(2060) Larus ichthyaetus.
THE GREAT BLACK-HEADED GULL.
larus ichthyaetus Pallas, Reis. Russ. Reichs., ii, p. 713 (1733) (Caspian idea) ; Blanf. & Qates, iv, p. 299.
Vernacular names. None recorded.
Description. - Breeding. Whole head and upper neck black, except two white patches above and below the back of the eye ; back, rump, scapulars and wing-coverts pale grey, the scapulars and inner secondaries tipped with white ; edge of wing and outer greater coverts white; first primary black on the outer web and with a narrow black sub-tip and a broad band about 45 mm. from the tip on the inner web, the rest white; second primary white with a broad black end, one white spot near the tip and the tip itself narrowly white; other primaries white with the terminal quarter black and the tips again white; outer secondaries white ; remainder of plumage white.
Colours of soft parts. Iris brown; bill yellow with a black sub-apical band, gape and tip crimson; legs and feet yellow to orange-yellow.
Measurements. "Wing 453 to 511 mm.; tail 181 to 196 mm.; tarsus 68 to 80 mm.; culmen 57 to 71 mm.
In Winter the black on the head is lost and the head and neck become white much streaked with black.
Young birds have no black head, the upper parts including the hind-neck are pale brown, each feather edged whitish, the head almost all white : the tail has a broad terminal band of brown, the extreme tip paler; primaries brown with a certain amount of white on the inner webs; outer secondaries brown, narrowly white-edged on the outer webs and with much broader edges to the inner webs.
Nestling in down. Very pale smoky-grey, a few darker stipplings, almost invisible, on the hind-neck and back ; below almost white.
Distribution. Breeding from the Caspian Sea to Eastern Turkestan, migrating South in Winter to North Eastern Africa, India and East as far as Amherst in Tenasserim. It has also occurred in Ceylon and Stevens shot one on the Ranganadi River in Assam.
Nidification. This fine Gull breeds during June in South Russia and Central Asia on the shores of the Caspian and Black Sea and on plains adjoining the great rivers and lakes. It lays three eggs in a depression in the ground with little or no nest. In colour they vary from creamy or yellowish-white to pale buff and are thickly blotched and spotted with various shades of brown. They measure about 77.1 x 53.2 mm.
Habits. The Great Black-headed Gull is a bird of inland seas and rivers, its great size and magnificent flight making it a conspicuous bird wherever it occurs. It lives principally on Crustacea, offal, fish etc. but has a bad reputation for stealing the young and eggs of other birds. Its call is a very loud, raucous cry, much like that of the Greater Black-backed Gull.