72 THE TERNS 



THE BLACK-TERN 

 [F. B. KIRKMAN] 



If we set aside the noddy (Anous stolidw), which is of very doubt- 

 ful occurrence in the British Isles, 1 and the rare gullbilled-tern 

 (Gelochelidon nilotica], our Terns fall into two groups, which may, 

 roughly speaking, be distinguished as the Marsh-Terns (Hydro- 

 chelidori) and the Sea-Terns (Sterna). The latter frequent chiefly 

 the sea and estuaries, and their principal food consists of fish ; the 

 former are birds of marsh and fen, and feed chiefly on aquatic insects. 

 The chief British representative of Hydrochelidon is the black-tern, 

 its congeners, the white-winged black-tern (H. leucoptera) and the 

 whiskered-tern (H. hybrida) being very rare exceptional visitors. The 

 black-tern is now also a comparatively rare visitor. At the beginning 

 of the last century it bred in hundreds in the Fens, the Norfolk 

 Broads, and possibly elsewhere, but it has been driven out of its 

 ancient haunts partly by cultivation and partly by persecution. It 

 visits them still in the spring on its way north to other breeding- 

 grounds in Denmark and the Baltic countries. In autumn, again, it 

 passes them with its young on its way to its African winter quarters. 



For an account of its habits we have to depend chiefly on foreign 

 sources, and these are very scanty, the information being of the usual 

 type supplied in the standard works. Though rare with us, the 

 species is very numerous as a summer visitor in certain parts of Europe, 

 for instance in Hungary and Holland. It arrives at its breeding 

 quarters in May. When migrating to or from these it flies at a great 

 height, from which it descends from time to time when feeding 

 quarters present themselves. The migration appears to be performed 

 in a leisurely manner, and the birds may pause for some days at a spot 

 which provides abundance of nourishment. Thousands migrate along 

 the Danube, following each bend in the river, feeding on their way, 



1 See R. J. Ussher, List of Birds, and T. A. Coward, Fauna of Cheshire, i. 93. 



