the Davis Strait into Arctic Canada in spring to breed. Apparently more females than males from the Canadian colony (14/18 females and 1/6 males) followed the shorter east-west flyway in fall. Spring migration was initiated later in the Canadian Arctic. Tracked movements ranged from sedentary birds that nested within 45 km of their wintering area in SW Greenland, to migration routes that exceeded 2000 km. Spring migration speeds averaged c. 60 km d(-1), less than half that during moult migration (142 km d(-1)) and autumn migration (190 km d(-1)). This suggests that Eiders must stop to feed whilst travelling to breed, are constrained by sea ice conditions, or both. Climatic and sea ice conditions differ between the eastern Arctic Canada and west Greenland which influence wintering sites, timing and routes of spring migration.
Keywords: Breeding Season; Common Eider; Nonbreeding Seasons; Migration; Somateria mollissima; Dispersal; SDJV funded; Population Delineation

Late winter distribution and abundance of sea-associated birds in south-western Greenland, the Davis Strait and southern Baffin Bay - Mosbech, Anders; Johnson, Stephen R. (Polar Research, 1999)
Sea-associated birds were recorded during systematic aerial surveys of marine mammals in south-western Greenland, the Davis Strait and southern Baffin Bay in March 1981, 1982, 1991, 1993 and in April 1990. Most surveys included the northern part of the south-west Greenland Open Water Area, which in most years lies between 62degree and 67degreeN, but none of the area south of 63degreeN was surveyed. The bird data are generally semi-quantitative and provide information on distribution and relative abundance in different areas during different years, under different ice conditions. In all years, regardless of ice conditions, large concentrations of king eiders Somateria spectabilis were found in waters <50 m deep on the shallow banks off south-west Greenland, especially on the northern portion of the Store Hellefiskebanke. We estimate that in 1981 and 1982 about 270 000 king eiders overwintered on the banks off south-west Greenland. Compared to king eiders, flocks of common eiders Somateria mollissima were considerably more dispersed. They were found mainly close to shore off south-west Greenland, where they were distributed along rocky coastlines. A few thousands of large guillemots Uria spp. were recorded in the study area in March 1981, 1982, 1991 and 1993, but large numbers (>65 000 birds) were recorded north of the south-west Greenland Open Water Area in April 1990, indicating that northward spring migration was underway at this time.
Keywords: Abundance, Distribution, and Trends; Common Eider; Sea Ducks - General; Nonbreeding Seasons; King Eider

Nesting of King Eiders Somateria-Spectabilis and Snowy Owls Nyctea-Scandiaca near Cape Churchill Manitoba Canada - Moser, T. J.; Rusch, D. H. (Canadian Field-Naturalist, 1988)
We report the nesting of King Eiders (Somateria spectabilis) (second and subsequent records for Manitoba), and Snowy Owls (Nyctea scandiaca) (first records of Manitoba since 1936), near Cape Churchill, Manitoba.
Keywords: Breeding Season; King Eider; Somateria spectabilis

Hooded mergansers at Afognak Island, Alaska - Mossman, Archie S. (Condor, 1957)
Keywords: Hooded Merganser; Lophodytes cucullatus

Wintering Sea Ducks in the Moray and Dornoch Firths Scotland Uk - Mudge, G. P.; Allen, D. S. (Wildfowl, 1980)
The numbers, distribution and behavior of seaducks in the Moray and Dornoch Firths are described for the winters of 1977-1978 and 1978-1979. This area is at present the major seaduck wintering site in Great Britain, with an average of .apprx. 20,000 birds. It holds internationally important concentrations of common scoter, Melanitta nigra, velvet scoter, M. fusca, long-tailed duck, Clangula hyemalis, and Red-breasted merganser, Mergus serrator, and nationally important concentrations of Elder, Somateria mollissima, and goldeneye, Bucephala clangula. The majority of the ducks occurred at 5 sites (Spey Bay, Burghead Bay, Culbin and Nairn Bars, Cromarty-Rosemarie-Nairn), and the northern outer Dornoch Firth in both winters Spey Bay was of overwhelming importance. The relative use of individual sites varies considerably year to year.
Keywords: Abundance, Distribution, and Trends; Sea Ducks - General; Nonbreeding Seasons

Surgical and immediate postrelease mortality of harlequin ducks (Histrionicus histrionicus) implanted with abdominal radio transmitters with percutaneous antennae - Mulcahy, Daniel M.; Esler, Daniel (Journal of Zoo and Wildlife Medicine, 1999)
Radiotelemetry is an essential tool in the study of free-ranging bird populations, and a variety of transmitter-attachment methods have been developed. A promising new method is abdominal implantation of a transmitter with a percutaneous antenna. Researchers using this technique should be concerned about and aware of mortality during surgery and during the immediate postrelease period (the 14-day period following surgery). Of 307 radio-implant surgeries performed between 1995 and 1997 in harlequin ducks (Histrionicus histrionicus), 7 (2.3%) deaths were documented during surgery or anesthetic recovery. Of 295 birds released with implanted radios, 10 (3.4%) died during the immediate postrelease period. Modifications to anesthetic procedures used in the 204 surgeries performed in 1996 and 1997 reduced mortality to 1.5% during surgery and 1.5% during the immediate postrelease period. Anesthetic modifications included intubation of all birds, placement of birds on an elevated platform that allowed the head to rest at a level lower than the body during surgery, placement of a heated water blanket under the birds during surgery, monitoring of body temperature, and use of electrocardiogram and Doppler ultrasound to monitor heart rates and arrhythmias. Low levels of mortality associated with abdominal implantation of radio transmitters may be unavoidable, but mortality can be minimized with adjustments to anesthetic technique.
Keywords: Nonbreeding Seasons; Harlequin duck; Histrionicus histrionicus; Techniques

Survival of Captive and Free-ranging Harlequin Ducks (Histrionicus histrionicus) following Surgical Liver Biopsy - Mulcahy, Daniel M.; Esler, Daniel (Journal of Wildlife Diseases, 2010)
We measured intra- and postoperative mortality rates or captive and free-ranging Harlequin Ducks (Histrionicus histrionicus) undergoing surgical liver biopsy sampling for determination of the induction of cytochrome P4501A, a biomarker of oil exposure. Liver biopsies were taken from and radio transmitters were implanted into 157 free-ranging Harlequin Ducks over three winters (55 in 2000, 55 in 2001, and 47 in 2002). No birds died during surgery, but seven (4.5%) died during recovery from anesthesia (three in 2001 and four in 2002). None of the deaths could be attributed directly to the liver biopsy. Four of the 150 (2.7%) birds that were released died in the 2 wk period after surgery. All post-release deaths occurred in 2001; no birds died after release in 2000 or 2002. No mortalities of 36 captive birds occurred during surgery or recovery or in the 2 wk period following surgery. Hemorrhage was a minor problem with one captive bird. Surgical liver biopsies appear to be a sale procedure, but anesthetic complications may occur with overwintering ducks.
Keywords: Nonbreeding Seasons; Harlequin duck; Histrionicus histrionicus; Techniques

Loss from Harlequin Ducks of abdominally implanted radio transmitters equipped with percutaneous antennas - Mulcahy, Daniel M.; Esler, Daniel; Stoskopf, Michael K. (Journal of Field Ornithology, 1999)
We documented extrusion and loss of abdominally implanted radio transmitters with percutaneous antennas from adult female Harlequin Ducks (Histrionicus histrionicus). Birds were captured during wing molt (late August to mid-September) in 1995-1997. Of 44 Harlequin Ducks implanted with radios and recaptured, 7 (16%) had lost their transmitters and 5 (11%) had radios in the process of extruding. Most (11 of 12) extrusions and losses occurred in birds implanted with radios in 1996 and recaptured in 1997. We suggest that transmitter extrusions and losses were due largely to changes in transmitter design made between 1995 and 1996. Transmitters implanted in 1996 were cylindrical rather than spherical, had a flat end with an abrupt edge, and the lower portion of the antenna was reinforced. Radio losses occurred after the 7-mo monitoring period and caused no apparent harm to the birds. Investigators using implanted radios with percutaneous antennas for long-term projects should be aware ofthe potential for radio extrusion and should minimize the problem by using transmitters that have no sharp edges and that are wide, rather than narrow.
Keywords: Nonbreeding Seasons; Harlequin duck; Histrionicus histrionicus; Techniques

Creche Formation in the Common Eider - Munro, J.; Bedard, J. (Auk, 1977)
The formation of creches was studied in the common eider (Somateria mollissima) nesting at high density on Bicquette Island [Canada] in the St. Lawrence River estuary. Aspects of social behavior relevant to creche formation are examined in detail. Data from 293 individually tagged females aided in elucidating the breeding history and in understanding the parental behavior of previously recognized categories of adult females ('B-Brooding,' 'A-Associate,' 'V-Visiting,' and 'N-Neutral'). Creches resulting from the encounter between 2 or more broods begin to form immediately after the nest exodus and last well into the rearing period (about 10 wk). The encounters themselves may be stimulated by alarm or predation or may sometimes result from the mutual attraction of ducklings. The rate of fixation of such encounters into permanent creches decreases from a high of 88% in broods reaching the shore of the nesting island to a low of 0-6% in encounters between groups meeting during the latter half of the rearing period (between the 4th and the 10th wk). Agonistic interactions among B-status females tending creches provoke a hitherto unexplained lowering of the ratio of females to ducklings in such groups. Instead of a loose system of cooperation between females rearing creches as was previously surmised, it was found that the organization of these groups is based upon a hierarchical ranking of females involved in tending. The creche is thus seen as an accidentally expanded family.
Keywords: Behavior; Breeding Season; Common Eider; Somateria mollissima

Gull Predation and Creching Behavior in the Common Eider - Munro, J.; Bedard, J. (Journal of Animal Ecology, 1977)
The nest exodus of 3399 Somateria mollissima ducklings was followed on densely populated Bicquette and Fraises islands in the St. Lawrence River estuary [Canada] in 1973 and 1974. In 1973, 2485 ducklings were attacked a total of 906 times by Larus argentatus and L. marinus between their arrival on the shore and their departure from the nesting island with the subsequent loss of 335 birds (overall predation success 37%). A 34-fold decrease in predation was noted in 1974 when 974 ducklings suffered only 27 attacks which led to the loss of 8 young. Predation acted as a proximate factor leading to amalgamation of several broods and/or creches. Groups of eiders coming within close range of each other would amalgamate 12 times more often when their encounter coincided with predation than when it did not. Predation was usually by gulls acting singly or in loose pairs, but a system of group predation involving from 5-40 gulls was observed on 16 occasions in 1973. Group predation always led to destruction of the entire creche attacked and increased in frequency as the hatching season progressed. Larger creches suffered more attacks than small ones but offered much higher duckling survival at least in the face of attack by lone gulls. The advantage of creching accrued through decreasing the risk to the duckling hidden into the group rather than through enhancing the detection of aerial predators. Creching remains advantageous even when the overall results of the 2 types of predation are combined. When group predation only is considered, creching is clearly disastrous, for large creches are much more vulnerable than small ones.
Keywords: Behavior; Breeding Season; Common Eider; Somateria mollissima; Trophic Interactions

The food and feeding habits of the red-breasted merganser in British Columbia - Munro, J. A.; Clemens, W. A. (Jour Wildlife Management, 1939)
The red-breasted merganser (Mergus serrator) is an abundant visitant to the coast regions of British Columbia from Sept. to Apr. inclusive. Thus the relation of the species to the fisheries is seasonal and centers chiefly about its feeding habits on the coast waters. The food of 96 specimens taken on the lower stretches of coastal streams consisted largely of salmon eggs and sculpins; that of 15 specimens taken on the sea comprised chiefly herring with a smaller percentage of salmonoids, eulachons, sticklebacks, sculpins, blennies, rockfishes, and crustaceans. || ABSTRACT AUTHORS: J. A. Munro
Keywords: Nonbreeding Seasons; Trophic Interactions; Mergus serrator; Red-breasted merganser

Observations on the birds of Mount Mc-Kinley National Park, Alaska - Murie, Adolph (Condor, 1946)
Notes are given on the nesting habits, behavior, and occurrence of 33 spp., 6 of which are new to the park: Shoveller (Spatula clypeata), Barrow Goldeneye (Glaucionetta islandica), Bonaparte Gull (Larus Philadelphia), Violet-green Swallow (Tachycineta thalassina), Tree Swallow (Iridoprocne bicolor), and White-winged Crossbill (Loxia leucoptera). The Dipper (Cinclus mexicanus) was listed on a previous hypothetical list for the park area. || ABSTRACT AUTHORS: D. J. Borror
Keywords: Breeding Season; Abundance, Distribution, and Trends; Barrow's Goldeneye; Bucephala islandica

Associations between persistent organic pollutants and vitamin status in Brunnich's guillemot and common eider hatchlings - Murvoll, Kari Mette; Skaare, Janneche Utne; Jensen, Henrik; Jenssen, Bjorn Munro (Science of the Total Environment, 2007)
The aim of the study was to examine associations between persistent organic pollutants and vitamin A (retinol), retinyl palmitate and vitamin E status (alpha-tocopherol) in two species occupying different trophic positions in the Arctic food web. Levels of polychlorinated biphenyls (PCBs), some selected organochlorine pesticides (OCPs), polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecane (HBCD) were analyzed in yolk sac of newly hatched chicks of Brunnich's guillemot (Uria lomvia) and common eider (Somateria mollissima) from Kongsfjorden, Svalbard (Norwegian Arctic) (79 degrees N). Morphological variables were measured, and levels of retinol, retinyl palmitate and alpha-tocopherol were analyzed in plasma and liver. Brunnich's guillemot had significantly higher levels of POPs than common eider, as expected from its higher trophic position. Morphological traits seemed to be negatively related to POPs in Brunnich's guillemots, but not in common eiders. In Brunnich's guillemot, negative relationships were found between some OCPs (hexachlorobenzene, oxychlordane, p,p '-DDE) and liver alpha-tocopherol levels. The negative relationships between these OCPs and liver alpha-tocopherol levels in Brunnich's guillemot hatchlings became less evident when the confounding effect of liver mass was corrected for. In common eider positive relationships were found between summed PCB (Sigma PCBs) and some OCPs (beta-hexachlorocyclohexane, oxychlordane) and liver alpha-tocopherol levels. Differences in relationships between POPs and vitamin status in the two species may be related to differences in POP exposure levels linked to their trophic position in the Arctic marine food web, or to intrinsic physiological differences between the species. (c) 2007 Elsevier B.V. All rights reserved.
Keywords: Breeding Season; Common Eider; Contaminants; Somateria mollissima; Physiology

Wintering ducks in the Czech Republic: changes in their population trends and distribution - Musilova, Zuzana; Musil, Petr; Polakova, Simona; Fuchs, Roman (Wildfowl, 2009)
The Czech Republic, as an inland Central European country, is not part of the core wintering area for most duck species in the Western Palearctic. Nevertheless, inter-seasonal changes in numbers and distribution of particular species are recorded, which may reflect climatic fluctuation. Waterbird counts were carried out annually at 48-639 wetland sites in the Czech Republic in 1966-2008, as part of the International Waterbird Census (hereafter IWC). These data were used to assess long-term trends in the number of duck wintering in the Czech Republic for the 15 most abundant species. Increasing trends were found for six species: Wigeon Anas penelope, Mallard Anas platyrhynchos, Pochard Aythya ferina, Tufted Duck Aythya fuligula, Smew Mergus albellus and Goosander Mergus merganser. Teal Anas crecca was the only species found found to be declining. Those with stable trends were: Pintail Anas acuta, Scaup Aythya marila, Velvet Scooter Melanitta fusca and Goldeneye Bucephala clangula. No (uncertain) trend was found in least abundant Gadwall Anas strepera, Shoveler Anas clypeata, Red-crested Pochard Netta rufina and Ferruginous Duck Aythya nyroca. Wintering distribution (measured as the ratio of the number of sites occupied by a given species to the total number of sites investigated) increased in six species (Wigeon, Gadwall, Mallard, Red-crested Pochard, Tufted Duck and Goosander) and decreased in two species (Teal and Ferruginous Duck). No significant changes in distribution were found for the seven remaining species. Changes in numbers correlated with changes in distribution in each species. Annual variation in the numbers and distribution of ducks wintering in the Czech Republic were more strongly associated with long-term trends in numbers than with annual variation in climate conditions. Nevertheless, the numbers of wintering birds recorded on standing waters were positively, correlated with climatic variables in 10 duck species.
Keywords: Abundance, Distribution, and Trends; Sea Ducks - General; Nonbreeding Seasons

Molecular Diagnosis of Toxoplasma gondii and Neospora caninum in Brain Tissues of Some Wild Birds - Muz, M. N.; Kilinc, O. O.; Isler, C. T.; Altug, E.; Karakavuk, M. (Kafkas Universitesi Veteriner Fakultesi Dergisi, 2015)
There are limited molecular studies about Toxoplasma gondii and Neospora caninum which are economically important livestock protozoons in wild birds investigated by polymerase chain reaction (PCR) method. Molecular prevalance of both parasites in brain tissues of wild birds in Turkey is unknown. Prevalance of T. gondii was 7%, N. caninum was 14% and mix infection was found 4% in brain tissues of 101 wild birds under 20 species from two different regions of Turkey. The chi-square test has been applied to the acquired data. This is the first molecular biologic investigation for the aim of PCR diagnosis of T. gondii in brain tissues of Corvus corone, Melanitta fusca, Aquila heliaca, Aquila pomarina, Buteo rufinus, Accipiter nisus, Strix aluco and N. caninum in brain tissues of Larus genei, Corvus corone, Melanitta fusca, Anas clypeata, Perdix perdix, Aquila heliaca, Buteo rufinus in the world. This also is the first molecular diagnostic investigation of T. gondii and N. caninum in brain tissues of wild birds in Turkey.
Muz, Mustafa Necati Orunc Kilinc, Ozlem Isler, Cafer Tayer Altug, Enes Karakavuk, Muhammet
Keywords: Melanitta fusca; White-winged Scoter; Parasites

Distribution and metabolism of polycyclic aromatic hydrocarbons (PAHs) injected into eggs of chicken (Gallus domesticus) and common eider duck (Somateria mollissima) - Naf, Carina; Broman, Dag; Brunstrom, Bjorn (Environmental Toxicology and Chemistry, 1992)
The present study focuses on the uptake, distribution, and metabolism of 16 polycylic aromatic hydrocarbons (PAHs) injected into eggs of chicken (Gallus domesticus) and common eider (Somateria mollissima). Of the total dose of 0.2 ppm, injected on day 4 of incubation, 94% was metabolized within the chicken egg by day 18. The gallbladder showed the highest PAH concentrations of the analyzed organs/structures (gallbladder, liver, kidney, adipose tissue) of the chick and eider embryos. The proportion of the total PAH content present in these organs/structures was higher in the eider embryo (40%) than in the chick embryo (16%). Chick embryos, eider embryos, and wild juvenile eiders had similar PAH concentrations and PAH profiles. The characteristics of this "PAH pool" seemed to be largely unrelated to the relative concentrations of the PAHs to which the birds were exposed, the age of the organisms, and the routes of exposure. The largest studied PAH molecule, coronene, was not taken up from the yolk by the embryo as efficiently as the other PAHs, but once taken up it was metabolized as readily as the others. Basal aryl hydrocarbon (benzo(a)pyrene) hydroxylase (AHH) activities of chick and eider embryos were of similar magnitude.
Keywords: Breeding Season; Common Eider; Contaminants; Somateria mollissima

Inuit Knowledge of the Ecology of the Common Eider in Northern Quebec Canada - Nakashima, D. J. (Reed, A. (Ed.). Canadian Wildlife Service Report Series, No. 47. Eider Ducks in Canada. V+177p. Canadian Wildlife Service: Ste-Foy, Quebec, Canada. Illus. Maps. Paper, 1987)
Keywords: Conservation; Common Eider; Somateria mollissima

Plastic debris ingestion by seabirds on the Korean Peninsula - Nam, K. B.; Kim, M.; Hong, M. J.; Kwon, Y. S. (MARINE POLLUTION BULLETIN, 2021)
Plastic ingestion studies in seabirds that analyse the frequency of occurrence and the characteristics of the plastics ingested by each species provide valuable information for marine environmental assessments by quantifying the impacts of marine debris on seabirds. We investigated the frequency of plastic ingestion from a sample of 387 individuals of 11 seabird species on the Korean Peninsula. We found evidence of plastic ingestion in redbreasted mergansers (Mergus serrator) (33.3%), Pacific loons (Gavia pacifica) (10.0%), Swinhoe?s storm petrels (Hydrobates monorhis) (93.7%), black-tailed gulls (Larus crassirostris) (12.9%) and ancient murrelets (Synthliboramphus antiquus) (0.9%). In particular, it was observed that Swinhoe?s storm petrels had the highest frequency of plastic ingestion, both in terms of the number of affected individuals, and the accumulated mass of plastic debris ingested. The majority of seabirds examined in our study had ingested microplastics, comprised predominantly of user plastics. This is the first report quantifying plastic ingestion in seabirds on the Korean Peninsula and in the broader area of the East Asian Seas.
Times Cited in Web of Science Core Collection: 13 Total Times Cited: 14 Cited Reference Count: 34
Keywords: BIRDS; SEA; Seabirds; BAY; TRENDS; MARINE DEBRIS; MICROPLASTICS; POLLUTION; Korean peninsula; Microplastic; Plastic debris; Plastic ingestion; THREAT

Temporal distribution of waterfowl in eastern South Dakota: Implications for aerial surveys - Naugle, David E.; Johnson, Rex R.; Cooper, Thomas R.; Holland, Matthew M.; Higgins, Kenneth F. (Wetlands, 2000)
The U.S. Fish and Wildlife Service and Canadian Wildlife Service incorporate information from annual aerial and ground counts of waterfowl into harvest management strategies. Timing of population surveys is thought to be optimal for early nesting species but may not reliably reflect the status of species with later migration chronology. The purpose of this study was to evaluate effects of survey timing on diving duck and duck brood abundance indices in eastern South Dakota. Findings indicate that timing of aerial breeding surveys occurred too early in eastern South Dakota to accurately reflect diving duck population status because birds had not yet settled into breeding habitats and aerial production surveys did not coincide with peak duck brood abundance. Diving duck abundance from aerial surveys conducted during 10-17 May were higher than indices from ground surveys conducted 2 weeks later because lesser scaup (Aythya affinis), ring-necked duck (Aythya collaris), and bufflehead (Bucephala albeola) were still migrating through eastern South Dakota. Ground-survey estimates of redhead (Aythya americana) and canvasback (Aythya valisineria) abundance exceeded the upper limit of 95% confidence intervals for aerial survey estimates. Results from our second year of study showed an 11-fold decrease in lesser scaup abundance and an 8-fold decrease in ring-necked duck abundance in the two weeks following aerial breeding surveys. Brood abundance of dabbling and diving ducks peaked 1-1.5 months after aerial production surveys conducted in early July. Late-nesting indices calculated from aerial surveys were unrelated (P = 0.21) to number of late-hatching broods, whereas number of broods hatching after aerial surveys was correlated with late-nesting indices from ground surveys (r2 = 0.74, P < 0.01) and with number of July ponds (r2 = 0.77, P < 0.01). We encourage scientists to initiate a more thorough evaluation of survey biases to ensure that trends accurately reflect status of duck populations and to explore the possibility of using a separate late May/early June aerial survey after diving ducks have settled into habitat as a way of assessing breeding population trends for these species.
Keywords: Breeding Season; Abundance, Distribution, and Trends; Sea Ducks - General; Techniques

Exposure of Sea Otters and Harlequin Ducks in Prince William Sound, Alaska, USA, to Shoreline Oil Residues 20 Years after the Exxon Valdez Oil Spill - Neff, Jerry M.; Page, David S.; Boehm, Paul D. (Environmental Toxicology and Chemistry, 2011)
We assessed whether sea otters and harlequin ducks in an area of western Prince William Sound, Alaska, USA (PWS), oiled by the 1989 Exxon Valdez oil spill (EVOS), are exposed to polycyclic aromatic hydrocarbons (PAH) from oil residues 20 years after the spill. Spilled oil has persisted in PWS for two decades as surface oil residues (SOR) and subsurface oil residues (SSOR) on the shore. The rare SOR are located primarily on the upper shore as inert, nonhazardous asphaltic deposits, and SSOR are confined to widely scattered locations as small patches under a boulder/cobble veneer, primarily on the middle and upper shore, in forms and locations that preclude physical contact by wildlife and diminish bioavailability. Sea otters and harlequin ducks consume benthic invertebrates that they collect by diving to the bottom in the intertidal and subtidal zones. Sea otters also dig intertidal and subtidal pits in search of clams. The three plausible exposure pathways are through the water, in oil-contaminated prey, or by direct contact with SSOR during foraging. Concentrations of PAH in near-shore water off oiled shores in 2002 to 2005 were at background levels (< 0.05 ng/L). Median concentrations of PAH in five intertidal prey species on oiled shores in 2002 to 2008 range from 4.0 to 34 ng/g dry weight, indistinguishable from background concentrations. Subsurface oil residues are restricted to locations on the shore and substrate types, where large clams do not occur and where sea otters do not dig foraging pits. Therefore, that sea otters and harlequin ducks continue to be exposed to environmentally significant amounts of PAH from EVOS 20 years after the spill is not plausible. Environ. Toxicol. Chem. 2011;30:659-672. (C) 2011 SETAC
Keywords: Nonbreeding Seasons; Harlequin duck; Histrionicus histrionicus; Contaminants

Low costs of salt turnover in common eiders Somateria mollissima - Nehls, Georg (Ardea, 1996)
The energetic costs of salt turnover were measured in Common Eiders Somateria mollissima by respirometry. Rates of salt intake in the field were estimated from salt content of their chief prey, the mussel Mytilus edulis. Metabolic rate in Eiders increases in response to salt intake and may double for a short time following a load of 5 g NaCl. With a load of 2.5 g and 5 g NaCl the metabolic rate remains elevated for about one h. Overall costs of salt turnover are estimated at 1.3 kJ g-1 NaCl. From the proportion of water content to flesh content of mussels collected in the Wadden Sea, the costs of salt turnover are calculated at 2.0-2.4% of metabolizable energy intake. In the field, salt intake per foraging bout reaches 4.3 g and salt excretion, as inferred from the frequency of head shaking, continues for over one h. The direct salt intake in wintering Eiders reaches about 50 g per day leading to a mass-specific salt intake of 24 mg g-1 body mass. However, total intake is somewhat higher as Eiders drink some water after swallowing a mussel. The mass-specific salt intake is higher than reported for other marine birds. The maximum rate of salt excretion in Eiders, as calculated from published data, hardly matches the rate of salt intake of feeding Eiders. It is concluded that the capacity for salt excretion may limit the rate of food intake in birds feeding on whole-shelled bivalves in times of high food demands and low flesh contents of the bivalves.
Keywords: Common Eider; Nonbreeding Seasons; Somateria mollissima; Energetics and Nutrition

Observations on the day-old young of the spectacled eider, Somateria fischeri - Nelson, Colleen H. (Auk, 1964)
Four day-old spectacled eiders were measured, observed and painted by the author at Round Lake Waterfowl Station, Round Lake, Minnesota, during June and July, 1963. Her description of the ducklings differed from most published accounts in 2 respects bill color and the nature of the "spectacle." The bill color was found to be pale grayish-blue. A dark-colored "spectacle", almost exactly similar to the light-colored "spectacle" of the adult, was found to be present in the downy young. From observations of the eiders over a 5-week period, it was concluded that previous illustrations of the downy yound showing a dark "question-mark" around the eye represented a stage in the molt from natal down to juvenal plumage rather than the downy young of 2-week age or less. Various early behavioral characteristics of the eiders' 1st week of life were described and illustrated. || ABSTRACT AUTHORS: Author
Keywords: Breeding Season; Somateria fischeri; Spectacled Eider; Physiology

Eye Color Changes in Barrows Goldeneye Bucephala-Islandica and Common Goldeneye Bucephala-Clangula-Americana Ducklings - Nelson, C. H. (Wilson Bulletin, 1983)
Keywords: Breeding Season; Bucephala clangula; Common Goldeneye; Techniques; Barrow's Goldeneye; Bucephala islandica

The identification of Barrow's Goldeneye Bucephala islandica and Common Goldeneye B. clangula americana ducklings - Nelson, Colleen Helgeson (Wildfowl, 1993)
Keywords: Breeding Season; Bucephala clangula; Common Goldeneye; Techniques; Barrow's Goldeneye; Bucephala islandica

A Definite Colorado Breeding Record for the Harlequin Duck - Nelson, C. H.; Parkes, K. C. (Auk, 1976)
Keywords: Breeding Season; Abundance, Distribution, and Trends; Harlequin duck; Histrionicus histrionicus

Blood parasites of some Maine waterfowl - Nelson, E. Clifford; Gash-Wiler, Jay S. (Jour Wildlife Management, 1941)
Blood smears were obtained from 130 waterfowl of 9 spp. live-trapped during banding operations. Leucocytozoon was found in 59% of 77 wood ducks and 89% of 29 black ducks. These birds came from the same area so perhaps black ducks are more prone to infection than wood ducks. No ducklings under 2 wks. of age were found infected but all from 3 to 7 wks. of age were infected. New hosts recorded for Leucocytozoon are the wood duck, American merganser, hooded merganser, American golden-eye, and green-winged teal. Haemoproteus was found in 64% of 77 wood ducks and 20% of 29 black ducks, which may indicate that wood ducks are more prone to this infection. Haemoproteus was also found in ring-necked ducks and coots. Ring-necked ducks, wood ducks, and coots are new hosts of this parasite. Microfilaria was found in 38% of the wood ducks and 31% of the black ducks, 1 of 6 ring-neck ducks, one of 3 hooded mergansers, 1 green-winged teal, and 1 of 2 coots. 3 types of microfilariae were found. The adult worms were not collected. No parasites were found in 2 lesser scaups. || ABSTRACT AUTHORS: E. C. Nelson
Keywords: Hooded Merganser; Lophodytes cucullatus; Parasites

Effects of lake characteristics and human disturbance on the presence of piscivorous birds in Northern Wisconsin, USA - Newbrey, Jennifer L.; Bozek, Michael A.; Niemuth, Neal D. (Waterbirds, 2005)
Despite Current anthropogenic alterations to riparian areas and littoral zones of lakes, little information is available on how human-induced alterations affect lacustrine habitat use by many piscivorous birds in northern Wisconsin, USA. The influence of lake characteristics and human disturbance on species richness and the presence of seven species of piscivorous birds was determined on 98 lakes located primarily in Vilas and Oneida counties, Wisconsin. Lakes were surveyed for species presence using shoreline perimeter surveys with total searching time standardized to two, one-hour surveys per lake. Piscivorous bird species richness was highest on large lakes with high pH levels. Using logistic regression, many species were found to be present on lakes possessing characteristics associated with high abundances of fish, including lake surface area, pH, and water clarity. At least one of these variables was included in the final models for species richness and presence of the Common Merganser (Mergus merganser), Bald Eagle (Haliaeetus leucocephalus), Great Blue Heron (Ardea herodias), and Ring-billed Gull (Larus delawarensis). Three species avoided lakes possessing characteristics associated with high levels of human disturbance; the Osprey (Pandion haliaetus) was not found on lakes with low percentages of macrophytes, the Common Merganser was absent on lakes with low water clarity, and the Common Loon (Gavia immer) was not present on lakes with many cottages. Many species of piscivorous birds were widespread regardless of the degree of human development, indicating that habituation to humans may have occurred. In addition, density-dependent factors may have precluded identification of optimal lake characteristics for some species due to habitat saturation.
Keywords: Breeding Season; Common merganser; Mergus merganser; Habitat

Diurnal activity and energy budgets of Goosander Mergus merganser wintering on Chew Valley Lake, North Somerset: Influence of time of day and sex - Newson, Stuart E.; Hughes, Baz (Wildfowl, 1999)
Diurnal activity of wintering Goosander was studied at Chew Valley Lake using instantaneous scan sampling. The sex ratio of 0.48 males per female was relatively consistent through midwinter 1995/1996. Daily energy expenditure calculations, based upon published basal metabolic rates, suggested that feeding activities incurred the second highest energy cost after resting although feeding occurred for only a small proportion of daylight hours (14% for males and 17% females). Males devoted less time to feeding activities than females, although theoretically males need more energy per day, due to their larger size. It was calculated that males need between 175.5 and 216.6 g/fish/hr spent feeding, compared to females requiring between 117.2 and 144.6 g/fish/hr spent feeding. Males are therefore either more efficient at energy conservation or foraging (e.g. taking larger fish with higher calorific value). Assuming an assimilation efficiency of 80%, and the food to have an energy content of 4.0 KJ/g, it was calculated that Goosander at Chew Valley Lake consumed about 10-13% of their body mass in fish per day.
Keywords: Behavior; Nonbreeding Seasons; Energetics and Nutrition; Common merganser; Mergus merganser

Behavior of Barrows goldeneye in Wyoming Bucephala islandica - Nickell, Walter P. (Wilson Bull, 1966)
Keywords: Behavior; Breeding Season; Barrow's Goldeneye; Bucephala islandica

The importance of wetlands to waterbirds in the Boreal Forest of Ontario - Nicoll, Fergus I.; Zimmerling, J. Ryan (Ontario Birds, 2006)
Keywords: Sea Ducks - General; Habitat

Studies on the preening behaviour of the Goldeneye (Bucephala clangula) Engl. summ. - Nilsson, Leif (Var Fagelvarld, 1965)
A description is given of the various comfort, bathing and preening movements of Goldeneyes with reference to the work of McKinney (1953). One one occasion it was observed that bill dipping gradually led to bathing. The frequencies of the preening movements in 90 preening series in different situations were noted and summarized. The differences in frequency between the movements suggest different threshold values for the movements. The duration of a normal preening series was found to be 2[long dash]4 min. in daytime. In the evening longer series are common. The comfort movements in "after discharge situations" were also studied. It was found that low intensity preening movements were commoner in preening after disturbance than high intensity forms. Wingflap was common after disturbance and aggressive encounters. In the latter it was commoner after aggressions of low intensity than after those of high intensity. After copulation the males have a special behaviour (post-copulatory steaming: but the females are devoid of ritualized post-copulatory behavior. Comfort behavior after copulation was found to be much commoner in females than in males. || ABSTRACT AUTHORS: From auth
Keywords: Behavior; Bucephala clangula; Common Goldeneye

Observations of the spring behaviour of the red-breasted merganser Engl. summ. - Nilsson, Leif (Var Fagelvarld, 1965)
General behavior, courtship and pre-copulatory display of the species are described. The population of the main study area gathered in the evening to a communal roosting place on a small islet. Courtship display, preening, and bathing were common when the birds congregated and went on land in the evening and before they left in the morning. The preening andbathing behavior of the red-breasted merganser was almost identical with that of other anatids. Aggressive behavior of the species is usually between males in groups. The different behavior patterns in the courtship display are described. Aerial chases and ten copulations were observed. The precopulatory display was initiated by the female adopting the prone-posture, as in other anatids. The male circled round the female with outstretched neck in most cases performing false-drinking, false-preening and water-twitch. No precopulatory "steaming" was performed. After copulation, which lasted 6-13 sec., the pair rotated and the male performed "Knix" belonging to the courtship display. After that the pair performed various bathing movements. ABSTRACT AUTHORS: From auth. summ
Keywords: Behavior; Mergus serrator; Red-breasted merganser

The behavior of the goosander (Mergus merganser) in the winter Engl. sum. - Nilsson, Leif (Var Fagelvarld, 1966)
Summarized observations on the general behavior, courtship display, choice of night-quarters and copulation of the species are given. ABSTRACT AUTHORS: From auth
Keywords: Behavior; Common merganser; Mergus merganser

Long-term trends and changes in numbers and distribution of some wintering waterfowl species along the Swedish Baltic Coast - Nilsson, Leif (Acta Zoologica Lituanica, 2005)
Regular counts of wintering waterfowl have been undertaken as a part of the International Waterfowl Census (IWC) and the National Swedish Environmental Monitoring Program since 1964. After the first years, a network of annually surveyed sites was established for the calculation of annual indices. Country-wide surveys (also including aerial counts) were undertaken 1971-1974, 1987-1989, 1992-1993 (partial) and 2004. During the survey period, increasing trends were found in Mallard (Anas platyrhynchos), Tufted Duck (Aythya fuligula), Pochard (Aythya ferina), Goldeneye (Bucephala clangula), Red-breasted Merganser (Mergus serrator), Mute Swan (Cygnus olor) and Cormorant (Phalacrocorax carbo). Some of these trends reflect genuine population changes; others are related to changing winter conditions, e.g. the establishment of a new wintering tradition for Wigeon (Anas penelope). Tufted Duck and Goldeneye decreased in the south and increased in the northern part of the coast. Mallard, on the other hand, increased in some coastal sites but not in others, but this species is also common inland.
Keywords: Abundance, Distribution, and Trends; Sea Ducks - General; Nonbreeding Seasons

Effects of ACTH, capture, and short term confinement on glucocorticoid concentrations in harlequin ducks (Histrionicus histrionicus) - Nilsson, Peter B.; Hollmen, Tuula E.; Atkinson, Shannon; Mashburn, Kendall L.; Tuomi, Pamela A.; Esler, Daniel; Mulcahy, Daniel M.; Rizz, Daniel J. (Comparative Biochemistry and Physiology Part A Molecular & Integrative Physiology, 2008)
Little is known about baseline concentrations of adrenal hormones and hormonal responses to stress in sea ducks, although significant population declines documented in several species suggest that sea ducks are exposed to increased levels of environmental stress. Such declines have been observed in geographically distinct harlequin duck populations. We performed an adrenocorticotropic hormone (ACTH) challenge to evaluate adrenal function and characterize corticosterone concentrations in captive harlequin ducks and investigated the effects of capture, surgery, and short term confinement on corticosterone concentrations in wild harlequin ducks. Harlequin ducks responded to the ACTH challenge with an average three-fold increase in serum corticosterone concentration approximately 90 min post injection, and a four- to five-fold increase in fecal glucocorticoid concentration 2 to 4 h post injection. Serum corticosterone concentrations in wild harlequin ducks increased within min of capture and elevated levels were found for several hours post capture, indicating that surgery and confinement maintain elevated corticosterone concentrations in this species. Mean corticosterone concentrations in wild harlequin ducks held in temporary captivity were similar to the maximum response levels during the ACTH challenge in captive birds. However, large variation among individuals was observed in responses of wild birds, and we found additional evidence suggesting that corticosterone responses varied between hatch year and after hatch year birds. (C) 2008 Published by Elsevier Inc.
Keywords: Harlequin duck; Histrionicus histrionicus; Physiology

No support for relatedness and kin selection to explain high rates of conspecific brood parasitism in colonial Red breasted Mergansers (Mergus serrator) - Noel, K.; Titman, R. D.; Craik, S. R. (CANADIAN JOURNAL OF ZOOLOGY, 2021)
Conspecific brood parasitism (CBP) has been observed in approximately half of all species of waterfowl, a philopatric group in which breeding females are frequently locally related. It has been suggested that kin selection can facilitate the evolution of CBP in waterfowl via fitness benefits for the host and parasite. One model demonstrates that discrimination of related and unrelated parasites by the host must be sufficient for kinship to promote CBP, provided that costs of brood parasitism to host fitness are sufficiently low. We parameterized the model using demographic data and behavioural observations from a population of colonial Red-breasted Mergansers (Mergus serrator Linnaeus, 1758) in which 47% of nests were parasitized by conspecifics. The costs of 1-3 foreign eggs to host hatching success were generally small (decline of 1.8% per additional egg). Nevertheless, model outputs revealed that brood parasites maximize their inclusive fitness by avoiding nests of relatives, primarily because of constraints on a host's ability to detect parasites at the nest. Indeed, hosts spent <8% of the diurnal period at the nest during egg laying, a period when parasite activity is greatest. It is thus highly unlikely that relatedness and kin selection promote brood parasitism in this population.
Times Cited in Web of Science Core Collection: 1 Total Times Cited: 1 Cited Reference Count: 64
Keywords: conspecific brood parasitism; INTRASPECIFIC NEST PARASITISM; kin selection; waterfowl; Mergus serrator; DUCKS; fitness; POPULATION; Red-breasted Merganser; EVOLUTION; alternative reproductive strategies; hatching success; HOST; PREDATION; COSTS; MELANITTA-FUSCA; CRECHING BEHAVIOR; relatedness; RELATIVES

Long-tailed Duck, Clangula hyemalis, eider, Somateria spp., and scoter, Melanitta spp., distributions in central Alaska Beaufort Sea lagoons, 1999-2002 - Noel, Lynn E.; Johnson, Stephen R.; O'Doherty, Gillian M. (Canadian Field-Naturalist, 2005)
During July and August 1999-2002, distributions of Long-tailed Ducks (Clangula hyemalis), ciders (Somateria spp.) and scoters (Melanitta spp.) were documented in three barrier island-lagoon systems in the central Alaska Beaufort Sea. Concentration areas for each species were determined during 16 aerial surveys. Kernel density procedures were used to delineate 75% and 50% "activity" or concentration areas for all three species. Long-tailed Ducks were 13 times more numerous than eiders and 38 times more numerous than scoters. The Long-tailed Duck 75% activity area encompassed all three lagoon systems and was three times as large as the eider activity area and one-third larger than the scoter activity area. Eider activity areas were located only in the eastern lagoon, and scoter activity areas were located only in the western lagoon. Density contours showed patterns of repeated habitat use for sea ducks over the four years of sampling and improve our understanding of sea duck habitat use within Beaufort Sea barrier island-lagoon habitats.
Keywords: Abundance, Distribution, and Trends; Nonbreeding Seasons; Clangula hyemalis; Long-tailed Duck; Dispersal

Common eider (Somateria mollissima v-nigrum) nest cover and depredation on central Alaskan Beaufort Sea barrier islands - Noel, Lynn E.; Johnson, Stephen R.; O'Doherty, Gillian M.; Butcher, Matthew K. (Arctic, 2005)
Female common eiders (Somateria mollissima v-nigrum) generally select nest sites in areas with driftwood cover. Previous studies of common eiders have shown a positive relationship between nest success and driftwood cover. Our observations led us to hypothesize that cover does not enhance nest success when mammalian predators are present. To evaluate nest cover selection in common eiders, we examined five years of nesting data to determine the interactions between the probability of nest activity and the amount of driftwood cover in the presence of avian versus mammalian predators. Most common eider nests were surrounded by low (40%) or moderate (38%) driftwood cover. Nest failure rates were high (32%-95%), and arctic foxes (Alopex lagopus), alone or with polar bears (Ursus maritimus), appeared to be more destructive than glaucous gulls (Larus hyperboreus) to eider nests. Logistic regression was used to model common eider nest activity associated with driftwood cover and predators. When glaucous gulls were the only predators, more driftwood cover consistently increased the probability of nest activity. But when foxes were present, nest activity consistently decreased with increasing cover. Our models support our I observations that nest cover was beneficial to eiders when glaucous gulls alone were predators. Driftwood cover may be most important for the thermal and structural protection it offers, rather than for the camouflage it provides. The energetic benefit provided by driftwood windbreaks coupled with the common eider's behavioral response of decreased nest attendance, or increased exposure to avian depredation of nests as energy reserves are depleted during incubation, provides an explanatory mechanism for our model results.
Keywords: Breeding Season; Common Eider; Somateria mollissima; Productivity; Habitat

Breeding Success of Some Coastal Birds in a Herring Gull Larus-Argentatus Colony - Nolet, B. A. (Limosa, 1988)
In the fifties and sixties, a serious decline in breeding numbers of coastal birds occurred along the Dutch coast, caused by dumping of pesticides. In contrast with Eider Somateria mollissima, Oystercatcher Haematopus ostralegus, and Herring Gull Larus argentatus, Common Tern Sterna hirundo, and Arctic Tern S. paradisaea did not recover fully. In order to gain insight in this difference the breeding success of these species on Rottumeroog was measured in 1986. Breeding success of Herring Gull appeared to be in accordance with the breeding density on the island. Breeding success of Eider, Oystercatcher, and Common and Arctic Tern were relatively low compared to other areas. Provisional calculations indicate that successes are too low to explain the population growth rates found in the area. Predation by Herring Gulls of eggs of Eiders and chicks of Oystercatchers, and Common and Arctic Terns is regarded as the main cause of the low breeding success in these species. Some measures are proposed to improve the situation.
Keywords: Breeding Season; Common Eider; Somateria mollissima; Productivity

Studies of the King Eider Somateria-Spectabilis in Svalbard - Norderhaug, A. M. (Norsk Polarinstitutt Arbok, 1977)
Data on the king eider (S. spectabilis) collected during the Norsk Polarinstitutt's ornithological expeditions in Svalbard [Arctic] (mainly 1965-1970) are summarized. The present breeding distribution, data on productivity and egglaying/hatching are figured. The average breeding period for 4 clutches was 23 days. Comparison is made of egg sizes and weights for the common eider and the king eider. Brief remarks are given on behavior on the breeding site and population size. The life cycle of the king eider is discussed, and information given on existing molting areas in Svalbard.
Keywords: Breeding Season; Nonbreeding Seasons; Molt; Productivity; King Eider; Somateria spectabilis

Variable responses of waterfowl breeding populations to long-term removal of introduced American mink - Nordstrom, Mikael; Hogmander, Jouko; Nummelin, Jukka; Laine, Jarmo; Laanetu, Nikolaj; Korpimaki, Erkki (Ecography, 2002)
It is suspected that feral American mink, an introduced predator in Europe, have seriously affected local densities of birds breeding in archipelagos and coastal areas. We studied the effects of mink removal on breeding densities of waterfowl in two manipulation and two control areas in the outer archipelago of SW Finland, Baltic Sea. The study was conducted in two phases: during 1992-2001 a total of 98 mink was removed from 60 islands and islets (total area 72 km2) whereas on 37 islands and islets (35 km2) mink was not removed. Additional mink removal and control areas were established during 1998-2001 to replicate the experiment. The breeding densities of the shelduck, tufted duck and the velvet scoter increased as a response to mink removal, while in the control areas their populations remained unchanged. The breeding densities of mallards increased during the first 7 yr of mink removal, but a steep decrease in the last study year resulted in a statistically non-significant overall increase. The species with low breeding densities (the gadwall, northern shoveler, pintail and the red-breasted merganser) increased as well. In contrast, the populations of large waterfowl species, the mute swan, greylag goose, common eider and the goosander, did not show obvious increases in breeding densities after mink removal. We conclude that feral mink may locally limit the breeding densities of some smaller waterfowl species and thus reduce the diversity of the waterfowl community in the outer archipelago.
Keywords: Breeding Season; Abundance, Distribution, and Trends; Sea Ducks - General; Trophic Interactions

Glucocorticoids, state-dependent reproductive investment and success in the face of danger in a long-lived bird - Noreikiene, K.; Jaatinen, K.; Steele, B. B.; Ost, M. (JOURNAL OF ORNITHOLOGY, 2021)
Glucocorticoid hormones may mediate trade-offs between current and future reproduction. However, understanding their role is complicated by predation risk, which simultaneously affects the value of the current reproductive investment and elevates glucocorticoid levels. Here, we shed light on these issues in long-lived female Eiders (Somateria mollissima) by investigating how current reproductive investment (clutch size) and hatching success relate to faecal glucocorticoid metabolite [fGCM] level and residual reproductive value (minimum years of breeding experience, body condition, relative telomere length) under spatially variable predation risk. Our results showed a positive relationship between colony-specific predation risk and mean colony-specific fGCM levels. Clutch size and female fGCM were negatively correlated only under high nest predation and in females in good body condition, previously shown to have a longer life expectancy. We also found that younger females with longer telomeres had smaller clutches. The drop in hatching success with increasing fGCM levels was least pronounced under high nest predation risk, suggesting that elevated fGCM levels may allow females to ensure some reproductive success under such conditions. Hatching success was positively associated with female body condition, with relative telomere length, particularly in younger females, and with female minimum age, particularly under low predation risk, showing the utility of these metrics as indicators of individual quality. In line with a trade-off between current and future reproduction, our results show that high potential for future breeding prospects and increased predation risk shift the balance toward investment in future reproduction, with glucocorticoids playing a role in the resolution of this trade-off.
Times Cited in Web of Science Core Collection: 2 Total Times Cited: 2 Cited Reference Count: 76
Keywords: COMMON EIDERS; SOMATERIA-MOLLISSIMA; Predation; BROOD PARASITISM; Eider; STRESS RESPONSIVENESS; BASE-LINE GLUCOCORTICOIDS; CORTICOSTERONE LEVELS; Corticosterone; Cost of reproduction; Individual quality; PARENTAL INVESTMENT; QUANTITATIVE PCR; Residual reproductive value; TELOMERE LENGTH

Nest cover and faecal glucocorticoid metabolites are linked to hatching success and telomere length in breeding Common Eiders (Somateria mollissima) - Noreikiene, K.; Ost, M.; Seltmann, M. W.; Boner, W.; Monaghan, P.; Jaatinen, K. (CANADIAN JOURNAL OF ZOOLOGY, 2017)
Habitat-associated crypsis may affect perceived predation vulnerability, selecting for different predator avoidance strategies. Glucocorticoids could mediate the adjustment of escape responses to the extent of crypsis, introducing an overlooked source of variation in glucocorticoid-fitness relationships. However, prolonged exposure to elevated glucocorticoids may be costly, leading to accelerated telomere loss and, consequently, senescence. Here, we examined how nest cover and immunoreactive faecal glucocorticoid metabolite (fGCM) levels are linked to hatching success and telomere length in breeding female Common Eiders (Somateria mollissima (L., 1758)). We hypothesized that the degree of nest crypsis, reflecting differences in perceived predation risk, would moderate the relationship between reproductive success and fGCM levels. We also expected that telomere length would be shorter in birds with higher glucocorticoid concentration. Results showed that individuals with high fGCM levels had higher hatching success in nests with low cover, while low fGCM levels were more successful in well-concealed nests. We found that shorter telomeres were associated with high fGCM in nesting sites offering little cover and with low fGCM in well-concealed ones. This study provides the first evidence of habitat-dependent moderation of the relationships between stress physiology, telomere length and hatching success.
Times Cited in Web of Science Core Collection: 5 Total Times Cited: 5 Cited Reference Count: 92
Keywords: Common Eider; Somateria mollissima; CLUTCH SIZE; PREDATION RISK; LIFE-HISTORY; INDIVIDUAL QUALITY; STRESS RESPONSIVENESS; AGE; BASE-LINE GLUCOCORTICOIDS; REPRODUCTIVE EFFORT; QUANTITATIVE PCR; cost of reproduction; ESCAPE DECISIONS; glucocorticoids; nesting habitat

Persistent Chlorinated Hydro Carbons and Mercury in Birds Caught Off the West Coast of Spitsbergen Norway - Norheim, G.; Kjos-Hanssen, B. (Environmental Pollution Series A Ecological and Biological, 1984)
The tissue concentrations of DDE, PCB [polychlorinated biphenyl], hexachlorobenzene (HCB) and Hg were determined in 5 spp. of migrating seabirds: glaucous gull Larus hyperboreus, fulmar Fulmarus glacialis, Brunnich's guillemot Uria lomvia, little auk Alle alle and eider Somateria mollissima. These birds nested on Svalbard and were shot in May, 1980, off the west coast of Spitsbergen. The highest levels of DDE, PCB and HCB were found in glaucous gull; low levels were found in Brunnich's guillemot, little auk and especially eider. Fulmars were intermediate. Higly significant correlations were found between the concentrations of HCB, DDE and PCB. These results indicated that the Gulf Stream probably was a common source of these substances. The highest Hg levels were found in the fulmar and glaucous gull and eider were intermediate; the lowest Hg levels were found in Brunnich's guillemot and little auk. There was no connection between the nutritional condition and concentrations of the pollutants determined. There seemed to be a close relationship between the levels of chlorinated hydrocarbons and the trophic levels of the birds in the food chain. A comparison between the present results and analyses of Antarctic seabirds indicated that the aquatic food chain in the Arctic was more loaded with persistent chlorinated hydrocarbons than in the Antarctic; more Hg seemed to be found in Antarctic birds.
Keywords: Breeding Season; Common Eider; Contaminants; Somateria mollissima

Sea birds and sea bird shooting by the Swedish east coast In Swedish with English summ. - Notini, Gosta; Westman, Hans (K Skogshogskoland Skrifter, 1956)
The Inst. of Forest Zool., completed investigations of the stocks and the shooting of sea birds that were instituted in 1944 and whose results up to 1948 were published in the Communications of the Swedish Sportmen's Assoication (1949). One of the principal considerations was to elucidate the effect of the amended regulations which came into force in 1950. [A list of amended regulations is given.] The investigations were concerned with the stock-taking of breeding birds in the Namdo skerries and the same areas.[long dash]Kalmar Sound, Blekinge skerries, and around Oland and Gotland[long dash]that had previously been studied in this respect. In addition, line estimates were made along the e. coast from Namdo skerries down to Vastervik. Taken into consideration in these stock-taking and estimates were eider, the velvet scoter, long-tailed ducks, garrots, tufted ducks, mergansers, and the black scoters.
Keywords: Conservation; Sea Ducks - General

Mechanisms of density dependence in ducks: importance of space and per capita food - Nummi, P.; Holopainen, S.; Rintala, J.; Poysa, H. (Oecologia, 2015)
The growth rate of populations usually varies over time, often in a density-dependent manner. Despite the large amount of literature on density dependence, relatively little is known of the mechanisms underlying the density-dependent processes affecting populations, especially per capita natality. We performed a 20-year study on the density dependence of brood production in two duck species differing in the stability of habitat use. Our study was conducted in a boreal watershed in southern Finland. We predicted that a diving duck common goldeneye Bucephala clangula, with more stable habitat use, would show stronger density dependence than a dabbling duck common teal Anas crecca. We investigated reproductive output in relation to the duck pair density per se as well as in relation to per capita food availability. As predicted, the reproductive output of the goldeneye showed a more density-dependent pattern than that of the teal. The number of goldeneye broods per pair decreased when the pair density increased. This was not the case with the teal. However, when the breeding success was measured by taking into account per capita food availability, both species showed density dependence. Our results imply that the occurrence of density dependent processes may vary even in sympatric ducks breeding in the same, relatively stable landscape. Our analysis also emphasizes that it is important to take into account per capita resource availability when studying the density dependence of breeding success. Both findings have important implications for the management and conservation of species.
Nummi, Petri Holopainen, Sari Rintala, Jukka Poysa, Hannu
Keywords: Breeding Season; Bucephala clangula; Common Goldeneye; Productivity

Wetland use by brood-rearing female ducks in a boreal forest landscape: the importance of food and habitat - Nummi, P.; Paasivaara, A.; Suhonen, S.; Poysa, H. (Ibis, 2013)
Times Cited: 0 Nummi, Petri Paasivaara, Antti Suhonen, Sari Poysa, Hannu 0
Keywords: Breeding Season; habitat; Sea ducks

Breeding success of ducks in relation to different habitat factors - Nummi, Petri; Poysa, Hannu (Ibis, 1995)
Breeding success of four duck species, Teal Anas crecca, Mallard Anas platyrhynchos, Wigeon Anas penelope and Goldeneye Bucephala clangula, was studied in a boreal watershed in southern Finland during 1988-1991 in relation to habitat type (based on vegetation development) and food abundance. Of the three common breeders, breeding success (broods/pair) was highest in Teal (1.7) and lower in Mallard (1.4) and Goldeneye (1.2). Over the years, Goldeneye brood densities were less variable than were pair densities, so breeding success varied more among years that did that of Mallard or Teal. In Teal, the yearly numbers of pairs and broods fluctuated together, whereas in Mallard neither varied appreciably. Breeding success by Goldeneye was higher where nektonic invertebrates were more abundant, whereas breeding success of the dabbling ducks had very few significant correlations with environmental factors.
Keywords: Breeding Season; Bucephala clangula; Common Goldeneye; Productivity; Habitat

Duck-fish competition in boreal lakes - a review - Nummi, P.; Vaananen, V. M.; Holopainen, S.; Poysa, H. (Ornis Fennica, 2016)
Ducks share the aquatic environment with invertebrate-eating fish. Thus, competitive interactions may take place. Fish have been introduced to many formerly fishless lakes, which has profoundly affected the competitive and predatory relations in these waters. In this paper we review recent findings on duck fish competitive interactions in boreal lakes. On a general level, analyses based on presence/absence data of fish have indicated that ducks can be negatively affected by fish. More rigorous studies where fish density has been considered have corroborated the pattern emerging from presence/absence studies. For the Common Goldeneye (Bucephala clangula) and Eurasian Perch (Perca fluviatilis), the effect of competition has been tested experimentally. In general, it appears that diving ducks such as Common Goldeneye, which forage in open water, are the most affected by fish, Common Teal (Arias crecca) is intermediate, whereas Mallard (A. platyrhynchos), which forage among the shore vegetation, is little affected. Likelihood or the strength of competition between ducks and fish may also depend on habitat productivity and structure. Numbers of invertebrates are higher among vegetation where there are less fish preying on them. Duck fish interactions are important to take into account when planning wetland creation and restoration for ducks. There is also an urgent need to mitigate the effects of fish introductions in wetlands.
Nummi, Petri Vaananen, Veli-Matti Holopainen, Sari Poysa, Hannu
Keywords: Bucephala clangula; Common Goldeneye; Trophic Interactions; Habitat

Competitive effects of fish in structurally simple habitats: perch, invertebrates, and goldeneye in small boreal lakes - Nummi, P.; Vaananen, V. M.; Rask, M.; Nyberg, K.; Taskinen, K. (Aquatic Sciences, 2012)
Times Cited: 4 Nummi, Petri Vaananen, Veli-Matti Rask, Martti Nyberg, Kari Taskinen, Keijo 4
Keywords: Breeding Season; Bucephala clangula; Common Goldeneye; Trophic Interactions

Steller's Eiders Polysticta stelleri wintering in Europe: numbers, distribution and origin - Nygard, Torgeir; Frantzen, Bjorn; Svazas, Saulius (Wildfowl, 1995)
Steller's Eider is among the roost northern-living of duck species at all seasons. The recent decline of the species in North America has now increased the awareness of the population wintering in northern Europe. The size of this wintering population is estimated from the available information at 30- 50,000 birds, which suggests that the western population is now of the same magnitude as the eastern one that winters in the Pacific. The most important western wintering area extends from Varangerfjorden in north-eastern Norway to the ice-edge on the Kola coast in north-west Russia. Important winter areas have been found recently on the coasts of Lithuania and Estonia in the eastern Baltic. Recent information about breeding Steller's Eiders on the tundras of Taymyr, Yamal and Gyda peninsulas confirms the existence of a substantial population west of Khatanga, that migrates to the west and winters in North Atlantic and Baltic waters.
Keywords: Abundance, Distribution, and Trends; Nonbreeding Seasons; Polysticta stelleri; Steller's eider

Numbers and distribution of wintering waterfowl in Norway - Nygard, Torgeir; Larsen, Bjorn Harald; Follestad, Arne; Strann, Karl-Birger (Wildfowl, 1988)
Keywords: Abundance, Distribution, and Trends; Sea Ducks - General; Nonbreeding Seasons

Salinity as a Constraint Affecting Food and Habitat Choice of Mussel-Feeding Diving Ducks - Nystrom, K. G. K.; Pehrsson, O. (Ibis, 1988)
Observations of freshwater drinking in Eiders feeding primarily on mussels led us to hypothesize that the highly saline sea water enclosed in mussels could cause salt-related dehydration problems in the ducks, since they consume entire mussels. The proportion of sea water increases with increasing mussel size. Small ducks species are more sensitive to the higher salt content of larger mussels than are larger ducks; however, salt stress may be avoided by feeding in habitats with lower salinity, by feeding on less salty food items, by utilizing smaller mussels, by drinking fresh water, or by employing low energy foraging techniques. A possible evolutionary strategy for solving the salt problem might be to increase body mass, enabling ducks to utilize larger mussels without passing an upper salt consumption limit. At the same time, foraging on larger mussels is more economical. Although large size facilitates the utilization of brackish and marine environments, it may be selected against in ducks breeding in fresh water, where fish competition may reduce optimal food item size. In conclusion, salinity is an important habitat barrier in both breeding and overwintering diving ducks, but there are various ways of crossing this barrier. To understand better how ducks utilize their habitats, however, it is necessary to measure habitat salinity levels and the size of both ducks and their preferred and less-preferred food types.
Keywords: Sea Ducks - General; Trophic Interactions; Habitat

Food of Juvenile Common Eiders Somateria-Mollissima in Areas of High and Low Salinity - Nystrom, K. G. K.; Pehrsson, O.; Broman, D. (Auk, 1991)
In a comparative survey of the food selected by the Common Eider (Somateria mollissima) in coastal waters of the Skagerrak and the northern Baltic proper, waters of high and low salinity, we showed that Mytilus edulis was the most heavily utilized food type. In waters of high salinity, ducks did not select large mussels, though they were available, and apparently ducks preferred food items with a low seawater content, like crustaceans and gastropods. Large birds, however, consumed larger mussels than did smaller birds. These results support previously proposed hypotheses that mussel-feeding ducks can minimize salt intake by feeding on smaller mussels, by consuming other types of food, and by increasing the allowable intake by being larger. There were indications that the size and number of grit fragments swallowed were related to the type of food consumed. However, we were unable to determine whether grit fragments were consumed involuntarily during mussel gathering or swallowed intentionally to help in grinding food items. A decline in body size over a 1,000-year period in eiders from the Baltic compared with birds from the Swedish west coast implies an evolutionary adaptation to lower salinity. We also describe a method of mussel size reconstruction from shell remnants.
Keywords: Common Eider; Somateria mollissima; Trophic Interactions

Organic pollutants in wild ducks from New York state: I. Interspecies differences in concentrations and congener profiles of PCBs and PCDDs/PCDFs - O'Keefe, Patrick W.; Clayton, William C.; Connor, Stephen; Bush, Brian; Hong, Chia-Swee (Science of the Total Environment, 2006)
Wild ducks of three species, common mergansers (Mergus merganser americanus), gadwalls (Anas streptera), and mallards (Anas platyrhynchos), were collected near industrial sites in the Massena, NY area of the St. Lawrence River (SLR) in 1988/89 and 1994. Additional samples were collected in 1994 near a former polychlorinated biphenyl (PCB) capacitor plant at Fort Edward, NY (a mallard and two wood ducks (Aix sponsa)), and at control sites (common mergansers, mallards and wood ducks). On a lipid basis, PCB concentrations in liver tissue from the 1994 collection ranged from 0.1 mu g/g in a control wood duck to 676 mu g/g in a common merganser from the SLR area. However, the highest total polychlorinated dibenzofuran (PCDF) concentrations were found in liver and fat tissues of gadwalls and mallards collected near the SLR industrial sites (2.8-12 ng/g lipid). These two species bioaccumulated non-2,3,7,8-substituted PCDFs in addition to 2,3,7,8-PCDF isomers, whereas common mergansers preferentially bioaccumulated 2,3,7,8-substituted PCDFs. The mergansers from the SLR sites were the only specimens contaminated with polychlorinated dibenzo-p-dioxins (PCDDs), which were all 2,3,7,8-substituted. The PCB and PCDF congener patterns in the duck tissues appear to have been influenced by both sampling location and species trophic level. (c) 2005 Elsevier B.V. All rights reserved.
Keywords: Contaminants; Common merganser; Mergus merganser

Studies on feather waxes of birds: VI. Further investigation of the free flowing preen gland secretion from species within the family of Anatidae - Odham, Goran (Ark Kem, 1967)
Featherwaxes of Dendrocygna viduata (white-faced whistling duck), Branta leucopsis (barnacle goose), Mergus serrator (red-breasted merganser), Cairina moschata (muscovy duck) and Somateria mollissima (common eider) have been investigated. Wax of Branta leucopsis is very different from that of Anser (true geese) and that D. viduata constitutes an intermediate between true geese and swans (Cvgnus) in this respect. M. serrator produces essentially the C12 acid 2,4,6-trimethylnonanoic acid (97%) while C. moschata has almost exclusively the C11 acid 2,4,6-trimethyloctanoic acid (99%). In addition the preen gland secretion of the latter contains 66% of the unsaturated hydrocarbon squalene. The wax acid moiety of S. mollissima is a very heterogenous mixture containing structures with both straight and branched chains. There is present a series of acids not previously found, namely such with 2 methyl groups. Most of the acids have the methyl substituents separated by more than 1 methylene unit but always with an odd number. || ABSTRACT AUTHORS: Author
Keywords: Common Eider; Somateria mollissima; Physiology; Mergus serrator; Red-breasted merganser

Selenium and Heavy Metals in San-Francisco Bay California USA Diving Ducks - Ohlendorf, H. M.; Lowe, R. W.; Kelly, P. R.; Harvey, T. E. (Journal of Wildlife Management, 1986)
We analyzed for selenium (Se) and heavy metals in greater scaups (Aythya marila) and surf scoters (Melanitta perspicillata) collected from southern San Francisco Bay in March and April 1982. There were no differences (P > 0.05) between species for liver concentrations of silver (Ag), mercury (Hg), or lead (Pb). Copper (Cu) (P < 0.001) and zinc (Zn) (P < 0.01) levels were higher in scaups, whereas Se was higher in scoters (P < 0.001). Chromium (Cr) and nickel (Ni) occurred in < 50% of the samples, and there was no difference (P > 0.05) between the 2 species. The geometric mean cadmium (Cd) concentration in scoter kidneys (24.6 ppm, dry wt) was higher than in scaups (15.5 ppm) (0.1 > P > 0.05). Liver concentrations of Hg and Se were correlated (P < 0.01). The toxicological significance of some elements in these species is not known. However, Se levels in scoters (34.4 ppm, dry wt) were similar to those in livers of dabbling ducks (Anas spp.) in the nearby San Joaquin Valley where reproduction was impaired severely.
Keywords: Nonbreeding Seasons; Melanitta perspicillata; Surf Scoter; Contaminants

Trace Elements and Organochlorines in Surf Scoters from San Francisco Bay 1985 California USA - Ohlendorf, H. M.; Marois, K. C.; Lowe, R. W.; Harvey, T. E.; Kelly, P. R. (Environmental Monitoring and Assessment, 1991)
Surf scoters (Melanitta perspicillata) were collected from 6 locations in San Francisco Bay during January and March 1985. Overall, mean concentrations of cadmium and zinc were higher in livers of scoters from the southern region of the Bay, whereas mean iron and lead were higher in those from the northern Bay region. Mean concentrations of arsenic, copper, lead, zinc, aluminum (January only) and iron (January) also differed among individual locations. Mean concentrations of copper and zinc increased, arsenic decreased, and cadmium remained the same between January and March. Selenium and mercury concentrations in scoter livers were not significantly correlated (P > 0.05), but cadmium concentrations in livers and kidneys were positively correlated (P < 0.0001), and body weight was negatively related to mercury concentration in the liver (P < 0.05). Body weight differed among locations but not between January and March. Body weight was correlated with lipid content (P < 0.0001). DDE and PCBs were each detected in 34 of 36 scoter carcasses. DDE increased significantly between January and March at Richmond Harbor, but PCBs did not differ between January and March at the 3 locations that could be tested.
Keywords: Nonbreeding Seasons; Melanitta perspicillata; Surf Scoter; Contaminants; Energetics and Nutrition

Spring phenology, latitude, and the timing of breeding in two migratory ducks: implications of climate change impacts - Oja, Heli; Poysa, Hannu (Annales Zoologici Fennici, 2007)
We studied whether the timing of hatching in the mallard (Anas platyrhynchos) and the common goldeneye (Bucephala clangula) is associated with the timing of lake ice break-up (a local climate index) and the North Atlantic Oscillation (NAO, a largescale climate index), and if the strength of these associations differ between southem and northem populations of the species. In both species, the date of hatching was associated with the date of ice break-up; more clearly so in northern Finland than in southern Finland. The date of hatching was neither associated with the winter NAO (December-March) nor with the spring NAO (March-May). There was no difference between southern and northern populations in terms of the annual differences (in days) between the timing of ice break-up and the timing of hatching. However, in both species, this difference decreased with increasing lateness of the spring in the north, the corresponding trend being less clear in the south.
Keywords: Breeding Season; Bucephala clangula; Common Goldeneye

Seasonal fluctuations of organochlorine levels in the common eider (Somateria mollissima) in Iceland - Olafsdottir, K.; Skirnisson, K.; Gylfadottir, G.; Johannesson, T. (Environmental Pollution, 1998)
Breast muscle of 55 common eiders (Somateria mollissima) and liver samples of 12 birds, caught at Skerjafjorour in SW-Iceland in February, May, June and November 1993 were analysed for organochlorine contamination (10-30 different congeners of PCBs, pp'-DDT, -DDE, -DDD, HCB, alpha-, beta-, and gamma-HCH). The levels of the contaminants were similar in both tissues and were at their lowest in February. A substantial increase (up to 10-fold) in the levels of all substances was observed in June, in the females, which at that point had lost about one-third of their late winter body weight. The increase may be due to relocation to other tissues of organochlorines stored in the shrinking bodyfat. During this period the birds must be vulnerable to the toxic effects of these chemicals as they can transiently reach high concentrations in the blood. The levels found were similar or higher than those recently reported for eiders from Spitsbergen, the NWT of Canada and Frans Josefs Land of Russia, especially the levels of PCBs.
Keywords: Breeding Season; Common Eider; Nonbreeding Seasons; Contaminants; Somateria mollissima

The food and feeding habits of goldeneye Bucephala clangula in Great Britain - Olney, P. J. S.; Mills, D. H. (Ibis, 1963)
The food and feeding habits of goldeneye are described, based on the analyses of 51 stomach contents and a brief review of the literature. The type of food taken depends on the type of habitat being used, the availability and size of the food items and on the methods of feeding[long dash]though animal material largely predominates. In estuarine and coastal areas, small crustaceans and in particular Carcinus maenas figured highly in the diet, with some molluscs and small fish. In 2 brackish-water feeding birds, seeds formed the bulk of the food, some caddis-fly larvae also being taken. In freshwater feeding birds insects predominated, particularly Trichoptera larvae, chironomid larvae and the adults of Corixa spp. Some crustaceans (Asellus, Gammarus) and small molluscs were taken and occasionally small fish. A small amount of plant material was taken in the form of seeds, mainly Potamogeton spp. The relation between goldeneye and fishing interests is briefly discussed and it is concluded that fish normally form a small part of the diet and it is unlikely that any serious depredation of fish stocks is common. || ABSTRACT AUTHORS: Authors
Keywords: Breeding Season; Nonbreeding Seasons; Bucephala clangula; Common Goldeneye; Trophic Interactions

International importance of the eastern Chukchi Sea as a staging area for migrating king eiders - Oppel, Steffen; Dickson, D. Lynne; Powell, Abby N. (Polar Biology, 2009)
The evaluation of habitats used by arctic birds on migration is crucial for their conservation. We explored the importance of the eastern Chukchi Sea (ECS) as a staging area for king eiders (Somateria spectabilis) migrating between breeding areas in Siberia and western North America and wintering areas in the Bering Sea. We tracked 190 king eiders with satellite transmitters between 1997 and 2007. In late summer, 74% of satellite-tracked king eiders migrating south staged in the ECS for 13 +/- A 13 (SD) days between late June and early November. During spring migration, king eiders staged in the ECS between mid-April and early June for 21 +/- A 10 days. All instrumented birds migrating to breeding grounds in western North America (n = 62), and 6 of 11 males migrating to breeding grounds in Siberia, used this area for at least 1 week during spring migration. The importance of this staging area renders it possible that industrial development could adversely affect king eider populations in both Siberia and North America.
Keywords: Nonbreeding Seasons; Migration; King Eider; Somateria spectabilis; SDJV funded

Effects of Lipid Extraction on Stable Isotope Ratios in Avian Egg Yolk: Is Arithmetic Correction a Reliable Alternative? - Oppel, Steffen; Federer, Rebekka N.; O'Brien, Diane M.; Powell, Abby N.; Hollmen, Tuula E. (Auk, 2010)
Many studies of nutrient allocation to egg production in birds use stable isotope ratios of egg yolk to identify the origin of nutrients. Dry egg yolk contains >50% lipids, which are known to be depleted in C-13. Currently, researchers remove lipids from egg yolk using a chemical lipid-extraction procedure before analyzing the isotopic composition of protein in egg yolk. We examined the effects of chemical lipid extraction on delta C-13, delta N-15, and delta S-34 of avian egg yolk and explored the utility of an arithmetic lipid correction model to adjust whole yolk VC for lipid content. We analyzed the dried yolk of 15 captive Spectacled Eider (Somateria fischeri) and 20 wild King Eider (S. spectabilis) eggs, both as whole yolk an after lipid extraction with a 2:1 chloroform:methanol solution. We found that chemical lipid extraction leads to an increase of (mean +/- SD) 3.3 +/- 11 parts per thousand in delta C-13, 1.1 +/- 0.5 parts per thousand in delta N-15, and 2.3 +/- 1.1 parts per thousand in delta S-34. Arithmetic lipid correction provided accurate values for lipid-extracted VC in captive Spectacled Eiders fed on a homogeneous high-quality diet. However, arithmetic lipid correction was unreliable for wild King Eiders, likely because of their differential incorporation of macronutrients from isotopically distinct environments during migration. For that reason, we caution against applying arithmetic lipid correction to the whole yolk delta C-13 of migratory birds, because these methods assume that all egg rnacronutrients are derived from the same dietary sources. Received 12 June 2008, accepted 27 May 2009.
Keywords: Breeding Season; Somateria fischeri; Spectacled Eider; King Eider; Somateria spectabilis; Energetics and Nutrition; Techniques

Assigning king eiders to wintering regions in the Bering Sea using stable isotopes of feathers and claws - Oppel, Steffen; Powell, Abby N. (Marine Ecology Progress Series, 2008)
Identification of wintering regions for birds sampled during the breeding season is crucial to understanding how events outside the breeding season may affect populations. We assigned king eiders captured on breeding grounds in northern Alaska to 3 broad geographic wintering regions in the Bering Sea using stable carbon and nitrogen isotopes obtained from head feathers. Using a discriminant function analysis of feathers obtained from birds tracked with satellite transmitters, we estimated that 88 % of feathers were assigned to the region in which they were grown. We then assigned 84 birds of unknown origin to wintering regions based on their head feather isotope ratios, and tested the utility of claws for geographic assignment. Based on the feather results, we estimated that similar proportions of birds in our study area use each of the 3 wintering regions in the Bering Sea. These results are in close agreement with estimates from satellite telemetry and show the usefulness of stable isotope signatures of feathers in assigning marine birds to geographic regions. The use of claws is currently limited by incomplete understanding of claw growth rates. Data presented here will allow managers of eiders, other marine birds, and marine mammals to assign animals to regions in the Bering Sea based on stable isotope signatures of body tissues.
Keywords: Breeding Season; Nonbreeding Seasons; King Eider; Somateria spectabilis; Techniques; SDJV funded; Population Delineation

Does winter region affect spring arrival time and body mass of King Eiders in northern Alaska? - Oppel, Steffen; Powell, Abby N. (Polar Biology, 2009)
Age- and sex-specific survival and dispersal are important components in the dynamics and genetic structure of bird populations. For many avian taxa survival rates at the adult and juvenile life stages differ, but in long-lived species juveniles' survival is logistically challenging to study. We present the first estimates of hatch-year annual survival rates for a sea duck, the King Eider (Somateria spectabilis), estimated from satellite telemetry. From 2006 to 2008 we equipped pre-fledging King Eiders with satellite transmitters on breeding grounds in Alaska and estimated annual survival rates during their first 2 years of life with known-fate models. We compared those estimates to survival rates of adults marked in the same area from 2002 to 2008. Hatch-year survival varied by season during the first year of life, and model-averaged annual survival rate was 0.67 (95% CI: 0.48-0.80). We did not record any mortality during the second year and were therefore unable to estimate second-year survival rate. Adults' survival rate was constant through the year (0.94, 95% CI: 0.86-0.97). No birds appeared to breed during their second summer. While 88% of females with an active transmitter (n=9) returned to their natal area at the age of 2 years, none of the 2-year old males (n=3) did. This pattern indicates that females' natal philopatry is high and suggests that males' higher rates of dispersal may account for sex-specific differences in apparent survival rates of juvenile sea ducks when estimated with mark recapture methods.
Keywords: Breeding Season; Nonbreeding Seasons; Migration; King Eider; Somateria spectabilis; SDJV funded; Population Delineation

Carbon isotope turnover in blood as a measure of arrival time in migratory birds using isotopically distinct environments - Oppel, Steffen; Powell, Abby N. (Journal of Ornithology, 2010)
Arrival time on breeding or non-breeding areas is of interest in many ecological studies exploring fitness consequences of migratory schedules. However, in most field studies, it is difficult to precisely assess arrival time of individuals. Here, we use carbon isotope turnover in avian blood as a technique to estimate arrival time for birds switching from one habitat or environment to another. Stable carbon isotope ratios (delta C-13) in blood assimilate to a new equilibrium following a diet switch according to an exponential decay function. This relationship can be used to determine the time a diet switch occurred if delta C-13 of both the old and new diet are known. We used published data of captive birds to validate that this approach provides reliable estimates of the time since a diet switch within 1-3 weeks after the diet switch. We then explored the utility of this technique for King Eiders (Somateria spectabilis) arriving on terrestrial breeding grounds after wintering and migration at sea. We estimated arrival time on breeding grounds in northern Alaska (95% CI) from red blood cell delta C-13 turnover to be 4-9 June. This estimate overlapped with arrival time of birds from the same study site tracked with satellite transmitters (5-12 June). Therefore, we conclude that this method provides a simple yet reliable way to assess arrival time of birds moving between isotopically distinct environments.
Keywords: Breeding Season; Nonbreeding Seasons; King Eider; Somateria spectabilis; Techniques

Age-Specific Survival Estimates of King Eiders Derived from Satellite Telemetry - Oppel, Steffen; Powell, Abby N. (Condor, 2010)
Age- and sex-specific survival and dispersal are important components in the dynamics and genetic structure of bird populations. For many avian taxa survival rates at the adult and juvenile life stages differ, but in long-lived species juveniles' survival is logistically challenging to study. We present the first estimates of hatch-year annual survival rates for a sea duck, the King Eider (Somateria spectabilis), estimated from satellite telemetry. From 2006 to 2008 we equipped pre-fledging King Eiders with satellite transmitters on breeding grounds in Alaska and estimated annual survival rates during their first 2 years of life with known-fate models. We compared those estimates to survival rates of adults marked in the same area from 2002 to 2008. Hatch-year survival varied by season during the first year of life, and model-averaged annual survival rate was 0.67 (95% CI: 0.48-0.80). We did not record any mortality during the second year and were therefore unable to estimate second-year survival rate. Adults' survival rate was constant through the year (0.94, 95% CI: 0.86-0.97). No birds appeared to breed during their second summer. While 88% of females with an active transmitter (n=9) returned to their natal area at the age of 2 years, none of the 2-year old males (n=3) did. This pattern indicates that females' natal philopatry is high and suggests that males' higher rates of dispersal may account for sex-specific differences in apparent survival rates of juvenile sea ducks when estimated with mark recapture methods.
Keywords: Breeding Season; Nonbreeding Seasons; King Eider; Somateria spectabilis; Dispersal; Survival; SDJV funded; Population Delineation

King Eider Foraging Effort During the Pre-Breeding Period in Alaska - Oppel, Steffen; Powell, Abby N.; Butler, Malcolm G. (Condor, 2011)
For reproduction, many arctic-nesting migratory birds rely on nutrients obtained on the breeding grounds, so they devote sufficient time to foraging immediately prior to nesting. However, little is known about the increase in foraging effort necessary to meet the energetic requirements of reproduction. In early June 2006 and 2008, we quantified the proportion of time spent foraging before breeding by a large sea duck, the King Eider (Somateria spectabilis), on its breeding grounds in northern Alaska. During > 235 hours of behavioral observations, both male and female King Eiders spent > 50% of the day loafing (resting, sleeping, comfort behavior, or being alert). Females foraged on average 30% of the time (mean 7.2 hr day(-1), 95% CI 6.0-8.4 hr day(-1)), three times as much as males (9%; 2.3 hr day(-1), 95% CI 1.5-2.8 hr day(-1)). The most common prey in ponds where the eiders foraged were chironomid larvae and worms ranging in length from 1 to 30 mm. If the King Eider's daily energy expenditure on its breeding grounds is similar to values published for related species, it would need to ingest only 0.2-0.6 g dry mass of invertebrates per minute of foraging to meet its energetic requirements. Males did not lose body mass before breeding, and we assume that their foraging effort was sufficient for energy balance. Therefore, female King Eiders appear to triple their foraging effort over maintenance requirements to meet the energetic challenges of egg formation.
Keywords: Behavior; Breeding Season; King Eider; Somateria spectabilis; Energetics and Nutrition; SDJV funded

Timing and distance of King Eider migration and winter movements - Oppel, Steffen; Powell, Abby N.; Dickson, D. Lynne (Condor, 2008)
Understanding the patterns, extent, and phenology of migration is important for estimating potential influences of habitat or climate changes on populations of migratory birds. We used satellite telemetry of >100 individual King Eiders (Somateria spectabilis) tagged in northwestern North America in 2002-2006 to describe the timing and extent of their migration and winter movements in the Bering Sea. We found high variability in timing of migration events and distances flown. Arrival on breeding grounds and onset of molt migration were the least variable events in duration. Fall migration was extremely variable, ranging from less than a week to several months. More than a third of King Eiders did not migrate after wing molt and wintered on or near wing-molting areas. We found diffuse migratory connectivity between breeding and wintering areas, and low intrayear fidelity to 25 km radius wintering sites. More than half of the King Eiders used several wintering sites in a given year, and their winter ranges were considerably larger than those of other sea duck species. We identified three distinct wintering regions in the Bering Sea that were several hundred km apart, among which no movements occurred from late December until April. The onset of spring migration was earlier for birds wintering farther south, but arrival time on breeding grounds was not correlated with wintering latitude. We conclude that high phenotypic plasticity in migratory traits may render King Eiders more likely to respond to environmental shifts than sea duck species that show stronger migratory connectivity.
Keywords: Breeding Season; Nonbreeding Seasons; Migration; King Eider; Somateria spectabilis; Dispersal; SDJV funded; Population Delineation

Using an algorithmic model to reveal individually variable movement decisions in a wintering sea duck - Oppel, Steffen; Powell, Abby N.; Dickson, D. Lynne (Journal of Animal Ecology, 2009)
Many migratory birds are assumed to remain fairly stationary during winter. However, recent research indicates that mid-winter movements are evident in a variety of bird species, and the factors causing individuals to move are poorly understood.We examined the winter movements of 95 individual king eiders (Somateria spectabilis, L.) tracked with satellite transmitters in the Bering Sea between 2002 and 2006 to explore whether environmental factors such as day length, location, sea ice, and habitat quality could explain the occurrence of winter movements longer than 50 km.We used a novel algorithmic random forest model to assess the importance of variables predicting whether a bird remained or departed from a wintering site.We found extremely high individual variability in winter movement decisions by king eiders, and the individual bird was the most important variable followed by location, date, and sea ice concentration.We conclude that individual strategies exist that interact with environmental conditions to form multiple movement patterns.While a minor proportion of winter movements may be forced by environmental conditions, we propose that many winter movements may be of an exploratory nature where individuals aim to acquire information about alternative wintering sites that may enhance their survival probability at some point in time when environmental fluctuation renders their preferred wintering site unsuitable.
Keywords: Nonbreeding Seasons; King Eider; Somateria spectabilis; Dispersal; SDJV funded

Using eggshell membranes as a non-invasive tool to investigate the source of nutrients in avian eggs - Oppel, Steffen; Powell, Abby N.; O'Brien, Diane M. (Journal of Ornithology, 2009)
Development of minimally invasive techniques to collect nutritional information from free-living birds is desirable for both ethical and conservation reasons. Here, we explore the utility of waterfowl eggshell membranes to determine the nutrient source of egg formation by using stable isotope ratios. We compared delta C-13 and delta N-15 of membranes from complete king eider (Somateria spectabilis) eggs to membranes of hatched or depredated eggs of the same clutch remaining after incubation. Despite large variation among membranes (delta C-13: -26 to -14%) we found a highly predictable relationship between delta(13)Cof complete egg membranes and remaining ( hatched or depredated) membranes from the same clutch. We did not find a consistent change in either delta C-13 or delta N-15 of eggshell membranes during incubation. We suggest that isotope ratios of membranes can be used to determine the source of exogenous nutrients for egg production in income breeders, and that membranes may offer a clutch-specific reference point for dietary nutrients ('income endpoint') in isotopic mixing models quantifying nutrient allocation in capital or mixed-strategy breeders.
Keywords: Breeding Season; King Eider; Somateria spectabilis; Energetics and Nutrition; Techniques

King eiders use an income strategy for egg production: a case study for incorporating individual dietary variation into nutrient allocation research - Oppel, Steffen; Powell, Abby N.; O'Brien, Diane M. (Oecologia (Berlin), 2010)
The use of stored nutrients for reproduction represents an important component of life-history variation. Recent studies from several species have used stable isotopes to estimate the reliance on stored body reserves in reproduction. Such approaches rely on population-level dietary endpoints to characterize stored reserves ("capital") and current diet ("income"). Individual variation in diet choice has so far not been incorporated in such approaches, but is crucial for assessing variation in nutrient allocation strategies. We investigated nutrient allocation to egg production in a large-bodied sea duck in northern Alaska, the king eider (Somateria spectabilis). We first used Bayesian isotopic mixing models to quantify at the population level the amount of endogenous carbon and nitrogen invested into egg proteins based on carbon and nitrogen isotope ratios. We then defined the isotopic signature of the current diet of every nesting female based on isotope ratios of eggshell membranes, because diets varied isotopically among individual king eiders on breeding grounds. We used these individual-based dietary isotope signals to characterize nutrient allocation for each female in the study population. At the population level, the Bayesian and the individual-based approaches yielded identical results, and showed that king eiders used an income strategy for the synthesis of egg proteins. The majority of the carbon and nitrogen in albumen (C: 86 +/- A 18%, N: 99 +/- A 1%) and the nitrogen in lipid-free yolk (90 +/- A 15%) were derived from food consumed on breeding grounds. Carbon in lipid-free yolk derived evenly from endogenous sources and current diet (exogenous C: 54 +/- A 24%), but source contribution was highly variable among individual females. These results suggest that even large-bodied birds traditionally viewed as capital breeders use exogenous nutrients for reproduction. We recommend that investigations of nutrient allocation should incorporate individual variation into mixing models to reveal intraspecific variation in reproductive strategies.
Keywords: Breeding Season; King Eider; Somateria spectabilis; Energetics and Nutrition; Techniques; SDJV funded

Within-season and between-year variation in the structure of Common Eider broods - Ost, Markus (Condor, 1999)
I studied within-season and between-year variation in Common Eider (Somateria mollissima) brood structure, by censusing broods for four years in the northern Baltic. I also examined within-season patterns of female aggressiveness, and explored whether between-year patterns could be related to female body condition at hatching. Multi-female tending was initially the dominant brood rearing strategy. Moreover, 25-38.1% of the lone-tended broods had more than six ducklings, indicating that they may contain adopted young. The number of ducklings per female increased with brood size, exposing some newly hatched ducklings to chilling due to unfavorably high ratios of ducklings to brooding females. Lone tenders became proportionally more common, the proportion of two-female tended broods was stable, and the proportion of broods with more than two females rapidly decreased during the season. Female aggression decreased in frequency over time, so the decline of broods with more than two females may relate to female aggressiveness. Family units began to break up when ducklings were 7 weeks old. Multi-female broods were initially more common in years when females were in good condition at hatching and less common in years when females were in poor condition. However, multi-female broods decreased in frequency over time in all years except the poorest year; multi-female tending strategy was most common in poor years and least common in good years. These between-year patterns may result from differences in body condition between lone tenders and multi-female tenders, indicating that female body condition may affect brood-caring decisions.
Keywords: Behavior; Breeding Season; Common Eider; Somateria mollissima

Parental effort and reproductive skew in coalitions of brood rearing female common eiders - Ost, Markus; Clark, Colin W.; Kilpi, Mikael; Ydenberg, Ron (American Naturalist, 2007)
Members of breeding groups face conflicts over parental effort when balancing antipredatory vigilance and feeding. Empirical evidence has shown disparate responses to manipulations of parental effort. We develop a model in which we determine the evolutionarily stable effort of partners given their body conditions, allowing the benefits of shared care to be unevenly divided, and we test this model's predictions with data on common eiders (Somateria mollissima). Eiders show uniparental female care; females may share brood rearing, or they may tend alone, and their body condition at hatching of the young shows large environmentally induced variation. The model predicts that parental effort (vigilance) in a coalition is lower than when tending alone, controlling for parental condition; this prediction is supported by the data. The parental effort in a coalition should be positively correlated with body condition, and this prediction is also supported. Finally, parental effort should increase when partner condition decreases and vice versa; this prediction is partially supported. The Nash bargaining game may provide promising avenues by which to determine the precise settlement of reproductive skew and effort between coalition partners in the future.
Keywords: Behavior; Breeding Season; Common Eider; Somateria mollissima

Relative Importance of Social Status and Physiological Need in Determining Leadership in a Social Forager - Ost, M.; Jaatinen, K. (Plos One, 2013)
Times Cited: 0 Ost, Markus Jaatinen, Kim Jaatinen, Kim/A-3221-2011; Ost, Markus/C-7376-2008 0
Keywords: Behavior; Breeding Season; Somateria mollissima; Physiology; Common eider

Smart and safe? Antipredator behavior and breeding success are related to head size in a wild bird - Ost, M.; Jaatinen, K. (Behavioral Ecology, 2015)
Increased brain size has been associated with greater sensitivity to environmental context, but this flexibility is potentially costly as sampling the environment is time and energy consuming and may even increase the risk of predation. However, these potential trade-offs remain virtually unexplored in natural populations. We hypothesized that large brain size is 1) beneficial under challenging conditions and allows better matching of antipredator responses to the actual threat by predators and 2) associated with thorough risk assessment, which can be costly under benign conditions. To test these hypotheses, we examined the relationship between relative head volume, reproductive decisions, and fitness components in female common eiders (Somateria mollissima) under variable predation risk and breeding phenologies. This species is ideal for this purpose because of highly variable predation pressure and a distinct seasonal decline in reproductive success. The results were consistent with our hypotheses. First, females with depredated nests had smaller heads than expected by chance when predation rate (killed females/nest) was highest ("challenging conditions"). Second, large-headed females, but not small-headed ones, took a shorter time to form antipredator brood-rearing coalitions in more dangerous years. Third, large-headed females had a later onset of breeding, and their nests were more likely to be depredated when annual median nesting was earliest and predation pressure on females was low ("benign conditions"). Thus, predation risk and annual phenology may exert temporally fluctuating selection on relative head size, maintaining intraspecific variation in cognitive ability.
Ost, Markus Jaatinen, Kim
Keywords: Behavior; Breeding Season; Common Eider; Somateria mollissima

A recent change in size distribution of blue mussels (Mytilus edulis) in the western part of the Gulf of Finland - Ost, Markus; Kilpi, Mikael (Annales Zoologici Fennici, 1997)
We sampled blue mussels (Mytilus edulis) in 1992-1996 from mussel beds that common eiders (Somateria mollissima) preferentially use during foraging in the Hanko archipelago, Finland. We also compared our data with an earlier study carried out in the same area. We found a consistent trend towards decreasing mussel size; the proportion of larger mussels in the population has decreased significantly. Since blue mussels are an essential part of the Baltic ecosystem, a shift in mean mussel size may have important consequences. A decrease in salinity during the last few decades may be the ultimate reason for the observed changes, as salinity affects growth, maximum size and reproduction of mussels. We also suggest that selective eider predation may be of local importance.
Keywords: Common Eider; Somateria mollissima; Trophic Interactions

Eider females and broods from neighboring colonies use segregated local feeding areas - Ost, Markus; Kilpi, Mikael (Waterbirds, 2000)
We studied the post-nesting site use of Common Eider (Somateria mollissima) females in the northern Baltic. We compared the dispersal pattern of lone females tending young, multi-female tenders and failed female nesters without young. We also examined if females from the same colony used the same sites and if the sites of birds from neighboring colonies were segregated. Primary movements, the distance from the nesting site to the first observation site, were similar in length irrespective of female breeding status or colony. Secondary movements, the median distance moved from the first observation onwards, tended to be shorter among lone tenders than females without young. Female home ranges were similar, irrespective of breeding status or time of the breeding season, but were smaller in the outer study area than in the innermost eider colony. Blue muscles (Mytilus edulis) were more abundant in the outer area, so food resources may influence home range size. Home range size correlated positively with the number of ducklings in broods, indicating that large broods need more food and also a larger feeding area. Females from the same colony were significantly aggregated to the same sites close (< one km) to their nesting island. A long-distance nest exodus after hatch was absent, compulsory for eider populations with separate nesting and feeding sites. The sites of neighboring colonies were essentially spatially separated. This may be due to females moving to the nearest available feeding site, or it may result from mutual avoidance or aggression between females from different colonies. Our results indicate that familiarity with post-nesting feeding sites may be advantageous during brood-rearing. Because multi-female tenders may originate from the same island, kin selection or reciprocity might affect post-hatch brood amalgamation behavior.
Keywords: Behavior; Breeding Season; Common Eider; Somateria mollissima; Dispersal

Top-down effects override climate forcing on reproductive success in a declining sea duck - Ost, M.; Lehikoinen, A.; Jaatinen, K. (OIKOS, 2022)
Population performance is predicted to be more strongly influenced by detrimental species interactions such as predation under benign climatic conditions, and by climate forcing under harsh conditions, reflected in geographical gradients in biotic interaction strength. Less appreciated is the potential for site-specific changes in drivers with the advent of anthropogenic alteration of predator-prey relationships, including apex predator restoration and spread of invasive predators. Particularly interesting is the relative impact of climate and biotic interactions on population performance when these conflict. In this 31-year study (1990-2020), we revisit a common eider Somateria mollissima population from SW Finland, Baltic Sea, fifteen years on from an earlier study showing that climate warming positively affected reproductive parameters and performance. However, the population is simultaneously exposed to increasing predation by the rapidly recovering native apex predator and invasive mammals. Based on the current population trend, we predicted 1) a weakening of the previously documented positive effects of a warming climate on vital rates, 2) intensified predation and 3) increasing top-down control of vital rates and accompanying population decline. Five out of seven breeding parameters (annual spread in female body condition, breeding phenology and synchrony, interval between arrival and breeding, fledgling production) were best explained by predation indices, whereas climate signals (winter NAO, Baltic Sea maximum ice cover) on breeding parameters have weakened. Particularly intriguing is that the previous positive association between mild ice winters and subsequent reproductive output has disappeared during the past 15 years, highlighting the non-linear nature of climate change responses. Indirect predation effects (selective disappearance, changed reproductive strategies, nest-site selection and population age distribution) can potentially explain also the remaining breeding parameters (annual mean body condition and clutch size). The observed regime shift in predation risk appears to prevent this now endangered population from reaping the potential benefits of a warming climate.
Times Cited in Web of Science Core Collection: 5 Total Times Cited: 5 Cited Reference Count: 70
Keywords: CONSEQUENCES; SOMATERIA-MOLLISSIMA; BODY CONDITION; SHIFTS; RESPONSES; PREDATION RISK; STRATEGIES; predator-prey; reproductive success; anthropogenic predation facilitation; antipredator behaviour; biotic interaction strength; climate forcing; LANDSCAPE; SYNCHRONY; TEMPERATURES

Causes and consequences of fine-scale breeding dispersal in a female-philopatric species - Ost, M.; Lehikoinen, A.; Jaatinen, K.; Kilpi, M. (Oecologia, 2011)
Times Cited: 9 Ost, Markus Lehikoinen, Aleksi Jaatinen, Kim Kilpi, Mikael Ost, Markus/C-7376-2008; Jaatinen, Kim/A-3221-2011 9
Keywords: Breeding Season; Dispersal; Common eider; somateria mollissima

To breed or not to breed: drivers of intermittent breeding in a seabird under increasing predation risk and male bias - Ost, M.; Linden, A.; Karell, P.; Ramula, S.; Kilpi, M. (OECOLOGIA, 2018)
Intermittent breeding may be adaptive for long-lived species subjected to large accessory reproductive costs, but it may also reflect reduced adaptation to the environment, reducing population growth. Nevertheless, environmental influences on breeding propensity, particularly that of predation risk, remain poorly understood and difficult to study, because non-breeders are typically not identified. Female eiders Somateria mollissima from the Baltic Sea provide an excellent testbed, because nesting females have been exposed to intensifying predation and growing male bias that may increase female harassment. We based our study on long-term data (14 years) on females captured and marked at the nest, and females individually identified at sea irrespective of capture status. We hypothesized that breeding propensity decreases with increasing predation risk and male bias, and increases with breeder age. Consistent with our hypotheses, females nesting on islands with higher nest predation risk were more likely to skip breeding, and breeding probability increased with age. In contrast, the steep temporal decline in breeding propensity could not be reliably attributed to annual adult sex ratio or to the abundance of white-tailed sea eagles (Haliaeetus albicilla), the main predator on females, at the nearby Hanko Bird Observatory. Breeding probability showed significant consistent individual variation. Our results demonstrate that spatiotemporal variation in predation risk affects the decision to breed and high incidence of non-breeding was associated with low fledging success. The increased frequency of intermittent breeding in this declining population should be explicitly considered in demographic models, and emphasis placed on understanding the preconditions for successful reproduction.
Times Cited in Web of Science Core Collection: 28 Total Times Cited: 28 Cited Reference Count: 64
Keywords: COMMON EIDERS; EIDERS SOMATERIA-MOLLISSIMA; POPULATION-DYNAMICS; CLIMATE; REPRODUCTION; STRESS; MODEL SELECTION; Breeding propensity; Eider; AGE; LONG-LIVED BIRD; COST; Environmental cues; Non-breeders; Reproductive strategies

Sex-specific effects of the in ovo environment on early-life phenotypes in eiders - Ost, M.; Noreikiene, K.; Angelier, F.; Jaatinen, K. (OECOLOGIA, 2020)
Maternal effects affect offspring phenotype and fitness. However, the roles of offspring sex-specific sensitivity to maternal glucocorticoids and sex-biased maternal investment remain unclear. It is also uncertain whether telomere length (a marker associated with lifespan) depends on early growth in a sex-specific manner. We assessed whether maternal traits including corticosterone (CORT; the main avian glucocorticoid) and in ovo growth rate are sex-specifically related to offspring CORT exposure, relative telomere length (RTL) and body condition in eiders (Somateria mollissima). We measured feather CORT (fCORT), RTL and body condition of newly hatched ducklings, and growth rate in ovo was expressed as tarsus length at hatching per incubation duration. Maternal traits included baseline plasma CORT, RTL, body condition and breeding experience. We found that fCORT was negatively associated with growth rate in daughters, while it showed a positive association in sons. Lower offspring fCORT was associated with higher maternal baseline plasma CORT, and fCORT was higher in larger clutches and in those hatching later. The RTL of daughters was negatively associated with maternal RTL, whereas that of males was nearly independent of maternal RTL. Higher fCORT in ovo was associated with longer RTL at hatching in both sexes. Duckling body condition was mainly explained by egg weight, and sons had a slightly lower body condition. Our correlational results suggest that maternal effects may have heterogeneous and even diametrically opposed effects between the sexes during early development. Our findings also challenge the view that prenatal CORT exposure is invariably associated with shorter telomeres.
Times Cited in Web of Science Core Collection: 7 Total Times Cited: 7 Cited Reference Count: 78
Keywords: Somateria mollissima; CLUTCH SIZE; COMMON EIDERS; SURVIVAL; BODY CONDITION; LONG-TERM; CORTICOSTERONE LEVELS; QUANTITATIVE PCR; BROOD SIZE; DEVELOPMENTAL STRESS; Early environment; Feather corticosterone; Prenatal growth; TELOMERE DYNAMICS; Telomere length

Small-scale spatial and temporal variation in the demographic processes underlying the large-scale decline of eiders in the Baltic Sea - Ost, M.; Ramula, S.; Linden, A.; Karell, P.; Kilpi, M. (Population Ecology, 2016)
The application of uniform conservation schemes often fails to account for small-scale spatial variation in the drivers of population decline. Demographic comparisons of imperilled populations across locations are therefore crucial for successful conservation, but progress is hampered by lack of long-term data from more than a single population. The recent large-scale decline of eider ducks (Somateria mollissima) in the Baltic Sea is ideal for determining to what extent mechanisms underlying population decline can be extrapolated over larger areas. We utilized stochastic demographic methods incorporating both environmental and sampling variation to assess small-scale spatial and temporal variation in the population dynamics of eiders at Soderskar (eastern range-margin) and Tvarminne (core breeding area), situated 130 km apart. The stochastic growth rate models accurately predicted the observed differences in the rate of decline between sites and time periods. At Soderskar, established breeder survival had by far the greatest elasticity, whereas elasticity was more evenly distributed among vital rates at Tvarminne. Although the study sites showed the single largest difference in fecundity, stochastic life table response experiment analyses revealed that reduced adult female survival at Tvarminne mainly determined the observed difference in growth rates between sites. In contrast, reduced fecundity primarily differentiated the past population increase from the present population decline at Soderskar. Our results demonstrate that different mechanisms may be associated with population decline across adjacent geographic locations, and indicate that dispersal of first-time breeders may be important for population dynamics. Safeguarding adult female survival and/or fecundity should be prioritized in management efforts.
Ost, Markus Ramula, Satu Linden, Andreas Karell, Patrik Kilpi, Mikael
Keywords: Breeding Season; Common Eider; Somateria mollissima; Population Model; Abundance, Distribution, & Trends

Personality, body condition and breeding experience drive sociality in a facultatively social bird - Ost, M.; Seltmann, M. W.; Jaatinen, K. (Animal Behaviour, 2015)
Adopting different behavioural strategies may reduce within-group conflict, selecting for behavioural consistency ('personality'). Personality may also affect grouping tendencies. The relationship between the personality dimensions sociability and boldness nevertheless remains unclear. This knowledge gap may reflect a failure to consider potential trade-offs between avoiding conspecifics, potentially alleviating social stress, and avoiding predation. Furthermore, the effects of personality and state (e.g. body condition or age affecting the costs and benefits of behavioural actions) on cooperativeness should be considered together. This is because state may explain predation vulnerability, which may affect boldness under predation risk, and thus antipredator grouping tendencies. To address the problem, we determined how group size preference and group-forming time depended on boldness (flight initiation distance, FID, in response to an approaching human), body condition and breeding experience in facultatively social eiders, Somateria mollissima, where females form coalitions or care for the young solitarily. Breeding adults and young are subject to high predation pressure, providing a strong incentive for brood-tending females to cooperate. Because hormonal differences may also explain differences in sociability, we included baseline and handling-induced serum corticosterone concentrations of incubating females as potential predictors of sociability. We also statistically controlled for availability of potential partners. The relationship between boldness (FID) and the number of coalition partners ranged from negative (females in poor body condition) to positive (females in good body condition), arguing against a uniform relationship between boldness and sociability. The number of coalition partners decreased with female breeding experience. The time taken to form a coalition was shortest close to the hatching peak in the population. Shyness (long FID) delayed group formation. Despite a need for safety in numbers by shy females in poor body condition, their entry into groups may be constrained by their personality, suggesting a possible trade-off between predator and conspecific avoidance. (C) 2014 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.
Ost, Markus Seltmann, Martin W. Jaatinen, Kim
Keywords: Behavior; Breeding Season; Common Eider; Somateria mollissima

Synchronized vigilance while feeding in common eider brood-rearing coalitions - Ost, Markus; Tierala, Tekla (Behavioral Ecology, 2011)
The timing of vigilance and feeding in groups determines the efficiency of shared predator detection and foraging success. Behavioral monitoring of conspecifics remains controversial although synchronization is commonly observed and need not compromise predator detection. The within-group timing of vigilance shows inconsistent associations with group size, and whether nearby nongroup conspecifics affect this timing is poorly understood. Finally, it is unknown whether socially breeding parents time their activities to each other based on offspring predation risk. We studied diving common eider females (Somateria mollissima) in brood-rearing coalitions subject to gull predation of ducklings. The within-group timing of vigilance was determined by comparing observed collective vigilance, the proportion of time during which at least 1 adult group member is vigilant, with that expected assuming independent timing of activities. We determined the predictors of within-group timing of vigilance, observed collective vigilance, individual vigilance, frequency of nearby nongroup females (group outsiders), and incidence of alarm reactions. Vigilance was synchronized regardless of brood composition. Synchronization and observed collective vigilance increased with female group size, whereas synchronization decreased with increasing ratios of ducklings to tending females. Individual vigilance increased in the presence of gull alarms. Within-group timing of activities was unrelated to the presence of group outsiders, but broods with fewer ducklings (less predation dilution) were more often associated with group outsiders, the frequency of which was negatively associated with the incidence of gull alarms. Increased offspring predation risk thus reduces overlapping vigilance among adult group members and enhances attraction to nearby nongroup conspecifics.
Keywords: Behavior; Breeding Season; Common Eider; Somateria mollissima

Condition and coalition formation by brood-rearing common eider females - Ost, Markus; Ydenberg, Ron; Kilpi, Mikael; Lindstrom, Kai (Behavioral Ecology, 2003)
Partner choice is important in nature, and partnerships or coalitions within which reproduction is shared are the subject of growing interest. However, little attention has been given to questions of which individuals are suitable partners and why. Common eider (Somateria mollissima) females sometimes pool their broods and share brood-rearing duties, and body condition affects care decisions. We constructed a model in which females, based on their body condition and the structure of the joint brood, assess the fitness consequences of joining a coalition versus tending for young alone. We tested the model's predictions by comparing data on the condition of females in enduring and transient coalitions. Our model showed that the range of acceptable brood arrays in a female coalition decreases with increasing condition of the female, so females tending alone should be in better condition than multifemale tenders. This prediction is in agreement with previous data. The model also predicts that females in good condition should join coalitions with females in poor condition and not with other females in good condition. This prediction was also supported by data: in enduring two-female coalitions, the positive correlation between the better female's condition and the difference in condition between the two females was stronger than would be expected by random grouping of females. In contrast, in transient coalitions of females, this correlation did not differ from the correlation expected under random grouping. Model assumptions seem to fit with eider natural history, and the model may prove to be a useful way to study brood amalgamation behavior of waterfowl in general.
Keywords: Behavior; Breeding Season; Common Eider; Somateria mollissima

Body condition and the grouping behavior of brood-caring female common eiders (Somateria mollissima) - Ost, Markus; Ydenberg, Ron; Lindstrom, Kai; Kilpi, Mikael (Behavioral Ecology and Sociobiology, 2003)
Both theoretical and empirical work has shown that group size increases with increasing ecological constraints on solitary breeding. Ecological constraints refer to extrinsic factors such as availability of breeding sites, food or mates. Common eider (Somateria mollissima) females pool their broods and share brood-rearing duties, or rear broods alone. Females are often in poor condition at hatching, as incubation is accomplished without feeding, and variation in body condition is largely environmentally induced and thus unpredictable. We found that the intensity of and duration of parental care that females provide is positively correlated with their body condition at hatching. This suggests that body condition is an ecological constraint on successful solitary breeding. We further observed that group productivity in common eider broods is a decelerating function of the number of tending females. As predicted, females in poorer condition (i.e., facing stronger ecological constraints) were found in larger groups. This result is straightforward if solitary tenders can enter any group at no cost. However, if entry is group-controlled, stable groups of non-relatives are predicted not to occur when per capita reproduction declines with group size. The N-person staying incentive model permits groups to form under these conditions, because reproduction is unevenly divided between dominants and subordinates in the group. We discuss the plausibility of these alternative models of group size for understanding the grouping behavior of brood-caring female common eiders.
Keywords: Behavior; Breeding Season; Common Eider; Somateria mollissima; Energetics and Nutrition

Do Barrow's goldeneyes, Bucephala islandica, breed south of the St. Lawrence estuary in the Gaspé Peninsula, eastern Canada. - Ouellet, J.-F., P. Fradette, and I. Blouin. (The Canadian Field Naturalist, 2010)
Keywords: Breeding Season; Abundance, Distribution, and Trends; Barrow's Goldeneye; Bucephala islandica

Spatial distribution and habitat selection of Barrow's and Common goldeneyes wintering in the St. Lawrence marine system - Ouellet, Jean-Francois; Guillemette, M.; Robert, M. (Canadian Journal of Zoology, 2010)
Our study addresses winter spatial distribution of Barrow's Goldeneyes (Bucephala islandica (Gmelin, 1789)) and Common Goldeneyes (Bucephala clangula (L.. 1758)) at the scale of the St. Lawrence marine system (estuary and northwestern gulf), eastern Canada. Our objectives were (i) to identify and compare the physical factors that control their distributions, (ii) to quantify the level of sympatry between the two species, and (iii) to compare their distribution patterns. We analyzed large-scale synoptic views of winter distribution of both goldeneye species obtained through helicopter-borne surveys. Habitat description was obtained through spatial analyses and remote sensing. Both species showed strong preference for the tidal zone and river mouths. A multiscale analysis showed a decreasing level of sympatry as spatial resolution was refined. The distribution of the Barrow's Goldeneye was more clustered compared with that of the Common Goldeneye, and Barrow's Goldeneye was repeatedly observed in the same few areas. A use-availability analysis identified the northern coast of the St. Lawrence estuary as the main wintering ground for Barrow's Goldeneye in eastern North America.
Keywords: Abundance, Distribution, and Trends; Nonbreeding Seasons; Bucephala clangula; Common Goldeneye; Habitat; Barrow's Goldeneye; Bucephala islandica

Levels of heavy metals, PCBs, pesticides and flame retardants in tissues of Barrow's Goldeneyes (Bucephala islandica) wintering in the St. Lawrence marine system - Ouellet, J. F.; Champoux, L.; Robert, M. (Canadian Technical Report of Fisheries and Aquatic Sciences, 2009)
Keywords: Nonbreeding Seasons; Contaminants; Barrow's Goldeneye; Bucephala islandica

Metals, Trace Elements, Polychlorinated Biphenyls, Organochlorine Pesticides, and Brominated Flame Retardants in Tissues of Barrow's Goldeneyes (Bucephala islandica) Wintering in the St. Lawrence Marine Ecosystem, Eastern Canada - Ouellet, J. F.; Champoux, L.; Robert, M. (Archives of Environmental Contamination and Toxicology, 2012)
Times Cited: 1 Ouellet, Jean-Francois Champoux, Louise Robert, Michel 1
Keywords: Nonbreeding Seasons; Contaminants; Barrow's Goldeneye; Bucephala islandica

Morphological and physiological aspects of takeoff aptitudes of female common eiders (Somateria mollissima) during the pre-laying period - Ouellet, J. F.; Guillemette, M.; Biler, P. U. (Canadian Journal of Zoology, 2008)
In many bird species, follicular growth and the accumulation of body reserves may impair flight takeoff capability of breeding females. The pre-laying period in common ciders, Somateria mollissima (L., 1758), is characterized by a dramatic sex-specific takeoff impairment, and we tested the hypothesis that pre-laying female common eiders compensate to diminish or delay their takeoff impairment. We addressed our question at three organizational levels: (1) measurement of wing morphology, (2) mass of flight musculature, and (3) measurement of the activity of key enzymes of aerobic and Glycolytic capacity in one locomotor muscle and one structural muscle. All measurements were performed on individuals of both sexes. We found that wing area was similar between sexes despite males being structurally larger. Our results also indicate that female mass gain is partly compensated by higher pectoralis mass, while the catalytic capacity of the tissue remains unchanged. We conclude that females diminish and delay their takeoff impairment differently according to organizational levels.
Keywords: Common Eider; Nonbreeding Seasons; Somateria mollissima; Physiology

The Body Size-Dependent Diet Composition of North American Sea Ducks in Winter - Ouellet, J. F.; Vanpe, C.; Guillemette, M. (Plos One, 2013)
Times Cited: 0 Ouellet, Jean-Francois Vanpe, Cecile Guillemette, Magella 0
Keywords: Nonbreeding Seasons; Trophic Interactions; Sea Ducks

Mortality of common goldeneye (Bucephala clangula) broods in relation to predation risk by northern pike (Esox lucius) - Paasivaara, Antti; Poysa, Hannu (Annales Zoologici Fennici, 2004)
We studied brood-rearing lake selection of the common goldeneye Buchephal clangula in relation to food abundance, vegetation structure, brood mortality and predation risk by northern pike Esox lucius. Movements of radio-tagged females and their broods were followed and duckling survival was determined until fledging or until the young had died. Food was more abundant in rearing lakes than in reference lakes. On the contrary, no difference was found between rearing and reference lakes with respect to the structure of shore vegetation. During the brood rearing period the mortality of young (1-23 days) ducklings increased with the increased predation risk by pike. Mortality of old (>23 days) ducklings was not associated with the predation risk by pike. These results suggest that pike predation is an important source of mortality in young common goldeneye ducklings, and that females may be imperfect in predicting pike predation risk when selecting the brood rearing lake.
Keywords: Breeding Season; Bucephala clangula; Common Goldeneye; Survival; Trophic Interactions

Survival of common goldeneye Bucephala clangula ducklings in relation to weather, timing of breeding, brood size, and female condition - Paasivaara, Antti; Poysa, Hannu (Journal of Avian Biology, 2007)
The survival of common goldeneye Bucephala clangula ducklings during their first week of life was studied in relation to hatching date, brood size, female condition, and weather (temperature and precipitation) during the first week post-hatch by using data from radio-marked females and their broods. Also, age-specific variation in the survival of the young was determined until fledging (over 50 d of age). Survival was lowest in the first week after hatching. Hatching date, brood size, and first week temperature and precipitation were poor predictors of duckling survival during the first week after nest exodus. Instead, the ducklings of females in a better body condition survived better in their first week of life. The results suggest that weather does not have a direct effect on downy ducklings' survival, but the condition of the female seems to be an important determinant of the survival of common goldeneye ducklings.
Keywords: Breeding Season; Bucephala clangula; Common Goldeneye; Survival

Habitat-patch occupancy in the common goldeneye (Bucephala clangula) at different stages of the breeding cycle: implications to ecological processes in patchy environments - Paasivaara, Antti; Poysa, Hannu (Canadian Journal of Zoology, 2008)
We studied the pattern of habitat-patch Occupancy of radio-tagged common goldeneye (Bucephala clangula (L., 1758)) females in two sequential stages of the breeding season, the nest stage and the brood stage, and whether the resources needed in nesting and brood-rearing are spatially inter-related as revealed by patch occupation rate of goldeneye females in these stages. We also studied patch-specific factors potentially explaining the rate of patch occupation separately during the nest stage and the brood stage. There was no association in patch occupation rate between the nest stap and the brood stage, indicating that all the critical resources needed to complete a successful breeding cycle were not met within the same habitat patch. At the nest stage, patch Occupation rate increased with nest-site availability and decreased with nest predation rate but was not affected by vegetation luxuriance or patch size. Vegetation luxuriance had a positive effect on patch occupation rate at the brood stage, whereas nesting success of the focal patch had no effect. Results suggest that nest-site selection and brood-stage habitat selection are governed by different ecological factors. We conclude that breeding-stage-specific resource requirements redistributed individuals among habitat patches across the landscape, implying dynamic distribution of ducks between nesting and brooding stage.
Keywords: Breeding Season; Bucephala clangula; Common Goldeneye; Habitat

Do parasitic common goldeneye Bucephala clangula females choose nests on the basis of host traits or nest site traits? - Paasivaara, Antti; Rutila, Jarkko; Poysa, Hannu; Runko, Pentti (Journal of Avian Biology, 2010)
Conspecific brood parasitism (CBP) is an important alternative breeding strategy for gaining reproductive output in birds. While interactions between hosts and parasites and consequences of CBP to breeding success of both parties have been studied a lot, the roles of host characteristics and nest site characteristics in CBP have received less attention. We studied the relative importance of host-related traits, such as female condition and breeding experience, and nest-site-related factors, such as overall nest site preference and occupation rate, in explaining the occurrence of CBP in a common goldeneye Bucephala clangula population. We used spatially and temporally extensive data sets, analysed the data with generalized linear mixed models that allowed us to account for the non-independency of individual nesting attempts across females and nesting sites, and used an information theoretic approach in model selection and inference. About half of the nests were parasitized annually during the seven year study period. The occurrence of CBP decreased with advancement of the breeding season but late nests were also frequently parasitized. We found that the occurrence of CBP was better explained by nest-site characteristics than host traits, implying that parasitic females target a given nest based on factors related to the nest site itself rather than on the host. Our results suggest that more attention should be paid to factors associated with nest site attractiveness and quality when studying laying decisions of parasites and the occurrence of CBP in general.
Keywords: Behavior; Breeding Season; Bucephala clangula; Common Goldeneye

Baseline Corticosterone in Wintering Marine Birds: Methodological Considerations and Ecological Patterns - Palm, E. C.; Esler, D.; Anderson, E. M.; Williams, T. D.; Love, O. P.; Wilson, M. T. (Physiological and Biochemical Zoology, 2013)
Times Cited: 0 Palm, E. C. Esler, D. Anderson, E. M. Williams, T. D. Love, O. P. Wilson, M. T. 0
Keywords: Melanitta fusca; Nonbreeding Seasons; Physiology; Techniques; white-winged Scoter

VARIATION IN PHYSIOLOGY AND ENERGY MANAGEMENT OF WINTERING WHITE-WINGED SCOTERS IN RELATION TO LOCAL HABITAT CONDITIONS - Palm, E. C.; Esler, D.; Anderson, E. M.; Williams, T. D.; Wilson, M. T. (Condor, 2013)
Times Cited: 0 Palm, Eric C. Esler, Daniel Anderson, Eric M. Williams, Tony D. Wilson, Matthew T. 0
Keywords: Melanitta fusca; Nonbreeding Seasons; Physiology; white-winged Scoter; energetics and Nutrition

Geographic and Temporal Variation in Diet of Wintering White-winged Scoters - Palm, E. C.; Esler, D.; Anderson, E. M.; Wilson, M. T. (Waterbirds, 2012)
Times Cited: 2 Palm, Eric C. Esler, Daniel Anderson, Eric M. Wilson, Matt T. 2
Keywords: Melanitta fusca; Nonbreeding Seasons; Trophic Interactions; white-winged Scoter

Icelandic Eiders a Few Observations - Palmer, R. S. (Wildfowl, 1973)
Keywords: Common Eider; Somateria mollissima; King Eider; Somateria spectabilis

King Eider Studies - Palmer, R. S. (British Birds, 1977)
Keywords: King Eider; Somateria spectabilis

The status of Velvet Scoter Melanitta fusca breeding in Georgia - Paposhvili, N. (WILDFOWL, 2018)
The first ever survey of all seven potential breeding lakes for Velvet Scoter Melanitta fusca fusca in the Javakheti plateau region of southern Georgia found that nesting was confined to just one traditionally occupied site, at Lake Tabatskuri. Intensive observations revealed that c. 25-35 pairs were present at Lake Tabatskuri during mid-May to mid-June in 2017 and 2018, but substantially fewer pairs actually nested at the lake, and all that did so built nests on the only island in the lake. Hatching success (65% of eggs successfully hatched in 2017, 51% in 2018) was lower than in North American White-winged Scoter M. f. deglandi studies (67-92%) and fledging success was relatively poor (29% of hatched ducklings survived to fledging compared to 5-10% in North America and 30% in Finland), suggesting challenges to the long-term perpetuation of the population. More research is required to determine the direct causes of the scoters' poor reproductive success. Information from a questionnaire survey of local residents and observations made during the study suggested that interactions with Armenian Gulls Lams armenicus nesting on the islands, disturbance and removal of eggs by humans, and drowning of ducklings in active or abandoned fishing nets all contributed to poor overall reproductive success. Conservation actions to ameliorate some of these factors have already been initiated, but further research, monitoring and conservation is needed to safeguard for future generations this tiny disjunct population at its last location in Georgia, potentially in the entire region.
Times Cited in Web of Science Core Collection: 1 Total Times Cited: 1 Cited Reference Count: 12
Keywords: SURVIVAL; DEGLANDI

Seasonal abundance and breeding biology of the Velvet Scoter Melanitta fusca at Lake Tabatskuri, Georgia - Paposhvili, N. (WILDFOWL, 2021)
Velvet Scoters Melanitta fusca from the disjunct Turkey, Georgia and Armenia nesting population were studied during 2017-2020 at what is now their last known breeding site, at Tabatskuri Lake in southern Georgia. Paired birds returned to the lake soon after thaw in April and females and young remained into November in some years. Early failing females and most males migrate to moult elsewhere in late July, although 11-19 males remained to moult on the lake each year, departing in late September/early October. Annual summer maxima ranged from 77-92 individuals, typically comprised of 43-55% females during April-August (although inevitably fewer during incubation). Nests were totally confined to one island, where the number of breeding pairs recorded ranged from 23-33 (in 2018 and 2019, respectively). Nest success (at least one duckling hatched) varied from 74% (in 2018 and 2020) to 52% (2019), recorded for 23 (2018), 33 (2019) and 31 nests (2020), although more females were present early in the season in each year. Camera traps monitoring 11 nests recorded egg predation by Marsh Harriers Circus aerginosus on two occasions. Hatching success for all eggs laid was 54% (in 2018), 36% (2019) and 49% (2020), with overall survival of the eggs to fledging ranging from 2% (in 2018 and 2019) to 13% (in 2020). Duckling mortality was likely due to predation by Armenian Gulls Larus armenicus soon after hatching and to drowning in fishing nets. Local community engagement has stopped egg collecting on the island and contributed to reduced fishing disturbance for Velvet Scoters in the ducklings' nursery areas, when newly hatched young are most vulnerable to gull predation. Additionally, gull numbers were lower in 2020, which also likely contributed to the improved breeding success in that year. We urge continued vigilance and further research to confirm the direct causes of the Velvet Scoters' poor breeding success at the site, to improve the conservation status of the species in the region.
Times Cited in Web of Science Core Collection: 0 Total Times Cited: 0 Cited Reference Count: 16
Keywords: conservation; habitat use; SURVIVAL; hatching success; DEGLANDI; nesting success; reproductive output

The functional anatomy of the ciliary muscle in four avian species - Pardue, Machelle T.; Sivak, Jacob G. (Brain Behavior and Evolution, 1997)
The functional anatomy of avian ciliary muscles has been difficult to describe, due to the muscle's inaccessible location inside the eye. The ciliary muscle of the chicken (Gallus gallus domesticus), the pigeon (Columbia livia), the kestrel (Falco sparverius), and the hooded merganser (Margus cucullatus) (four species with differing accommodative needs) was examined histologically in both the relaxed and contracted states. The ciliary muscle of all four species can be divided into three main muscle fibre groups based on insertion and origin: anterior, posterior and internal. The anterior muscle fibre group originates at the sclera under the scleral ossicles and inserts into the inner lamellae of the cornea. During accommodation these fibres pull the cornea posteriorly, changing the curvature of the cornea. The posterior muscle fibre group originates on the sclera and inserts posteriorly onto the baseplate of the ciliary body. The posterior fibre group acts on the baseplate of the ciliary body, pulling it forward to change the curvature of the lens during accommodation. The internal muscle fibre group extends from the baseplate of' the ciliary body to the inner lamellae of the cornea and thus has a role in both corneal and lenticular accommodation. Species differences do exist, as seen in subgroups determined by the orientation of the fibres between the relaxed and contracted states and the percentage of fibres within the main muscle fibre groups. In general, the majority of ciliary muscle fibres in chickens, pigeons, and kestrels are in the anterior muscle fibre group, suggesting an emphasis on corneal accommodation; in the ciliary muscle of the hooded merganser, the majority of fibres are in the internal and posterior muscle fibre groups, indicating that lenticular accommodation is the predominant form of accommodation.
Keywords: Physiology; Hooded Merganser; Lophodytes cucullatus

Patterns of Nutrient and Energy Expenditure in Female Common Eiders Nesting in the High Arctic - Parker, H.; Holm, H. (Auk, 1990)
In 1982 we studied weight loss, changes in body composition, and energy expenditure in breeding female Common Eiders (Somateria mollissima borealis) in Svalbard Norway. Feeding ceased during laying and incubation. From prelaying to hatching, total weight declined by 46.4%, lipid by 81.4%, and protein by 36.8%. Daily energy expenditure during laying was 2,528 kJ, times greater than during incubation. Rate of lipid expenditure during laying was 3.3 times greater than during incubation, and rate of protein expenditure was 8.8 times greater. Of the birds' total prelaying energy, 33.8% was expended during laying 34.6% during incubation, and 31.6% remained at hatching. An estimated 31.6% of the energy expended during laying was investigated in eggs. Sixteen- and 18-carbon fatty acids dominated in lipid of the fattest and leanest birds. The major nutrient and energy donors during breeding were 16:0 and 18:1 fatty acids. Svalbard eider eggs weighed ca. 17.5% less and were incubated ca. 1.5 days shorter than eggs from the species' most southerly range limit. This apparent adaptation to arctic existence gave an estimated energy savings of 6.5% during breeding.
Keywords: Breeding Season; Common Eider; Somateria mollissima; Energetics and Nutrition

Influence of Sea-Ice on Nesting Density in the Common Eider Somateria-Mollissima in Svalbard Arctic Ocean - Parker, H.; Mehlum, F. (Norsk Polarinstitutt Skrifter, 1991)
High arctic Common Eiders often nest in dense colonies on small islands, particularly in years when late breakup of sea-ice limits the number of nesting islands available. High-density nesting under these conditions appears to be a forced response, and it was predicted that if provided with more space in the form of more islands, nesting Eiders would choose to disperse maximally, thereby mainimizing nest density. This prediction was tested during 6 years of generally favorable ice conditions and results indicated that nesting females did disperse when provided with more space, but that the dispersal response was both slower and less complete than predicted. The observed lag in dispersal was suggested to be a result of site-tenacity, i.e. females tended to return to previously used nesting islands despite having originally been "forced" to nest there due to late spring breakup.
Keywords: Breeding Season; Common Eider; Somateria mollissima; Dispersal; Habitat

The generic name of the spectacled eider - Parkes, K. C. (Auk, 1955)
Brandt in 1847 described it under the subgeneric name Lampronetta. but rather than revert to an unfamiliar name, author accepts view of Delacour and Mayr (Wilson Bul. 57: 33, 1945) that the species should be placed with other eiders in the genus Somateria. Its correct name would become S. fischeri (Brandt). || ABSTRACT AUTHORS: L. M. Bartlett
Keywords: Taxonomy; Somateria fischeri; Spectacled Eider

Foraging guilds of aquatic birds on productive boreal lakes: environmental relations and concordance patterns - Paszkowski, Cynthia A.; Tonn, William M. (Hydrobiologia, 2006)
We surveyed aquatic birds on 41 eutrophic lakes at the southern edge of the boreal forest in Alberta, Canada to determine if patterns of species composition of five foraging guilds paralleled patterns of lake characteristics (morphometry, water chemistry, fish assemblage, and landscape features) and if composition patterns were concordant among guilds. We encountered 49 species of nonpasserine birds that could be classified into five foraging guilds: Diving Carnivores, Diving Omnivores, Herbivores, Surface-foraging Carnivores, and Shoreline Omnivores. Individual lakes supported three to five guilds and guild composition was most strongly and frequently related to lake area, maximum depth, water color, pH, a fish assemblage index, and catchment slope. Randomization tests of matrix concordance based on Principal Components Analyses indicated similar patterns between lake characteristics and species composition for four of five guilds (Diving Carnivores excepted). Randomization tests also showed that patterns of species composition among lakes were similar between foraging guilds for eight out of 10 pairwise comparisons (both exceptions involved Surface-foraging Carnivores). Because of the largely concordant patterns among different guilds, monitoring the status of one guild should provide a useful bioindicator of the status of the aquatic bird assemblages as a whole.
Keywords: Sea Ducks - General; Habitat

The Control of Fox Movement by Electric Fencing - Patterson, I. J. (Biological Conservation, 1977)
On the Sands of Forvie National Nature Reserve, Aberdeenshire, Scotland, a low electric fence was tested as a barrier to foxes [Vulpes vulpes] preying on sandwich terns [Sterna sandvicensis] and eiders [Somateria mollissima]. The fence was an effective deterrent, reducing fox visits to the general area by 2/3 and turning back .apprx. 60% of those which did visit. Fox activity beyond the fence was reduced to .apprx. 16% of that expected without the fence. Crossing of the fence was rare (6% of encounters), but foxes were able to pass round the ends of the fence on unprotected intertidal areas. Where this became common it enabled selective removal of an individual fox causing damage, since the fence steered the animal to a predictable place.
Keywords: Breeding Season; Common Eider; Somateria mollissima; Techniques

Ten polymorphic autosomal microsatellite loci for the Eider duck Somateria mollissima and their cross-species applicability among waterfowl species (Anatidae) - Paulus, K. B.; Tiedemann, R. (Molecular Ecology Notes, 2003)
We describe the isolation and characterization of the first microsatellite loci specifically developed for the Common Eider duck, Somateria mollissima. Our 10 loci show Mendelian inheritance and no linkage disequilibrium between any pair of loci. In the Eider duck, we observed between two and 16 alleles per locus, an expected heterozygosity between 0.31 and 0.97, and an observed heterozygosity between 0.14 and 1.00. Most primers also yield reproducible results in several other anatid species. These loci comprise a set of autosomal molecular markers for various applications, from moderately polymorphic loci suitable for population studies to highly polymorphic loci for pedigree analysis in waterfowl.
Keywords: Common Eider; Somateria mollissima; Techniques

Patterns of Molt in Long-tailed Ducks (Clangula hyemalis) during Autumn and Winter in the Great Lakes Region, Canada - Payne, A. M.; Schummer, M. L.; Petrie, S. A. (Waterbirds, 2015)
Molt and migration can coincide in Arctic nesting waterfowl because they have little time between fledging and the severe weather that precipitates migration. Objectives were to observe how patterns in autumn and winter molt by Long-tailed Ducks (Clangula hyemalis) were influenced by nutrient reserves or seasonal life-cycle events. Molt scores and nutrient reserves were determined for birds salvaged during autumn 2011 (n = 79) and collected during winter 2002-2004 (n = 255). Differences in molt among sex-age classes and correlation between molt and nutrient reserves were determined. It was predicted that adult females and juveniles of both sexes suspended molt during autumn migration to limit energetic overlap; however, greater molt in juveniles during autumn than winter was detected. Correlation between molt and nutrient reserves were not detected. Molt was less in adult males than females and juveniles during winter, which may suggest that the effects of reproduction (females) and growth (juveniles) extended their molt into winter. Observed molt patterns are consistent with fixed cues associated with the timing of seasonal life-cycle events of this species. This could have important implications in understanding the life-cycle events of Long-tailed Ducks and provide novel explanations of seasonal molt.
Payne, Andreanne M. Schummer, Michael L. Petrie, Scott A.
Keywords: Molt; Clangula hyemalis; Long-tailed Duck; Energetics and Nutrition; Nonbreeding season

Common Merganser (Mergus merganser) - Pearce, John, Mark L. Mallory and Karen Metz (The Birds of North America, 2015)
Keywords: Mergus merganser; Common Merganser

Site fidelity is an inconsistent determinant of population structure in the hooded merganser (Lophodytes cucullatus): Evidence from genetic, mark-recapture, and comparative data - Pearce, John M.; Blums, Peter; Lindberg, Mark S. (Auk, 2008)
The level of site fidelity in birds is often characterized as "high" on the basis of rates of return or homing from mark-recapture data. For specie:; that exhibit site fidelity, Subsequent biological assumptions have included population Structure, demographic independence, and that the extirpation of a site-faithful group might be irreversible because of low immigration. Yet several genetic Studies have observed patterns Of Population differentiation that are incongruous with strong site fidelity, Which Suggests recent isolation, gene flow, or both. Using a 13-year live-recapture and dead-recovery data set, as well as nuclear and mitochondrial DNA collected across the range of the Hooded Merganser (Lophodytes cucullants), an obligate cavity-nester endemic to North America, we found evidence that gene flow persists across portions of the species' range even though the probability of female breeding-site fidelity is high (0.92; 95% confidence interval [CI]: 0.64-0.98) and disjunct breeding ranges of this species have been isolated for :10,000 years. By combining inferences from genetic, band-recovery, mark-recapture, and comparative data from another cavity-nesting species of water fowl, We conclude that a high level of site fidelity should not be considered a universal proxy for population structure and demographic independence. Our results also suggest that an accurate assessment of site fidelity-and its implications for population dynamics and delineation-requires cross-species comparisons and multiple data types, such as mark-recapture and genetic information, to best infer patterns across a range of geographic and temporal scales.
Keywords: Breeding Season; Nonbreeding Seasons; Dispersal; Techniques; Hooded Merganser; Lophodytes cucullatus; Population Delineation

Comparative population structure of cavity-nesting sea ducks - Pearce, J. M.; Eadie, J. M.; Savard, J. P. L.; Christensen, T. K.; Berdeen, J.; Taylor, E. J.; Boyd, S.; Einarsson, A.; Talbot, S. L. (Auk, 2014)
A growing collection of mtDNA genetic information from waterfowl species across North America suggests that larger-bodied cavity-nesting species exhibit greater levels of population differentiation than smaller-bodied congeners. Although little is known about nest-cavity availability for these species, one hypothesis to explain differences in population structure is reduced dispersal tendency of larger-bodied cavity-nesting species due to limited abundance of large cavities. To investigate this hypothesis, we examined population structure of three cavity-nesting waterfowl species distributed across much of North America: Barrow's Goldeneye (Bucephala islandica), Common Goldeneye (B. clangula), and Bufflehead (B. albeola). We compared patterns of population structure using both variation in mtDNA control-region sequences and band-recovery data for the same species and geographic regions. Results were highly congruent between data types, showing structured population patterns for Barrow's and Common Goldeneye but not for Bufflehead. Consistent with our prediction, the smallest cavity-nesting species, the Bufflehead, exhibited the lowest level of population differentiation due to increased dispersal and gene flow. Results provide evidence for discrete Old and New World populations of Common Goldeneye and for differentiation of regional groups of both goldeneye species in Alaska, the Pacific Northwest, and the eastern coast of North America. Results presented here will aid management objectives that require an understanding of population delineation and migratory connectivity between breeding and wintering areas. Comparative studies such as this one highlight factors that may drive patterns of genetic diversity and population trends.
Pearce, John M. Eadie, John M. Savard, Jean-Pierre L. Christensen, Thomas K. Berdeen, James Taylor, Eric J. Boyd, Sean Einarsson, Arni Talbot, Sandra L.
Keywords: Taxonomy; Bucephala clangula; Common Goldeneye; SDJV funded; Bucephala albeola; Bufflehead; Bucephala islandica; Barrow’s Goldeneye; Population Delineation

Nesting ecology of Spectacled Eiders Somateria fischeri on the Indigirka River Delta, Russia - Pearce, John M.; Esler, Daniel; Degtyarev, Andrei G. (Wildfowl, 1999)
In 1994 and 1995 we investigated breeding biology and nest site habitat of Spectacled Eiders on two study areas within the coastal fringe of the Indigirka River Delta, Russia (71degree 20' N, 150degree 20' E). Spectacled Eiders were first observed on 6 June in both years and nesting commenced by mid-June. Average clutch size declined with later nest initiation dates by 0.10 eggs per day; clutches were larger in 1994 than 1995 and were slightly larger on a coastal island study area compared to an interior area. Nesting success varied substantially between years, with estimates of 1.6% in 1994 and 27.6% in 1995. Total egg loss, through avian or mammalian predation, occurred more frequently than partial egg loss. Partial egg loss was detected in 16 nests and appeared unrelated to nest initiation date or clutch size. We found no difference among survival rates of nests visited weekly, biweekly, and those at which the hen was never flushed, suggesting that researcher presence did not adversely affect nesting success. A comparison of nine habitat variables within each study area revealed little difference between nest sites and a comparable number of randomly located sites, leading us to conclude that Spectacled Eiders nest randomly with respect to most small scale habitat features. We propose that large scale landscape features are more important indicators of nesting habitat as they may afford greater protection from land-based predators, such as the Arctic Fox. Demographic data collected during this study, along with recent conservation measures implemented by the Republic of Sakha (Yakutia), lead us to conclude that there are few threats to the Indigirka River Delta Spectacled Eider population. Presently, the Indigirka River Delta contains the largest concentration of nesting Spectacled Eiders and deserves continued monitoring and conservation.
Keywords: Breeding Season; Somateria fischeri; Spectacled Eider; Productivity; Habitat

Nest materials as a source of genetic data for avian ecological studies - Pearce, J. M.; Fields, R. L.; Scribner, K. T. (Journal of Field Ornithology, 1997)
We examined the utility of feathers and egg shell membranes, deposited in the nests of Spectacled Eiders (Somateria fischeri), as a source of DNA for genetic studies at both the population and individual level. The potential for feather DNA contamination as a result of female behavioral interactions (e.g. nest parasitism), reuse of nest sites from previous years, or other unknown occurrences was acknowledged and specifically tested. DNA was successfully extracted from both feathers and egg shell membranes and waterfowl microsatellite loci were used to construct individual genotypes. We found no difference in the genotypes obtained from nest feathers or blood of the incubating female. Detection of nest feather contamination was possible with as little as one feather when samples from multiple females were intentionally mixed. Triplicate DNA extractions from 33 nests provided a means of detecting contamination in 3 nests. Egg membranes proved a viable source of offspring DNA and can contribute valuable data to investigations of parentage when assayed jointly with maternal feather DNA. Nest materials provide an efficient, non-invasive method of genetic sampling that can be readily incorporated into field research. However, the natural history traits and mating strategies of a species must be considered during sample collection to identify the possible sources of nest materials (e.g., paternal, maternal, parasite, etc.). Specific experiments should also be designed to test sampling assumptions.
Keywords: Breeding Season; Somateria fischeri; Spectacled Eider; Techniques

Migratory Patterns and Population Structure among Breeding and Wintering Red-Breasted Mergansers (Mergus Serrator) and Common Mergansers (M. Merganser) - Pearce, John M.; McCracken, Kevin G.; Christensen, Thomas K.; Zhuravlev, Yuri N. (Auk, 2009)
Philopatry has long been assumed to structure populations of waterfowl and other species of birds genetically, especially via maternally transmitted mitochondrial DNA (mtDNA), yet other migratory behaviors and nesting ecology (use of ground vs. cavity sites) may also contribute to population genetic structure. We investigated the effects of migration and nesting ecology on the population genetic structure of two Holarctic waterfowl, the Red-breasted Merganser (Mergus serrator) and Common Merganser (M. merganser), using mtDNA control-region sequence data. Red-breasted Mergansers (a ground-nesting species) exhibited lower levels of population differentiation across their North American range, possibly as a result of post-Pleistocene range expansion and population growth. By contrast, Common Mergansers (a cavity-nesting species) breeding in western and eastern North America were strongly differentiated, as were continental groups in North America and Europe. Our hypothesis that population differentiation of breeding female Common Mergansers results from limited migration during non-breeding periods was not supported, in that equally heterogeneous mtDNA lineages were observed in males and females on several wintering areas. The interspecific differences in mtDNA patterns for these two closely related species may have resulted from factors related to nesting ecology (ground vs. cavity nesting) and responses to historical climate change. Received 17 September 2008, accepted 20 April 2009.
Keywords: Breeding Season; Nonbreeding Seasons; Dispersal; Common merganser; Mergus merganser; SDJV funded; Mergus serrator; Red-breasted merganser; Population Delineation

Post-fledging Movements of Juvenile Common Mergansers (Mergus merganser) in Alaska as Inferred by Satellite Telemetry - Pearce, John M.; Petersen, Margaret R. (Waterbirds, 2009)
We implanted satellite transmitters into eight juvenile Common Mergansers to investigate post fledging movements from their natal river in southcentral Alaska Subsequently they moved widely throughout poitions of western and southcentral Alaska up to 750 km from their natal areas during fall and winter months Iiinsmittei s of two birds (one male and one female) continued to send location datiinto their second}eat and allowed us to determine the location and timing of the flightless molt period for each bud ye, all out data suggest that juveneile Common Mergansers range widely immediately after fledging that second year males and females may) differ in then movement patterns and that these movements have implications for population genetic structure of this species cies Received 2 April 2008 accepted 6 July 2008
Keywords: Breeding Season; Nonbreeding Seasons; Molt; Migration; Common merganser; Mergus merganser; Population Delineation

Geographic variation in survival and migratory tendency among North American Common Mergansers - Pearce, John M.; Reed, John A.; Flint, Paul L. (Journal of Field Ornithology, 2005)
Movement ecology and demographic parameters for the Common Merganser (Mergus merganser americanus) in North America are poorly known. We used band-recovery data from five locations across North America spanning the years 1938-1998 to examine migratory patterns and estimate survival rates. We examined competing time-invariant, age-graduated models with program MARK to Study sources of variation in survival and reporting probability We considered age, sex, geographic location, and the use of nasal saddles on hatching year birds at one location as possible Sources of variation. Year-of-banding was included as a covariate in a post-hoc analysis. We found that migratory tendency, defined as the average distance between banding and recovery locations, varied geographically. Similarly, all models accounting for the majority of variation in recovery and Survival probabilities included location of banding. Models that included age and sex received less Support, but we lacked sufficient data to adequately assess these parameters. Model-averaged estimates of annual survival ranged from 0.21 in Michigan to 0.82 in Oklahoma. Heterogeneity in migration tendency and survival suggests that demographic patterns may vary across geographic scales, with implications for the population dynamics of this species.
Keywords: Breeding Season; Nonbreeding Seasons; Dispersal; Survival; Common merganser; Mergus merganser

Demography, genetics, and the value of mixed messages - Pearce, John M.; Talbot, Sandra L. (Condor, 2006)
Iverson et al. (2004) used estimates of the homing rate for molting adult Harlequin Ducks (Histrionicus histrionicus) in Alaska to draw inferences about population structure. Homing rates, defined as one minus the ratio of birds recaptured elsewhere to those recaptured at the original banding site, were high (0.95-1.00) for males and females. Iverson et al. (2004) concluded that these high rates of homing are indicative of demographic independence among molting groups separated by small distances (tens to hundreds of kilometers) and that conservation efforts should recognize this fine-scale population structure. Were-examined their use of the homing rate, because their assumption of equal detection probability across a wide sampling area could have led to an upward bias in their estimates of site fidelity. As a result, we are hesitant to agree with their conclusion of high adult homing to molting areas and that molt-site fidelity is evidence for demographic independence. Our hesitancy stems from the fact that little is known about juvenile and adult movements within and among years, breeding area origins, and the variation of demographic parameters (e.g., survival and productivity) among molting groups. Furthermore, population genetic data of these molting groups suggest gene flow at both nuclear and mitochondrial loci. Such mixed messages between demographic (i.e., banding) and genetic data are increasingly common in ornithological studies and offer unique opportunities to reassess predictions and make more robust inferences about population structure across broad temporal and spatial scales. Thus, we stress that it is this broader scale perspective, which combines both demography and genetics, that biologists should seek to quantify and conservation efforts should seek to recognize.
Keywords: Nonbreeding Seasons; Harlequin duck; Histrionicus histrionicus; Dispersal; Population Delineation

Limited genetic differentiation among breeding, molting, and wintering groups of the threatened Steller's eider: the role of historic and contemporary factors - Pearce, John M.; Talbot, Sandra L.; Petersen, Margaret R.; Rearick, Jolene R. (Conservation Genetics, 2005)
Due to declines in the Alaska breeding population, the Steller's eider (Polysticta stelleri) was listed as threatened in North America in 1997. Periodic non-breeding in Russia and Alaska has hampered field-based assessments of behavioral patterns critical to recovery plans, such as levels of breeding site fidelity and movements among three regional populations: Atlantic-Russia, Pacific-Russia and Alaska. Therefore, we analyzed samples from across the species range with seven nuclear microsatellite DNA loci and cytochrome b mitochondrial (mt)DNA sequence data to infer levels of interchange among sampling areas and patterns of site fidelity. Results demonstrated low levels of population differentiation within Atlantic and Pacific nesting areas, with higher levels observed between these regions, but only for mtDNA. Bayesian analysis of microsatellite data from wintering and molting birds showed no signs of sub-population structure, even though band-recovery data suggests multiple breeding areas are present. We observed higher estimates of F-statistics for female mtDNA data versus male data, suggesting female-biased natal site fidelity. Summary statistics for mtDNA were consistent with models of historic population expansion. Lack of spatial structure in Steller's eiders may result largely from insufficient time since historic population expansions for behaviors, such as natal site fidelity, to isolate breeding areas genetically. However, other behaviors such as the periodic non-breeding observed in Steller's eiders may also play a more contemporary role in genetic homogeneity, especially for microsatellite loci.
Keywords: Breeding Season; Nonbreeding Seasons; Population Delineation; Polysticta stelleri; Steller's eider

Lack of spatial genetic structure among nesting and wintering King Eiders - Pearce, John M.; Talbot, Sandra L.; Pierson, Barbara J.; Petersen, Margaret R.; Scribner, Kim T.; Dickson, D. Lynne; Mosbech, Anders (Condor, 2004)
The King Eider (Somateria spectabilis) has been delineated into two broadly distributed breeding populations in North America (the western and eastern Arctic) on the basis of banding data and their use of widely separated Pacific and Atlantic wintering areas. Little is known about the level of gene flow between these two populations. Also unknown is whether behavioral patterns common among migratory waterfowl, such as site fidelity to wintering areas and pair formation at these sites, have existed for sufficient time to create a population structure defined by philopatry to wintering rather than to nesting locations. We used six nuclear microsatellite DNA loci and cytochrome b mitochondrial DNA sequence data to estimate the extent of spatial genetic differentiation among nesting and wintering areas of King Eiders across North America and adjacent regions. Estimates of interpopulation variance in microsatellite allele and mtDNA haplotype frequency were both low and nonsignificant based on samples from three wintering and four nesting areas. Results from nested clade analysis, mismatch distributions, and coalescent-based analyses suggest historical population growth and gene flow that collectively may have homogenized gene frequencies. The presence of several unique mtDNA haplotypes among birds wintering near Greenland suggests that gene flow may now be more limited between the western and eastern Arctic, which is consistent with banding data.
Keywords: Breeding Season; Nonbreeding Seasons; King Eider; Somateria spectabilis; Population Delineation

Mechanisms of Population Heterogeneity among Molting Common Mergansers on Kodiak Island, Alaska: Implications for Genetic Assessments of Migratory Connectivity - Pearce, John M.; Zwiefelhofer, Denny; Maryanski, Nate (Condor, 2009)
Quantifying population genetic heterogeneity within nonbreeding aggregations can inform our understanding of patterns of site fidelity, migratory connectivity, and gene flow between breeding and nonbreeding areas. However, characterizing mechanisms that contribute to heterogeneity, such as migration and dispersal, is required before site fidelity and migratory connectivity can be assessed accurately. We studied nonbreeding groups of Common Mergansers (Mergus merganser) molting on Kodiak Island, Alaska, from 2005 to 2007, using banding data to assess rates of recapture, mitochondrial (mt) DNA to determine natal area, and nuclear microsatellite genotypes to assess dispersal. Using baseline information from differentiated mtDNA haplogroups across North America, we were able to assign individuals to natal regions and document: population genetic heterogeneity within and among molting groups. Band-recovery and DNA data suggest that both migration from and dispersal among natal areas contribute to admixed groups of males molting on Kodiak Island. A lack of differentiation in the Common Merganser's nuclear, bi-parentally inherited DNA, observed across North America, implies that dispersal can mislead genetic assessments of migratory connectivity and assignments of nonbreeding individuals to breeding areas. Thus multiple and independent data types are required to account for such behaviors before accurate assessments of migratory connectivity can be made.
Keywords: Nonbreeding Seasons; Molt; Dispersal; Common merganser; Mergus merganser; Population Delineation

Shell Thinning and Residues of Organo Chlorines and Mercury in Sea Bird Eggs Eastern Canada 1970-1976 - Pearce, P. A.; Peakall, D. B.; Reynolds, L. M. (Pesticides Monitoring Journal, 1979)
Organochlorine and Hg concentrations are reported for 252 eggs of Leach's storm-petrel (Oceanodroma leucorhoa), double-crested cormorant (Phalacrocorax auritus), common eider (Somateria mollissima), common tern (Sterna hirundo), razorbill (Alca torda), common murre (Uria aalge), black guillemot (Cepphus grylle) and Atlantic puffin (Fratercula arctica) from the Bay of Fundy, the Gulf of St. Lawrence and the open Atlantic shore of Canada during 1970-1976. Concentrations of all organochlorines except DDE and polychlorinated biphenyls (PCB) were low. DDE, PCB and Hg residues were highest in cormorant and petrel, intermediate in alcids and lowest in eider and tern. Temporal and spatial aspects of contamination patterns are discussed. Only in cormorants were DDE residues high enough to cause, through eggshell thinning, local population declines.
Keywords: Breeding Season; Common Eider; Contaminants; Somateria mollissima

Mercury in Waterfowl from Eastern Canada - Pearce, P. A.; Price, I. M.; Reynolds, L. M. (Journal of Wildlife Management, 1976)
Average wet-weight concentrations of total Hg were 0.15 and 0.31 ppm in breast muscle of 146 dabbling (Anatinae) and 61 diving ducks (Aythyinae) from 21 sites in eastern Canada sampled prior to the 1970 hunting season and during the 1971 season. Concentrations exceeded 0.5 ppm in only a few samples, mostly taken near known industrial sources of Hg contamination. In 128 pooled samples of muscle from the wings of 1480 ducks harvested in 13 regions during the 1970 season, Hg concentration averaged 0.13 ppm in both dabblers and divers. A highly significant relationship between Hg levels in wing muscle and those in breast muscle was found in black ducks (Anas rubripes) and lesser scaups (Aythya affinis). Ducks collected in 1971 and 1972 from the Wabigoon-English River watershed in northwestern Ontario were very highly contaminated, extreme concentrations of 9.43, 9.10 and 14.7 ppm being noted in the breast muscle of the mallard (Anas platyrhynchos), blue-winged teal (A. discors), and common goldeneye (Bucephala clangula), respectively. There was a suggestion that ducks collected within 80 km of the industrial source of Hg at Dryden had higher residues than those collected farther downstream. Wabigoon-English River waterfowl-Hg levels declined as the hunting season progressed, possibly due to the influx of uncontaminated ducks from the west and north. [Concern that people who eat waterfowl might be exposed to high Hg levels prompted this study.].
Keywords: Nonbreeding Seasons; Bucephala clangula; Common Goldeneye; Contaminants

Persistent organic pollutant and mercury concentrations in eggs of ground-nesting marine birds in the Canadian high Arctic - Peck, L. E.; Gilchrist, H. G.; Mallory, C. D.; Braune, B. M.; Mallory, M. L. (Science of the Total Environment, 2016)
We collected eggs of eight marine bird species from several colony sites in the Canadian high Arctic located at approximately 76 degrees N and analyzed them for concentrations of legacy persistent organic pollutants (POPs) and mercury. We provide the first report on concentrations of POPs in eggs of three Arctic species (Thayer's gull Larus thayeri, Sabine's gull Xema sabini, Ross's Gull Rhodostethia rosea), and we found significant differences in each of the POP profiles among the five species with sufficient data for statistical comparisons (Thayer's gull, black guillemot Cepphus grylle, Sabine's gull, Arctic tern Sterna paradisaea and common eider Somateria mollissima borealis). The Ross's Gull had unexpectedly high POP concentrations relative to the other species examined, although this was based on a single egg, while glaucous gull Larus hyperboreus eggs from our sampling location had very low POPs. Sabine's gulls had the lowest Hg of the eggs studied, consistent with their low trophic position, but concentrations of their legacy POPs were higher than expected. We also noted that total hexachlorocyclohexanes were higher than reported elsewhere in the circumpolar Arctic in three species. (C) 2016 Elsevier B.V. All rights reserved.
Peck, Liam E. Gilchrist, H. Grant Mallory, Conor D. Braune, Birgit M. Mallory, Mark L.
Keywords: Breeding Season; Common Eider; Contaminants; Somateria mollissima

Waterfowl Use of Exotic Wild Rice Habitat in Northern Saskatchewan - Peden, D. G. (Canadian Field-Naturalist, 1977)
The density of waterfowl populations in the boreal forests of Saskatchewan [Canada] is known to be much lower than that of the parklands and prairies to the south. A few widely scattered pockets of relatively high density, however, occur in areas such as the Saskatchewan River Delta. Surveys conducted during 1975 near La Ronge, Saskatchewan, suggest that planting of wild rice (Zizania aquatica) has created locally important high density waterfowl habitat. Even though the total area of wild rice is small, the majority of the waterfowl numbers 93% of 2795 sightings, occurred in wild rice habitat. Lesser scaup (Aythya affinis), goldeneye (Bucephala clangula) and mallard (Anas platyrhynchos), respectively, ranked as the 3 most common species. Either waterfowl are attracted directly to the wild rice or wild rice is adapted to the same habitat features that waterfowl select. If the 1st explanation is true, then abundance of waterfowl has likely increased with man's importation of wild rice. If the 2nd explanation is valid, waterfowl, especially lesser scaup and mallard, could be a useful indicator of potential sites for future wild rice seeding.
Keywords: Breeding Season; Abundance, Distribution, and Trends; Bucephala clangula; Common Goldeneye; Habitat

Spring Migration of Common Scoters across Southwest Jutland Denmark - Pedersen, M. B. (Dansk Ornitologisk Forenings Tidsskrift, 1988)
In the years 1985-87, regular counts of night-migrating Common Scoters were made during spring in Southwest Jutland. Spring migration across Jutland is more frequent than previously assumed. The peak is reached in the first half of April. The direction is towards NE. It is suggested that several thousand Common Scoters use this overland flyway, in order to reduce the distance to the breeding grounds in Fennoscandinavia and the Soviet Union [USSR].
Keywords: Nonbreeding Seasons; Migration; Black Scoter; Melanitta nigra

Land-based census of wintering waterfowl: Reliability and conservation implications - Pehlak, Hannes; Lohmus, Asko; Kuresoo, Andres; Luigujoe, Leho (Waterbirds, 2006)
The International Waterbird Census (IWC) is one of the longest-running bird monitoring schemes in the Western Palearctic. Most of its data are collected with land-based counts, the reliability of which is largely unknown. This study compared estimates of land-based vs. aerial counts, and the relative conservation values of coastal sites obtained with the two methods. The data were collected in the West-Estonian archipelago of the Baltic Sea in 1993, and analyzed at two spatial scales (mean area of plots 9 and 36 km(2)). Among nine waterfowl species, land-based and aerial census provided closely correlated local population estimates for the Mute Swan (Cygnus olor), Steller's Eider (Polysticta stelleri), Long-tailed Duck (Clangula hyemalis) and, at the larger scale, for the Mallard (Anas platyrhynchos). However, small numbers of all species, except the swan, remained undetected with the land-based census, and numbers of Mallard and Steller's Eider were also systematically underestimated. The areas having the highest conservation value were reliably identified with the land-based census, particularly at the larger scale. Hence, land-based studies are in general accordance with the aims of the IWC, but the absolute population estimates should be interpreted with care.
Keywords: Abundance, Distribution, and Trends; Sea Ducks - General; Nonbreeding Seasons; Techniques

Studies of resting and wintering sea-fowl in the inner archipelago of southern Bohuslan Engl. summ. - Pehrsson, Olof (Var Fagelvarld, 1965)
The study area is situated 25 km north of Gothenburg and is composed of 2 adjacent parts [long dash] the Nordo area rich in islets and skerries and the shallow, shelving bay, called Odsmals kile. In the area 30 spp. of sea-birds in addition to gulls can be observed. Of these only 4 breed there. Somateria mollissima, Mergus serrator, Tadorna tadorna and Cygnus olor. In autumn, hundreds of Anas platyrhynchos rest in Odsmals kile during the day. In the late autumn the mallards obtain most of their food in submarine meadows of Zostera marina, and Chorda filum. Providing water-level is not too high they can easily reach the molluscs Rissoa and Hydrobia which live in great numbers on top of the plants. During the cold winter of 1963, however, the shallow Zostera meadows were ruined when the ice froze solid to the bottom and the birds lost their main source of subsistence. Exceptionally high water-level has been found to reduce the frequency of river ducks, Anas. Some male mallards molted on the open shallow water during June. Anas crecca is common on the shallowest water in autumn, and in spring it stays longer on this resting place than the mallard. Anas penelope hunts for food among the teals or in Zostera[long dash]Chorda meadows, where it can be seen pulling up eel-grass plants. Flocks of Aythya marila, A. fuligula, and a few A. ferina have no regular resting places in the area but stay for varying lengths of time on depths of from 1[long dash]2 m wherever the vegetation is abundant and rich in molluscs. In Oct. the 1st flocks of Bucephala clangula arrive, but they only occasionally rest here on their way towards the south-west. It is not until Nov. or Dec. that goldeneyes arrive here for their winter quarters. The birds are then usually found on particular favorite haunts, on depths of about 1-2 m, with vegetation of Ruppia and Zostera. In the spring following a long covering of ice the goldeneyes have their feeding stations on flat and bladder wrack, Fucus. In 1961, after a succession of mild winters, the waters froze as early as the middle of Dec. A thousand goldeneyes gathered on the reduced surface of the water in the Nordo area. Extensive shooting during the following month greatly reduced the number. This shooting in the province seems to have caused a great decrease of the goldeneye population during the subsequent cold winter. The breeding population of Somateria mollissima is increasing in the area. Before the eiders leave the inner archipelago in autumn, they feed on Mytilus communities on submerged rocks and shallows. An unsuccessful attack by a seal, Phoca vitulina, was observed. Families of Mergus serrator keep together until Nov. when courtship behavior is observed. This bird is a regular winterer, as is M. merganser. A few specimens of M. albellus are observed every winter. Tadorna tadorna leaves the area as soon as the young are ready to fly. In summer about 100 non-breeding Cygnus olor rest on shallow waters; the number fluctuates however, from day to day. In winter the number increases, but if the winter is severe the number again decreases and is exceeded by that of C. cygnus. The 1st whooper swans arrive at the end of Oct. Both spp. may appear in about 300 specimens. During both mild and cold winters the whooper swan seems to save energy by sleeping for long periods, while the mute swan is more restless in searching for food. This habit has certainly contributed to the fact that the whooper swan withstands the winter better than the mute swan. Flocks of about 40 Fulica atra have tried to winter in the area. They were feeding on Zostera meadows of between 1 and 3 m depth, from which they were observed to pull up the plants. Parts of the plants were consumed. || ABSTRACT AUTHORS: Author
Keywords: Sea Ducks - General; Nonbreeding Seasons

Chief Prey as a Factor Regulating Populations of Eider Somateria-Mollissima and Long-Tailed Duck Clangula-Hyemalis - Pehrsson, O. (Zoologisk Revy, 1973)
Keywords: Common Eider; Clangula hyemalis; Long-tailed Duck; Somateria mollissima; Population Dynamics; Trophic Interactions

Duckling Production of the Oldsquaw in Relation to Spring Weather and Small-Rodent Fluctuations - Pehrsson, O. (Canadian Journal of Zoology, 1986)
The duckling production of the Oldsquaw (Clangula hyemalis) was studied between 1969 and 1974 in Torne Lapmark in northern Sweden. The degrees of relationship among various indices of reproductive output, climatic factors, and fluctuations in small rodents were estimated. Total brood and duckling production were calculated. A correlation between first observations of broods and time of arival of spring indicated that the Oldsquaw breeds as early as possible, an adaptation to the utilization of ephemeral lakes. Peaks in duckling production correlated well with peaks in the abundance of small rodents but not as well with climatic variables. Twice as many ducklings were produced during the rodent peak years as during the intervening years, and the densities of the Oldsquaw population were highest the year after these peaks in brood production. The positive correlation between duckling production and population in size in small rodents seems to be analogous to grouse-rodent cycles, and both are best explained by the predator-shift or the alternative prey hypothesis.
Keywords: Breeding Season; Clangula hyemalis; Long-tailed Duck; Productivity

Growth and Movements of Oldsquaw Ducklings in Relation to Food - Pehrsson, O.; Nystrom, K. G. K. (Journal of Wildlife Management, 1988)
In a study of oldsquaw (Clangula hyemalis) in northern Sweden from 1970 through 1974, we compared the growth rates of ducklings among years differing in brood and duckling, densities due to changing nest predation pressure. A new photographic method was used to estimate growth rates of wild ducklings. Growth rates were lower, distances traveled longer, and brood losses higher during a duckling peak year than during other years. The adverse effects on ducklings is attributed to the heavy exploitation of food resources by high numbers of ducklings released fom predation pressures when rodent populations provided an alternative source of prey for several predators. When suggest that small clutch size of oldsquaw is an adapation to a stable food resource early in the season, to unstable climate, and to predation pressure.
Keywords: Breeding Season; Clangula hyemalis; Long-tailed Duck; Physiology; Dispersal

A mathematical model for the control of swimmer's itch - Peirce, J. P.; Pellett, J. J.; Sandland, G. J. (NATURAL RESOURCE MODELING, 2020)
Swimmer's itch is an emerging disease caused by flatworm parasites that often use water birds as definitive hosts. When parasite larvae penetrate human skin they initiate localized inflammation that leads to intense itching. Concerns about this issue have been growing recently due to an apparent increase in the global occurrence of swimmer's itch and its subsequent impacts on recreational activities and associated revenues. Past study has identified the common merganser as a key definitive host for these worms in the United States; a number of snail species serve as intermediate hosts. Although previous attempts at controlling swimmer's itch have targeted snails, a handful of efforts have concentrated on treating water birds with the anthelmintic drug, praziquantel. We construct a mathematical model of swimmer's itch and its treatment within the infected merganser population. Our goal is to identify merganser treatment regimes that minimize the number of infected snails thereby reducing the risk of human infections. Optimal control of bird hosts is defined analytically and we include numerical simulations assuming different resource-allocation strategies. Results from the study may help identify treatment protocols that lower merganser infection rates and ultimately reduce the occurrence of swimmer's itch in freshwater systems throughout the Midwest. Recommendations for Resource Managers Regardless of the time and monetary resources available, praziquantel treatment frequency should increase as mergansers arrive on the lake with continued treatments (albeit at reduced levels) until the end of the residency period. Allocating plenty of resources towards the treatment of mergansers predicted a sharp drop in infected birds, which then remained close to zero throughout the remainder of the residency period. This approach reduced schistosome infection in mergansers and kept snail infections within the idealized range during times of peak recreational activity. Consequently, human cases of swimmer's itch would be expected to be low to nonexistent. Furthermore, our treatment-longevity computation suggested that subsequent praziquantel dosing would not be required for a number of years. Under more limited resources, the number of birds treated per day was much smaller throughout the residency period; however, even under these circumstances (which equated to treating approximately one bird every 5 days), simulated infected merganser densities were reduced to the point where snail infections remained below epidemic levels through to the end of the recreational period. Treatment longevity was shorter compared with the high-resource option, but still extended 122 days into Season 2 (posttreatment). We also used our model to investigate situations where lake managers and/or federal agencies might be taxed in terms of the time available to continuously treat mergansers on a given lake. An individual scientist may only have a single day (or two) to dose birds, rather than continuously administering praziquantel throughout the birds' residency period. If <77% of the total number of arriving birds can be treated in a single day, we recommend praziquantel administrations when the number of mergansers reaches the maximum that can be successfully treated. In addition, model simulations demonstrate that if managers are able to treat a large number of birds, they should wait until the end of the migration period.
Times Cited in Web of Science Core Collection: 3 Total Times Cited: 3 Cited Reference Count: 41
Keywords: Mergus merganser; LAKE; INFECTIONS; COPPER; optimal control; practical control; praziquantel; SNAILS; swimmer's itch; TREMATODA-SCHISTOSOMATIDAE; Trichobilharzia

It is time to move: linking flight and foraging behaviour in a diving bird - Pelletier, David; Guillemette, Magella; Grandbois, Jean-Marc; Butler, Patrick J. (Biology Letters, 2007)
Although the adaptive value of flight may seem obvious, it is the most difficult behaviour of birds to monitor. Here, we describe a technique to quantify the frequency and the duration of flights over several months by implanting a data logger that records heart rate (f(H)), hydrostatic pressure (diving depth) and the body angle of a large sea duck species, the common eider (Somateria mollissima). According to the mean f(H) recorded during flight and the parameters recorded to identify the f(H) flight signature, we were able to identify all flights performed by 13 individuals during eight months. We cumulated local flight time (outside migrations) and found that activity occurs primarily during dawn and morning and that flying activities are strongly related to diving activities (Pearson's r=0.88, permutation test p < 0.001). This relationship was interpreted as a consequence of living in a dynamic environment where sea currents move the ducks away from the food patches. We believe that the technique described here will open new avenues of investigation in the adaptive value of flight.
Keywords: Common Eider; Somateria mollissima; Energetics and Nutrition

To fly or not to fly: high flight costs in a large sea duck do not imply an expensive lifestyle - Pelletier, David; Guillemette, Magella; Grandbois, Jean-Marc; Butler, Patrick J. (Proceedings of the Royal Society Biological Sciences Series B, 2008)
A perennial question in ornithology is whether flight has evolved mostly to facilitate access to food or as an anti-predator strategy. However, flight is an expensive mode of locomotion and species using flight regularly are associated with an expensive lifestyle. Using heart rate (HR) data loggers implanted in 13 female common eiders (Somateria mollissima), our objective was to test the hypothesis that a high level of flight activity increases their energy budget. We used the long-term recording (seven months) of HR as an index of energy expenditure and the HR flight signature to compile all flight events. Our results indicate that the eider is one of the thriftiest volant birds with only 10 minutes of flight time per day. Consequently, we were not able to detect any effect of flight activity on their energy budget despite very high flight costs (123-149 W), suggesting that flight was controlled by energy budget limitations. However, the low flight activity of that species may also be related to their prey landscape requiring few or no large-scale movements. Nevertheless, we suggest that the (fitness) benefits of keeping flight ability in this species exceed the costs by allowing a higher survival in relation to predation and environmental harshness.
Keywords: Common Eider; Somateria mollissima; Energetics and Nutrition

Nest Parasitism by Red-Breasted Mergansers in Wisconsin - Pelzl, H. W. (Auk, 1971)
Keywords: Behavior; Breeding Season; Mergus serrator; Red-breasted merganser

Transmission Dynamics of Highly Pathogenic Avian Influenza at Lake Constance (Europe) During the Outbreak of Winter 2005-2006 - Penny, M. A.; Saurina, J.; Keller, I.; Jenni, L.; Bauer, H. G.; Fiedler, W.; Zinsstag, J. (EcoHealth, 2010)
Highly pathogenic avian influenza virus (HPAI) H5N1 poses a serious threat to domestic animals. Despite the large number of studies on influenza A virus in waterbirds, little is still known about the transmission dynamics, including prevalence, behavior, and spread of these viruses in the wild waterbird population. From January to April 2006, the HPAI H5N1 virus was confirmed in 82 dead wild waterbirds at the shores of Lake Constance. In this study, we present simple mathematical models to examine this outbreak and to investigate the transmission dynamics of HPAI in wild waterbirds. The population dynamics model of wintering birds was best represented by a sinusoidal function. This model was considered the most adequate to represent the susceptible compartment of the SIR model. The three transmission models predict a basic reproduction ratio (R (0)) with value of approximately 1.6, indicating a small epidemic, which ended with the migration of susceptible wild waterbirds at the end of the winter. With this study, we quantify for the first time the transmission of HPAI H5N1 virus at Lake Constance during the outbreak of winter 2005-2006. It is a step toward the improvement of the knowledge of transmission of the virus among wild waterbirds.
Keywords: Sea Ducks - General; Nonbreeding Seasons; Disease

Response to acute stress in the Harlequin Duck (Histrionicus histrionicus) during the breeding season and moult: Relationships to gender, condition, and life-history stage - Perfito, N.; Schirato, G.; Brown, M.; Wingfield, J. C. (Canadian Journal of Zoology, 2002)
Seasonal adjustments and individual responses to environmental perturbations have been well characterized in many passerine species but similar studies in other groups of birds are sparse. Larger-bodied and longer-lived avian species have different life-history strategies and different energy-storage and -utilization patterns. We investigated the response to capture stress in male and female Harlequin Ducks (Histrionicus histrionicus) during the breeding season on montane rivers and during moult on coastal waterways of Washington State. Females arrived at the breeding grounds in better condition and had a smaller rise in circulating corticosterone during 1 h of restraint than males. As the breeding season progressed, body condition declined in females and their adrenocortical response to acute stress became more pronounced. A potentially disruptive environmental condition, high river flow during the breeding season, was not associated with lower nesting success, lower body condition indices, or higher corticosterone levels (baseline or maximum concentration). The maximum corticosterone concentration reached over 1 h of restraint was negatively correlated with body condition in females during the breeding season. Lastly, males and females had similar adrenocortical responses to capture and handling during moult. We relate differential responses to acute stress between males and females to different selective pressures during the breeding season.
Keywords: Breeding Season; Nonbreeding Seasons; Harlequin duck; Histrionicus histrionicus; Physiology

Foraging Behavior of Long-tailed Ducks in a Ferry Wake - Perry, M. C. (Northeastern Naturalist, 2012)
Times Cited: 1 Perry, Matthew C. 1
Keywords: Behavior; Nonbreeding Seasons; Clangula hyemalis; Long-tailed Duck

25 Year Trends in Diving Duck Populations in Chesapeake Bay USA - Perry, M. C.; Munro, R. E.; Haramis, G. M. (Transactions of the North American Wildlife and Natural Resources Conference, 1981)
Keywords: Abundance, Distribution, and Trends; Sea Ducks - General; Nonbreeding Seasons

Atypical Feeding Behavior of Long-tailed Ducks in the Wake of a Commercial Fishing Boat while Clamming - Perry, M. C.; Osenton, P. C.; White, T. P. (NORTHEASTERN NATURALIST, 2017)
A foraging group of Clangula hyemalis (Long-tailed Duck) was observed on 10 February 2010 diving behind a commercial boat that was clamming near Monomoy Island, Nantucket Sound, MA. We used a shotgun to collect 9 of the ducks, and our analyses of gizzard and gullet (esophagus and proventriculus) revealed 37 food items in the gizzard and 16 in the gullet. Mollusca were the dominant food in the gizzard (49%), whereas Crustacea were dominant in the gullet (57%). Crustacea were the second most important food in the gizzard (38%), whereas Mollusca were the second most important food in the gullet (31%). Relatively high volumes of the Amphipoda Caprella sp. (skeleton shrimp) and the Decopoda Crangon septemspinosa (Sand Shrimp) were recorded in the gullet and gizzard. Ensis directus (Atlantic Jackknife Clam) formed the greatest volume of Mollusca in the gizzard (15%) and in the gullet (15%). Long-tailed Ducks had fed on this Bivalvia and several other species of Mollusca that had no shell or broken shell when consumed. Many of the food organisms were apparently dislodged and some damaged by the clamming operation creating an opportunistic feeding strategy for the Long-tailed Ducks.
Times Cited in Web of Science Core Collection: 3 Total Times Cited: 3 Cited Reference Count: 25
Keywords: SEA DUCKS; SEABIRDS; FOOD-HABITS; OCEAN

Behavioural vs. molecular sources of conflict between nuclear and mitochondrial DNA: the role of male-biased dispersal in a Holarctic sea duck - Peters, J. L.; Bolender, K. A.; Pearce, J. M. (Molecular Ecology, 2012)
Times Cited: 7 Peters, Jeffrey L. Bolender, Kimberly A. Pearce, John M. Peters, Jeffrey/I-5116-2012 7
Keywords: Common merganser; Mergus merganser; Population Delineation

Seabird bycatch in fishing gear in Iceland - Petersen, Aevar (Natturufraedingurinn, 2002)
An overview is given of the issue of bycatch of seabirds in Icelandic waters, more detailed than presented earlier (see Aevar Petersen 1998a). A systematic survey has not been carried out of this mortality factor in the Icelandic fisheries in general. Representative data need to be compiled on, for instance, the bird species affected, the type of fishing gear involved, the spatial and temporal distribution of bycatch and, most importantly, whether incidental take in fishing gear affects the bird populations. Whatever the result, this is also an animal welfare issue, as drowning in nets or getting hooked cannot be seen as humane methods of killing birds. Furthermore, bycatch is to a large extent both wasteful and unnecessary. Icelandic environmental and fishery authorities have been urged to consider bycatch as a serious conservation problem. It is pointed out that FAO has issued a plan of action to reduce seabird bycatch in longline fisheries (FAO 1995, 1998, 1999). The Arctic Council working group CAFF (Conservation of Arctic Flora and Fauna) has considered bycatch a significant source of mortality in Arctic seabirds. In the North Atlantic bycatch in nets is considered more serious than longline (Bakken & Falk 1998). Assessing and reducing mortality of murres (Uria spp.) in commercial fishing gear is an action item of the International Murre Conservation Strategy and Action Plan (CAFF 1996), which all the Arctic countries have endorsed. Four surveys have been carried out on incidental take in individual bird species and the impact of this on their populations. All these surveys related only to Lumpsucker fishing nets and/or only a small part of the respective bird populations. Two of them dealt with the Black Guillemot Cepphus grylle (Aevar Petersen 1981, Frederiksen & Aevar Petersen 1999). The other two were aimed at the Common Eider Somateria mollissima, although one of these also included all other birds caught (Aevar Petersen & Jon Gudmundsson ms, Vilhjamur porsteinsson & Gudrun Marteinsdottir 1992). None of these surveys could show significant influences of bycatch on the respective bird populations. Other sources of information on the bycatch issue in Iceland include data from the Icelandic Bird Ringing Scheme (cf. Aevar Petersen 1998a) and the scientific bird skin collection, both at the Icelandic Institute of Natural History. Other sources are the sale (illegal) of bycaught birds at fish markets (cf. Aevar Petersen 1998a), official reports from the Lumpsucker fishery (not required any more) and incidental information from newspapers and other informal sources. Examples of incidental take are numerous in Iceland. Some of the most exceptional ones include 10000 alcids killed in 24 hours off Grimsey island in 1990. In April 2001 one fishing vessel caught 8000 alcids in nets in 24 hours in Faxafloi Bay. However, bycatch is very variable according to type of fishing gear, time of year and region. Probably the most important fishing gear in this respect are cod nets, Lumpsucker nets and longline, although various other gear has been registered in bird recoveries of the Icelandic Bird Ringing Scheme and in the scientific bird collection at the Icelandic Institute of Natural History. In 1997 as many as 70 thousand murres (mostly Common Murre Uria aalge) were estimated killed annually in nets, Common Murre being by far the most common species (Gudmundur A. Gudmundsson, Aevar Petersen & Arnpor Gardarsson 1997). Thousands if not tens of thousands Fulmars Fulmarus glacialis have been estimated killed in the Icelandic longline fishery (Dunn & Steel 2001). Somewhere between 100 and 200 thousand seabirds are estimated killed in fishing gear from the Icelandic fleet each year, possibly more. Altogether, 20 seabird species have been registered from fishing gear. It is suggested as a start that an overall status report of the bycatch issue in Icelandic waters be compiled. More concentrated studies are needed of (1) the alcids (especially Common Murre, Thick-billed Murre and Razorbill Alca torda), (2) Red-throated Loon Gavia stellata and Common Loon G. immer, (3) Great Cormorant Phalacrocorax carbo and Shag P. aristotelis, (4) continued research on Black Guillemot, (5) a repeated survey of Common Eiders, and (6) Fulmar. A compilation of mitigation measures with particular reference to Iceland is also required, leading to cooperation with the fishery industry in solving, or at least reducing, the bycatch problem in Icelandic fisheries.
Keywords: Conservation; Common Eider; Sea Ducks - General

Recent increase in annual survival of nesting female Common ScoterMelanitta nigrain Iceland - Petersen, I. K.; Frederiksen, M.; Petersen, A.; Robson, H. J.; Einarsson, A.; Nielsen, R. D.; Harrison, A. L.; Cervencl, A.; Fox, A. D. (JOURNAL OF ORNITHOLOGY, 2021)
Despite their unfavourable conservation status, little is known about the population status, trends and demography of Common ScoterMelanitta nigra.Capture-mark-recapture (CMR) data from 154 recapture events of 88 individually marked breeding female Common ScoterMelanitta nigrain the Aoaldalur valley, northeast Iceland, during 2009-2018 generated an estimated annual apparent survival probability of 0.848 (95% CL 0.775-0.901). This exceeds a previous Icelandic CMR estimate (0.783, 95% CL 0.715-0.839) from nesting females during 1925-1958 at the nearby Myvatn (45 km to the SSE) when the population was declining at c. 2% per annum. Spring count data from Myvatn show that numbers of male and female Common Scoter at this important breeding site (thought to constitute over 80% of the Icelandic breeding national total) have increased by c. 1.8% per annum since 1974, and by 4-5% per annum since 2009. A population model showed that the observed change in survival corresponded well with the observed change in population growth rate. We reflect on causes of the increase in mean expected lifespan (from 4.1 to 6.1 years) between 1925-1958 and 2009-2018, speculating whether changes in food supply and/or reduction in gill-net fishing on Myvatn in the last 25 years could have been contributing factors to explain recent increases in breeding females there. An alternative, not necessarily mutually exclusive explanation could also be that the dramatic declines in chronic marine oil spill pollution in European waters could have contributed to higher recent female annual survival. While fully recognising the challenges of comparing survival rates from two sites in two different periods, survival rate has increased significantly between the two studies in a way that could potentially explain the increase in abundance at Myvatn. This could indicate that female survival has increased in the population as a whole. We strongly recommend demographic monitoring as a contribution to monitoring sea duck populations, species that are difficult to count and otherwise monitor annual changes in abundance in any meaningful way across large geographical ranges.
Times Cited in Web of Science Core Collection: 0 Total Times Cited: 0 Cited Reference Count: 38
Keywords: SEABIRDS; Sea duck; SCOTER MELANITTA-NIGRA; Aoaldalur; Capture-mark-recapture; Demography; DUCK POPULATIONS; LAKE MYVATN; Mortality; Myvatn; NORTH-SEA; OIL POLLUTION

Observations of Wing Feather Molt and Summer Feeding Ecology of Stellers Eiders Polysticta-Stelleri at Nelson Lagoon Alaska USA - Petersen, M. R. (Wildfowl, 1980)
The population size, molt chronology, food habits and feeding behavior of Steller's eiders P. stelleri were studied at Nelson Lagoon, Alaska, from May-Oct. 1977. Sub-adults were flightless from late July to late Aug. and the adult males were flightless from late Aug. to mid Sept. Adult females were rarely flightless at Nelson Lagoon, but commonly flightless at Izembek Bay. Steller's eiders ate primarily bivalve mollusks and amphipod Crustacea, with Mytilus edulis and Anisogammarus pugettensis the most important foods. Eiders took Amphipoda prior to the wing feather molt, bivalves during the wing feather molt and both types of invertebrates after the wing feather molt. Steller's eiders fed primarily at low tide by diving (flock-feeding) or head-dipping, during the day and at night. There was no difference in feeding behavior between ages or sexes. Eiders fed almost exclusively by diving after the wing feather molt and apparently fed more as the season progressed.
Keywords: Behavior; Abundance, Distribution, and Trends; Nonbreeding Seasons; Molt; Trophic Interactions; Polysticta stelleri; Steller's eider

Populations Feeding Ecology and Molt of Stellers Eiders Polysticta-Stelleri - Petersen, M. R. (Condor, 1981)
The temporal and spatial distribution of Steller's eiders (P. stelleri) during molt along the north side of the Alaska Peninsula [USA] from Port Heiden to Bechevin Bay was considered. Subadult eiders molted primarily at Nelson Lagoon, adult males at Nelson Lagoon and Izembek Bay, and adult females primarily at Izembek Bay. Only a few eiders used Bechevin Bay, Seal islands and Port Heiden. Although the flightless period overlapped among different age and sex classes, subadults were flightless 1st, then adult males, and last, adult females. Eiders maintained spatial and temporal separation during the flightless period, thereby reducing competition for food resources. Eiders at Nelson Lagoon were observed feeding only by head-dipping during the pre-flightless period in 1979, a significant change from 1977 when they fed both by diving and dipping. During both 1977 and 1979 eiders foraged for approximately equal amounts of time during each stage of molt. Foods consisted primarily of bivalve mollusks and amphipods. These foods were consumed in different proportions before and after the wing-feather molt, with mussels being most important when eiders were growing remiges. Comparisons between the amount of energy in blue mussels (Mytilus edulis), clams (Macoma balthica) and gammarid amphipods showed that mussels yield the most energy per gram of whole wet weight. Apparently, Steller's eiders have adjusted to the increased energy demands of molt by eating invertebrates with high caloric content, rather than by increasing the amount of time feeding.
Keywords: Behavior; Abundance, Distribution, and Trends; Nonbreeding Seasons; Molt; Energetics and Nutrition; Trophic Interactions; Polysticta stelleri; Steller's eider

Predation on Sea Birds by Red Foxes Vulpes-Fulva at Shaiak Island Alaska USA - Petersen, M. R. (Canadian Field-Naturalist, 1982)
Two red foxes (V. fulva) that invaded Shaiak Island before the 1976 nesting season had a marked impact on the nesting success of 5 of 7 spp. of seabirds breeding on the island that year. Common eiders (Somateria mollissima), glaucous-winged gulls (Larus glaucescens) and common murres (Uria aalge), that nest in areas accessible to foxes, did not raise any young to fledging. Double-crested cormorants (Phalacrocorax auritus) were only slightly more successful; 13 (4.3%) of 300 pairs raised 1 or more young to fledging. Evidence suggested that 21 (35.6%) of 62 pairs of tufted puffins (Lunda cirrhata) lost eggs or chicks to foxes, and foxes killed at least 13 (8.3%) of 156 adult puffins on 10 sample plots. Conversely, black-legged kittiwakes (Rissa tridactyla) and pelagic cormorants (Phalacrocorax pelagicus), which nested primarily on cliffs inaccessible to foxes, lost very few nests. There was no apparent change in general nest site selections by seabirds the following year, when foxes were no longer present. Any avoidance by birds of areas vulnerable to fox predation would probably be discernible only after several years of continuous predation.
Keywords: Breeding Season; Common Eider; Somateria mollissima; Productivity; Trophic Interactions

Spectacled Eider (Somateria fischeri) - Petersen, Margaret R., J. Barry Grand and Christian P. Dau (The Birds of North America, 2000)
Keywords: Somateria fischeri; Spectacled Eider

Multiple Spring Migration Strategies in a Population of Pacific Common Eiders - Petersen, Margaret R. (Condor, 2009)
Spring migration strategies vary within and among species. Examination of this variability extends our understanding of life histories and has implications for conservation. I used satellite transmitters to determine migration strategies and evaluate factors influencing the timing of spring migration of Pacific Common Eiders (Somateria mollissima v-nigrum) that nest along the western Beaufort Sea coast. Adult females were marked at nesting colonies in the summers of 2000, 2001, and 2003, and were followed throughout spring migration the following year. Each year approximately equal proportions of eiders used three distinct migration strategies varying in duration, staging locations (waters near the Chukotka Peninsula, Russia, and the Chukchi and Beaufort seas, Alaska), and arrival dates at the nesting areas. It is unlikely that differences in the timing of movements to stopover sites in the Chukchi and Beaufort seas were a result of responses to changes in weather, particularly wind direction. Ice distribution and melt/movement patterns vary substantially among staging areas and thus may affect risk of starvation and reproductive potential. Long-term (decadal) changes in climate may favor birds using one strategy during "warmer" and another during "colder" years.
Keywords: Common Eider; Nonbreeding Seasons; Migration; Somateria mollissima; SDJV funded

Breeding and moulting locations and migration patterns of the Atlantic population of Steller's eiders Polysticta stelleri as determined from satellite telemetry - Petersen, Margaret R.; Bustnes, Jan O.; Systad, Geir H. (Journal of Avian Biology, 2006)
This study was designed to determine the spring, summer, autumn, and early winter distribution, migration routes, and timing of migration of the Atlantic population of Steller's eiders Polysticta stelleri. Satellite transmitters were implanted in 20 eiders captured in April 2001 at Vadso, Norway, and their locations were determined from 5 May 2001 to 6 February 2002. Regions where birds concentrated from spring until returning to wintering areas included coastal waters from western Finnmark, Norway, to the eastern Taymyr Peninsula, Russia. Novaya Zemlya, Russia, particularly the Mollera Bay region, was used extensively during spring staging, moult, and autumn staging; regions of the Kola, Kanin, and Gydanskiy peninsulas, Russia, were used extensively during spring and moult migrations. Steller's ciders migrated across the Barents and Kara seas and along the Kara Sea and Kola Peninsula coastal waters to nesting, moulting, and wintering areas. The majority of marked eiders (9 of 15) were flightless in near-shore waters along the west side of Novaya Zemlya. Eiders were also flightless in northern Norway and along the Kanin and at Kola Peninsula coasts. We compare and contrast natural history characteristics of the Atlantic and Pacific populations and discuss evolutionary and ecological factors influencing their distribution.
Keywords: Breeding Season; Nonbreeding Seasons; Migration; Population Delineation; Polysticta stelleri; Steller's eider

Re-colonization by common eiders Somateria mollissima in the Aleutian Archipelago following removal of introduced arctic foxes Vulpes lagopus - Petersen, M. R.; Byrd, G. V.; Sonsthagen, S. A.; Sexson, M. G. (Journal of Avian Biology, 2015)
Islands provide refuges for populations of many species where they find safety from predators, but the introduction of predators frequently results in elimination or dramatic reductions in island-dwelling organisms. When predators are removed, re-colonization for some species occurs naturally, and inter-island phylogeographic relationships and current movement patterns can illuminate processes of colonization. We studied a case of re-colonization of common eiders Somateria mollissima following removal of introduced arctic foxes Vulpes lagopus in the Aleutian Archipelago, Alaska. We expected common eiders to resume nesting on islands cleared of foxes and to re-colonize from nearby islets, islands, and island groups. We thus expected common eiders to show limited genetic structure indicative of extensive mixing among island populations. Satellite telemetry was used to record current movement patterns of female common eiders from six islands across three island groups. We collected genetic data from these and other nesting common eiders at 14 microsatellite loci and the mitochondrial DNA control region to examine population genetic structure, historical fluctuations in population demography, and gene flow. Our results suggest recent interchange among islands. Analysis of microsatellite data supports satellite telemetry data of increased dispersal of common eiders to nearby areas and little between island groups. Although evidence from mtDNA is suggestive of female dispersal among island groups, gene flow is insufficient to account for recolonization and rapid population growth. Instead, near-by remnant populations of common eiders contributed substantially to population expansion, without which re-colonization would have likely occurred at a much lower rate. Genetic and morphometric data of common eiders within one island group two and three decades after re-colonization suggests reduced movement of eiders among islands and little movement between island groups after populations were re-established. We predict that re-colonization of an island group where all common eiders are extirpated could take decades.
Petersen, Margaret R. Byrd, G. Vernon Sonsthagen, Sarah A. Sexson, Matthew G.
Keywords: Taxonomy; Breeding Season; Common Eider; Somateria mollissima; Dispersal; SDJV funded; Population Delineation

Winter ecology of Spectacled Eiders: Environmental characteristics and population change - Petersen, Margaret R.; Douglas, David C. (Condor, 2004)
We described characteristics of the wintering area used by Spectacled Eiders (Somateria fischeri) in the Bering Sea, Alaska, and evaluated these characteristics in relation to long-term population trends. Remoteness, limited daylight, and extreme weather conditions precluded direct observations, so we derived the location of the wintering area from satellite telemetry, ice conditions from remotely sensed data, weather conditions from archived data sets, and benthic communities from the literature. Based on analyses of two indices spanning 1957-2002 and 1988-2002, we identified no single environmental parameter that explained the precipitous decline in nesting populations in western Alaska. In general, we found that the number of days with extreme sea ice in winter, extreme winds, and winds in spring explained the greatest variability in annual indices. These analyses support the conclusion that annual population estimates on the breeding grounds can be negatively impacted by extended periods of dense sea-ice concentration and weather during the previous winter. Examination of population indices did not support the hypothesis that changes in benthic community on the wintering grounds have contributed to the decline or inhibited the recovery of the Spectacled Eider breeding population in western Alaska.
Keywords: Somateria fischeri; Spectacled Eider; Abundance, Distribution, and Trends; Nonbreeding Seasons; Population Dynamics; Habitat

Use of implanted satellite transmitters to locate spectacled eiders at-sea - Petersen, Margaret R.; Douglas, David C.; Mulcahy, Daniel M. (Condor, 1995)
Keywords: Breeding Season; Somateria fischeri; Spectacled Eider; Nonbreeding Seasons; Techniques

EFFECTS OF SEA ICE ON WINTER SITE FIDELITY OF PACIFIC COMMON EIDERS (SOMATERIA MOLLISSIMA V-NIGRUM) - Petersen, M. R.; Douglas, D. C.; Wilson, H. M.; McCloskey, S. E. (Auk, 2012)
Times Cited: 2 Petersen, Margaret R. Douglas, David C. Wilson, Heather M. McCloskey, Sarah E. 2
Keywords: Nonbreeding Seasons; Somateria mollissima; Dispersal; Common eider; habitat

Population structure of Pacific Common Eiders breeding in Alaska - Petersen, Margaret R.; Flint, Paul L. (Condor, 2002)
We used satellite telemetry to study the migration routes and wintering areas of two allopatric breeding populations of Pacific Common Eiders (Somateria mollissima vnigrum) in Alaska: the Yukon-Kuskokwim Delta, and the western Beaufort Sea coast. Only 6% (2 of 36) of females wintered within the wintering area of the other breeding population. Both breeding populations wintered in the closest available ice-free habitat, perhaps to minimize migratory distance. Two Beaufort Sea females wintered in areas used by Yukon-Kuskokwim Delta females, implying potential gene flow among breeding areas. Yet, we conclude that these two populations are largely geographically isolated throughout the annual cycle and the environmental factors influencing survival and reproduction likely differ between these groups of birds. Thus, regardless of the potential gene flow among breeding populations, we suggest that birds from these two breeding areas should be managed as separate populations.
Keywords: Breeding Season; Common Eider; Nonbreeding Seasons; Somateria mollissima; SDJV funded; Population Delineation

Spectacled eider: Somateria fischeri - Petersen, Margaret R.; Grand, J. Barry; Dau, Christian P. (Birds of North America, 2000)
Keywords: Breeding Season; Somateria fischeri; Spectacled Eider; Nonbreeding Seasons

At-sea distribution of Spectacled Eiders: A 120-year-old mystery resolved - Petersen, Margaret R.; Larned, William W.; Douglas, David C. (Auk, 1999)
The at-sea distribution of the threatened Spectacled Eider (Somateria fischeri) has remained largely undocumented. We identified migration corridors, staging and molting areas, and wintering areas of adult Spectacled Eiders using implanted satellite transmitters in birds from each of the three extant breeding grounds (North Slope and Yukon-Kuskokwim Delta in Alaska and arctic Russia). Based on transmitter locations, we conducted aerial surveys to provide visual confirmation of eider flocks and to estimate numbers of birds. We identified two principal molting and staging areas off coastal Alaska (Ledyard Bay and eastern Norton Sound) and two off coastal Russia (Mechigmenskiy Bay on the eastern Chukotka Peninsula, and the area between the Indigirka and Kolyma deltas in the Republic of Sakha). We estimated that >10,000 birds molt and stage in monospecific flocks at Mechigmenskiy and Ledyard bays, and several thousand molt and stage in eastern Norton Sound. We further identified eastern Norton Sound as the principal molting and staging area for females nesting on the Yukon-Kuskokwim Delta, and Ledyard Bay and Mechigmenskiy Bay as the principal molting and staging areas for females nesting on the North Slope. Males marked at all three breeding grounds molt and stage in Mechigmenskiy Bay, Ledyard Bay, and the Indigirka-Kolyma delta region. Males from the Yukon-Kuskokwim Delta molt and stage mainly at Mechigmenskiy Bay. Equal numbers of males from the North Slope molt and stage at all three areas, and most males from arctic Russia molt and stage at the Indigirka-Kolyma delta region. Postbreeding migration corridors were offshore in the Bering, Chukchi, and Beaufort seas. In winter, eiders were in the Bering Sea south of St. Lawrence Island. Our estimates from surveys in late winter and early spring suggest that at least 333,000 birds winter in single-species flocks in the pack ice in the Bering Sea.
Keywords: Breeding Season; Somateria fischeri; Spectacled Eider; Abundance, Distribution, and Trends; Nonbreeding Seasons; Molt; Migration; Population Delineation

Post-breeding distribution of Long-tailed Ducks Clangula hyemalis from the Yukon-Kuskokwim Delta, Alaska - Petersen, M. R.; McCaffery, B. J.; Flint, P. L. (Wildfowl, 2003)
Breeding populations of Long-tailed Ducks Clangula hyemalis have declined in western Alaska, particularly on the Yukon-Kuskokwim (Y-K) Delta, and the species is currently considered a species of particular concern by the U.S. Fish & Wildlife Service in Alaska. Potential factors that may have contributed to this decline that occurred away from the breeding grounds could not be considered since moulting and wintering areas for this population were unknown. A study was conducted in 1998 and 1999 to locate the moulting and wintering areas of the Y-K Delta breeding population. VHF and satellite transmitters were deployed to identify areas used by moulting birds. Based on the locations identified by satellite telemetry, aerial surveys were flown to locate birds marked with VHF transmitters, then low-level aerial surveys were designed and conducted to determine the number of birds using these and adjacent areas. Moulting locations of 54 marked female Long-tailed Ducks were identified: 13 marked females were found in wetlands and large lakes on the Y-K Delta, 11 in coastal lagoons at St Lawrence Island, Alaska, and two along the coast of the Chukotka Peninsula, Russia. A autumn staging area was identified along the east coast of the Chukotka Peninsula which was used by seven of 10 birds with satellite transmitters providing locations during that period. Birds wintered in coastal waters of the North Pacific Ocean north of 50degreeN and between 150degreeE and 130degreeW. The wide distribution of birds in winter suggests little probability of a single factor in winter contributing to the decline.
Keywords: Nonbreeding Seasons; Molt; Clangula hyemalis; Long-tailed Duck; Dispersal; Population Delineation

Foods of Spectacled Eiders Somateria fischeri in the Bering Sea, Alaska - Petersen, Margaret R.; Piatt, John F.; Trust, Kimberly A. (Wildfowl, 1999)
The winter diet of Spectacled Eiders living in marine habitats is known only from two individuals described by Cottam (1939). Here we examine marine diets from 36 stomachs collected near St. Lawrence Island, Bering Sea, Alaska, during May-June in 1987 and 1992. All Spectacled Eiders ate Mollusca, including Gastropoda (snails; frequency of occurrence 20.0%; sole taxon 0.0%) and Bivalvia (bivalves; 80.0%; 48.0%), and Crustacea (barnacles, amphipods and crabs; 30.6%; 0.0%). One bird ate a cod. The predominant species group eaten was Macoma Clams (72.0%; 36.0%). Prey species of Spectacled Eiders occur predominantly in waters 25-60 m deep in the Bering Sea. To obtain these prey, especially the bivalves, on the winter area Spectacled Eiders must forage in waters exceeding 40 m. We speculate that Spectacled Eiders regularly forage at depths of 45-70 m throughout winter.
Keywords: Somateria fischeri; Spectacled Eider; Nonbreeding Seasons; Trophic Interactions

Variation in migration strategies of North American sea ducks - Petersen, M. R. and J.-P. L. Savard (Studies in Avian Biology, 2015)
Migration exerts strong effects on population dynamics, so consideration of migration as a driver of population change is an important area of inquiry. Sea ducks (Mergini) exemplify the wide range in types of migration strategies, which become more variable with the addition of a third migration to distinct molting areas. We discuss the three migrations, summer, fall, and molt, and emphasize similarities and differences within and among species. For each migration, we focus on timing, routes and stopover sites, nutrient reserve acquisition, stopover behavior, flight behavior, interannual constancy at stopover sites, and variation among sexes and ages. Last, we describe individual variation of annual flight paths, discuss inter- and intra-annual fidelity at stopover sites, examine the role of the environment on migration paths, and evaluate variability and limitations of speed and duration of migration.
Keywords: Behavior; Molt; Migration; Energetics and Nutrition

Nest Site Use by Cavity-Nesting Birds of the Cariboo Parkland British-Columbia Canada - Peterson, B.; Gauthier, G. (Wilson Bulletin, 1985)
We studied nest site use by 6 species of cavity nesters in southcentral British Columbia. Discriminant function analysis was performed using nest site characteristics that differed significantly among 4 species (European Starlings, Sturnus vulgaris; Tree Swallows, Tachycineta bicolor; Northern Flickers, Colaptes auratus; and Buffleheads, Bucephala albeola). Cavity volume and, to a lesser extent, entrance area were the most important variables characterizing nest sites. Habitat variables were relatively unimportant except for canopy height, which also explained a significant amount of the variance. The analysis correctly classified only 62% of the cases, reflecting the high overlap in cavity use, especially between Buffleheads and starlings. We tested the prediction of Erskine and McLaren (1976) that competition for nest sites would increase in this community following its invasion by starlings 30 years ago by comparing nest site characteristics found in this study with similar data collected in 1959. Swallows now use significantly smaller cavities, bluebirds tend to use smaller bud deeper cavities, and all species use cavities with a smaller entrance area. It is not clear, however, if these changes resulted from an intensification of competition or from a change in the resource available.
Keywords: Breeding Season; Habitat; Bucephala albeola; Bufflehead

Variation in Oldsquaw Rectrix Numbers - Peterson, S. R. (Auk, 1976)
Keywords: Molt; Clangula hyemalis; Long-tailed Duck

Incidence of Body Shot in Lake Michigan Oldsquaws - Peterson, S. R.; Ellarson, R. S. (Journal of Wildlife Management, 1975)
Keywords: Conservation; Nonbreeding Seasons; Clangula hyemalis; Long-tailed Duck

Total Mercury Residues in Livers and Eggs of Oldsquaws - Peterson, S. R.; Ellarson, R. S. (Journal of Wildlife Management, 1976)
Total Hg was determined in 99 oldsquaw (Clangula hyemalis) livers and 11 composite clutches collected on Lake Michigan and in northwest Hudson Bay. Residue levels were similar in different sex and age-classes collected during the same time period on Lake Michigan. Hg levels were higher in oldsquaws collected in Hudson Bay than in those taken on Lake Michigan. Residues in the hen and clutch were positively correlated. Hg in duckling livers was negatively correlated with the weight of the liver.
Keywords: Breeding Season; Nonbreeding Seasons; Clangula hyemalis; Long-tailed Duck; Contaminants

Food Habits of Oldsquaws Wintering on Lake Michigan Michigan USA - Peterson, S. R.; Ellarson, R. S. (Wilson Bulletin, 1977)
The food habits of oldsquaws wintering on Lake Michigan [Michigan, USA] were examined from material collected in 2 periods: 1951-1954 and 1969-1972. Grit averaged 25% of total contents in the earlier sample, and 90% of all grit was sand. Animal food constituted about 99% by volume of the food organisms present in the 1951-1954 sample. The principal food item was an amphipod Pontoporeia affinis which occurred in 52-96% of the earlier sample and in 88-95% of the 1969-1972 sample. Clams occurred frequently in both samples but the volume ingested was relatively low. The occurrence of fish and fish eggs in the diet varied with the locality and individual flocks. Oldsquaws are related to the coregonid fishery in Lake Michigan through the common food organism P. affinis. Oldsquaws will also eat fish eggs when available. The decline in oldsquaw carcass lipids during the winter may be related to a decrease in the volume of food ingested during that period, but a rise in the volume of ingested food during early spring does not appear to be associated with a premigratory increase in lipid deposition. Oldsquaws apparently decrease their feeding activity just prior to migration and do not resume heavy feeding while on spring migration.
Keywords: Nonbreeding Seasons; Clangula hyemalis; Long-tailed Duck; Trophic Interactions

Bursae Reproductive Structures and Scapular Color in Wintering Female Oldsquaws - Peterson, S. R.; Ellarson, R. S. (Auk, 1978)
Female oldsquaws [Clangula hyemalis] were collected on Lake Michigan [USA] between Dec. and May 1951-55 and 1969-73. Measurements taken on bursae, ovaries and oviducts were related to age class and scapular color. Bursae were significantly deeper in juveniles than in adults, and the adult females with gray scapulars had significantly deeper bursae than adult females with brown scapulars. Juvenile female ovaries were smaller than adult ovaries throughout the winter and spring and did not enlarge significantly in the spring as did the adult female ovaries. Oviduct weights were significantly different in immature females, gray-scapulared adult females and brown-scapulared adult females. The data support behavioral evidence that oldsquaws do not reach sexual maturity their 1st yr. Gray scapulars in adults are indicative of a nonbreeding subadult cohort.
Keywords: Nonbreeding Seasons; Clangula hyemalis; Long-tailed Duck; Physiology

P P Dde Poly Chlorinated Bi Phenyls and Endrin in Oldsquaws in North America 1969-1973 - Peterson, S. R.; Ellarson, R. S. (Pesticides Monitoring Journal, 1978)
Organochlorinated compounds were monitored in oldsquaws (Clangula hyemalis) and their food [almost entirely Pontoporeia affinis] from Lake Michigan between October and May, 1969-72; in adult oldsquaws, eggs, young and food from northwest Hudson Bay in 1971; and in oldsquaws from 5 wintering areas other than Lake Michigan in 1971-73. Analyses were conducted on 300 carcasses, 14 wings, 29 gullet samples and 11 clutches. Average residues in carcasses from Lake Michigan ranged from 4-107 ppm PCB [polychlorinated biphenyls], 2 to 42 ppm DDE, and < 0.1-0.7 ppm endrin. Differences in DDE levels occurred between several sex and age classes during Dec. on Lake Michigan; these differences were not apparent in the spring. Increases in DDE and PCB residues for oldsquaws occurred on Lake Michigan between Dec. and May. DDE residues in the wing and carcass were significantly correlated. Residues were relatively low in oldsquaw foods from Lake Michigan; concentration factors between the food and the ducks varied between 1 .times. 22 .times., depending on the date and compound. Organochlorinated residues were lower in Arctic than in Lake Michigan food samples. DDE in paired male and female oldsquaws was highly correlated, as was DDE in females and clutches. Eggshell thickness had declined 4.5% compared with eggs collected before 1947. Residues were highest in oldsquaws wintering on the Great Lakes and lowest in oldsquaws from coastal areas.
Keywords: Nonbreeding Seasons; Clangula hyemalis; Long-tailed Duck; Contaminants

Changes in Oldsquaw Clangula-Hyemalis Carcass Weight - Peterson, S. R.; Ellarson, R. S. (Wilson Bulletin, 1979)
Oldsquaws were collected from commercial fishing gear between Dec. and May on Lake Michigan and in the Arctic during the breeding season. Carcasses were analyzed for lipids, moisture and dry weight content. Males were heavier than females in the same age class, and matures were heavier than juveniles in the same sex class, but differences were not always significant within a particular month. Carcass weights varied seasonally; the heaviest weights were recorded in Jan. and May and the lightest birds were found in April and late summer. During the summer, adult females steadily lost weight from the time they arrived on the breeding grounds in early June until the eggs hatched in early Aug. During the winter and spring, changes in the carcass weight and the component fractions varied together in the different age and sex classes. Trends in the lipid and dry weight fractions were similar to those exhibited in carcass weights, but the moisture fraction generally varied opposite to lipids and dry weight. Most seasonal variability in carcass weight could be accounted for by changes in the lipid fraction.
Keywords: Breeding Season; Nonbreeding Seasons; Clangula hyemalis; Long-tailed Duck; Energetics and Nutrition

Rapid increase and subsequent decline of zebra and quagga mussels in Long Point Bay, Lake Erie: Possible influence of waterfowl predation - Petrie, Scott A.; Knapton, Richard W. (Journal of Great Lakes Research, 1999)
Distribution and density of two introduced dreissenid species of mollusks, the zebra mussel Dreissena polymorpha and quagga mussel D. bugensis, were monitored in the Inner Bay at Long Point, Lake Erie, 1991-1995. Since populations of certain waterfowl species have been reported to alter their dietary intake and migration patterns in response to the ready availability of zebra mussels, the percent occurrence of zebra mussles in the diet of 12 duck species (552 birds) was studied concurrently, and several spring and fall aerial waterfowl surveys were flown between 1986 and 1997 (n = 75), to document changes in duck populations at Long Point. The first reproductive population of zebra mussels on the bay most likely appeared in 1990. After an initial rapid increase in density and colonization of the Inner Bay, zebra mussels began to steadily and consistently decline in absolute numbers, density per station and occupied area. Mean density per station in 1995 was 70% less than in 1991, the first year of rapid colonization, and 67% less than in 1992, the year of peak abundance in the bay (P < 0.05). Occupied area peaked in 1992, with 80% of sampling stations supporting mussels; the following 3 years showed consistent declines in the proportion of stations supporting mussels: 1993 = 75.9%, 1994 = 63.2% and 1995 = 57.1% (P < 0.05). Mussels in size class 0 to 5 mm were most abundant in 1991, 1993 and 1995, whereas those in size class 6 to 10 mm predominated in 1992 and 1994 (P < 0.05). Very few mussels over 15 mm were found. Lesser Scaup Aythya affinis (75.4 to 82.5% occurrence), Greater Scaup A. marila (66.7 to 81.5% occurrence), and Bufflehead Bucephala albeola (46.7 to 60% occurrence) were the only three waterfowl species that consistently incorporated zebra mussels in their diet, and the mussel decline coincided with a substantial increase in the populations of these species at Long Point. Waterfowl days for Lesser and Greater Scaup combined increased rapidly from 38,500 in 1986 (prior to the zebra mussel colonization of Long Point) to 3.5 million in 1997 (P = 0.012). Bufflehead days increased from 4,700 to 67,000 during the same period (P = 0.001). Oligotrophication of Lake Erie, through reduced plankton and chlorophyll concentrations, has occurred since the invasion of zebra mussels, probably a result of filtering activities of introduced mussels. While a reduction in plankton availability may have contributed to the zebra mussel decline, high rates of waterfowl predation probably had the most substantial effect on mussel densities at Long Point. Waterfowl predation also probably influenced the size structure of the zebra mussel population, since waterfowl are size-selective foragers, and increased water clarity would have facilitated their ability to select preferred medium and large size classes of mussels. Quagga mussels, which were first detected in 1993, experienced a decline in both density and area occupied over the next two years. Quagga mussels rarely attached to soft substrates, and their decline is possibly related to the decline of suitable hard substrates, such as zebra mussels, as well as to predation by waterfowl.
Keywords: Nonbreeding Seasons; Trophic Interactions; Bucephala albeola; Bufflehead

Chromatographic separation of the enantiomers of marine pollutants: Part 6. Comparison of the enantioselective degradation of alpha-hexachlorocyclohexane in marine biota and water - Pfaffenberger, Bernd; Huehnerfuss, Heinrich; Kallenborn, Roland; Koehler-Guenther, Angela; Koenig, Wilfried A.; Kruener, Guenter (Chemosphere, 1992)
The enantiomeric ratios of the chiral marine pollutant alpha-hexachlorocyclohexane (alpha-HCH) was determined in blue mussels (Mytilus edulis L.), flounders (Platychthys flesus (L.)), Common eider ducks (Somateria mollissima (L.)), and in North Sea water of experimental sites in the German Bight by means of capillary gas chromatography using beta-cyclodextrin derivatives as chiral stationary phases. Different enzymatic degradation pathways are revealed by opposite enantioselective enrichments of the alpha-HCH enantiomers: while in the liver of Common eider ducks the preferable degradation of (-)-alpha-HCH leads to an enrichment of (+)-alpha-HCH (i.e., (+)-alpha-HCH/(-)-alpha-HCH apprxeq 1.4 - infin ), the enantiomeric ratios measured in the liver samples of flounders ((+)-alpha-HCH/(-)-alpha-HCH apprxeq 0.80 - 0.94), in blue mussels ((+)-alpha-HCH/(-)-alpha-HCH apprxeq 0.84 - 0.93) and in the North Sea water samples ((+)-alpha-HCH/(-)-alpha-HCH apprxeq 0.84) imply enzymatic processes in the course of which common structural elements are preferred represented by (+)-alpha-HCH.
Keywords: Common Eider; Contaminants; Somateria mollissima

Movements of the King Eider during the non-breeding period revealed by satellite telemetry - Phillips, L. M.; Oppel, S.; Powell, A. N. (Journal of Ornithology, 2006)
Keywords: Nonbreeding Seasons; King Eider; Somateria spectabilis; Dispersal

Evidence for wing molt and breeding site fidelity in King Elders - Phillips, Laura M.; Powell, Abby N. (Waterbirds, 2006)
Fidelity of King Eiders (Somateria spectabilis) to breeding and wing molt sites was examined using satellite telemetry data obtained opportunistically when battery life of transmitters provided locations in a second year. Consecutive breeding locations were obtained for eleven female and 23 male King Eiders. All females exhibited breeding site fidelity by returning to sites within 15 km of first year breeding areas on the North Slope of Alaska. Breeding locations of males in a subsequent year were located on average > 1000 km from their prior breeding sites and were primarily outside Alaska, on the coasts of Russia and Canada. Second-year wing molt locations were obtained for two female and six male King Eiders. Wing molt sites of males were located 6.2 +/- 3.1 km apart on average in successive years, while female wing molt locations averaged almost 50 km apart. Our results demonstrate site fidelity of female King Eiders to a breeding area on the North Slope of Alaska, document the dispersal of male King Eiders between breeding seasons, and present the first evidence for wing molt site fidelity in males.
Keywords: Breeding Season; Nonbreeding Seasons; Molt; King Eider; Somateria spectabilis; Dispersal; SDJV funded; Population Delineation

Brood Rearing Ecology of King Eiders on the North Slope of Alaska - Phillips, Laura M.; Powell, Abby N. (Wilson Journal of Ornithology, 2009)
We examined King Eider (Somateria spectabilis) brood survival in the Kuparak oil field in northern Alaska in 2002 and 2003 by monitoring hens with broods using radiotelemetry. We observed complete brood loss in eight of 10 broods. Broods survived less than 2 weeks on average, and most mortality occurred within days of hatch. Distance hens traveled overland did not affect brood survival. Apparent King Eider brood survival in our study area was lower than reported for eider species in other areas. We recommend future studies examine if higher densities of predators in oil fields reduces King Eider duckling survival. Received 26 September 2008. Accepted 18 January 2009.
Keywords: Breeding Season; Productivity; King Eider; Somateria spectabilis; Survival; SDJV funded

Large-scale movements and habitat characteristics of King Eiders throughout the nonbreeding period - Phillips, Laura M.; Powell, Abby N.; Rexstad, Eric A. (Condor, 2006)
King Eiders (Somateria spectabilis) breeding in western Canada and Alaska molt wing feathers and spend the winter in remote areas of the Bering Sea, precluding direct observation. To characterize timing of migration and habitat used by King Eiders during the nonbreeding period, we collected location data for 60 individuals (27 females and 33 males) over three years from satellite telemetry and utilized oceanographic information obtained by remote sensing. Male King Eiders dispersed from breeding areas, arrived at wing molt sites, and dispersed from wing molt sites earlier than females in all years. Males arriving earlier at wing molt sites molted flight feathers at higher latitudes. Distributions of molt and winter locations did not differ by sex or among years. Of the variables considered for analysis, distance to shore, water depth, and salinity appeared to best describe King Eider habitat throughout the nonbreeding period. King Eiders were located closer to shore, in shallower water with lower salinity than random locations. During the winter, lower ice concentrations were also associated with King Eider locations. This study provides some of the first large-scale descriptions of King Eider migration and habitat outside the breeding season.
Keywords: Nonbreeding Seasons; Molt; Migration; King Eider; Somateria spectabilis; Dispersal; Habitat; SDJV funded

Use of the Beaufort sea by king eiders breeding on the north slope of Alaska - Phillips, Laura M.; Powell, Abby N.; Taylor, Eric J.; Rexstad, Eric A. (Journal of Wildlife Management, 2007)
We estimated areas used by king ciders (Somateria spectabilis) in the Alaskan Beaufort Sea, how distributions of used areas varied, and characteristics that explained variation in the number of days spent at sea, to provide regulatory agencies with baseline data needed to minimize impacts of potential offshore oil development. We implanted sixty king ciders with satellite transmitters at nesting areas on the North Slope of Alaska, USA, in 2002-2004. More than 80% of marked eiders spent >2 weeks staging offshore prior to beginning a postbreeding molt migration. During postbreeding staging and migration, male king ciders had much broader distributions in the Alaskan Beaufort Sea than female eiders, which were concentrated in Harrison and Smith Bays. Distribution did not vary by sex during spring migration in the year after marking. Shorter residence times of riders and deeper water at locations used during spring migration suggest the Alaskan Beaufort Sea might not be as critical a staging area for king eiders during prebreeding as it is postbreeding. Residence time in the Beaufort Sea varied by sex, with female king eiders spending more days at sea than males in spring and during postbreeding. We conclude the Alaskan Beaufort Sea is an important staging area for king riders during postbreeding, and eider distribution should be considered by managers when mitigating for future offshore development. We recommend future studies examine the importance of spring staging areas outside the Alaskan Beaufort Sea.
Keywords: Breeding Season; Abundance, Distribution, and Trends; Nonbreeding Seasons; Migration; King Eider; Somateria spectabilis; SDJV funded

Immediate Impact of the Exxon Valdez Oil Spill on Marine Birds - Piatt, J. F.; Lensink, C. J.; Butler, W.; Kendziorek, M.; Nysewander, D. R. (Auk, 1990)
On 24 March 1989, the oil tanker 'Exxon Valdez' spilled 260,000 barrels of crude oil in Prince William Sound, Alaska [USA]. Oil eventually drifted over 30,000 km2 of costal and offshore waters occupied by approximately one million marine birds. More than 30,000 dead birds of 90 species were retrieved from polluted areas by 1 August 1989. Of those identified, murres (74%), other alcids (7.0%), and sea ducks (5.3%) suffered the highest mortality from oil, and most (88%) birds were killed outside of Prince William Sound. A colony of 129,000 murres at the Barren Islands was probably devastated. Another 7,000 birds were retrieved between 1 August and 13 October, but most of those birds appeared to have died from natural causes. This later die-off was composed largely of shearwaters and other procellariids (51%), gulls (22%), and puffins (14%). Based on aerial and ship-based surveys for populations at risk, and extrapolating from the number of dead birds recovered, we estimate that the total kill from oil pollution was from 100,000 to 300,000 birds.
Keywords: Sea Ducks - General; Nonbreeding Seasons; Contaminants

Effects of forest harvesting on Bufflehead and Common Loon foraging behavior - Pierre, Johanna P.; Boss, Shelly M.; Paszkowski, Cynthia A. (Ornithological Science, 2005)
We compared foraging behavior of Bufflehead (Bucephala albeola Linnaeus) and Common Loon (Gavia immer Brunnich) on eight lakes in harvested and unharvested boreal mixedwood forest in northern Alberta, Canada. For one summer before (1996) and two Summers after (1997, 1998) forest harvesting around three of the eight lakes, we recorded the duration of Bufflehead and Common Loon dives. After logging, forested buffer strips 100m-wide separated cut-blocks from lakes ('harvested lakes'). 'Unharvested lakes' were surrounded by >= 450m of undisturbed forest throughout the study. There were no detectable differences in dive duration between harvested and unharvested lakes for Bufflehead or Common Loon. Correlations between environmental variables (water clarity, fish biomass, depth) and the duration of Common Loon dives were not significant. However, the duration of Bufflehead dives differed between lakes, unrelated to forest harvesting. The duration of Bufflehead dives was negatively correlated with water clarity but was not significantly cot-related with fish biomass. While our study shows that the foraging behavior of Buffleheads was affected by lake conditions, the utility of aquatic birds as indicators of the effects of forestry on western boreal lakes remains unproven.
Keywords: Conservation; Behavior; Breeding Season; Bucephala albeola; Bufflehead

Impact of winter climate on wintering coastal waterbirds in Denmark, 1987-1996 - Pihl, Stefan (Dansk Ornitologisk Forenings Tidsskrift, 2000)
During 1987-1992 the National Environmental Research Institute carried out countrywide surveys of waterbirds in mid-winter (Pihl et al. 1992a, Laursen et al. 1997) as part of Wetlands International's International Waterfowl Census (Rose 1995). Beginning in 1993, the mid-winter surveys were restricted to certain areas according to a "reduced site list programme" developed in co-operation with the National Forest and Nature Agency in Copenhagen and Wetlands International. The programme aimed at providing good coverage of important species and of habitats and geographical regions, including internationally important wetlands and waterbird wintering areas (Fig. 1, Table 2.). This paper presents annual mid-winter indices for 19 waterbird species during the period 1987-1996, calculated on basis of count results from the reduced site list areas using the program UINDEX4 (provided by M.C. Bell from the Wildfowl and Wetlands Trust, UK). Trends over time were analysed using Spearman rank correlations (Table 4), and the relationship between indices and winter climate was analysed by regressing indices against the sum of daily mean temperatures during periods with frost at six localities in Denmark (MAK), and against MAK of the previous year (Table 5). Also the year-to-year change in the indices was regressed against MAK. Twelve of the 19 species showed increasing trends, the rest being constant (variation coefficient < 75%) or fluctuating (variation coefficient > 75%). Unfortunately, however, the only severe winters during the period were the first and last. If the analysis is restricted to 1991-1996, only 3-4 species show a positive trend, six a negative trend, while the rest are stable or fluctuating. There is a general concordance with trends found at a European scale (Table 6). Some species show an immediate numerical response to spells of cold weather by moving out of the covered sites. This group includes the herbivorous Wigeon and the piscivorous Cormorant as well as the omnivorous Mallard and the Tufted Duck, feeding on benthic invertebrates. Severe winters seem to have a common impact on several waterbird species, expressed by changes in index values, although the various strategies adopted by different species during cold weather could not be clarified in detail in the present analysis. Great Crested Grebe, Mallard, Pochard, Tufted Duck, Sinew and Goosander occur primarily in lakes, and when these freeze over the birds move to other areas that may or may not be covered by the reduced site list programme. Great Crested Grebes are displaced to offshore areas (Laursen et al. 1997) and Mallards to coastal areas, while Pochards concentrate at sheltered coasts, and if the cold weather persists a large proportion of the birds move out of the country. Tufted Ducks concentrate in open marine areas, often harbours. The alternative wintering areas used by these four species are not particularly well covered by the reduced site list programme, so indices will decrease during severe weather. In contrast, Smew and Goosander move to well covered coastal areas, and since the populations may furthermore be supplemented by birds moving out of the Baltic Sea, the index for these species will remain unaffected, or may even increase, in case of severe weather. A third group is comprised of Grey Heron, Shelduck, Wigeon, Teal and Pintail that all have their northernmost European wintering grounds in Denmark. These species almost entirely leave Denmark during severe winters. Mute Swan and Coot both show negative correlations with the severity of the previous winter. These species are sedentary and suffer increased mortality in cold winters (Andersen-Harild 1981, Nilsson 1984).
Keywords: Abundance, Distribution, and Trends; Sea Ducks - General; Nonbreeding Seasons; Common merganser

Selenium status in sea ducks (Melanitta fusca, Melanitta nigra and Clangula hyemalis) wintering on the southern Baltic coast, Poland - Pilarczyk, B.; Tomza-Marciniak, A.; Pilarczyk, R.; Kavetska, K.; Rzad, I.; Hendzel, D.; Marciniak, A. (Marine Biology Research, 2012)
Times Cited: 0 Pilarczyk, Bogumila Tomza-Marciniak, Agnieszka Pilarczyk, Renata Kavetska, Katarzyna Rzad, Izabella Hendzel, Diana Marciniak, Andrzej Kavetska, Katarzyna /K-4001-2012 0
Keywords: Melanitta fusca; Nonbreeding Seasons; Clangula hyemalis; Long-tailed Duck; Contaminants; white-winged Scoter; Black Scoter; Melanitta nigra

Invertebrate communities inhabiting nests of migrating passerine, wild fowl and sea birds breeding in the High Arctic, Svalbard - Pilskog, H. E.; Solhoy, T.; Gwiazdowicz, D. J.; Grytnes, J. A.; Coulson, S. J. (Polar Biology, 2014)
Nests of birds often possess a diverse invertebrate fauna, but almost no descriptions of the invertebrate fauna of bird nests from the High Arctic exist in spite of numerous studies at lower latitudes. Seventy-seven nests belonging to common eider, barnacle goose, glaucous gull, black-legged kittiwake and snow bunting were examined for the invertebrate fauna from Kongsfjorden and Longyearbyen, Svalbard. Twenty-seven nest-living species were found and thirty-one species in soil under common eider nests. The diversity in most of the nests was poor. True nidiculous species were absent, and ectoparasites dominated in nests of all bird species; the flea; Ceratophyllus vagabundus vagabundus in the nests of common eider, barnacle goose and glaucous gull, Mioctenopsylla arctica arctica in the nests of black-legged kittiwake; and the parasitic mesostigmatid mite Dermanyssus hirundinis in the nests of snow bunting. The most diverse group in nests was opportunistic soil-living oribatid mites. If soil samples taken beneath common eider nests are included, five species or genera of invertebrates not previously recorded from Svalbard were found: Cyrtozetes sp., Liochthonius simplex (Acari: Oribatida), Protaphorura subuliginata (Collembola: Onychiuridae) and larvae of Parochlus kiefferi and Paralimnophyes sp. (Diptera: Chironomidae). Of these, Cyrtozetes sp. is probably an undescribed species. The chironomid larvae from black-legged kittiwake nests have probably been transported together with nest material. With the exception of the ectoparasites, little indicates that invertebrates preferentially exploit nests in Svalbard, as most species were free living and are normally common in soils.
Pilskog, Hanne Eik Solhoy, Torstein Gwiazdowicz, Dariusz J. Grytnes, John-Arvid Coulson, Stephen J.
Keywords: Breeding Season; Common Eider; Somateria mollissima; Parasites

Disturbance of waterbirds by ships on lakes Ketelmeer and IJsselmeer - Platteeuw, Maarten; Beekman, Jan H. (Limosa, 1994)
During two consecutive days in winter 1990/91, observations were made on disturbance of waterbirds by ships ( Fig. 1) at lake Ketelmeer. These ship-based observations only involved the determination of the specific "critical disturbance distance", defined as the distance within which at least 20% of a certain species exhibits abnormal behaviour, e.g. alertness, swimming or diving away from the approaching ship or flying off. Many waterbirds may be found resting close to the polderdikes bordering the lakes. Since a shipping lane is planned for lake Ketelmeer at 440-560 m from the SW dike, the distances of the resting Aythya ducks from the dikes have been recorded as well. Of the two piscivorous species, Great Crested Grebe and Goosander, critical disturbance distances were estimated at 300 and well over 300 m respectively (Tab 1, 2). Two diurnal benthos (mainly Zebra Mussel Dreissena polymorpha) feeders, Coot and Goldeneye, showed markedly different reactions. While the first species hardly reacted at all to the approach or passing of the ship, the latter flew off at distances of up to 500 m or more. The critical distances were estimated at less than 100 m for the Coot and at possibly 1000 m for the Goldeneye (Tab. 1, 2). The three nocturnal musselfeeders Pochard, Scaup and Tufted Duck were disturbed at distances of 300, little over 400 and well over 400 m respectively (Tab. 1, 2). It is argued that disturbance of feeding birds may have a more markedly negative impact on the individual energy budgets of the birds than disturbance of resting birds, since both the loss of feeding time and the extra energy expenditure must be compensated for A diurnal forager as vulnerable to disturbance as the Goldeneye may well be limited in its possibilities to exploit take Ketelmeer's mussel resources by the frequent passing of ships at distances below its critical range. On the other hand, the confident Coot can exploit any musselbank. The feeding pressure of all musselfeeders on the local zebra mussel stock seems to be so severe, that any increase in intra- or interspecific interference, due to the need of compensate for extra energy losses, may lead to a lower rather than a higher food intake. Since both Pochard and Tufted Duck may be resting at distances of up to 300 m from the nearest polder dike and the planned shipping route will be at 440-560 m from the southwestern dike (offering shelter from the prevailing winds), many ships will pass at distances well below their critical disturbance distance. However, the concentration of all ship movements within a confined area leads to more predictable ship activity (important for habituation) and to less pressure on other zones within the lake Therefore, it is considered unlikely that the take will be abandoned by resting Aythya ducks as a consequence of the projected shipping route.
Keywords: Conservation; Behavior; Nonbreeding Seasons; Bucephala clangula; Common Goldeneye; Common merganser; Mergus merganser

Food and Feeding Habits of the Common Eider at Seafield Edinburgh in Winter - Player, P. V. (Wildfowl, 1971)
Keywords: Common Eider; Nonbreeding Seasons; Somateria mollissima; Trophic Interactions

Movement ecology and habitat use differences in Black Scoters wintering along the Atlantic coast - Plumpton, H. M.; Gilliland, S. G.; Ross, B. E. (AVIAN CONSERVATION AND ECOLOGY, 2020)
For migratory species such as Black Scoters (Melanitta americana) whose range encompasses a variety of habitats, it is especially important to obtain habitat use information across the species' range to better understand anthropogenic threats, e.g., marine development and climate change. The objective of our study was to investigate the winter movement patterns and habitat use of Black Scoters in the Atlantic Ocean by quantifying the following key movement indices: number of wintering sites, arrival and departure dates to and from the wintering grounds, days at a wintering site, area of a wintering site, distance between wintering sites, and differences in habitat features of wintering sites. We also tested if winter movement patterns varied by sex or along a latitudinal gradient. To quantify winter movement patterns of Black Scoters, we used satellite telemetry data from 2009 to 2012 (n = 29 tagged females and 15 males for a total of 66 winter seasons, 38 female winter seasons, 28 male winter seasons). Our results indicated that the average wintering site area and distance between wintering sites varied with latitude. Wintering sites located at southern latitudes were larger and further apart than wintering sites located at more northern latitudes. Additionally, wintering sites varied in bathymetry, distance to shore, and the slope of the ocean floor at different latitudes; northern wintering sites were in deeper waters, closer to shore, and on steeper slopes than southern wintering sites. Our results suggest that habitat use may differ by latitude, indicating that habitats used in northern locations may not be representative of habitats used in more southern wintering areas. Understanding variation of habitat use along a latitudinal gradient will enable managers to focus sampling effort for Black Scoter abundance and distribution along the Atlantic coast and provide insight on the wintering ecology and movement of Black Scoters.
Times Cited in Web of Science Core Collection: 2 Total Times Cited: 2 Cited Reference Count: 74
Keywords: BIRDS; COMMON EIDERS; EIDERS SOMATERIA-MOLLISSIMA; Black Scoter; PATTERNS; SELECTION; KING EIDERS; Melanitta americana; SEA DUCKS; CONSERVATION; BODY CONDITION; SURF SCOTERS; movement; geographic variation; wintering ecology

Black Scoter habitat use along the southeastern coast of the United States - Plumpton, H. M.; Silverman, E. D.; Ross, B. E. (ECOLOGY AND EVOLUTION, 2021)
While the Atlantic Coast of the United States and Canada is a major wintering area for sea ducks, knowledge about their wintering habitat use is relatively limited. Black Scoters have a broad wintering distribution and are the only open water species of sea duck that is abundant along the southeastern coast of the United States. Our study identified variables that affected Black Scoter (Melanitta americana) distribution and abundance in the Atlantic Ocean along the southeastern coast of the United States. We used aerial survey data from 2009 to 2012 provided by the United States Fish and Wildlife Service to identify variables that influenced Black Scoter distribution. We used indicator variable selection to evaluate relationships between Black Scoter habitat use and a variety of broad- and fine-scale oceanographic and weather variables. Average time between waves, ocean floor slope, and the interaction of bathymetry and distance to shore had the strongest association with southeastern Black Scoter distribution.
Times Cited in Web of Science Core Collection: 0 Total Times Cited: 0 Cited Reference Count: 47
Keywords: habitat use; BIRDS; COMMON EIDERS; Black Scoter; PATTERNS; SELECTION; Melanitta americana; SEA DUCKS; ECOLOGY; MODELS; WHITE-WINGED SCOTERS; WINTER; GUIDE; oceanographic; weather