I have long been trying to ascertain how birds in the nest obtain the liquid they require. Do the succulent caterpillars, on which young sparrows are fed, provide them with sufficient moisture, or do the parents water them? Although I spent several hours in watching those sparrows, I am not able to answer the question satisfactorily. I placed a bowl of water on the ground near the cage, hoping that this would tempt the hen bird to drink, and that I should see her carry some of the liquid to her offspring. But she took no notice of the water. She certainly used to come to the cage sometimes with her beak apparently empty, and yet insert it into the open mouth of a young one. Was she then watering the nestling, or did her beak hold some small seeds that did not protrude? It seems incredible that unfledged birds exposed to the temperature of an Indian summer require no water; nevertheless, I never actually saw any pass from the crop of the parents to those of the youngsters.
THE CARE OF YOUNG BIRDS
AFTER THEY LEAVE THE NEST
It has been urged as an objection to the Darwinian theory that Natural Selection, if that force exists, must tend to destroy species rather than cause new ones to come into being. Nearly all birds leave the nest before they are fully developed. When they first come out of the nursery they have attained neither their full powers of flight nor complete skill in obtaining food. Every young bird, no matter how fine a specimen it be, leaves the nest an inexperienced weakling, and can therefore stand no chance in competition with the fully grown and experienced members of the species. Natural Selection takes an individual as it finds it and pays no attention to potentialities.
That such an objection should have been urged against the theory of Natural Selection is proof of the fact that naturalists are inclined to forget that, with many, if not all, species of birds, the duties of the parents towards their offspring by no means cease when the young birds leave the nest.
The parent birds, in many cases, continue to feed their young long after these are apparently well able to fend for themselves. This fact is not sufficiently emphasised in books on natural history. On the other hand, such works lay stress upon the fact that in many species of birds the parents drive their offspring away from the place of their birth in order that the numbers of the species in the locality shall not outgrow the food supply. How far this is a general characteristic of birds I do not know. What I desire to emphasise is that the driving-away process, when it occurs, does not take place until some time after the young have left the nest. The fact that the parent birds tend the young long after they have left the nest, and even after they are fully capable of holding their own in the struggle for existence, disposes of the above-cited objection to the theory of Natural Selection. Nature is so careful of the young warriors that she prolongs the instinct of parental affection longer than is absolutely necessary. So important is it that the young should have a fair start in life that she errs on the safe side.
It is common knowledge that foster-parents feed cuckoos when these have grown so large that, in order to reach the mouth of their spurious babes, the little foster-mothers have to perch on their shoulders.
The sight of a tiny bird feeding the great parasite is laughable, but it is also most instructive. It demonstrates how thoroughly bird mothers perform their duties.
Crows tend their young ones for weeks after they have left the nest. I have had ample opportunity of satisfying myself as to this.
It was my custom in Madras to breakfast on the verandah. A number of crows used to assemble daily to watch operations and to pick up the pieces of food thrown to them. They would go farther when the opportunity occurred, and commit petty larceny.
The crows were all grey-necked ones, with the exception of two belonging to the larger black species. But these latter are comparatively shy birds, and consequently used to hang about on the outskirts of the crowd.