Resources related to Breeding Habits

Pre-hatch brood amalgamation in common eiders: why do eiders adopt eggs?

Pre-hatch brood amalgamation(intraspecific nest parasitism) was studied for three years (1991-1993) in a colony of common eiders (Somateria mollissima) breeding near Churchill, Manitoba. The amalgamation rate was highest (42.4% of nests) during the year with the highest nest density and good environmental conditions, and was lowest in the year with low nest density and poor conditions (20.2% of nests). Over the nesting season, foreign eggs were laid at the same time as normally laid eggs. Most foreign eggs were laid while the attendant female was laying her first and second eggs.

The effect of body condition on subsequent creche attendance in Common Eiders (Somateria mollissima)

Creches are groups containing any number of adult female(s) and duckling(s), two or more of which are parentally unrelated. Several authors have suggested that the body condition of ducks is a determining factor in parental care and that females in poor condition more readily abandon their young. In 1997 and 1998, 285 adult female Common Eiders breeding on Green Island were captured and nasal tagged. Our objective was to examine the relationship between adult female condition, using multiple measures of body size, and subsequent membership in creche.

Breeding Biology Of King Eiders Nesting On Karrak Lake, N.W.T.

Department of Biology, University of Saskatchewan, 112 Science Place, Saskatoon, Saskatchewan, Canada S7N 5E2 ALISAUSKAS, RAY T. Prairie and Northern Wildlife Research Centre, Canadian Wildlife Service, 115 Perimeter Road, Saskatoon, Saskatchewan, Canada S7N 0X4 We studied various aspects of the breeding biology of king eiders (Somateria spectabilis) nesting at Karrak Lake, south of Queen Maud Gulf in the central Canadian Arctic. We found 41 nests distributed among 10 islands in Karrak Lake; to our knowledge, this represents the largest number of king eider nests studied at one site.

Evidence of Population Declines among Common Eiders Breeding in the Belcher Islands, Northwest Territories

Information regarding the status of common eiders Somateria mollissima breeding in the Canadian Arctic is lacking. In 1997, we surveyed five island archipelagoes in the Belcher Islands in Hudson Bay (56 00'-57 30'N, 79 30'-80 00'W) from 3 - 23 July 1997. Our results were compared with eider surveys of the same islands completed between 1985-89 using a standard protocol. This study represents the first population trend data of any common eider population breeding in the eastern Canadian Arctic. 1416 nests were found on 431 islands; most (94.1%) while the female was still incubating.

Atlantic Flyway Seaduck Study

The Atlantic Seaduck Project is being conducted to learn more about the breeding and molting areas of seaducks in northern Canada and more about the feeding ecology of seaducks on wintering areas, especially Chesapeake Bay. Satellite telemetry is being used to track surf scoters wintering in Chesapeake Bay, Maryland, and black scoters on migrational staging areas in New Brunswick, Canada, to breeding and molting areas in northern Canada.