Vultures and the Marabou stork fly at enormous altitudes. Ibelieve that every species keeps to its own particular elevation, and that the atmosphere contains regular strata of birds of prey, who, invisible to the human eye at their enormous height, are constantly resting upon their wide-spread wings, and soaring in circles, watching with telescopic sight the world beneath. At that great elevation they are in an exceedingly cool temperature, therefore they require no water; but some birds that make long flights over arid deserts, such as the Marabou stork, and the buzzard, are provided with water-sacks; the former in an external bag a little below the throat, the latter in an internal sack, both of which carry a large supply. As the birds of prey that Ihave enumerated, invariably appear at a carcase in their regular succession, I can only suggest that they travel from different distances or altitudes. Thus, the Marabou stork would be farthest from the earth; the large bare-necked vulture would be the next below him, followed by the red-faced vulture, the buzzard, and the crow that is generally about the surface. From their immense elevation, the birds of prey possess an extraordinary field of vision; and, although they are invisible from the earth, there can be no doubt that they are perpetually hunting in circles within sight of each other. Thus, should one bird discover some object upon the surface of the earth below, his sudden pounce would be at once observed and imitated by every vulture in succession. Should one vulture nearest the earth perceive a body, or even should he notice the buzzards collecting at a given point, he would at once become aware of a prey; his rush towards the spot would act like a telegraphic signal to others, that would be rapidly communicated to every vulture at successive airy stations.
If any animal be skinned, the red surface will attract the vultures in an instant; this proves that their sight, and not their scent, has been attracted by an object that suggests blood.
I have frequently watched them when I have shot an animal, and my people have commenced the process of skinning. At first, not a bird has been in sight, as I have lain on my back and gazed into the spotless blue sky; but hardly has the skin been half withdrawn, than specks have appeared in the heavens, rapidly increasing. "Caw, caw," has been heard several times from the neighbouring bushes; the buzzards have swept down close to my people, and have snatched a morsel of clotted blood from the ground. The specks have increased to winged creatures, at the great height resembling flies, when presently a rushing sound behind me, like a whirlwind, has been followed by the pounce of a red-faced vulture, that has fallen from the heavens in haste with closed wings to the bloody feast, followed quickly by many of his brethren. The sky has become alive with black specks in the far-distant blue, with wings hurrying from all quarters. At length a coronet of steady, soaring vultures, forms a wide circle far above, as they hesitate to descend, but continue to revolve around the object of attraction. The great bare-necked vulture suddenly appears. The animal has been skinned, and the required flesh secured by the men; we withdraw a hundred paces from the scene. A general rush and descent takes place; hundreds of hungry beaks are tearing at the offal. The great bare-necked vulture claims respect among the crowd; but another form has appeared in the blue sky, and rapidly descends. A pair of long, ungainly legs, hanging down beneath the enormous wings, now touch the ground, and Abou Seen (father of the teeth or beak, the Arab name for the Marabou) has arrived, and he stalks proudly towards the crowds, pecking his way with his long bill through the struggling vultures, and swallowing the lion's share of the repast. Abou Seen, last but not least, had arrived from the highest region, while others had the advantage of the start. This bird is very numerous through the Nile tributaries of Abyssinia, and may generally be seen perched upon the rocks of the water-side, watching for small fish, or any reptile that may chance to come within his reach. The well-known feathers are situated in a plume beneath the tail.
