We must not omit to mention the American SAILOR SWALLOWS (Progne), partly because they have frequently been seen in Europe, but more especially as they form the connecting link between the Swallows and the Swifts; they are powerful birds, with long, broad wings, extending beyond the very decidedly forked tail. Their beak is strong, broad at the base, compressed at its sides, much arched, and terminates in a hook; the legs are robust, the tarsi bare, and the toes thicker and more fleshy than those of other Swallows. The plumage is very dense.
THE PURPLE SWALLOW.
The PURPLE SWALLOW (Progne purpurea) is seven inches and a half long and fifteen and a half broad; the wing measures about five, and the tail two and a half inches; the centre feather of the latter does not exceed two inches. The female is a trifle smaller and more slender than her mate. The plumage is of a deep blackish blue, shaded with purple; the quills and tail-feathers are blackish brown; the eye dark brown, the beak blackish brown, and the foot purplish black. The head of the female is brownish grey, spotted with black; the upper part of the body is greyer in tint than that of the male, and streaked with black.
This bird is a particular favourite with the Americans, and has been described at great length by many writers. According to Audubon, the Purple Swallows appear in New Orleans about February, and at once come sweeping about the towns or over the streams and rivers. Near the Falls of the Ohio, they are not seen till March, and in Missouri not before the middle of April. In August they leave for more southern countries, assembling like their European brethren upon steeples or high trees, preparatory to starting upon their travels. The flight of this species resembles that of the Roof Swallow, but upon the earth and among the branches of trees its movements are far more easy, and it frequently alights to seek for insects on the ground. Whilst upon the wing, it often bathes and drinks in the same manner as our English Swallows, and like them seizes its prey as it darts through the air. Its disposition is bold and courageous, insomuch that it will frequently chase cats, dogs, Falcons, Cranes, or even Vultures, with great intrepidity.
The nest of the Purple Swallow, which is long and flask-shaped, is formed of dry twigs, grass, leaves, feathers, and other elastic materials, and is either built against a tree or placed in similar situations to those selected by its congeners. The female produces two and sometimes three broods, and lays from four to six purely white eggs; the first family is fully fledged by May, and the second about July. Both parents assist in the work of incubation; the male proves himself a most tender and devoted spouse, and often spends whole hours at the side of his mate, singing to her with great vivacity. Should several pairs brood near the same spot, the utmost harmony prevails among them.
Pursuant to our intention of laying a natural classification of the Animal Kingdom before our readers, we shall now proceed to describe the SWIFTS, although we are well aware that many modern naturalists consider that they should not be grouped with the Swallows.
The family of the SWIFTS (Cypseli) are small or moderate-sized birds, with a long slender body, short neck, broad flat head, and small delicate beak, which is broad at its base, slightly curved, and somewhat compressed at its tip. The gape is uncommonly wide; the wings are narrow and curved like a sabre; the tail is very variously formed, being sometimes long, sometimes short, and more or less deeply incised at its extremity; the feet and toes are stunted, the latter armed with short, powerful, and much curved claws. The plumage is thick and composed of small feathers, it is usually of a dusky hue, but occasionally exhibits considerable metallic lustre. The various members of this family are found throughout all the divisions of our earth, except its most northern portions, and inhabit every situation from the sea-coast to the snow boundary of lofty mountain ranges. From early morning till late in the evening, they may be seen skimming through the air with astonishing rapidity, or soaring to such an elevation as to be almost beyond the reach of our vision. So powerful are their wings that no amount of exertion appears to fatigue them; their pinions, which when extended form a crescent, are wielded with a force and rapidity rivalling the activity of the Humming Birds—they dart with the velocity of an arrow upon their prey, or indulge in every conceivable variety of flight or motion, as they skim through what may certainly be called their native element; even when among the branches of trees, they display considerable agility, but are perfectly helpless upon the ground. All the members of this family are of a restless disposition; they spend but a few hours of the night in repose, and require a very large amount of food to enable them to support their prolonged exertions, so that they consume insects in enormous quantities, seizing them whilst upon the wing.
