Prairie potholes are small, shallow lakes that are somewhat rare in Wisconsin. Surrounded by open grassland, they are irresistible to marshland songbirds and waterfowl of all types. The Willow River SNA and Three Lakes are a collection of small lakes that attract Ruddy Ducks, Blue-wing, Northern Shoveler and Canada Geese in good numbers. Herons and egrets and gulls use the area along with Pied-billed Grebes. In the grasslands surrounding the potholes, you-Æll find Sedge Wrens, Dickcissels, Bobolinks, Western Meadowlarks, and Common Yellow-throated Warblers, as well as Grasshopper Sparrows, Northern Harriers and Short-eared Owls.