366 THE NIGHTJAR 



more often perhaps than is commonly supposed, it looks for it chiefly 

 in the air. Like the Swifts and Himndinidce, it may be seen twisting 

 and turning in its flight this way and that as it snaps at some moth 

 or flying beetle. Its gape is enormous, so much so that it seems to 

 sunder the head in two. The corners on each side are furnished with 

 strong black bristles, directed downward, which act like bars to 

 prevent the victims from escaping before the mandibles have had 

 time to close upon them. Some have imagined that the bird flies with 

 the mouth kept wide open. Observation of individuals in captivity 

 has not shown this to be the case. 1 



It has also been thought that the bird at times catches its prey 

 with its feet. This was the view of Gilbert White, who " saw it dis- 

 tinctly, more than once, put out its short leg while on the wing, and, 

 by a bend of the head, deliver something into its mouth," and he 

 adds that if " it takes any part of its prey with its foot, as I have now 

 the greatest reason to suppose it does these chafers, I no longer 

 wonder at the use of its middle toe, which is curiously furnished with 

 a serrated claw." 2 But it is quite possible the action he describes 

 was not a delivery of something into the mouth, but simple scratching 

 of the head, beak, or angle of the gape. The nightjar, in common with 

 other species, is infested by parasitic insects, and no doubt finds it 

 necessary, like the swifts observed by Gilbert White himself, to 

 "wriggle and scratch themselves in their flight to get rid of that 

 clinging annoyance." 3 There is at present no clear proof that 

 the bird ever uses its foot to seize its prey. It has not been 

 seen to do so in captivity, though food was thrown into the air 

 for it to catch. 4 



The curious serrated or pectinated middle claw to which White 



1 Journal fur Ornithologie, 1909, 56 (Dr. O. Heinroth). 



2 Letter to Pennant, 1771. 



3 Letter to Harrington, September 28, 1774. The nightjar has been seen to scratch itself in 

 captivity, thrusting its foot up between the wing and the body after the manner of swifts, 

 woodpeckers, and the Pafiseres generally, not over the wing, as is said to be the habit of most 

 non-Passerine species. Journal filr Ornithologie, 1909, 71-73 (Heinroth). 



4 Journal fur Ornithologie, 1009, 50. 



