Waubay National Wildlife Refuge, established in 1935 by President Franklin D. Roosevelt in response to record low waterfowl numbers caused by severe drought, transformed a former hunting camp into a refuge for waterfowl and other migratory birds. Its name comes from the Lakota Sioux word "wa-bay," meaning "a place where numbers of birds make their nests." The refuge includes 4,650 acres of marsh, prairie, and forest habitat that attract 245 species of birds, with more than 100 nesting there. Located in the Central Flyway, it contains prairie pothole habitat marked by numerous wetlands ranging from large lakes to small puddles, with extreme wet and dry cycles that increase wildlife productivity. European settlement reduced the area's woods for fuel and fenceposts and plowed many native grasslands for cropland and homesteads, while drought and growing white-tailed deer populations threatened tree regrowth. Today the refuge preserves a glimpse of eastern deciduous forest surrounded by open prairie, with bur oak as the dominant tree and eastern plants such as basswood, American elm, wild grape, jack-in-the-pulpit, and Dutchman's breeches. Former farm fields have been allowed to return to grasses or have been restored with native plantings, creating important habitat for nesting waterfowl and grassland-dependent species such as western meadowlarks, savannah sparrows, and bobolinks. Waubay is part of the National Wildlife Refuge System, begun in 1903 when President Theodore Roosevelt established the first refuge at Pelican Island in Florida to protect egrets and pelicans from market hunters; today that system, managed by the U.S. Fish and Wildlife Service, includes more than 535 refuges in all 50 states totaling 93 million acres, as well as over 2.5 million acres of Waterfowl Production Areas in South Dakota and other prairie pothole states.