This large white-winged Gull is an annual visitor to the north of Scotland, but southwards it becomes scarcer, and it is only in very severe weather that it visits the south of England. Its breeding range is circumpolar, its nearest breeding-place to our shores being in Iceland.
GREATER BLACK-BACKED GULL
Larus marinus
Summer (right). Young, first autumn (left)
The mantle and wings are pearl-grey, with white tips to the secondaries and outermost webs of the quills. Orbital ring vermilion. Legs pink. Immature birds are whitish uniformly and thickly mottled with ash grey. Length 29 in.; wing 18 in.
THE ICELAND GULL
Larus leucopterus, Faber
This species is very closely allied in plumage and habits to the preceding. It is a winter visitor to the shores of Scotland, only coming south in severe weather. It breeds on Jan Mayen Islands and Greenland, and is only a winter visitor to the island whose name it bears.
Except in size it is almost a counterpart of the Glaucous Gull, but the orbital ring is flesh-coloured, and the legs yellowish. Length 22 in.; wing 16 in.
THE KITTIWAKE GULL
Rissa tridactyla (Linnæus)
With the Kittiwake we come to a species of Gull which differs in its general build from those we have hitherto dealt with. It is rather shorter in the leg, which gives it a somewhat “squat” appearance, and it does not run about on land with the same facility. In correlation with this we find it to be a much more pelagic species, and though found commonly round our shores, it gets most of its food on the water and is rarely to be found among the large flocks of other Gulls that spend much of their time on the shore itself. Its food consists almost entirely of fish, in pursuit of which it dives and swims under water with ease.
It nests on the ledges of precipitous cliffs in immense colonies, and in some cases the population of these colonies must amount to very many thousands. The nest is built of seaweed and other flotsam, and is often larger than the narrow ledge on which it is placed. The eggs, two or three in number, are usually pale greyish white, blotched and zoned with ash grey and brown; the shell is rougher in texture than in the other species. They are laid very late in the season, so that it is generally July before the young are hatched. Both sexes take part in the incubation, and the young are entirely nidicolous, not leaving the nest till they are well able to fly.