Daniel D. Gibson
University of Alaska
Fairbanks, Alaska
Abstract
Seabird population estimates are generally lacking for the 1,800-km-long Aleutian Islands. Only the locations of the larger colonies are known, and for these there are only imprecise estimates of colony sizes and often even of species composition. Changes in the status of several species and populations resulting from geologic and marine actions and from human intrusions are evident. Accounts are given for 25 species of marine birds breeding in these islands.
The 1,800-km-long chain of islands known as the Aleutians provides nesting habitat for various species of marine birds, including three species of Procellariiformes and three of cormorants (Phalacrocorax spp.), one species of gull (Larus glaucescens), both kittiwake species (Rissa spp.), two species of terns (Sterna spp.), and at least 13 species of alcids.
Seabird population estimates of known accuracy are lacking for this isolated area. Locations of larger colonies of breeding seabirds are known, however, and sufficient data are available to place colonies in broad size ranges. Published information on the breeding biology of marine birds is also lacking from the Aleutians, but some studies are under way. The distribution of nesting marine birds away from the nesting cliffs is totally unknown.
Introduced predators, primarily arctic foxes (Alopex lagopus), are now found on nearly every island. Breeding marine bird populations have suffered drastic reductions as a result. They have probably also changed because of natural habitat modifications caused by earthquakes, volcanic eruptions, tidal waves, and marine erosion.
The purpose of this paper is to summarize the known present distribution and status of breeding marine birds in the Aleutian Islands.
Description of the Aleutian Islands