Order GAVI^E. 



Family LARID^). 

 Subfamily STERNIN^.. 



THE BLACK TERN. 



Hydrochelidon nigra (Linnaeus). 

 Plate 70. 



Owing to the extensive drainage of the fens and marshy places in our eastern 

 counties and other localities, the Black Tern, or " Blue Darr," as it was called in 

 Norfolk, has long ceased to nest in the British Islands, where it once was a common 

 summer visitant, and at the present time only visits its old haunts in small numbers 

 on passage, the last record of its breeding in Norfolk having been in 1858, according 

 to Stevenson. 



This species breeds in many parts of Europe, but apparently not beyond 6o° N. 

 latitude, whilst it ranges as far east as Siberia and Turkestan, and in winter 

 migrates to Africa. It is purely a fresh-water species, frequenting reedy lakes and 

 marshes, and feeds on various winged insects, including dragon-flies, and also on 

 worms, leeches, small fishes, etc. 



The nest, built of dead reeds and other plants, is placed in wet places in 

 morasses, and contains three eggs, in ground-colour dull buff or olive, blotched 

 and spotted with dark brown and purplish-grey. The birds, which breed in 

 colonies, are very noisy when disturbed, their notes being loud and shrill. 



The sexes are alike in colour, and the immature bird is very much the same as 

 that of the White-winged Black Tern, shown on plate 70. 



THE WHITE-WINGED BLACK TERN. 



Hydrochelidon leucoptera (Schinz). 

 Plate 70. 



Though never known to have bred in our islands, this species occasionally 

 visits England and Ireland in spring and autumn when on passage. It nests 



55 



