Follow’d the creaming furrow of the prow,
With easy pinion, pleasurably slow;
Then on the waters floated like a fleet
Of tiny vessels, argosies complete,
Such as brave Gulliver, deep wading, drew
Victorious from the forts of Blefuscu.”
Of all the methods of obtaining food to which birds resort, none makes greater demands on their physical powers than that which we human beings term scavenging—the seeking-out and devouring of the multifarious edible objects left, unclaimed by the owners, on the face of the land or the sea. No bird can eke out an existence by scavenging unless it be endowed with wonderful power of flight, the keenest eyesight, and limitless energy, to say nothing of the ability and the will to fight when necessity arises. Thus it happens that it is to the despised scavengers that we must direct our eyes if we would behold the perfection of flight. The vultures, the kites, and the gulls are verily the monarchs of the atmosphere.
Bird scavengers are of two kinds—specialists and general practitioners. The former confine themselves to one particular kind of food—the bodies of dead animals. Of such are the vultures. In the polity of the feathered folk might is right, so that these great birds enjoy the prerogative of picking and choosing their food. The lesser fry have to be content with that which the vultures do not require, with the crumbs that fall from the vulturine table; they are ready to devour “anything that is going.” All is grist that comes to their mill.
The kites and gulls are the chieftains of the clan of general scavengers. The sway of the former extends over the land: the latter have dominion over the seas. Kites cannot swim; their operations are in consequence necessarily confined to the land, and to water in the neighbourhood of terra firma. Sea-gulls, on the other hand, are as buoyant as corks, and have webbed feet; they are, further, no mean swimmers, and are eminently adapted to a seafaring life. They are birds of powerful flight, and almost as much at home on land as at sea. They confine their attention mainly to the sea, not because they are compelled by their structure to do so, but because they encounter less opposition there.
Among birds, similarity in feeding habits often engenders similarity in appearance—a professional likeness grows up among those that pursue the same calling. The likeness between swifts and swallows is a remarkable instance of this. The separate sphere of influence occupied by kites and gulls sufficiently explains the dissimilitude of their plumage. In nearly all other respects the birds closely resemble one another. In habits, gulls are marine kites. Grandeur of flight is the most marked attribute of each. They do not cleave the air at great velocity, like swifts or “green parrots.” It is the effortlessness, the perfect ease with which kites and sea-gulls perform their aerial movements for hours at a time, rather than phenomenal speed, that compels our admiration. A dozen gentle flaps of the wings in a minute suffices to enable a gull to keep pace with a fast steamship.