AVES. 309 



spot. It builds its nest usually on the ground, and breeds throughout the 

 United States. 



Several South American species are known, though their history has 

 never been investigated ; they are C. palustris, C. histrionicus, which is a 

 bird remarkable for its gaily striped plumage, and others. 



The only hawk which possesses a musical voice, the singing hawk of the 

 old authors {Melierax musicus), belongs to this sub-family. It is a 

 common bird in Southern Africa, and is described by Le Vaillant as 

 capable of performing quite respectably a considerable variety of notes. It 

 appears to be a timid species, living upon reptiles, and partaking of the 

 general habits of its family. 



Here also has been classed a curious African genus, Polyhoroides, the 

 species of which have entirely bare faces, and necks also bare to some 

 extent. They appear, however, to be more nearly related to the Poly- 

 horince, or to the vultures. Little is known about them beyond the mere 

 fact of their existence in Western and Southern Africa, and future investi- 

 gations must decide their claims to classification. 



The extraordinary and apparently anomalous genus Serpeniarius has 

 also been assigned by late ornithologists to this sub-family. The only 

 species is the secretary, or great serpent-eater, of the plains of Southern 

 Africa, which, with a decidedly aquiline head and beak, has the long legs 

 of a crane, and lengthened crest and tail. It lives almost exclusively upon 

 the larger snakes, the most poisonous species of which it is said to seize 

 with much dexterity and despatch with great quickness, regardless of their 

 bites upon its long and well shielded tarsi. Spending its time in search of 

 serpents, this powerful bird constantly walks upon the ground, presenting 

 more the appearance of a crane, or large heron, than a bird of prey. It is 

 a shy and very cautious bird, and is regarded by the colonists as very 

 useful in destroying serpents, which it pursues on foot. The stomach of a 

 specimen examined by the celebrated Le Vaillant contained no less than 

 three snakes, eleven lizards, and portions of others. 



With this sub-family we conclude the Falconidee, and now proceed to 

 the last family of rapacious birds. 



Fam. III. Strigid^, or Owls. Head usually very large ; eyes large, 

 directed forwards, and surrounded by a circle more or less complete of 

 slender hair-like feathers, forming a facial disk. Bill short, generally 

 strong, and partially concealed by projecting bristles, curved and much 

 hooked. Wings usually strong. Tarsi short, and usually thickly clothed 

 with short feathers, but sometimes naked or partially covered ; claws long 

 and acute. Plumage soft, habits almost exclusively nocturnal. 



This family embraces the nocturnal birds of prey, all of which are 

 familiarly known under the general cognomen of owls. They differ in 

 many respects from the birds of the two preceding families, but yield to 

 them in nothing of the ferocity or destructiveness characteristic of this 

 class. The most striking and peculiar external character of the owls is 

 the position of their large and staring eyes, which enables them to look 

 directly forwards, and is not the case in any other birds. Their soft and 



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