Status of Common Eiders, Somateria mollissima, nesting in the Digges Sound region, Nunavut

Status of Common Eiders, Somateria molissima, nesting in the Digges Sound region, Nunavut.Canadian Field-Naturalist 116(1): 22-25.There is little information available on status of Common Eider, Somateria mollissima, populations nesting in Arctic Canada.We surveyed Common Eiders in the Digges Sound region, Nunavut, on 19-20 July 1999, for comparison with similar surveys in 1980-1983.On six islands for which data were available in both periods, there were 4-5 times as many nests in 1999 as in the early 1980s.The mean clutch size late in incubation in 1999 (3.3 eggs per nest) was similar to that in 1983 (3.2 eggs), but lower than in 1982 (3.9 eggs); timing of hatching was similar in the two periods.All three females caught during incubation were of the subspecies S. m. borealis.In contrast to Common Eiders S. m. sedentaria nesting in the Belcher Islands, Common Eiders nesting in the Digges Sound region appear to be faring well.Key Words: Common Eider Somateria mollissima, clutch size, Digges Sound, egg size, populations, timing of hatching.Common Eiders, Somateria mollissima, are an Ivujivik, Québec, which lies in the heart of the important subsistence and cultural resource for Inuit region (Gaston et al. 1985).In this paper, we report people in Canada's eastern Arctic, in additon to being -_ the results of our 1999 surveys and make comparimportant components of arctic marine ecosystems isons with observations from 1980-1983, to assess (Reed 1986).Despite this, there is little information the status of the Common Eider population nesting available on status and trends of arctic-nesting in this region.Common Eider populations.Historical data exist for only a few locations in eastern Arctic Canada: the Study Area Belcher Islands and nearby Québec coast The Digges Sound region, and its seabird commu-(Nakashima and Murray 1988), Ungava Bay nity, was described in detail by Gaston et al. (1985;(Chapdelaine et al. 1986), the West Foxe Islands _ see Figure 1).It is dominated by a very large aggre-(Cooch 1977; Cooch 1986), the Hell's Gate-gation (300 000 pairs) of Thick-billed Murres, Uria Cardigan Strait region (Prach et al. 1986), and the Jlomvia, that breed on the tall cliffs of East Digges Digges Sound region (Gaston et al. 1985).There is Island and the Québec mainland south and west of evidence that Common Eider, S. m. sedentaria, pop-Cape Wolstenholme.There are also many small, ulations nesting in the Belcher Islands have declined low-lying islands that support nesting colonies of sharply (Robertson and Gilchrist 1998).There also is Common Eiders and other marine birds.Potential evidence of long-term declines in S. m. v-nigra pop-_ predators on Common Eider eggs and ducklings that ulations of northern Alaska and the western we saw on these small islands included Herring Canadian arctic (Suydam et al. 2000).Updated infor-Gulls, Larus argentatus, Glaucous Gulls, L. hypermation on other populations is urgently required in boreus, and Great Black-backed Gulls, L. marinus.order to assess their status and devise effective con-The former two species breed in colonies throughout servation strategies (compare Reed and Erskine Digges Sound (note that there were >31 adult 1986; Dickson 1997).Glaucous Gulls with > 6 ca.15 to 20 day old youngWe counted Common Eider nests on six islands on South Skerry #3 on 19 July in 1999; this colony in the Digges Sound region, Nunavut, on 19-20 __was not reported in Gaston et al. 1985).Only one July 1999.Lying at the western end of Hudson Great Black-backed Gull, a first-summer bird, was Strait, Digges Sound appears to be near the south-seen in the Digges Sound region during 1980-1983, ern limit of the breeding range of the migratory S. but there were three adult-plumaged birds near South m. borealis subspecies, and near the northern limit Skerry #1 on 19 July in 1999; we saw no sign of of the breeding range of the non-migratory S$. m. breeding.There was no evidence of predation by sedentaria subspecies (Abraham and Finney 1986).© Arctic Foxes, Alopex lagopus, on any islands that we Common Eiders are an important source of meat, visited.A single Polar Bear, Ursus maritimus, was eggs, and down for people from the community of _ present in Digges Sound in mid-July in 1999, but we pe

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