The Occurrence and Distribution of Birds on Middleton Island, Alaska

A survey of the birds of Middleton Island was made in June 1956. Forty-five species of birds were recorded. Of these, at least 16 species were breeding, four other species were possibly breeding, and 2.5 species were regarded as transients. The distribution of the breeding birds was correlated with six major ecological formations. Five of the latter were based on vegetational characteristics, while the rocky cliffs comprised the sixth. The avian fauna of Middleton Island consists mainly of species found in the Prince William Sound region, to the north. An important exception was the Lapland Longspur, which previously has not been known to breed east of the Alaska Peninsula at the latitude of Middleton Island. Both murres and kittiwakes were found to be nesting on level ground along the top of the cliffs. Flocks of nonbreeding shorebirds were observed. These and other findings are discussed