14 BRITISH BIRDS. WITH THEIR NESTS AND EGGS. 



May or early in June, are inseparable by size or colour. Mr. Booth saw this 

 species, in the Norfolk Broads, hawking, in company with thousands of Sand 

 Martins, across the surface of the water, and during a whole afternoon kept up 

 their pursuit of insects in precisely the same manner as the Martins. Small fishes 

 and aquatic animals constitute additional items of this bird's food. Maggots have 

 also been found, on dissection, in its stomach. 



The plumage-changes that the White-winged Black Tern undergoes, after 

 leaving the nest till it attains maturity, take place in the same manner and at the 

 same seasons as in the last species. 



The nestling on issuing from the egg, about the beginning or middle of 

 July, is covered on the upper side with a yellowish-brown down, mottled with 

 black, and is of a uniform pale cinnamon-brown beneath. In a few weeks the 

 down is succeeded by the bird's first plumage, in which the forehead, sides of the 

 neck, rump, under wing-coverts and all the lower surface are white; the crown, 

 nape of the neck, and a spot on the ear-coverts, are brownish-grey, or mottled 

 with black ; " the mantle, the scapulars and the wing-coverts dark slate-grey, with 

 buff margins and brown sub-margins " (Seebohm) ; after the spring moult, the 

 back, the scapular region, the upper tail-coverts and the tail feathers are pearly 

 or slate-grey, tipped or mottled with brown of lighter or darker shades ; primary- 

 webs darker than in the adult ; bill brown. After the first spring and during the 

 bird's first summer, the brown-tipped feathers of the upper surface as just described 

 pass gradually away, chiefly by a change of colour, though a few feathers perhaps 

 moult, leaving only the margin of the wing mottled ; the black of the under side 

 shows a brownish tinge, and the tail, especially towards the tips, is grey. The 

 rump, between the grey back and grey tail, is white 



With its first autumnal moult is assumed the winter garb of this species, 

 which is described as follows by Mr. Howard Saunders : " in the latter part of 

 July, when the moult begins (in Europe), the bird is curiously parti-coloured, the 

 new feathers of the head, neck, and under parts being white, and those of the 

 back grey ; the adult birds have white tails, but in the immature ones it is grey, 

 which serves to distinguish them. Later, the under parts, including the under 

 wing-coverts and axillaries, become white, the crown of the head and the nape 

 being merely mottled with black ; but by the following April the black colour 

 has reappeared to a considerable extent, especially on the axillaries " the next 

 spring moult bringing the Tern into its full nuptial dress. The tail-feathers may 

 remain for several seasons of a greyish, instead of a pure white. 



The present species is distinguished from the Black Tern at all seasons by 

 its longer and more slender toes and claws, and the deeper indentations of the 



