Historically, Wisconsin had over 4.1 million acres of savanna habitat. Currently, less than 10,000 acres remain. Necedah National Wildlife Refuge has been restoring savanna since 1959. Through plant propagation, refuge staff have brought species back that have been missing since the 1930s. With more than 3,000 acres in savanna it provides 110 species of migratory birds, three species of amphibians, 14 types of reptiles, and over 44 species of butterflies.