Rare white snowball shrouded in mystery. Nonbreeding birds have buffy fringes to head and back feathers that wear to white by spring. Breeding males almost pure white except for limited black in wings. Breeding females have dark streaking on back. Breeds almost exclusively on St. Matthew Island in the Bering Sea; winters on the coast of western Alaska. Very similar to Snow Bunting but paler, usually with white rump; intermediate birds may be hybrids.