Both sexes take part in nest-construction. After the formation of the cross-bar at the mouth of the bell one of the birds sits inside and the other outside, and they pass the strands to each other and thus the weaving proceeds rapidly. While working at the nest the bayas, more especially the cocks, are in a most excited state. They sing, scream, flap their wings and snap the bill. Sometimes one cock in his excitement attacks a neighbour by jumping on his back! This results in a fight in which the birds flutter in the air, pecking at one another. Often the combatants "close" for a few seconds, but neither bird seems to get hurt in these little contests.
Every bird-lover should make a point of watching a company of weaver-birds while these are constructing their nests. The tree or trees in which they build can easily be located by sending a servant in July to search for them. The favourite sites for nests in the United Provinces seem to be babul trees that grow near borrow pits alongside the railroad.
In the rainy season two other birds weave nests, which are nearly as elegant as those woven by the baya. These birds, however, do not nest in company. They usually build inside bushes, or in long grass.
For this reason they do not lend themselves to observation while at work so readily as bayas do. The birds in question are the Indian and the ashy wren-warbler.
The former species brings up two broods in the year. One, as has been mentioned, in March and the other in the "rains."
The nest of the Indian wren-warbler (Prinia inornata) is, except for its shape and its smaller size, very like that of a weaver-bird. It is an elongated purse or pocket, closely and compactly woven with fine strips of grass from 1/40 to 1/20 inch in breadth. The nest is entered by a hole near the top. Both birds work at the nest, clinging first to the neighbouring stems of grass or twigs, and later to the nest itself when this has attained sufficient dimensions to afford them foothold. They push the ends of the grass in and out just as weaver-birds do. Like the baya, the Indian wren-warbler does not line its nest. The eggs are pale greenish-blue, richly marked by various shades of deep chocolate and reddish-brown. As Hume remarks: "nothing can exceed the beauty or variety of markings, which are a combination of bold blotches, clouds and spots, with delicate, intricately woven lines, recalling somewhat ... those of our early favourite—the yellow-hammer."
The ashy wren-warbler (Prinia socialis) builds two distinct kinds of nest. One is just like that of the tailor-bird, being formed by sewing or cobbling together two, three, four or five leaves, and lining the cup thus formed with down, wool, cotton or other soft material. The second kind of nest is a woven one. This is a hollow ball with a hole in the side. The weaving is not so neat as that of the baya and the Indian wren-warbler. Moreover, several kinds of material are usually worked into the nest, which is invariably lined.
The building of two totally different types of nest is an interesting phenomenon, and seems to indicate that under the name Prinia socialis are classed two different species, which anatomically are so like one another that systematists are unable to separate them. Both kinds of nests are found in the same locality and at the same time of the year. Against the theory that there are two species of ashy wren-warbler is the fact that there is no difference in appearance between the eggs found in the two kinds of nest. All eggs are brick-red or mahogany colour, without any spots or markings.
Many of the Indian cliff-swallows, of which the nests are described in the calendar for March, bring up a second brood in the "rains."