In the dusk of the evening the Nightjar may commonly be seen hawking for moths and beetles after the manner of the Swallow-tribe, only that the flight is less rapid and more tortuous. I once saw one on the common mentioned above, hawking seemingly in company with Swifts and Swallows during the bright glare of a summer afternoon; but most frequently it spends the day either resting on the ground among heath or ferns or on the branch of a tree, always (according to Yarrell and others) crouching close down upon it, in the line of the limb, and not across it. When perched on the ground it lies very close, 'not rising (a French author says) until the dogs are almost on it, but worth shooting in September'. The poet Wordsworth, whose opportunities of watching the Nightjar in its haunts must have been numerous, knew that the whirring note is an accompaniment of the chase:
The busy Dor-Hawk chases the white moth With burring note----
The burring Dor-Hawk round and round is wheeling: That solitary bird Is all that can be heard In silence, deeper far than deepest noon.
One point in the economy of the Nightjar is still disputed (1908) the use which it makes of its serrated middle claw. White, and another observer, quoted by Yarrell, have seen the bird while on the wing capture insects with the claw and transfer them to the mouth. Wilson, on the other hand, states that the use of this singular structure is to enable the bird to rid itself of vermin, to which it is much exposed by its habit of remaining at rest during the heat of the day. As he has actually observed a bird in captivity thus employing its claw, it would follow that the same organ is used for a twofold purpose.
The Nightjar is a migratory bird and the last to arrive in this country, appearing not before the middle of May. It is found more or less sparingly in all parts of England, especially those which abound most in woods interspersed with heaths and brakes. In the wooded valleys of Devonshire it is of frequent occurrence, and here it has been known to remain so late in the season as November, whereas from most other localities it migrates southwards about the middle or end of September. It builds no nest, but lays its singularly beautiful eggs, two in number, on the ground among the dry herbage of the common.