Breeding Densities, Biogeography, and Nest Depredation of Birds on Igloolik Island, N.W.T.
Keywords:Animal distribution, Animal migration, Animal mortality, Animal reproduction, Arctic foxes, Bird nesting, Birds, Food, Hunting, Inuit, Meteorology, Plant distribution, Polynyas, Predation, Igloolik Island (69 23 N, 81 40 W), Nunavut
The avifauna of Igloolik Island and immediate vicinity was studied during two breeding seasons in 1985-86. This is the first study to compile an intensive record of avifaunal migration patterns and nesting activity, density and success for Igloolik Island. Data for these years are supplemented by the observations of earlier explorers and researchers. During our two seasons of survey, we recorded 40 species of birds, of which 25 nested on the island. Combining our records with previously published data, a total of 48 species have been recorded, with 30 species nesting. Several interspecies matings of gulls and the first confirmed breeding record of purple sandpiper (Calidris maritima) for the Melville Peninsula area were recorded. The density of breeding birds on Igloolik Island (28.5 pairs/sq. m) is similar to other eastern high arctic sites at that latitude. Issues related to the biogeographic comparisons of arctic sites are discussed. In late August, the eastern end of the island acts as a significant staging area for gull species, oldsquaw (Clangula hyemalis) and arctic tern (Sterna paradisaea). A combined average of 58.3% of the nests of six species were depredated. As many as 73% of red-throated loon (Gavia stellata) and 93% of arctic tern nests suffered mainly human-related egg predation.
Key words: Arctic, Igloolik Island, breeding avifauna, density, interspecies matings, biogeography