It serves as a calving ground for an immense caribou herd and a place for half of the polar bears in Alaska to den. It is also where the eastern, western and Rocky Mountain flyways converge for birds that head to the Arctic. About 130 migrating species in total treat the coastal plain as a hub. A number of other species, such as the musk oxen, live there year-round. The diversity is so rich and the wildlife so plentiful that Bruce Babbit, outgoing U.S. Secretary of the Interior, has referred to it as America's Serengeti.
Mosquitoes also emerge in the spring, beginning a succession of hatches.