642 CASPIAN TERN. 



July 9th 1875. To the waters of France, Switzerland, and the 

 interior of the Continent, this Tern is only a straggler ; but it breeds 

 on the eastern shores of Spain, as well as on some islets near 

 Sardinia, and is generally distributed throughout the Mediterranean ; 

 it also nests by the Black and Caspian Seas, from the latter of which 

 it was first recorded by Pallas. It arrives at the northern limit of 

 its range in spring, and departs for the south in autumn ; but is 

 resident on the northern littoral of Africa, and along both sides of 

 that continent, as far as Cape Colony. In Asia it ranges from the 

 Caspian to China, crossing the lofty mountains on its migrations 

 to India and Burma in winter; while it breeds on the shores of 

 the Persian Gulf, as well as in Ceylon. In Australia and New 

 Zealand it is resident. In America this hardy species is found from 

 Labrador to the Yukon, breeding as far north as the Great Slave 

 Lake and a little beyond the Arctic circle ; while southward it can 

 be traced to both sides of Mexico. 



The Caspian Tern lays in May or June on the bare sand, in a 

 slight hollow which is occasionally lined with pieces of shell or a 

 few bents ; the eggs are 2-3 in number, and in colour stone-buff, 

 spotted and scrolled with ash-grey and dark brown : measurements 

 2 "5 by 17 in. The ordinary food consists of iish. The note 

 is a loud, harsh krdke-kra, uttered freely by the bird when its 

 breeding-haunts are invaded. This species is nearly as partial to 

 brackish lakes as to the sea-shore, and when searching for food it 

 has a habit of keeping its bill pointed downwards, almost at a right 

 angle to its body. 



The adult in summer-plumage has the bill vermilion-red ; crown 

 and nape glossy greenish-black ; neck and under-parts pure white ; 

 mantle pale french-grey, darker at the tips of the primaries, 

 on which the frosting quickly wears off; tail white with a greyish 

 tinge, and only slightly forked ; legs and feet black. Average length 

 20 in. (bill 3"3), wing 16-5 in. ; the male being larger than the 

 female and having a stronger bill, though there is considerable 

 individual variation, irrespective of locality. In winter the crown is 

 streaked with black, and there is a dark patch behind the ear-coverts. 

 The young bird has the forehead and crown white ; upper surface 

 mottled with ash-brown ; quills ash-grey ; bill reddish horn-colour. 



In the Caspian Tern the tail is very short, less than one-third the 

 length of the wing ; while the bill is exceptionally stout and deep. 

 For these reasons Kaup made this species the type of the genus 

 Hydroprogne, which I have adopted (Cat. B. Brit. Mus. xxv., p. 4), 

 but its acceptance in this work is not pressed. 



