Pigeon Island is located about 15 km south of Kingston in the eastern basin of Lake Ontario. It is flat, about 5 ha in size, dominated by limestone bedrock, and has a thin covering of soil and guano that supports grass and herbaceous plant communities. The only woody vegetation is a clump of dead lilac bushes near the centre of the island. A tall metal tower is present, which supports an automatic navigational light.
Pigeon Island supports a mixed-species colony of about 6,200 pairs of five species. Of this total, 479 Caspian Tern nests were recorded in 1990. This represented about 1.5% of the estimated North American Caspian Tern population, and almost 6.8% of the estimated Great Lakes Caspian Tern population. In 1998, however, only 130 pairs of Caspian Terns were recorded, which is still greater than 1% of the estimated Great Lakes population. Large numbers of Ring-billed Gulls (5,017 pairs - approaching national significance) were also present. Other nesting colonial birds on the island included: Double-crested Cormorant (638 nests in 1990; 818 nests in 1993; and 1,818 nests in 1998), Herring Gulls (55 nests in 1990), and Great Black-backed Gulls (5 nests in 1990; 14 nests in 1998). Black-crowned Night-Herons and Cattle Egrets used to nest on Pigeon Island but their nesting habitat was altered by cormorants.
BirdLife International (2021) Important Bird Areas factsheet: Pigeon Island. Downloaded from http://www.birdlife.org on 06/12/2021.