Cuckoo (Cuculus Linn), a genus of birds of the order scansores and family cuculidce, inhabiting the temperate and warmer regions of the old world. The cuckoos of America belong to another subfamily of the same order. The true cuckoos, as exemplified in the genus cuculus, have the bill broad, rather depressed at the base, curved, gradually compressed to the acute tip; the nostrils are round and exposed; the wings are long and pointed, the third quill being the longest; the tail is long and graduated, or even, and the outer feather of each side is shorter than the others; the tarsi are very short and partially feathered; the toes, two before and two behind, are unequal, the outer anterior one being the longest, and united to the inner at the base. More than 40 species are well determined, of which the best known and most interesting is the common European cuckoo (C. canorus, Linn.). In this bird the corners of the mouth and eyelids, and the inside of the mouth, are of an orange color; the plumage of the head, neck, breast, and upper parts, is a deep bluish gray; the under parts and the axillary feathers are white with distinct black bars; the quills are blackish gray, the inner webs with transverse white bars; the tail is darker, approaching to black at the end, and often with a green gloss, tipped with white, and each feather marked along the shaft with triangular white spots, which, meeting similar spots on the outer feathers, give an almost barred appearance to the tail; the feet are gamboge-yellow, and the bill black.

The length of the bird is 14 in., and the extent of wings 25 in. The young birds are of a brown tint, with reddish brown bars and white markings, the white of the under parts being barred with black. The female very closely resembles the male. The cuckoo is associated with the return of sunny skies and the renewal of vegetation, and is a most welcome "messenger of spring;" it arrives from southern Europe in Great Britain in April, and generally departs in August. It is very generally distributed over Europe, decreasing in numbers toward the north; according to Temminck, it extends its migrations to northern Africa. The most singular habit of the cuckoo is that it deposits its eggs in the nests of other birds, leaving the care of the young entirely to the foster parents thus selected; the latter adopt the young cuckoo as their own, often to the destruction of their proper offspring, which are thrust out of the nest by the usurping stranger The reason of this departure from the usual habit of birds is not well ascertained; it is common in the genus cuculus, and is also practised by our cow bird (molothrus pecoris, Swains.). (See Cow Bird.) The cuckoo selects the nest of a bird smaller than itself, and of a great variety of species, as the warblers, sparrows, finches, and larks, and in it deposits a single egg, very small compared to the size of the bird; it is believed by Montague and others that the female has the power of retaining the egg in the oviduct until she can find a nest suitable for its reception; she lays several in the course of the season.

The young cuckoo is said to eject its companions from the nest by lifting them out on its shoulders; from this habit has arisen the German saying, "as ungrateful as a cuckoo." The well known notes of this bird, as heard in the breeding season, resemble very much its name; the song is loud and joyful, and confined to the males, and is silent before their departure. Its food consists of the larvae of insects and caterpillars; before swallowing the latter it cuts off the hinder end and frees the body from the intestinal canal by repeated jerks with its sharp bill. The males are more numerous than the females, and are bold and fierce, and rarely kept as pets. In autumn they are fat and esteemed as food; the ancients were very partial to them, and their flesh was supposed to have valuable medicinal properties. - The American cuckoos belong to the subfamily coccyzinae, or ground cuckoos, and to the genus coccyzus. In this genus the bill is long and rather slender, and curved; the nostrils are oval; the third and fourth quills are the longest; the tail is long, broad, and rounded on the sides; the tarsi are shorter than the middle toe, and naked; the toes are unequal, and the claws long, compressed, curved, and acute.

Three species are described belonging to North and Central America, though a few stragglers have occasionally been seen in Europe; they are shy birds, frequenting the dense woods and solitary swamps. I. The yellow-billed cuckoo (C. Americanus, Bonap.) has a length of 12 1/2 in., and an extent of wings of 16 in.; the bill is an inch long, for the most part yellow; the iris is hazel; the general color of the upper parts, with the wing coverts and two middle tail feathers, is light greenish brown, deeper anteriorly; the other tail feathers black, with a broad white space at the end of the three outermost, the fourth white on the outer web; the primaries have their inner webs brownish orange; the under parts are grayish white.

European Cuckoo (Cuculus canorus).

European Cuckoo (Cuculus canorus).

Yellow billed Cuckoo (Cuculus Americanus).

Yellow-billed Cuckoo (Cuculus Americanus).

The female differs little from the male. Its notes resemble the word "cow, cow," repeated several times with increasing rapidity; hence one of its names, cow bird; it is also called rain crow and coucou. It is found in all parts of the United States, though nowhere in abundance. Its food consists of caterpillars, insects, wood snails, berries (especially the mulberry), and grapes; it sucks the eggs of other birds, and itself falls a victim to many species of hawks. Its flight is rapid, but the gait on the ground is very awkward; its favorite retreat is the thickest foliage. This bird builds its nest and rears its young in the usual manner; the flat nest is very simply composed of a few dry sticks and grass, on a horizontal branch of a low tree; the eggs are four or five, of a bright green color. It migrates southward, generally beyond the limits of the United States, as cold weather approaches, in flocks and high in the air; single birds begin to enter our borders early in March, arriving as far as New York early in May. II. The black-billed cuckoo (C. erythrophthalmus, Bonap.) is a littl smaller than the preceding species, from which it is also distinguished by its dark bill, a bare scarlet space around the eyes, and the browner tint of the under parts.

The present species does not frequent the interior of deep woods, but prefers the edges of forests on the border of the sea and lakes. It feeds principally on shellfish and aquatic larvae and insects; it is very fond of the small frogs so numerous after summer showers. Its flight is more rapid than that of the yellow-billed species; in other respects, as in its migrations, general habits, and manner of constructing its nest, it much resembles the last named bird, and has frequently been mistaken for it. The eggs are greenish blue. III. The mangrove cuckoo (C. minor, Cab.) is 12 in. long and 15 in. in extent of wings; the general color of the upper part is light greenish brown, the head tinged with gray; primaries umber-brown; tail feathers, excepting the two middle ones, brownish black with white tips; the under parts brownish orange. In other characters it much resembles the yellow-billed cuckoo. Its habits are the same as those of the other species; it feeds on insects, fruits, and the eggs of other birds; it is vigilant and shy, not extending its migrations northward beyond Florida; it prefers the mangrove-covered islands, building its nest amid their dark foliage. The flight is rapid and elevated during migration.

The female is paler than the male, especially on the lower surface, which is grayish.