The White-tailed Kite (Elanus leucurus) is an elanid kite found in western North America as well as parts of South America. It was formerly known as the Black-shouldered Kite.
The earliest name for this bird was the White-tailed Kite, and it was given the systematic name Elanus leucurus. However, there was debate that it was a subspecies of a European and African species (Elanus caeruleus) -, at the time known as the Black-shouldered Kite (see, for example, Parkes, 1958), and therefore the recognized name was changed.
More recently, Clark and Banks (1992) argued that the White-tailed Kite differed from the Old World species in size, shape, plumage and behavior, and that these differences were sufficient to warrant specific status. This argument was accepted by the American Ornithologists’ Union thus giving the White-tailed Kite back its original name. Meanwhile E. caeruleus has been renamed as the Black-winged Kite, and the name Black-shouldered Kite is now reserved for an Australian species (Elanus axillaries) which had also been merged into E. caeruleus but is also now regarded as a separate species.
The White-tailed Kite was rendered nearly extinct in the 1930s and 1940s because of shooting and egg-collecting, however they are once again common in California. Their distribution is erratic; they can be seen in the Central Valley and southern coastal areas, and also around the San Francisco Bay. They are also found in southern Texas, on the Baja California peninsula, and in eastern Mexico.
White-tailed Kites feed mainly on rodents. They are readily seen patrolling or hovering over lowland scrub or grassland. Their coloration is similar to a gull, but their shape and flight are falcon-like, with a markedly forked tail. Mainly white underneath, they have black wingtips and shoulders. Outside the breeding season they roost communally in colonies of up to 100.