374 THE NIGHTJAR 



The two brown and grey down-covered chicks are born after 

 sixteen to eighteen days' incubation, and are able to move about when 

 a day old. 1 In the course of a few days they leave the nest, either 

 impelled by mere restlessness or by their eagerness to meet the 

 parents returning with food. Later, when the returning parent is un- 

 able to find the whereabouts of the chicks, the latter run to where 

 they hear the summoning notes. They may be found, therefore, several 

 yards away from the nest, sometimes in one place, sometimes in 

 another, sometimes back again in a place previously occupied. Both 

 young and old, it may be added, run easily. The adults have been 

 seen to pursue one another over the ground, " seeming, thus, to run 

 without legs, for these were at no time visible." 2 Dr. Heinroth 

 observed that in the daytime his tame nightjars, when nervous, and 

 anxious to alter their position, would, instead of flying, creep away 

 furtively over the floor. 



Owing to the difficulty of seeing clearly in the dusk, the nightjar's 

 method of feeding its young remained for long a mystery. In 1887 

 a well-known German naturalist, Dr. Liebe, announced that he had 

 distinctly seen the old bird take not only the head, but almost half 

 the body, of its offspring into its capacious mouth, and so let it 

 feed itself on what was therein provided. 3 This statement is 

 nowadays chiefly interesting because it provides a good instance 

 of the necessity of exercising caution in believing even one's own 

 eyes. Curiously enough, in 1898, Mr. E. Selous, after watching the 

 action of feeding for the first time, was of the same opinion as 

 Dr. Liebe. 4 Unlike the latter, however, he sought to verify his 

 first impression, and successive observations left him certain that 

 what actually happened was the exact opposite of what he at first 

 thought had taken place. The old bird did not take the young bird's 

 head into its mouth, it put its own into that of the young, and regur- 

 gitated the food down its throat. That this is the true version was 



1 British Birds, in. 196. * E. Selous, op. cit., p. 37. 



3 Liebe's statement is quoted in full in Naumann's Vogel Mitteleuropas, iv. 251 (published 

 1901), where it is assumed to be correct. * Zoologist, 1899, 488. 



