THE DIET OF STELLER' S EIDERS WINTERING IN VARANGERFJORD, NORTHERN NORWAY

摘要

We examined the winter diet of Steller' s Eiders (Polysticta stelleri) in Varangerfjord, northern Norway, by analyzing the esophagus content of 29 individuals (12 juveniles and 17 adults). A total of 8389 Prey items of 31 species were identified: 13 species of gastropods (making up 68.4/100 of total number of items); 4 species of bivalves (18.5/100); 12 species of crustaceans (13/100); and species of echinoderms (<0.1/100). In terms of percentage aggregate wet weight 31.4/100 was gastropods, 22.6/100 was bivalves, and 41.4/100 was crustaceans. Juvenile eiders ate more crustaceans (x=61/100 aggregate w.w) than adults (x=26/100, p<0.05), possibly Because they were in poor body condition and may have had higher energy requiremengy requirements than adults.