1494. Larus affinis.
The Dark-backed Herring-Gull.
Larus fuscus. apud Blyth, J. A. S. B. xvi. p. 792; id. Cat. p. 2S8, pt.; Jerdon, B. I. iii, p. 830; Blyth, Ibis, 1867, pp. 176, 314; Blanf, Eastern Persia, ii, p. 290; nec Linn. (conf. Hume, S. F. iv, p. 502). Larus affinis, Bernhardt, Vidensk. Meddel. 1853, p. 78; Saunders, P. Z. S. 1878, p. 171 ; Hume, S. F. vii, p. 463; id. Cat. no. 978 ter ; Vidal, S. F. ix, p. 94 ; Butler, ibid. p. 439 ; Barnes, Birds Bom. p. 424 ; Saunders, Cat. B. M. xxv, p. 254. Larus fuscescens, Hayes Lloyd, Ibis, 1873, p. 420. Larus occidentalis, apud Hume, S. F. i, p. 273 ; ii, p. 50 ; iv, pp. 414, 418.
Coloration. Head and neck all round, rump, tail, and whole under surface, with wing-lining, white; mantle slate-grey; all quills and longer scapulars with white tips, and the first 6 to 8 primaries partly black; on the first primary the black extends from the coverts, with the exception of a grey wedge on the inner web, to within about 2.5 in. of the tip, then comes a broad white band, and then a subterminal black bar and white tip ; on the second the grey wedge comes farther down the inner web, the rest is black, except the white tip about half an inch long, and in some birds a white spot near the tip ; in the third and subsequent primaries the grey base comes farther and farther down both webs, the black is reduced to a subterminal band and finally disappears.
The only difference in winter is that there are almost always a few brown spots on the crown and hind neck.
Young birds are brown above with broad whitish edges to the feathers; quills blackish brown; rump and upper tail-coverts white, with large brown spots : rectrices dark brown, mottled with white towards the base and tipped white; lower surface brownish at first, then white, blotched with brown at the sides. In the next phase the back-feathers and scapulars are irregularly banded with light brown, which afterwards becomes grey, and there is a gradual passage to the adult plumage, which is said only to be attained after the fourth autumnal moult.
Bill in adults yellow, with a bright red patch on lower mandible near the tip ; gape and eyelids orange-red; irides pale yellow to white; legs and feet pale yellow: young birds have the bill black at the end, fleshy white at the base; irides brown ; legs greyish fleshy (Hume).
Length of males 24; tail 7; wing 17; tarsus 2.75; middle toe and claw 2.4 ; bill from gape 3. Females are slightly smaller.
Distribution. This Gull breeds in N. E. Europe and Siberia, and visits the coast of Somaliland, Southern Arabia, Baluchistan, and Western India in winter, extending south on the Malabar coast as far as Katnagiri or farther, but not occurring, so far as is known, on the east coast of the Peninsula. It is particularly abundant at Karachi.
Habits, &c. A comparatively familiar bird, often haunting towns and villages near the sea-shore. Hume found it abundant about the fishermen's houses at Karachi. The mantle does not appear to become darker in the breeding-season as that of L. fuscus does.