Other Names: none
Distribution: discontinuously throughout the western United States and Mexico.
Size: 47-54 cm in length with a 125-135 cm wingspan.
Plumage: Generally white with a darker gray mantle, dark eye, reddish eye ring, and greenish legs. The bill of the breeding adult has a red spot overlapped by black at the tip. Juveniles and non-breeding adults have a black bar on the bill and lack the red eye ring of adults.