Birds of the Plains

by Douglas Dewar

Mr. Herrick is a very keen bird photographer. As every one knows, he who wishes to obtain good photographs of birds has two great difficulties to overcome. The first is to get near to his subjects, and the second is to find them and their nests in situations suitable for photography.

The former is usually overcome by the photographer concealing himself and his camera in a tent or other structure. At first the birds are afraid of the concealing object, but soon maternal affection overcomes their fear.

Mr. Herrick’s method of overcoming the second of these two difficulties is to remove the nest to be photographed from the concealed situation in which it is usually built, and place it in a more open place. If the nest be thus moved when the young are some seven or eight days old, the parents will almost invariably continue to feed their young in the new situation, for at that particular period the parental instinct is at its zenith. In addition to obtaining a splendid series of photographs, Mr. Herrick has observed, from a distance of a few inches, the nesting habits of several American birds. As the result of these observations he is able to declare that nest-cleaning follows each feeding with clock-like regularity. “The excreta of the young,” he writes, “leave the cloaca in the form of white opaque or transparent mucous sacs. The sac is probably secreted at the lower end of the alimentary canal, and is sufficiently consistent to admit of being picked up without soiling bill or fingers. The parent birds often leave the nest hurriedly bearing one of these small white packages in bill, an action full of significance to every member of the family. . . . Removing the excreta piecemeal and dropping it at a safe distance is the common instinctive method, not only of insuring the sanitary condition of the nest itself, but, what is even more important, of keeping the grass and leaves below free from any sign which might betray them to an enemy.” These packets of excrement are quite odourless, and they are often devoured by the parent bird instead of being carried away. The digestion of very young birds must be feeble, and doubtless much of the food given them passes undigested through the alimentary canal, so that it is capable of affording nourishment to the parents. Birds are nothing if not economical.

Of course, all birds are not so careful of the sanitation of the nest. Every one knows what a filthy spectacle a heronry is. According to Mr. Herrick, the instinct of inspecting and cleaning the nest is mainly confined to the great passerine and picarian orders. It is obviously not necessary in the case of those birds, such as fowls, of which the young are able to run about when born; nor is it needful in the case of birds of prey, who take no pains to conceal the whereabouts of the nest. Young raptores eject their semi-fluid excreta over the edge of the nursery; thus the nest is kept clean, but the droppings on the ground betray its presence to all the world.

Coming now to our other question: How do young birds obtain the water which they require? we have no help from Mr. Herrick. He makes no mention of this in his most interesting book. It is possible that nestlings are not given anything to drink, that the juicy, succulent insects or fruits with which they are supplied contain sufficient moisture for their requirements. We must remember that the skin of birds is very different from that of man. It contains no sweat glands, so that a bird, like a dog, can only perspire through its mouth.

The breath of mammals is so surcharged with moisture that when it is suddenly cooled the water vapour in it condenses; the result is we can “see the breath” of a mammal on a cold day. I have never succeeded in seeing a bird’s breath, so am of opinion that the fowls of the air do not exhale so much moisture as mammals do. But even allowing for this, a considerable amount of moisture must be given out in expiration, so that it seems probable that young birds require more moisture than they obtain in their food. Drops of water have to be administered to hand-reared birds. Many birds fill up the crop with food and then discharge the contents into the gaping mouths of their young. In this condition the food must be mixed with a considerable quantity of saliva and possibly with water. The crop of a bird is a receptacle into which the food passes and remains until actually utilised. There seems no reason why water should not be stored for a short time in this receptacle just as food is. Perhaps birds “bring up” water as they do solid food, and thus assuage the thirst of their young. Such a process would be very difficult to detect; it would be indistinguishable from ordinary feeding to the casual observer. I hope that some physiologist will take up the matter. A quantitative analysis of the air exhaled by a bird should not be very difficult to make.

BULBULS

More than fifty species of bulbul are found in India—bulbuls of all sorts and conditions, of all shapes and sizes, from the brilliant green bulbuls (which, by the way, strictly speaking, are not bulbuls at all) to the dull-plumaged but blithe white-browed member of the community, so common in Madras; from the rowdy black bulbuls of the Himalayas to the highly respectable and well-behaved red-vented bulbuls. He who would write of them is thus confronted with an embarras de richesses. The problem that he has to solve is, which of the many species to take as his theme.

The polity of birds is said to be a republic. The problem may, therefore, well be elucidated on democratic principles. The first and foremost of these—the main plank of every demagogue’s platform—is, of course, “one bulbul, one vote.” The second is like unto the first, “every bulbul for itself.” Therefore, on being asked to elect a representative to be the subject-matter of this paper, each will vote for his own species, and the result of the poll will be: Bulbuls of the genus Molpastes first, those of the genus Otocompsa a good second, and the rest a long way behind. Let us then conform to the will of the majority and consider for a little these two species of bulbul, which resemble one another very closely in their habits.

Molpastes is a bird about half as big again as the sparrow, but with a longer tail. The whole head is black and marked by a short crest. There is a conspicuous crimson patch of feathers under the tail. The remainder of the plumage is brown, but each feather on the body is margined with creamy white, so that the bird is marked by a pattern that is, as “Eha” points out, not unlike the scales on a fish. Both ends of the tail feathers are whitish.