Wolfe Island lies at the extreme northeast corner of Lake Ontario, where the waters of the lake flow into the St. Lawrence River. It is about 3 km south of Kingston, Ontario, and about 3 km north of Cape Vincent in New York state. Wolfe Island is divided into two by Bayfield Bay, with the largest landmass to the west and a long narrow extension on the eastern side. It is the western section that is most productive for land birds. In this habitat, vole (Microtus) populations occur at higher densities than in areas within the nearby mainland. The island is fairly flat, and it consists mainly of farmland interspersed with woodlots and areas of marsh. A network of gravel roads criss-crosses the island. The shoreline is deeply indented, with numerous secluded bays that contain sand and gravel beaches as well as offshore bars. The largest town, Marysville, lies along the northwest coast of the island.

Large numbers of several waterfowl species congregate around Wolfe Island during the spring migration. One-day peak counts of as many as 15,000 Greater Scaup (March 1996) and 7,500 Canvasbacks (April 1995) have been recorded (about 2% and 1% of their respective North American populations). Large numbers of Canada Geese have also been recorded during spring migration, with over 10,000 being observed in March of 1997. Although it is likely that this estimate contained individuals from both the migratory Atlantic and resident Great Lakes population, the figure still represents greater than 1% of their combined biogeographic populations. Other notable one-day counts include: 5,000 Ring-necked Ducks, 4,000 Common Goldeneye, 3,700 Redheads, 1,222 American Black Ducks, 350 Snow Geese, 50 Tundra Swans, and 46 American Golden Plovers.

Large numbers of landbirds, such as the 10,000 Tree Swallows counted in October 1994, have also been observed at this site. Wolfe Island, together with Amherst Island, is internationally known as a site for large winter concentrations of hawks and owls. Some of the largest winter totals in Ontario for Snowy Owl and Rough-legged Hawks have occurred here. Some peak winters for Snowy Owls have been: 1972 (87 Snowy Owls), 1974 (69), 1965 (55), and 1980 (32). During December Christmas Bird Counts of the 1990s, 76 Red-tailed Hawks (1993), 22 Rough-legged Hawks (1995) and 18 Short-eared Owls (1995) have been recorded. Other high counts include 106 Rough-legged Hawks (1985), and 47 (1977) Short-eared Owls. The latter species, which is nationally vulnerable, sometimes breeds on the island after winter invasions.

Least Bittern (nationally vulnerable), Black-crowned Night-Heron and Black Tern have all bred in the Big Sandy Bay Wetland. Also, historically, the nationally endangered Henslows Sparrow was recorded on the island (1950).

As with many islands located in close proximity to heavily populated cities, housing and recreational developments may threaten some of the remaining natural habitat on Wolfe Island. With increased recreational use also comes the potential for increased levels of disturbance.