In summer the adults very closely resemble the common Gull, but it is a smaller bird, and the black legs, on which the hind toe is absent, form an unfailing characteristic. In winter the nape and hind neck are grey like the mantle. Length 15·5 in.; wing 12 in.
The young bird in its first autumn has the nape greyish but darker than in the adult, and the wing coverts and inner secondaries are thickly spotted with brownish black.
KITTIWAKE
Rissa tridactyla
Summer (below). Winter (above)
THE IVORY GULL
Pagophila eburnea (Phipps)
Some thirty or forty examples of this Arctic Gull have been taken in these islands; it is entirely circumpolar in distribution and breeds on Spitzbergen, Franz Josef Land, Novaya Zemlya, and other Arctic regions.
The adult is entirely white; bill greenish grey with a red tip; legs black, the hind toe being well developed. The young bird is mostly white, but spotted on the back, wings, and tail with brownish black. Length 18 in.; wing 13 in.
THE GREAT SKUA
Megalestris catarrhactes (Linnæus)
The Skuas are a group of birds closely allied to the Gulls, being very similar in general build, but both the claws and beaks are sharper and more hooked.
As a rule they chase Gulls and Terns, compelling them by so doing to disgorge their last meal; this the Skua then devours, leaving the Gull in peace to hunt for more. They are not, however, always content with this second-hand dinner, but sometimes kill and eat the Gulls themselves; they also devour offal and carrion.