The park's location on Lake Ontario makes it a perfect stop over for migrating birds along the Michigan Flyway. For this reason is it also an important location for viewing migrating birds and monarch butterflies. The park's long beaches make it particularly appealing to migrating shorebirds. Limestone islands near the park area support large nesting colonies of double-crested cormorants, Caspian and common terns, several gull species, great blue herons, great egrets, and black-crowned night-herons. In early spring, Presqu'ile Bay is an important staging area for thousands of migrating waterfowl. The park also includes a large marsh which provides nesting habitat for rails, bitterns and other wetland birds. There are also forested areas and open fields: a wide variety of habitats in a relatively small park. There is also a fairly substantial population of white-tailed deer, whose grazing is doing significant damage to native plants in general, and to tree regeneration in particular. Presqu'ile has been identified as a Canadian Important Bird Area. In all this small park has seven distinct ecosystems.