Deer, black bear and coyote are common, and the plateau and mountains support a small but stable population of mountain lions, which typically flee from humans. Smaller mammals such as raccoons, skunks, and gophers are common. Parts of the Bandelier backcountry have been closed seasonally due to nesting bald eagles. The Rio Grande supports a significant migratory flyway that brings many other birds (notably sandhill cranes) to the plateau during migration seasons, and three species of hummingbirds are abundant during summer. White Rock Canyon, the major canyon containing the Rio Grande into which the plateau's canyons empty, is notorious for rattlesnakes.