244 THE BIRDS OF AUSTRALIA 



This Nightjar usually frequents scrub-covered country, and 

 is strictly nocturnal in its activities. It is frequently called the 

 "chop-chop" bird, from the peculiar call the bird makes; like 

 the other Nightjars, it is most difficult to detect when on the 

 ground. By day it rests on the ground in some shady recess, 

 and hawks for its insect prey in the dusk of evening or early 

 dawn. Two eggs are laid on the bare ground, pinkish-cream 

 in colour, and faintly blotched with purplish markings. They 

 measure about 1.23 x .86 inch. 



Suh-order Cypseli. 



Family Cypselidce. Swifts. 

 Swallow-like birds with short legs, forked tails and extremely 

 long wings and extraordinary powers of sustained flight. Very 

 wide gape in association with the capture of insects while on the 

 wing. Tail quills 10. The arrangement of the feather-tracts on 

 the body connects them with the Humming-birds, and separates 

 them widely from the Swallows and Martins. 



Suh-family Chaeturince. 

 Wing always reaching far beyond the end of the tail. 



Genus Salangana. 

 Shafts of tail quills without spinous points. 



The Edible-nest Swiftlet. 



Salangana esculenta. 

 China and Japan to North Queensland. 

 Black above, especially the crown of the head; grey below. 



These birds nest in caves or recesses of cliffs. "The nest, 

 when pure and of the first make, is composed entirely of 

 inspissated mucus from the salivary glands of the bird. It is 

 very small, bluntly triangular in form, and slightly concave 

 within; of a semitransparent, fibrous sort of texture, bluish- 

 white in colour, and with the fibres, as it were, crossed and 

 interlaced. "When the nests of the first make are taken away, 



