Autumn and winter diet of Long-tailed Duck in the Belcher Islands, Nunavut, Canada

We examined the diet of Long-tailed Ducks (Clangula hyemalis) in the autumn and winter of 1998-99 in the Belcher Islands, Nunavut, Canada. Collections were made in early November before spa ice had formed and in February and March, the time of maximum ice cover. Eight birds collected in the autumn a nd 19 collected in the winter had food items in the proventriculus/esophagu s. For birds collected in the fall, 89% (aggregate wet mass) of the diet co nsisted of the amphipod Calliopius laeviusculus. The remainder consisted of other smaller amphipods (5%) and sandlance (sandeels, Ammodytes sp.; 6%). In winter Long-tailed Duck diet consisted of the amphipod Is-chyrocerus anq uipes (69%), fish eggs (probably sandlance; 24%), sandlance (1%) and other amphipods (5%). Long-tailed Duck foraging at tile landfast ice flee edge al ong coasts fed mostly on fish and fish eggs, while those in polynyas among islands fed on amphipods. Consuming soft-bodied prey with high energy densi ties is likely to allow Long-tailed Ducks to successfully winter in the pre dominately ice-covered Hudson Bay.