THE BLACK TERN. 9 



the upper tail-coverts, the tail and wings slate-grey ; the edge of the wing paler ; 

 the primary shafts dull white, the webs dark slate-grey, except when new and 

 unworn ; the thighs, the under tail and under wing-coverts, white ; greater under 

 wing-coverts and axillaries pearl-grey ; bill black ; feet reddish-brown. Total 

 length pi inches ; wing 8J ; middle toe and claw '85 ; tarsus '6 inch. 



The Black Tern is one of the earliest to make its appearance every year on 

 our coasts and river valleys, for a week or two in April and May, on its return 

 from its warmer winter retreats on its way to its breeding quarters ; and considerable 

 numbers may then be seen together in incipient summer plumage hawking 

 over rivers and marshes for flies and other winged insects like Swallows, or 

 dropping suddenly down out of the air, Gannet-like, and deftly picking from the 

 surface of the water minnows, small fishes, worms, or other morsels of food. 

 Finding no undisturbed spot within our bounds, as they once did, to rear their 

 young upon, they make but a short stay with us, and growing every day more 

 and more into their nuptial attire, they hurry on their way to the suitable and 

 safe quarters, which the countries to the north and east of us afford, to undertake 

 their parental duties. These duties over, the parents generally preceded by the 

 young of the year pay us, in the autumn, on their way back again to the more 

 genial south, a somewhat longer visit than in the spring. The Black Tern rarely 

 makes its nest on the sea coast ; it is a fresh-water-loving bird, and builds in 

 large colonies in reed-covered inland marshes where its nest, composed of vegetable 

 debris piled together to form a fairly large structure, is placed on water-surrounded 

 clumps of fixed vegetation, or occasionally on accumulations of pond material 

 floating on the surface. 



It rarely nests before the end of May, and in some localities it may not begin 

 for even a month or six weeks later. Never more than three eggs are laid (in 

 size about ij inches long by i inch, or a little more, in diameter), with a ground 

 colour varying from deep olive or pale chocolate to greenish-grey or buff, covered 

 with black or umber, often confluent, blotches, scattered dots, or convoluted streaks, 

 generally forming an irregular belt round the larger end. No part of the egg is 

 free from markings. Dr. Coues has recorded that he saw a colony breeding on 

 the Red River in North America, and found the eggs placed on masses of floating 

 vegetation of the previous year's reeds, and that they had to be carefully searched 

 for, as they were " laid directly on the moist matting without any nest in any 

 instance, and readily eluded observation from their similarity in colour to the bed 

 of reeds they rested on." 



After about three weeks incubation, the chicks emerge covered with soft down 

 of a reddish-brown colour, with the head, wings, and back marked with black ; 



Vol.. VI C 



