Great Black-backed Gull Larus marinus
Scarce, but widely spread around the island group. Most common on Bjørnøya, along the west coast of Spitsbergen and on the south-west of Svalbard. Was first found breeding on Svalbard early in the last century, and since then has increased in numbers. The breeding population today is probably more than 150 pairs. Sometimes forms mixed pairs with Glaucous Gull.
Features: A large gull of 64-79 cm and 1.3-2.5 kg. ♂=♀, the male is somewhat larger and bulkier. Younger age-groups have different plumages and there is some variation within the age-groups. Typical «big gull call», but deeper and more strident than the Glaucous Gull. At the nest site gives prolonged and loud calls. Vigorous warning and diving at intruders, even when they are far from the nest or young.
Breeding: Breeds very scattered, often solitarily or in sparse breeding groups of up to five pairs on islands, pillars and rocks along the coast where there are no Arctic Foxes. Very much bound to the same traditional nest sites. Lays two or three eggs in a large nest built of seaweed, grass, moss and feathers.