Why does southeastern Arizona have so many different species of hummingbirds?
As with other kinds of real estate, the secret of wildlife habitat is location. Southeastern Arizona lies at the crossroads of five major biogeographic regions. The plants and animals of its mountains, deserts, grasslands and streamside forests include species typical of the Rocky Mountains, the Sierra Madre of Mexico, and the Chihuahuan, Sonoran and Mojave deserts as well as species found nowhere else on earth. Its birdlife is particularly diverse because many species pass through in migration between nesting grounds in the northwestern U.S. and western Canada and wintering grounds in Mexico and Central America. Almost half of the hummingbird species found in southeastern Arizona are rare to unheard of elsewhere in the U.S. but relatively common in northwestern Mexico.
