Nest construction obviously gives the little builders great pleasure. They frequently build supernumerary nests, purely from the joy of building. Each time the cock bird approaches the nest with a beakful of material he cries out with delight. Every now and again in the midst of weaving material into the structure of the nest he bursts into song.
Weaver birds usually build in company; ten or a dozen different nests being found in the same tree. As each little craftsman is in a very excited state, fights between neighbouring cocks frequently ensue, but these are never of a serious nature. I was once the witness of an amusing piece of wickedness on the part of a cock baya. The bird in question flew to a branch near the nest belonging to another pair of weaver birds who were absent. After contemplating it for a little he flew to the nest, and having deliberately wrenched away a piece of it with his beak, made off with the stolen property and worked it into his own nest! Four times did he visit his neighbour’s nest and commit larceny; two of the stolen strands he utilised and the remaining ones fell to the ground. I am inclined to think that the thief was actuated by motives of jealousy; for he deliberately dropped some of the stolen material on to the ground and extracted it from the place at which the nest was attached to its branch, thus weakening its attachment. The victim of the outrage on his return did not appear to notice that anything was amiss.
Not the least interesting feature of the nest is the clay which is studded about it in lumps. In one nest Jerdon found no fewer than six of these lumps, weighing in all three ounces. The clay has, I think, three uses: it helps to balance the nest, it prevents it being blown about by every gust of wind, and keeps it steady while the bird is entering it.
A story is abroad, and is repeated in nearly every popular book on ornithology, to the effect that the weaver bird sticks fireflies on these lumps of clay, and thus illuminates the nursery, or renders it terrifying to predacious creatures. Jerdon scoffs at this firefly story, and I, too, am unable to accept it. Nevertheless it is so universally believed by the natives of India that there must be some foundation for it.
Some time ago a correspondent living on the West Coast of India informed me that weaver birds are very abundant in that part of the country, that their nests are everywhere to be seen, and that he had noticed fireflies stuck into many of them. He asked if I could explain their presence. I suggested in reply that he had made a mistake and requested him to look carefully next nesting season, that is to say in August, and, if he came upon a single nest on to which a firefly was stuck, to take it down, fireflies and all, and send it to me at my expense. Since then August has come and gone thrice, and I have heard nothing from my correspondent! Thus it is that I am still among those that disbelieve the firefly story.
My theory is that the bird brings the clay to the nest in its bill in a moist condition. Now wet clay retains moisture for some time and would shine quite brightly in the moonlight, so might easily be mistaken for a firefly. Unfortunately the weaver bird is not common where I am now stationed, so that I have not had an opportunity of putting this theory to the test. I have, however, noticed how the nests built by solitary wasps shine when the clay that composes them is wet.
The natives of Northern India attribute great medicinal value to the nest of the weaver bird. They assert that a baby will never suffer from boils if it be once washed in water in which a weaver bird’s nest has been boiled!
A great many half-finished weaver birds’ nests are seen in India. Most of these are the work of the cock, who thus amuses himself while his wife is incubating. A few are nests which have gone wrong, nests which do not balance nicely and so have not been completed.
Two eggs are usually laid; they are pure white and without any gloss. On these the hen sits very closely. On one occasion Hume took home a very fine specimen of the nest and hung it from one of a pair of antlers on his dining-room wall. Three days later the inmates of the bungalow became aware of a very unpleasant odour, which was traced to the nest. On taking it down it was found to contain a female baya dead upon two dead half-hatched chicks.