The white-rumped munia (Lonchura striata) or white-rumped mannikin, sometimes called striated finch in aviculture, is a small passerine bird from the family of waxbill "finches" (Estrildidae). These are not close relatives of the true finches (Fringillidae) or true sparrows (Passeridae).
It is native to tropical continental Asia and some adjacent islands, and has been naturalized in some parts of Japan. Its domesticated descendant, the society finch or Bengalese finch, is found worldwide as a pet and a biological model organism.
The white-rumped munia is approximately 10 to 11 cm in length, with a stubby grey bill and a long black pointed tail. The adults are brown above and on the breast, and lighter below; the rump is white. There is some variation between the subspecies, but the sexes are almost impossible to distinguish in all subspecies; males have a more bulky head and bill.