620 WHITE-WINGED BLACK TERN. 



found in flocks on the marshes and ' vleys ' of Africa down to the 

 Transvaal and Damara-land. During summer it inhabits the tem- 

 perate regions of Asia from the Caspian to the Amoor, Mongoha and 

 Northern China ; wintering as far south as Celebes, and visiting 

 Ceylon, though rare on the mainland of India. Two examples in 

 full nuptial dress were shot in the province of Nelson, New Zealand, 

 on December 12th 1868; and in North America an adult female 

 was obtained on Lake Koskonong, Wisconsin, on July 5th 1S73. 



This gregarious species nests in marshes, and may sometimes be 

 found in company with the Black Tern, as in Central Europe, in which 

 the latter is in the ascendant ; but in Southern Russia large and dis- 

 tinct colonies are formed. The eggs, deposited on floating vegetation 

 in May or June, are 3 in number, and resemble those of the preceding 

 species : average measurements 1*35 by i in. Its flight is more 

 rapid and its cry is said to be harsher than that of its congener ; 

 the food consists of dragon-flies and other aquatic insects. 



The adult in summer has the head, neck and back glossy black, 

 in strong contrast to the white on the carpal joint of the wing ; 

 greater wing-coverts grey, and secondaries lead-grey ; primaries 

 frosted with pearl-grey, which soon wears off, leaving the webs sooty- 

 black ; upper tail-coverts and tail pure white, the latter very slightly 

 forked ; under parts black, with a brownish tinge on the abdomen ; 

 vent white; under wing-coverts and axillaries black; bill livid red ; 

 legs and feet orange-red, the webs very much indented. Length 

 9*5 in. ; wing 8-25 in. After the autumn moult the liead^ neck, and 

 ttndt'r parts inclusive of the wiiig-covcrts are white, and the mantle 

 and tail are grey. The young bird — which resembles the adult in 

 winter-plumage, though at first mottled with brown on the upper 

 parts, may be distinguished from the immature H. nigra by its 

 shorter bill, longer toes with more deeply incised webs, paler rump 

 and tail, and more defined wedge of white on the inner webs of 

 each primary. Neither the feathers on the carpal joint nor those of 

 the tail become pure white until the third year. 



The late G. R. Gray erroneously identified this species with the 

 Sterna fiigra which Linnaeus described as " found on the small reedy 

 islands about Upsala," and which was, of course, the Black Tern. 

 Being considered an authority on nomenclature, especially by 

 foreigners, his unfortunate precedent has been only too widely 

 followed, and has occasioned much confusion. 



