The White-rumped Munia or White-rumped Mannikin (Lonchura striata), sometimes called Striated Finch in aviculture, is a small passerine bird from the family of waxbill "finches". More info inside.
The White-rumped Munia is about 10-11cm in length with a stubby grey bill and a long black pointed tail. Adult birds are brown above and on the breast and lighter below. Sexes are almost impossible to distinguish in all subspecies.
The bird is a resident breeder ranging from South Asia, to Southern China, East to Taiwan and South to Sumatra. It frequents open woodland, grassland and scrub and adapts well to agricultural land use. It is a gregarious bird which feeds mainly on seeds, moving through the undergrowth in groups. The nest is a large domed grass structure in a tree, bush or grass into which 3-8 white eggs are laid. It is a common and widespread species across a large range and is not considered a threatened species by the IUCN.
I photographed this bird in our garden. It was having a drink in the bird bath when I noticed it and luckily the camera, with the 100-400mm, was with me. I had to push the ISO to 1600 as it was late evening and the light wasn't good. The fact that the birdbath was in the shadow of a tree didn't help matters either. I'm pretty happy that I managed to capture a sharp image of the bird using a shutter of 1/40, handheld.