Birds in the eastern part of Heuglin's Gull's range are often paler grey above and are frequently considered to be a separate subspecies.
Heuglin's Gulls breed in the tundra of northern Russia from the Kola Peninsula east to the Taymyr Peninsula. They are regularly reported from Finland and may breed there. They migrate south to winter in Southwest, South, East Asia, and East Africa. Small numbers are seen in Southeast Asia, it has been recorded in South Africa and it may occur as a vagrant in Western Europe.
They are large gulls with a rounded head, strong bill and long legs and wings. Length is from 70 cm, wingspan is from 160 cm and body mass is from 1,400 gm. The back and wings are dark grey, variable in shade. In winter the head is only lightly streaked with brown but there is heavier streaking on the hindneck. The legs are usually yellow but can be pink.