THE SERPENT HAWK.
The SERPENT HAWK (Polyboroides typicus) is a very remarkable member of the Hawk family, inhabiting the same parts of Africa as the bird last mentioned; a very similar species is also met with in Madagascar. The Serpent Hawk is recognisable by the smallness of its head and body, bare cheeks, slender beak, and enormous wings; the tail is long, broad, and slightly rounded; the tarsi high and thin, and the toes small. The plumage is dark greyish blue upon the upper portion of the body, front of neck, and breast; the primary quills are black, the upper secondaries grey, with a black spot near the tip; the tail-feathers are black tipped with white, and have a broad white streak across the middle. The belly, hose, and tail-covers are white, delicately marked with black. The eye is brown, the beak black, the feet lemon colour, the cere and bare patches round the eyes pale yellow. The male bird is one foot eleven inches and a half long, and four feet four inches across the span of the wings; these latter are sixteen and the tail eleven inches in length; the tarsus measures three inches and a quarter, and the middle toe not more than one and a half.
This species is met with throughout the woodland districts of Eastern Soudan, where it frequents such localities as are in the immediate vicinity of water, as it there finds in abundance the reptiles on which it principally subsists. The manner in which this Hawk obtains its prey is very remarkable, as it is enabled to draw its victims from their holes by the aid of a most curious contrivance; the tarsus is so constructed as to allow the foot to be turned in all directions, backwards as well as to the sides, and the claws being comparatively small, the leg can be introduced through a very narrow aperture; it is then moved rapidly into every recess and cranny of the hole, to the inevitable discovery of its helpless occupant. The Serpent Hawks rarely pass much time upon the wing, and, indeed, do little more than fly from one tree to another, exhibiting in all their habits that sluggish and unsocial temperament common to most reptile-eating birds; they live for the most part alone, and spend their time in perching lazily on a bough, or flitting from tree to tree. Verreaux tells us that they will sometimes pursue small birds or quadrupeds.
The succeeding families of RAPTORIAL BIRDS are distinguished by the circumstance that, although they pursue and kill living prey, they will likewise occasionally eat carrion; in order, however, to make the arrangement of this heterogeneous multitude at all clear to the general reader, we must subdivide them into several different groups.
EAGLES.
THE EAGLES.
THE EAGLES (Aquilæ) are distinguishable by the following characteristics: their body is stoutly and compactly built, their head is of moderate size and entirely covered with feathers, and the beak, which is straight to a considerable distance from its base, terminates in a curve or hook; the upper mandible is without teeth, but is slightly waved at its sides; the cere is bare, the tarsi are of moderate size, strong, and more or less covered with feathers, extending in some cases down to the toes; these latter are very powerful, often of great length, and armed with large, much curved, and sharply pointed talons. The wings of some species reach as far as the end of the tail, in others no farther than its root; in all they are rounded at the tip, the fourth and fifth quills being longer than the rest; the tail is long, broad, and either rounded or straight at its extremity. The plumage consists of large and usually pointed feathers, rich in texture, often very soft, but occasionally coarse and harsh. One of the distinguishing features in the plumage of the Eagle is that the feathers on the back of the head and nape are either pointed or considerably prolonged. The eye is large and fiery, and the eyebrows very distinctly marked, thus giving an expression of fierceness to the face.