This species breeds in the Far North, in Greenland, Jan Mayen, and Novaya Zemlya, migrating southwards in winter. A good many examples have from time to time been taken in Great Britain, chiefly, as would be expected, in Scotland and Ireland.

The adult is white, streaked on the upper parts with black, and sometimes slightly spotted below. Young birds are much more heavily marked. Length 21 in.; wing 14·5 in. The female is slightly larger.

This Falcon may be distinguished in all ages by the prevailing ground colour being white.