Anatomy of a munia’s nest

Tan Teo Seng brought me an abandoned bird nest from his fruit farm in Kota Tinggi, Johor recently. Measuring 300 x 130 mm, it is firmly lodged between the narrow forking twigs of a jambu (Syzygium sp.) plant that grew around the farm (above).

When examined closely, it was found to be made up of two components (below).

The nest itself is an oval structure, 80 x 60 mm, with a small round opening of 35 mm diameter near the top (above, below right). Overhanging the opening is a porch, not very prominent and slightly downward pointing.

The nest has a small oval chamber of 80 x 60 mm that is placed slightly higher, such that the upper roof is 60 mm thick while the base is 80 mm thick (below).

This oval nest sits smugly on a mass of leafy materials that fill up the narrowing end of the slender branches making up the fork (above left).

The external nest is made of mainly dried bamboo leaves, interspersed with slender grass stems and inflorescence branches, like Panicum sp. The porch is of mainly grass inflorescence branches.

Field ornithologist Wang Luan Keng identified it as a nest of a munia. I checked with Wells (2007) and the closest fit is that of White-rumped Munia (Lonchura striata). However, Restall (1996) describes the entrance to the nest as “low down on one side…” versus “end entrance” in Wells as well as in the collected specimen. Both authors do not mention that the nest is made up of two components.

YC Wee & Tan Teo Seng
Singapore
April 2008

References:
1. Restall, R. (1996). Munias and mannikins. East Sussex: Pica Press.
2. Wells, D.R. (2007). The birds of the Thai-Malay Peninsular. Vol. II, Passerines. Christopher Helm, London.