The diet of Thick-billed Murres (Uria lomvia) in west Hudson Strait and northeast Hudson Bay

Abstract

We collected feeding adult Thick-billed Murres at several different localities within the foraging range of the colonies at Digges Sound through the breeding seasons in 1980, 1981, and 1982. Examination of prey remains from the stomach and foregut showed that the majority of birds contained prey covering a range of sizes from 0.01 to 47 g wet weight at ingestion. The total energy equivalent of prey found in the majority of stomachs was less than 10% of the birds' probable daily requirements. Comparison of species diversity of prey with that recorded for Thick-billed Murres in the high Arctic suggested that a greater range of prey is available in the low Arctic waters of Hudson Strait. We found little indication of consistent variation in pery occurrence among different feeding areas or within seasons. However, significant variation in diet occurred among years. Problems inherent in the method and the extent of variation among individual birds from the same sample make it difficult to make valid generalizations about the importance of different prey taxa in the diet of the murres.