The Fish and Wildlife Service is the lead federal agency for managing and conserving migratory birds in the United States. Conservation of migratory birds is often considered the central connecting theme of the National Wildlife Refuge System. More than 200 National Wildlife Refuges have been established specifically to provide breeding or wintering habitat for migratory birds. More than one million acres of wetlands on 356 refuges and more than 3,000 waterfowl production areas are actively managed for the benefit of waterfowl and other birds.