353 
of the United States . 
Sexes perfectly similar in color. Female a little smaller. 
Young differing from the adult, but only before their first or 
second moult. Moult twice in the year, changing the colors 
of the head only. Plumage silky. Colors white, with bluish 
tints, with some black; or black with some white. Young 
skirted with blackish, ferruginous, he. 
Live in small flocks near water, especially on the sea. Fly 
almost continual!} 7 high in the air, playing in different direc- 
tions, or skim the surface of the water, alighting occasionally 
on the beach, on rocks, or naked poles, but hardly ever on 
the water : swim awkwardly, and never from choice. Feed on 
living animals, principally fishes, which they catch by turning 
rapidly near the surface of the water, or by flying at a mode- 
rate height, and darting headlong upon their prey as soon as 
discovered ; the larger and more powerful species prey also 
on the young of water birds and their eggs : some do not 
avoid swallowing insects as they fly along, and the weaker 
pecies feed entirely upon them. Lay socially on the ground, 
sandy beaches, or on rocks, without the least preparation : 
eggs few, 2 — 4 ; sedulously protect their offspring. Voice 
sharp, shrill, often repeated, especially in fine weather, when 
soaring. 
Widely spread over the waters of the globe. Closely 
allied to the following genus, into which they pass insensibly. 
Analogous to the Swallows. 
* White , hack wings and tail , pearl-gray. 
284. Sterna cayana, Lath- Bill elongated, stout, orange ; 
quill shafts white ; tail not much forked ; tarsus one inch 
and a quarter long, black ; webs entire. 
Summer plumage, whole crown black : winter, hind head 
only marked with black. 
Cayenne Tern , Sterna cayana , JYoh. Am. Orn in. pi. 
Inhabits the tropical seas of America : common on the 
coasts of the southern states. 
