THE NIGHTJAR. Ir 
FAMILY CAPRIMULGID. 
To XTERNALLY the Nightjars agree with the Swifts in having a small bill, 
J.» wide gape, ten primaries, and the same number of tail-feathers; but 
according to the late Prof. Huxley they differ considerably in the modifications of 
their cranial bones. Jerdon says that their general anatomy is much like that of 
the Cuckoos, and Seebohm observes that the muscles and digestive organs approach 
those of the Bee-eaters and Rollers. . 
In the sober soft colouring of their plumage the Nightjars somewhat resemble 
the Owls, whilst their long tails more nearly approach those of the Cuckoos: they 
are almost cosmopolitan, but are absent from the Arctic regions, from New Zealand, 
and Polynesia. 
In their habits these birds are chiefly nocturnal, they frequent not only open 
moorland and heath, but also well wooded country. They lay their eggs, usually 
two in number, on the bare ground. Their food consists of insects caught upon 
the wing. 
Although there are about ninety species of Nightjars, only one genus— 
Caprimulgus—chiefly characterized by its numerous and strong rictal bristles, is 
represented in our islands. Of this genus three species have been obtained; but 
only one, in my opinion, has a right to be called a British bird, only a single 
example of each of the others having been known to visit us. 
Whether it would be possible to keep Nightjars in aviaries, it is difficult to 
say without experiment; but it seems extremely improbable; and, in any case, 
the result would be most unsatisfactory: that these birds can be reared from the 
nest and kept for a time in a cage has been proved in Germany, but I should 
expect them to behave in the same manner as the //zrwndinide—gorge to repletion 
and take little or no exercise: moreover, being practically birds of darkness, they 
must be almost as dull as Owls in the daytime, and the aviculturist having neither 
bright plumage nor song to compensate him for his trouble in fostering them, 
must be satisfied to keep and worry over them simply for show purposes—which, 
to my mind, is one of the worst purposes to which any bird-keeper can devote his 
leisure time. 
