After completing the nest LINK, the pair of Red-whiskered Bulbul (Pycnonotus jocosus) was absent for a few days from the Belimbing (Averrhoa carambola) nesting tree. Then one day the female returned, stayed for some time and laid an egg.
Unlike the period when the pair was building their nest when the air was filled with their loud songs, the early incubation period was a much quieter affair. But I did capture a more discreet series of five different songs alerting the bird in the nest by its partner coming to relieve it of its incubating duty (video below).
In another clip below, the pair was seen flying in together. As one flew into the nest to incubate the egg/s, the other flew through.
However, during the later periods between the bulbul flying out of the nest and the mate subsequently flying in, there were, at times, loud singing and duetting. Duetting did not involve the incubating bulbul.
According to Fishpool & Tobias (2005), two to four eggs (usually three) are laid and incubation last 12-14 days. According to Wells (2007), both adults tend to the nestlings and fledglings but no mention of egg incubation.
As the adult in the nest flew off, the other may be around but would only enter the nest after a lapse of some time. The pair sometimes flew to the tree together, one entering the nest while the other flew onwards. At other times the mate was conspicuously absent, at least not captured by the videocam.
1. Fishpool, L. D. C. & J. A. Tobias, 2005. Family Pycnonotidae (bulbuls). In: del Hoyo, J., A. Elliott & D. A. Christie (eds.), Handbook of the birds of the world. Vol. 10. Cucuoo-shrikes to Thrushes. Lynx Editions, Barcelona. Pp. 124-251.
2. Wells, D.R., 2007. The birds of the Thai-Malay Peninsular. Vol. II, Passerines. Christopher Helm, London. 800 pp.