Cuckoo
Cuckoo, a book-name for the Cuculidae, in Huxley's classification ranged under the Coccygomorphae, and in older systems placed among the Picarian birds. The family contains 180 species, arranged in 35 genera, and characterised by a slender body, wings of moderate length, a long graduated tail of from eight to twelve feathers, the beak with sharp edges, and the feet generally long and powerful, with short toes. They abound in warm climates, but in cold and temperate regions they are sparsely distributed, or appear only as visitors. Many of them are parasitic in habit, and some have a strange resemblance to other birds of widely different genera. Thus the Common Cuckoo is very like a hawk, and in some parts of England it is believed that it actually does change into a hawk in the winter; and one of the Bush Cuckoos (Carpococcyx radiatus) closely resembles a pheasant in appearance and gait. The type-genus (Cuculus) contains about 20 species, distributed through the Palae-arctic, Ethiopian, and Oriental regions, some of them ranging to the Moluccas and Australia. They have the bill broad at the base, the wings long and pointed, the upper tail-coverts long, the feet slender and very short, and the legs feathered behind almost to the toes. All are parasitic. The Common Cuckoo (C. canorus) breeds in all the northern portions of the Old World, visiting India, China, Java, and South-western Africa in its southern migration. The male is about 14 inches long, deep ash-grey above, greyish white with black markings below; the neck, cheeks, throat, pure ash-grey; tail feathers, black, spotted with white. The eyes are bright yellow, as are the feet, the beak with a yellowish tinge at the base. The female is about an inch shorter, but has scarcely perceptible reddish stripes on the back and under side of the neck. The young birds are blackish, mottled with yellow and grey, with a good deal of white about the hind neck. The Cuckoo, which arrives in England in April or May and leaves again in August or September, is probably the best known of our feathered visitants. The cry of the male, whence the bird is named, is familiar to everyone. The female has two calls - one resembling that of the male, but sharper, and one which Brehm syllables kwikwikwik, that seems to exert an extraordinary influence on all the males within hearing. Old birds feed entirely on insects and their larvae, seemingly preferring hairy caterpillars. These they devour in great numbers, and the hairs adhere so closely to the mucous membrane of the stomach as to convey the impression that that organ is covered with hairs. The young birds will occasionally feed on berries. The flight is light and elegant, somewhat like that of a falcon.
The Cuckoo's parasitic habit has been known since the days of Aristotle. The hen bird lays her eggs singly on the ground - sometimes as many as eight in the season - taking each egg as soon as laid in her bill and depositing it in the nest of some bird that feeds its own young on insects. Some fifty birds are said to act as unconscious foster-parents to young cuckoos, but the eggs are most frequently deposited in the nests of the hedge sparrow, water wagtail, titlark, yellow ammer, green linnet, and whinchat. The fact that hen cuckoos have been shot with eggs in their bills has given rise to the story, which has no foundation in fact, that they suck the eggs of other birds. The young Cuckoo frequently repays the hospitality accorded it by ejecting the rightful brood, and it always monopolises the bulk of the food, of course to their loss. To account for the parasitism of these birds Darwin supposes that the progenitor of the European Cuckoo occasionally laid an egg in another bird's nest, that some advantage accrued to the old bird or to the fostered young, and that "the young thus reared would be apt to follow by inheritance the occasional and aberrant habit of their mother."