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.
The populations of colonial birds on this island are monitored regularly by the Canadian Wildlife Service. In addition to population changes, research on the biomagnification of contaminants (from forage fish caught in Lake Ontario) has also been completed. Shooting of adult cormorants, and associated nest desertion and low reproductive output have been documented at this site. Disturbance of the colony by recreational boaters and other curious visitors is also concern during the breeding season.
The island is owned by the Ontario Provincial Government. Due to its small size, and inaccessible location it is unlikely that it will ever be seriously considered for development.IBA Criteria Habitats Land Uses Potential or Ongoing Threats Conservation Status