NESTING-SERIES OF BRITISH BIRDS. 33 



No. 87. SWIFT. (Cypselus apus.) 



This common summer-visitor to the British Islands arrives towards 

 the end of April and remains till the end of August, when the majority 

 depart southward to their winter-quarters, though individuals some- 

 times remain till much later in the year. The food consists entirely of 

 insects, taken on the wing in the course of the bird's extraordinarily 

 rapid flight. The nest, a slight structure of straws, cobwebs and a few 

 feathers, is placed under the eaves of buildings, in crevices of cliffs, or 

 even in hollow trees. Two oval white eggs are laid in the end of May 

 or early in June and incubation lasts for eighteen days. As a rule, only 

 one brood is produced in a season. 



Forfar. Eggs. 6th of June : young, 2nd and 20th of July. 

 Presented by Dr. Thomas Dewar. 



No. 88. NIGHTJAR or GOATSUCKER. 



(Caprimulgus europseus.) 



This regular summer-migrant is one of the latest to visit the British 

 Islands, seldom arriving before the middle of May, and departing in 

 September, though individuals sometimes linger in the south of England 

 till November. Its favourite haunts are woodland glades, commons and 

 heaths, where heather, ferns and gorse flourish ; and its food consists of 

 insects, most of which are captured on the wing at twilight, or during 

 the night. No nest is made and, towards the end of» May, two 

 beautifully marbled oval eggs are deposited on the ground. Incubation 

 lasts for eighteen days, and the young when hatched are covered with 

 thick greyish down. 



Norfolk, May. 



Presented by Lord Walsingham, F.R.S. 



No. 89. BLACK-THROATED DIVER. 



(Colymbus arcticus.) 



Tolerably common during the breeding-season about the larger lochs 

 of the north and west of Scotland, and occasionally found in the winter 

 off the coasts of England and Ireland. In winter the plumage is 

 entirely different from that of spring, for after the autumn moult the 

 upper parts become ashy brown and the under parts white. The flight 

 is very strong and rapid, and the movements both on and below the 

 surface of the water are active and varied, though slow and awkward on 

 land. The food consist? principally of fish, which are captured by diving 



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