The Pelee Archipelago is a series of limestone islands, in the western basin of Lake Erie. In the Canadian portion of the basin, the archipelago consists of six islands: Middle Sister, North Harbour, East Sister, Big Chicken, Hen, and Middle. Pelee Island, the largest in the archipelago, is not included in this IBA; specific sites on Pelee Island have been identified separately as IBAs.
All of the islands have a base of limestone bedrock and rocky shores. Middle Island, Middle Sister Island, and East Sister Island (the largest islands in the archipelago) have predominantly wooded interiors with forests of Hackberry and Black Maple. Middle Sister Island is probably the most natural and undisturbed of the islands in the archipelago. Over 40 nationally rare plant species have been record, and several of the plant communities have been identified as nationally significant (e.g., mature hackberry forest, hop tree dominated scrub community with blue ash). In addition, the entire population of the nationally endangered Lake Erie Water Snake is restricted to the archipelago.
The Pelee Island Archipelago supports one of the richest assemblages of nesting colonial birds in Lake Erie. At least 5 species are present in numbers of national significance, including more than 1% of the estimated northeast North American Double-crested Cormorant population, and greater than 1% of the estimated North American Herring Gull population. In particular, the heronry on East Sister Island, is significant with combined estimate of about 500 pairs of Great Blue Herons, Black-crowned Night-Herons and Great Egrets. It is one of the largest heronries in Canada, and the supports the largest population of nesting Great Egrets in Canada.
The islands in the archipelago are also thought to be significant as migratory bird stop-overs. Although detailed studies have not been completed, many have reported large concentrations of songbirds during spring migration. Given the location of the islands, it is likely that large numbers of migrants make use of them.
BirdLife International (2020) Important Bird Areas factsheet: Pelee Island Archipelago. Downloaded from http://www.birdlife.org on 04/06/2020.