This IBA regularly supports 50,000 waterfowl during the spring and fall migration, including 20 different species of ducks. On occasion Cinnamon Teal and Long-tailed Ducks have been observed. In winter, Black Dog Lake supports more than 5000 waterfowl, mainly Mallards and Canada Geese with an annual congregation of Bald Eagles. More than 50,000 American Coots and 1000 Tundra Swans have been counted during migration. The area supports at least 50 breeding pairs of Forster's and Black Terns. A rookery with more than 1000 nests can be found on the Wilkie Unit of the National Wildlife Refuge. It supports over 100 breeding pairs of Great Blue Herons and Great Egrets. Black-crowned Night Herons have been documented in the rookery and Green Herons have been noted on other areas within the IBA.
This site supports an exceptional diversity of birds, with over 260 species being documented and 100 of those nesting in the area. There are eight species of nesting warblers including species of concern such as the Prothonotary Warbler, which is found in the extensive floodplain habitats of the National Wildlife Refuge and State Park.