White-rumped Munia

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" (Estrildidae). These are close relatives of the true finches (Fringillidae) and true sparrows (Passeridae).
It is native to tropical continental Asia and some adjacent islands, and has been naturalized in spome parts of Japan. Its domesticated hybrid descendant, the Society Finch or Bengalese Finch, is found worldwide as a pet and a biological model organism.