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upon young game birds. The mistake in the former case must have arisen in this way. The habits of the bird are crepuscular. It is seldom seen in broad daylight unless disturbed, but as soon as twilight supervenes and moths and dor-beetles begin to be upon the wing, it comes forth from its noonday retreat and is exceedingly busy and active in the pursuit of these and other insects. Montagu says he has observed as many as eight or ten on the wing together in the dusk of the evening, skimming over the surface of the ground in all directions, like Swallows in pursuit of insects. Cattle, as they graze in the evening, disturb numerous moths and flies, and the Nightjar, unalarmed by the animals, to whose presence it becomes accustomed, dashes boldly down to seize a moth which is hovering round their feet, or a fly which has settled upon the udder. Being detected in this act in the twilight by unobservant persons, the story has gone forth that the Goatsucker steals the milk.
From the keeper's point of view it is a Nighthawk in the worst sense of the word, a hawk that under cover of the night flits noiselessly but rapidly by and carries off the unsuspecting chick. But here again the observer has been misled by appearances, associating the pointed wings and long tail with the idea of a hawk, entirely overlooking the small slender claws and mandibles, which are quite unequal to the task of holding and cutting up live and resisting feathered prey, and entirely also overlooking the fact that at the time the Nightjar is abroad, the young pheasants and partridges are safely brooded under their respective mothers.
Attentive observation of its habits, and examination of numerous specimens after death, have revealed the real nature of its food, which consists of moths, especially Hepialus humuli,y which from its white colour is readily seen by the bird, fernchafers and dor-beetles. Macgillivray says: "The substances which I have found in its stomach were remains of coleopterous insects of many species, some of them very large, as Geotrupes stercorarius, moths of great size also, and occasionally larvae. I have seen the inner surface slightly bristled with the hairs of caterpillars, as in the Cuckoo." He adds, "as no fragments of the hard parts of these insects ever occur in the intestine, it follows that the refuse is ejected by the mouth." From its habit of capturing dor-beetles, the bird in some parts of the country is known as the Dor-hawk. Wordsworth has referred to it by this name in the lines—
1 Mr. Robert Gray of Glasgow has seen it in grass fields, cleverly picking ghost-moths (Hepialus kutnuli) off the stems, from the points of which these sluggish insects were temptingly hanging. But as a rule, he adds, the Nightjar captures its prey while in flight.
"The busy Dor-hawk chases the white moth
Elsewhere it is called the Eve-jar, and Churnowl. The latter name is bestowed by Gilbert White in his "Naturalist's Summer Evening Walk": —
"While o'er the cliff the awaken'd Churn-owl hung, Through the still gloom protracts his chattering song."
In his 37th Letter to Pennant, the same author refers to it as "the Caprimulgus, or Fern-owl," and gives an agreeable account of its movements as observed by himself.
Amongst other things he says :—" But the circumstance that pleased me most was, that I saw it distinctly more than once put out its short leg while on the wing, and by a bend of the head deliver somewhat into its mouth. 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."
Yarrell has figured the foot, in a vignette to his work on British Birds, in order to show this peculiarity of structure, the use of which has puzzled so many.
The correctness of the view expressed by Gilbert White and confirmed by other authors,1 has been disputed on the ground that many other birds, as Herons, Gannets, and, I may add, Coursers, have a pectinated claw upon the middle toe, and yet do not take insects upon the wing, or even seize their prey with their feet.
1 See Atkinson's "Compendium of Ornithology," p. 108, and Stanley's " Familiar History of Birds," p. 260.
It has been ingeniously suggested that perhaps the serrated claw may be used for brushing away the broken wings and other fragments of struggling insects which doubtless adhere occasionally to the basirostral bristles with which the mouth of this bird is furnished. This is very possible; at the same time it may be observed that Hawks, Parrots, and other birds habitually cleanse the bill and sides of the gape with their feet, and yet have no pectination of the middle claw.
A theory advanced by Mr. Sterland,1 and endorsed by Mr. Robert Gray,2 is that since the Nightjar sits lengthwise and not crosswise upon a bough, the serrated claw gives a secure foothold, which in so unusual a position could not be obtained by grasping. But to this theory the objection above made also applies, namely, that many birds, such as Coursers and Thick-knees,
1 "The Birds of Sherwood Forest," p. 172. * "The Birds of the West of Scotland," p. 212.