The wildlife of South Sudan refers to the natural flora and fauna of South Sudan. South Sudan includes the Sudd, one of the world's largest wetlands.[1] According to the American biologist and conservationist, J. Michael Fay, South Sudan "could present the biggest migration of large mammals on earth",[1] while Wildlife Conservation Society (WCS) reports southeast Sudan has a migration of 1.3 million antelopes. The region has a low density human population, with approximately 7 million people spread over approximately 619,745 km2 (239,285 sq mi).[2]