I have observed a number of Brown-throated Sunbird Anthreptes malacensis nests over the years. For a common bird, it is interesting that there is no information on incubation and nestling periods (Wells 2007; Cheke & Mann 2020). I am observing a nest this week in the forest and hope to offer some of this data.
The nest is built 6 meters up, on an outer branch of a Vitex pinnata, Malayan Teak tree (see Plate 1), along a broad trail in mixed secondary and primary forest. It is hidden in the foliage with leaves also above the nest. The nest consists of plant fibre with a lot of plant cotton included and there is a rudimentary tail to the nest.
Of note in this nesting observation:
1. The nest is lined with cotton of winged seeds (see Plate 2 with close up). Wells (2007) notes that “nests are lined with soft seed-pappus, including of Imperata grass, plus sometimes bryophytes”.
2. Although the female does most of the building, the male does get involved to a small degree (see Plate 3). Most times the male is perched on a nearby branch to apparently watch for predators and was once heard giving a warning call.
3. Peak building activity was mid-morning (1000hrs) with visits every 2 minutes (video recording). The female used her body to shape the inside of the nest.
4. Of interest was the absence of Asian Weaver Ants Oecophylla smaragdina which I have seen at all prior nest encounters. As Wells (2007) notes “many nest trees (24 of a sample 25 in Perak) are colonised by … Oecophylla smaragdina that must deter non-flying predators …”
I saw a different female sunbird collecting nesting material about 50 meters away from this nest. I am still a bit uncertain if it is a Brown-throated Sunbird or a Red-throated Sunbird Anthreptes rhodolaemus (most likely Brown-throated Sunbird). It fluttered repeatedly to gain access to a hanging, dried up gourd; broke open the side and collected the ‘cotton-like’ internal seed padding (see plate 4). It flew off in a different direction and I was not able to follow and find the nest.
References:
1. Cheke, R. and C. Mann (2020). Brown-throated Sunbird (Anthreptes malacensis), version 1.0. In Birds of the World (J. del Hoyo, A. Elliott, J. Sargatal, D. A. Christie, and E. de Juana, Editors). Cornell Lab of Ornithology, Ithaca, NY, USA.
2. Wells, D.R. (2007). The Birds of the Thai-Malay Peninsula: Vol. 2 (Passerines). London: Christopher Helm.
