Irfan Choo photographed three Chestnut-winged Babblers (Stachyris erythroptera) perching together at the Sandakan Rainforest Discovery Centry, Sabah, Malaysia during the last Christmas holidays. The three birds all show their iridescent blue throat patches.
An earlier post by KC Tsang describes the male Chestnut-winged Babbler exposing his bluish patches on either side of his puffed up throat whenever he sings his courtship song. Dr Jonathan WK Cheah similarly describes a male exposing his patches while singing and bobbing his head.
Can it be assumed that only males have the blue patches? And that the three babblers in the image are all males?
Smythies (1999) describes the ritual thus: “Members of this group, while calling and displaying, lean forwards with head and tail down, rump feathers fluffed up, and slide along their perches, chase and snap at one another. The body, tail and perch are all vibrated. This behaviour is exactly like that described for Chestnut-rumped Babbler.” However, there is no mention of the blue patches being exposed.
Collars (2007), on the other hand, simply states that this babbler, “…when singing, shows blue, pale-green or violet bare neck skin.” But there is no mention whether these patches are seen in both sexes or only in the male.
Wells (2007) describes thus, “…two or more birds regularly perch huddled together side by side. …members sway from side to side, crane heads forward or up, and swell throats to expose lateral patches of bare blue skin (Teesdale, 1972).” Again, no indication that only the male exposes the blue patches.
Among birds, mostly the male sings. And if the Chestnut-winged Babbler sings and displays the blue patches, then it can be assumed that it is the male that has the patches. However, in some species both the males and females sing (Kroodsma, 2004) and we have no information that only the male Chestnut-winged Babbler sings, not the female.
So can anyone confirm that only the male Chestnut-rumped Babbler has the blue patches?
1. Collar, N. J. & C. Robson, 2007. Family Timaliidae (Babblers). In: del Hoyo, J., A. Elliott & J. Sargatal (eds.). Handbook of the birds of the world. Vol. 12. Picathartes to Tits and Chikadees. Lynx Editions, Barcelona. Pp. 70-291.
2. Kroodsma, D. E., 2004. Vocal behavior. In: Clark, G. A. Jr., 2004.. Pp. 3.1-3.70 in Podulka, S., Rohrbaugh, R.W. Jr & Bonney, R. (eds.), Handbook of bird biology. The Cornell Lab of Ornithology, Ithaca, NY. Pp. 7.99-7.98.
3. Smythies, B. E., 1999. Birds of Borneo. Natural History Publications & The Sabah Society, Kota Kinabalu. (4th ed., revised). 853 pp.
4. Wells, D.R., 2007. The birds of the Thai-Malay Peninsular. Vol. II, Passerines. Christopher Helm, London. 800 pp.
Image by Irfan Choo.