6l8 BLACK TERN. 



The irregular occurrences recorded from Ireland are chiefly those of 

 immature birds in autumn. 



This species is not known to breed north of about lat. 60° in the 

 Baltic, the Gulf of Finland or Russia, but over the rest of the 

 Continent it is abundant in suitable localities down to the Medi- 

 terranean ; it also nests in the marshes of North Africa. Even in 

 winter it does not seem to go further south than the Cameroons 

 (4° N. lat.), w'hence I have an example; all the specimens recorded 

 under the name of H. tiigra from Damara-land on the west side 

 or the Transvaal on the east, having proved to be H. kucoptera, the 

 next species. As regards Asia, Drs. Radde and Walter do not 

 record the Black Tern from the district between the Caspian and 

 the Merv oasis, and there is no authentic instance of its occurrence 

 in India or China. It inhabits America, from Canada in summer to 

 ' Chili in winter, the adults found there being, as a rule, of a browner 

 black on the under parts than any European specimens, though 

 some are identical with ours. 



From about the third week in May this bird may be found in 

 colonies on wet marshes or by shallow pools, making its nest of 

 decayed plants on heaps of wrack which rise and fall with the water, 

 or on the firmer hummocks of the bog. The eggs, 3 in number, are 

 ochreous-clay, olive-brown or olive-green in ground-colour, boldly 

 blotched with darker brown: average, measurements [•45 by i in. 

 The Black Tern feeds chiefly on aquatic insects, many of which — 

 such as dragon-flies — it takes on the wing, and Mr. F. S. Mitchell 

 has watched it swooping down upon the field-crickets {Ac/uia cam- 

 pesiris) during their momentary appearance at the entrances of their 

 burrows ; it is also very partial to leeches, and will take small fish 

 &c. The note is a shrill crick, crick. 



The adult in nuptial-dress (figured in the foreground) has the 

 head and neck dark lead-grey, nearly black on the crown and nape ; 

 back, wings and tail slate-grey, the latter sligl'.tly forked ; throat, 

 breast and belly dark lead-grey ; under wing-coverts pale grey ; vent 

 white ; bill black ; legs and feet short, reddish-brown. Females 

 have usually lighter coloured under parts than males. Length 10 in. ; 

 wing 8*5 in. After the autumn moult the forehead, throat and nape 

 are white, as are also the under parts for a short time — though usually 

 barred with grey. The young bird (in the background) is mottled 

 with brown on the head and mantle, but by the following spring the 

 upper parts have become lead-grey, with a darker line remaining 

 along the carpal joint ; the full dress is not acquired till the second 

 spring, when breeding takes place. 



