The Chestnut-winged Babbler (Stachyris erythroptera) is an uncommon resident. It is designated as nationally vulnerable due to its small, localised populations. However, the species is relatively common in the Malay Peninsular and the island of Borneo. This is a forest species and in Singapore it is confined to the Bukit Timah Nature Reserve and Central Catchment forest.
Earlier, we posted a seldom reported courtship ritual where the male, whenever he calls or sings, exposed a pair of bluish patch around his throat.
A pair of courting birds was recently seen in the forest by Dr Jonathan Cheah (above). The male was perching upright and singing. At the same time he was continuously bobbing his head. On either side of his neck was a patch of iridescent light blue, obviously showing off his skin colour.
The patches were even aparent when he had his head down. The female by his side was crouching low and paying full attention to what was going on by her side.
There was a nest nearby, not at all apparent, looking like a mass of dead leaves (above right). The opening to the nest was also not obvious at all, probably hidden somewhere behind.
As Dr Cheah recounted: “The birds appear tame during the breeding season, meticulously choosing dead leaves and oblivious to threats. The fledglings participate in nest building, building practice homes that are not used. Most of the time there are more than one nest, in fact in a space of a small room, you can have like four to five nests, all of which may not be used. If a used nest is found, care must be taken not to disturb it. Even though the bird inside appears undisturbed and not fly out, the next day the nest would be abandoned, as safety has been compromised. Hence, finding a stable CW Babbler nest is truely a gem!
“Babblers normally move round our waist level, hopping amongst vines, dead leaves, and other thick vegetation in search of morsels (right top). When they feel threatened, they will change their calls from the ho… ho ho ho ho ho ho to the raspy screeching and chattering. They will then move higher before flying over to another spot.
“The birds are normally in pairs or in groups of four (family) onwards, as observed in Upper Pierce (right bottom). The leader of the pack would make the first move and one by one the rest of the family would follow. This behaviour is similar to that of the White-crested Laughingthrush (Garrulax leucolophus seen in the Bukit Batok Nature Park areas.”
According to our field ornathologist Wang Luan Keng, “The appearance of the blue patches on the throat while the Chestnut-winged Babbler was singing has been reported in Borneo. But there is no mention of whether that is a courtship display or just a singing display. Dr. Cheah’s photo of another bird staring at the blue patch of a singing bird is interesting observation.”
For the records, MacKinnon & Phillipps (1993) mention the exposure of the patch of pale blue skin on the sides of the neck whenever throat is puffed out. Smythies (1999) has this to say: “The blue naked patch behind eye is diagnostic… eye and throat skin blue… Ordinary call a Stachyris run of about ten notes on the same pitch, very rapidly, others in the party making churring notes; soft rolling huh-huh-huh-huh-huh on a high note followed by ho-ho-ho-ho-ho on a lower note made by vibrating their throats like barbets, fully revealing blue patches of skin on either side of the throats. Others huskily rolling their “r”s and churr.”
Input and images by Dr Jonathan Cheah Weng Kwong.
References:
MacKinnon, J. & Phillipps, K. (1993). A field guide to the birds of Borneo, Sumatra, Java and Bali. The Greater Sunda Islands. Oxford University Press, Oxford.
Smythies, B. E. (1999). Birds of Borneo. Kota Kinabalu: Natural History Pub. (Borneo) Sdn. Bhd. & The Sabah Society. 4th ed, revised by G. W. H. Davison.
