THE BLACK-HEADED GULL 
the pairing and nesting period. ‘This Gull is eminently 
gregarious, not only during winter, but in summer. 
It begins to gather at the breeding-stations—reed-fringed 
pools and swampy meres—in March, and in April nest- 
building commences. ‘The nests are mostly made on 
the wet ground amongst the tufts of rushes and sedge ; 
but sometimes the low trees and bushes are occupied. 
In some cases the nests are little more than hollows in 
the ground or tufts of herbage; in others they are 
compactly made of reeds, flags and coarse grass, often 
increased in bulk to protect them from being washed 
away. ‘The three, or more rarely four, eggs differ in 
colour to an astonishing extent, but are usually of some 
shade of brown or green in ground, marked in a variety 
of ways with brown and grey of many shades. In some 
places the birds are very carefully protected and the 
eggs systematically gathered for culinary purposes. At 
all times a gullery of this species is a remarkably pretty 
sight, but when the birds are disturbed the air becomes 
filled with clamouring hosts, the whole scene best being 
likened to a dense snowstorm, in which each flake is an 
anxious, protesting, fluttering, noisy bird. But one 
brood is reared, and as soon as the young are sufficiently 
matured the old wandering life along the coasts and 
tidal rivers is resumed. 
The adult Black-headed Gull in winter plumage has 
the hind head marked a little with grey, a dark spot in 
front of the eye, another larger one on the ear-coverts, 
the mantle, scapulars, innermost secondaries, and wing- 
coverts delicate grey, the primaries white tipped with 
black and the longest margined with black ; the remainder 
of the plumage white. Bill crimson; tarsi, toes, and 
webs crimson; irides brown. Length 16% inches. 
Early in spring—even in January, but more usually 
in February and March—the adult assumes a dark 
smoke-brown hood or mask, the feathers changing colour 
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