Order XII. CUCULIFORMES.
The Order Cuculiformes commences the last great division of Carinate Birds. It contains the Sub-Orders Cuculi and Psittaci; the former consisting of the Families Cuculidae, or Cuckoos, and Musophagidae, or Plantain-eaters; the latter of the Psittacidae, or Parrots, Parrakeets, Macaws, and Cockatoos, and the Trichoglossidae, or Lory group. Zygodactylous feet (p. [10]) are characteristic of the Order, while further structural details are to be found below. Dr. Gadow confirms the close connexion of the two Sub-Orders.[[214]]
Fam. I. Cuculidae.–Here we may accept, in default of full anatomical investigation, the Sub-families of Captain Shelley,[[215]] namely, (1) Cuculinae, (2) Centropodinae, (3) Phaenicophainae, (4) Neomorphinae, (5) Diplopterinae, and (6) Crotophaginae.
The bill is generally long and curved, being strongly arched in Hyetornis, Piaya, Taccocua, and Zanclostomus; it is straight in Saurothera and Rhinortha, abnormally large in Rhamphomantis and Scythrops, and has the maxilla compressed into a thin elevated plate in Crotophaga. The scutellated metatarsi are commonly stout, and are especially long in the cursorial genera Coua and Geococcyx; in Centropus the hallux terminates in an elongated spur-like claw. The wings are long and straight in the Cuculinae, Diplopterinae, and Crotophaginae, short and curved elsewhere; the primaries numbering ten, and the secondaries usually nine or ten, but thirteen in Scythrops; in the Neomorphinae the quills are about equal in extent. The rounded or wedge-shaped tail is nearly always long, and has ten feathers, except in the Crotophaginae, which have eight; it is forked in two species of Surniculus. Diplopterus has the upper coverts half as long as the rectrices, Dromococcyx has them of the entire length. The impervious nostrils, usually pierced in a swollen membrane, are hidden by bristly plumes in Dasylophus and Lepidogrammus. The furcula is Y-shaped, the tongue is sagittate with retroverted spines on the posterior margin, the syrinx is tracheo-bronchial or occasionally bronchial. Distinct eyelashes are often visible, the after-shaft is rudimentary or absent, the nestlings are naked, and down is only found in adults on the unfeathered spaces.
The plumage of the more typical Cuckoos is brownish or grey, usually with barred under parts, the long flank-feathers covering half the metatarsi; Chrysococcyx, however, contains several beautiful emerald-green forms; while Chalcococcyx is scarcely less brilliant; but Surniculus and Cuculus clamosus are black. Crotophaga is also black. Coccystes, and several species of Coua, have well-developed crests, while Lepidogrammus has a rounded tuft, Guira one of long narrow plumes, and Geococcyx mexicanus an erectile patch. Fork-tipped feathers on the head and neck are not uncommon. The colour of the bill, feet, and iris varies much; the cheeks and orbits are often naked, and may be bright red, blue, or greyish, as in the Phoenicophainae and Centropodinae. Strong glossy feather-shafts, often with filiform extremities, are found in Coua, Taccocua, Phoenicophaës, Rhopodytes and elsewhere, on the head, neck, mantle and chest; Crotophaga has stiff, scale-like borders, and Lepidogrammus metallic horny tips, to the feathers of the first two of these; Dasylophus has fine crimson hair-like tufts springing from above each eye. The beak may be black, green, yellowish, or even, as in Rhamphococcyx, chiefly red. The sexes are alike in most cases.
The Ethiopian and Indian Regions are richest in Cuculidae. New Zealand possesses only two species; but Madagascar, besides other forms, claims the entire genus Coua. In all there are more than a hundred and sixty species of some forty-two genera.
Sub-fam. 1. Cuculinae.–Cuculus canorus, the familiar Cuckoo of Britain and nearly all the Old World, is greyish-brown above and on the throat, the lower parts being white barred with dusky, and the wings and tail shewing a few white markings. A chestnut-brown or "hepatic" phase is sometimes met with. The young are brown mottled with white on the nape. Its flight and general coloration give the Cuckoo a distinctly Hawk-like appearance, and cause it to be systematically mobbed by small birds, while ignorant peasants persecute it mercilessly, and assert that it "changes to a Hawk" in winter. Certain other members of the Family have the same raptorial aspect, notably the Asiatic Hawk-Cuckoo (Hierococcyx); whereas several of the Centropodinae unconsciously mimic Pheasants in their colour, in their red orbits and their wedge-shaped tail. Geococcyx is still more like a Galline bird in some respects; and Surniculus is a decidedly good imitation of a Drongo (Dicruridae).
Fig. 69.–Cuckoo. Cuculus canorus. × 2⁄7.
In early April the Cuckoo's note heralds the approaching summer in Britain, and continues to be heard until June, after which it becomes hoarser and the first syllable is doubled; in July the adults begin to disappear, yet stray examples–chiefly, if not entirely, young–remain up to October, when they migrate as far as South Africa, Ceylon, and Celebes. None breed south of North Africa and the Himalayas. The eggs are invariably deposited in the nests of other birds, which rear the intruder and feed it until it leaves the country; but it is doubtful how many are produced in a season–possibly five or six–or whether the same hen ever places two or more in one nest. It is now certain that the egg is laid on the ground and conveyed to the chosen nursery in the bill, an occurrence said to have been actually witnessed by Adolf Müller, a forester in Darmstadt.