Diamante colilargo Poephila acuticauda

A small brownish bird with gray head, black throat, narrow black lores, very long black tail, and either a red bill (Northern Territory) or pale yellow bill (Western Australia). Note white rump in flight. Juveniles similar but duller, with dark bill. Compare with Masked Finch, which has black mask and lacks gray head. Inhabits grasslands and grassy woodlands across northwestern Australia.