All the members of this order are characterised by the shape of the bill, which is "strong, curved, sharp-edged, and sharp-pointed, often armed with a lateral tooth" (Owen). The upper mandible is the longest (fig. 348, B), and is strongly hooked at the tip. The body is very muscular; the legs are robust, short, with three toes in front and one behind, all armed with long, curved, crooked claws or talons (fig. 348, A); the wings are commonly pointed, and of considerable size, and the flight is usually rapid and powerful. The Birds of Rapine are monogamous, and the female is larger than the male. They build their nests generally in lofty and inaccessible situations, and rarely lay more than four eggs, from which the young are liberated in a naked and helpless condition.
Fig. 348. - A, Foot of the Peregrine Falcon ; B, Head of Buzzard.
The order Raptores is divided into two great sections - the Nocturnal Birds of Prey, which hunt by night and have the eyes directed forwards; and the Diurnal Raptores, which catch their prey by day, and have the eyes directed laterally.
The section of the Nocturnal Raptores includes the single family of the Strigidae, or Owls. In these birds the eyes are large and are directed forwards. The plumage is exceedingly loose and soft, so that their flight (even when they are of large size) is almost noiseless; and it is generally spotted or barred with different shades of grey, brown, or yellow. The beak is short, strongly hooked, furnished with bristles at its base, and having the nostrils pierced in a membranous "cere" at the base of the upper mandible. The cranial bones are highly pneumatic, and the head is therefore of large size. The feathers of the face usually form an incomplete or complete "disc" or circle round each eye (fig. 349, B), and a circle of plumes is likewise placed round each eiternal meatus auditorius. Besides this auricular circle of featlers, the external meatus of the ear is likewise protected by fold of skin. The legs are short and strong, and are furnisied with four toes, all armed with strong crooked talons. The outer toe can be turned backwards, so that the foot has someresemblance to that of the Scansores. The tarso-metatarsus is densely feathered (fig. 349, A), and the plumes sometimes exend to the extremities of the toes. The oesophagus is not ilated into a crop; and the indigestible portions of the food are rejected by regurgitation from the stomach in the form of small pellets. The Owls hunt their prey in the twilight or on moonlight nights, occasionally by day, and they live mostly upon the lesser Mammalia and small birds, though they will also eat insects or frogs.
Fig. 349.-A, Foot of Tawny Owl (Ulula stridula) ; B, Head of White Owl (Strix flammed).
The section of the Diurnal Raptores includes the four groups of the Falconidae, the Vulturidae, the Cathartidae, and the Gypogeraiidae. The eyes in this section are much smaller than in the preceding, and are placed laterally; and the plumage is not sot. As regards their power of flight, they show a decided advance upon the Nocturnal Birds of Prey. The wings are long and pointed; the sternal keel and pectoral muscles are greatly developed; and many of the members of this section exhibit a more rapid power of locomotion than is seen in any other division of the animal kingdom. The bill is long and strong, with a large "cere" at the base of the upper mandible, in which the nostrils are pierced. The tarso-metatarsus and toes are usually covered by scales, and are rarely feathered.
Lastly, the oesophagus is dilated into a capacious crop, the gizzard is thin, the intestinal caeca are rudimentary, and the intestinal canal is generally short and wide.
In the Falconidae (fig. 348, B) the head and neck are always clothed with feathers, and the eyes are more or less sunk in the head, and provided with a superciliary ride or eyebrow. It is to a great extent to the presence of this rilge that many of these birds owe their fearless and bold expresion. In this family are the Falcons, Hawks, Buzzards, Kites, Harriers, and Eagles, most of which are so well known that any description is unnecessary.
Fig. 350. - Head of Vulture (Neophron percnopteru).
The Old World Vultures ( Vulturidae), as shown by Professor Huxley, are really closely allied to the Falconidae proper, from which they are hardly separable as a family. They live however, principally upon carrion, are destitute of an eyebrow, and have the head and neck frequently naked or covered only with a short down (fig. 350). In this group are the typical "Vul-tures" (Vultur, Neophron, &c), and the great Bearded Vultures or Lammergeyer (Gypaetos barbatus) of the mountain-ranges of the south of Europe and the west of Asia.
The American Vultures form the separate family of the Cathartidae. They have no eyebrows; the head and upper part of the neck are unfeathered; the bill is not powerfully raptorial; the feet have the anterior toes partially webbed ; the talons are blunt and little curved; there is no inferior larynx; and the gullet dilates into a very large crop. They all feed principally upon carrion, and are filthy and cowardly birds. The wings, however, are long and strong, and they possess great powers of flight. This group comprises the Californian Vulture (Cathartes Californianus) of Western North America, the King Vulture (Sarcoramphus papa) of tropical America, and the famous and gigantic Condor (Sarcoramphus gryphus) of South America.
Lastly, the family of the Gypogeranidae includes only the single genus Gypogeranus or Serpentarius, including only the curious "Secretary Bird" of Africa. In this singular bird, the legs are long and slender, with an unfeathered tarso-metatarsus, thus resembling a typical Wader; whilst the wings are long and armed with blunt spurs. The Secretary-bird lives principally upon Snakes and other reptiles, which it kills by blows from its feet and wings.
As regards their distribution in time, the Raptores seem to make their first appearance in the Eocene Tertiary, where both sections of the order are represented, the Diurnal forms by the Lithornis vulturinus of the London Clay, and the Nocturnal by the Bubo leptosteus of the Eocene of Wyoming. Amongst the later representatives of the group may be mentioned the Har-pagornis of the Post-Tertiary of New Zealand, a colossal Bird of prey, which was a contemporary of the Moas.