NESTING-SERIES OF BRITISH BIRDS. 169 
No. 87. SWIFT. (Cypselus apus.) 
This commou 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 
imsects, 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 eges are laid in the end of May 
or early in June and incubation lasts for eighteen days. Asa 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 europeus.) 
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 i ‘alsingham. 
No. 89. BLACK-THROATEL 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 consists principally of fish, which are captured by diving 
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