Other Names: none
Distribution: arctic tundras worldwide.
Size: 53-63 cm in length with a 109-134 cm wingspan.
Plumage: 3 color phases occur: blackish, white, and gray-brown. All phases are scaled with black on the back and streaked with black on the underside. They have a uniformly-colored head and throat. The beak is pale with a black tip and the eyes are black.