The wasteland behind Bhandup pumping station was full of chittering flocks of Baya weaver birds (Ploceus philippinus). They breed in monsoon, and the males were still in their startling yellow breeding plumage. They looked wonderful in the soft morning light. Among these birds the male makes the intricate hanging nest, mates, and then leaves the rest of the child bearing to the female. I began to wonder how the female chose the nest and its maker. When it comes to common birds, almost every question you ask will have been answered. I found that the question had been answered fourteen years ago.
The female’s choice mostly depended on the location of the nest: nests high up on strong branches in thorny trees were preferred. This preference cannot be unknown to males, so there must be intense competition between them. The result is that the female most often chooses males who are able to chase rivals off their chosen site, whether she means to do it or not. In captive flocks the males are seen to create a pecking order which is pretty stable, indicating that this kind of competition is resolved with a minimum of physical violence. Among equally desirable sites, the female chooses nests made of finer fibers. Since nesting occurs during the monsoon perhaps this allows nests to be better knit and dry. So male behaviour seems to be pretty strongly driven by the choices of females. I wonder whether it works the other way round too.