FORAGING OF COMMON EIDER (SOMATERIA MOLISSIMA) WINTERING IN VELIKAYA SALMA STRAIT (KANDALAKSHA BAY, THE WHITE SEA)статья
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Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 29 мая 2015 г.
Аннотация:The foraging habits and diet of common eider (Somateria mollissima) were studied in the Velikaya Salma Strait
(the Kandalaksha Bay, the White Sea (66°34′ N, 33°07′ E) in March, 2001 and 2002. The number of common
eiders in the study area was estimated at 650 ± 30 ind. in both years. In early March, the eiders fed mainly at
the depths of 15–17 m, while in late March and early April, they preferred to stay close to the ice edge. Du
rations of the dive bouts (time spent under water and on the surface) significantly correlated with the depth
(р < 0.001): the eiders spent 72 ± 3.5 s under water and 52 ± 2.2 s on the surface when diving deeper than 12
m; at a depth range of 2–4 m, the mean time spent under water was 21 ± 2.0 s with the intervals of 19 ± 2.2
s. The coprological analysis revealed the presence of more than 20 species of benthic invertebrates, as well as
remains of fishes and algae in the faeces samples. The most common food objects were polychaetes (Lepi/
donotus squamatus) (86% of the samples), bivalvian mussels (Mytilus edulis, 67% and Elliptica elliptica, 51%),
and tunicates (Styela rustic) (63%). According to the benthic survey data, the average biomass for the subtidal
zone of the Velikaya Salma Strait is about 237 g/m2. With account of the known daily consumption rate of the
wintering eiders, over five months, a wintering flock would consume up to a quarter of overall available mac
robenthos in the area. Considering the fact that most of the benthic population is composed of the longliving
invertebrates, one could assume that the size of the winter congregation of eiders in the study area approaches
the upper limit of the biotope capacity.