Birds in Flight

by W. P. Pycraft

This but few birds have mastered, and to-day it is rarely to be seen in our islands, for eagles, falcons, and buzzards are, unfortunately, only to be found in a few favoured localities. Happily, however, one may yet realize the delight of watching a soaring buzzard, or raven, among the hills of Westmorland, or in parts of Cornwall and Wales. But to see the past-masters in the art, one must seek the haunts of pelicans, vultures, and adjutant storks. The last-named is perhaps the finest performer of them all. For the first hundred feet or so he rises by rapid and powerful strokes of the wings, and then, apparently without the slightest effort, or the suspicion of a wing-beat, he sweeps round in great spirals, gaining some ten or twenty feet with each gyration, the wings and tail all the while being fully extended and the primary feathers widely separated at their tips. During the first part of every turn he is flying slightly downward: at the end of the descent he sweeps round and faces the wind, which carries him upward. Round, round, he goes, mounting ever higher and higher, until at last he attains a height of perhaps two miles.

The adjutant thus goes aloft apparently for the mere delight the movement affords him. But not so with the vulture, who is a close rival in this art. He soars for his very existence, for dead bodies are not to be found everywhere. Possessing powers of sight infinitely greater than ours, he mounts aloft for the purpose of taking observations. If nothing “toothsome” can be seen from his vast range, he turns his attention to the movements of such of his fellows as may be up on the same errand miles away. Should he see one swooping earthwards he instantly tracks him down, and is soon at the feast. This accounts for the mysterious way in which vultures will gather together to the feast, in a place where an hour ago not one was to be seen. A caravan of camels, perchance, is making its toilsome way across a burning desert. One falls by the way. In a few hours its bones will be picked clean by a horde of these ravenous birds.

Longfellow sang the song of the vultures hunting in stately verse:—

"Never stoops the soaring vulture
On his quarry in the desert,
On the sick or wounded bison,
But another vulture, watching
From his high aerial look-out,
Sees the downward plunge and follows,
And a third pursues the second,
Coming from the invisible ether,
First a speck, and then a vulture,
Till the air is thick with pinions."

Black-game.

Darwin, in his wonderful “Journal of a Voyage Round the World” gives a marvellously vivid word-picture of the largest, and most interesting of all the vultures, the Condor of the Andes—one of the largest of flying birds, having a wing-span of something over nine feet:—

"When the condors are wheeling in a flock round and round any spot, their flight is beautiful. Except when rising from the ground, I do not recollect ever having seen one of these birds flap its wings. Near Lima, I watched several for nearly half an hour, without once taking off my eyes; they moved in large curves, sweeping in circles, descending and ascending without giving a single flap. As they glided close over my head, I intently watched, from an oblique position, the outlines of the separate and great terminal feathers of each wing; and these separate feathers, if there had been the least vibratory movement, would have appeared as if blended together; but they were seen distinctly against the blue sky. The head and neck were moved frequently, and, apparently, with force, and the extended wings seemed to form the fulcrum on which the movements of the neck, body, and the tail acted. If the bird wished to descend, the wings for a moment collapsed; and then again expanded with an altered inclination, the momentum gained by the rapid descent seemed to urge the bird upwards with the even and steady movement of a paper kite. In the case of any bird soaring, its motion must be sufficiently rapid, so that the action of the inclined surface of its body on the atmosphere may counterbalance its gravity. The force to keep up the momentum of a body moving in a horizontal plane in the air (in which there is so little friction) cannot be great, and this force is all that is wanted. The movement of the neck and body of the condor, we must suppose, is sufficient for this. However this may be, it is truly wonderful and beautiful to see so great a bird, hour after hour, without apparent exertion, wheeling and gliding over mountain and river."

Those who “go down to the sea in ships” have to face many perils, but the “wonders of the great deep” are for them a lure. One of these is to watch the marvellous “sailing” flights of the wandering albatross. His wings have, when expanded, a peculiarly “ribbon-like” form, and measure from tip to tip, over eleven feet—thus exceeding that of the condor, which, however, is the heavier bird of the two. The “ribbon-like” form of the wings is due to the extreme shortness of the flight-quills—the primaries and secondaries, and the great length of the arm and fore-arm. And it may be to these structural peculiarities that the “sailing” flight just alluded to is due. Resembling soaring in many of its aspects, yet it differs materially in that it is performed low down, not at immense heights. The most graphic description of these movements is surely that of Mr. Froude: “The albatross,” he tells us, "wheels in circles round and round, and for ever round the ship—now far behind, now sweeping past in a long rapid curve, like a perfect skater on a perfect field of ice. There is no effort; watch as closely as you will, you will rarely see, or never see, a stroke of the mighty pinion. The flight is generally near the water, often close to it. You lose sight of the bird as he disappears in the hollow between the waves, and catch him again as he rises over the crest; but how he rises, and whence comes the propelling force, is, to the eye, inexplicable; he alters merely the angle at which the wings are inclined; usually they are parallel to the water and horizontal; but when he turns to ascend, or makes a change in his direction, the wings then point at an angle, one to the sky, the other to the water."