BIRDS AND MAMMALS OF COATS ISLAND, NWT

We summarize records of birds and mammals obtained at Coats Island, No rthwest Territories during one visit by a National Museum of Natural S ciences expedition and fourteen visits by Canadian Wildlife Service fi eld crews to the northeast corner of the island, as well as records ob tained from the journals of the Hudson's Bay Company post active on th e island from 1920 to 1924. The terrestrial mammal fauna is very depau perate, lacking any small herbivores. Consequently, predators speciali zing in small mammals-such as ermine, snowy owl, and long-tailed jaege r, all common on nearby Southampton Island-are rare or absent from Coa ts Island, except in passage. In addition, there are no snow goose col onies on Coats Island, although good numbers of Canada geese breed the re, and some brant may also do so. This means that grazing on the isla nd is mainly confined to the resident caribou population. The absence of small mammals and the relatively low density of geese may have acco unted for the poor results of fox trapping during the period when the Hudson's Bay Company post was operating. Numbers of most marine mammal s appear to have changed little since the 1920s, although bowhead whal es may have become rarer, with only two sightings since 1981, compared to several annually in the 1920s. Winter records from the 1920-24 pos tjournals suggest that waters off Coats Island are within the winterin g range of beluga, walrus, and thick-billed murres. Eighty-four specie s of birds have been seen since 1975; this number includes many sighti ngs of vagrant birds well outside their normal ranges. This may be acc ounted for by the comparative lushness of the vegetation surrounding t he thick-billed murre colony, which attracts birds from long distances .