This southern species has only once been taken on our shores, though, as it visits the west of France not uncommonly, there is no great improbability in its occurrence here. Its true habitat is the Mediterranean basin.
It is slightly smaller than the preceding species, and the head is jet black, not brown. The beak is also stouter. In young birds the first five primaries are chiefly dark brown, whereas in our species the shafts and contiguous portion of the inner webs are white. Length 15·5 in.; wing 11·75 in.
THE GREAT BLACK-HEADED GULL
Larus ichthyaëtus, Pallas
This species is found in Egypt, the Levant, the Red Sea, and Persian Gulf, and only one example is known to have occurred on our shores.
The large size and black head are sufficient to distinguish this species when adult; young birds may be recognised by the clear-cut dark band across the tail and by the white margins to the outer webs of the secondaries. Length of male 26 in.; wing 19 in. The female is much smaller.
COMMON GULL
Larus canus, Linnæus
This bird is by no means the commonest of our Gulls, but may nevertheless be found in fair numbers along all our coasts in winter.
It does not breed in England, and in Ireland there are comparatively few colonies; but in Scotland, on the low islets round the coast as well as on the lochs and tarns inland, it is abundant in summer as well as in winter.
It usually nests in small colonies of six or eight pairs on some low-lying islet near the coast or on a lake, but it avoids during the breeding season precipitous coasts and exposed situations. The nest is placed on the ground and composed of a few bits of grass, seaweed, and heather without any attempt at concealment. The eggs, usually three in number, are olive brown streaked and spotted with blackish; like most Gull’s eggs, however, they vary considerably in colour. In food and habits it closely resembles the Black-headed Gull. Its ordinary note is a harsh cry, but during the nesting season it tries, somewhat feebly, to imitate the well-known call of the larger Gulls.
In summer the plumage, with the exception of the wings and mantle, is pure white. The mantle and most of the wing feathers are delicate bluish grey, but the three outer pairs of flight feathers are black with a white mirror towards the tip. Bill greenish with yellowish tip, legs greenish yellow. The sexes are alike, and in winter the head is flecked with brown. The young in autumn may be distinguished by the black bar on the tail and brownish wing coverts. Length about 17 in.; wing about 15 in.