Description wikipedia

The buff-rumped thornbill (Acanthiza reguloides) is a small passerine bird species belonging to the genus Acanthiza, most of which are endemic to Australia. Measuring 8–10 cm in length, this unassuming thornbill is characterised by its plain greenish brown upperparts and very pale-yellow underparts, with a distinctive buff coloured rump. The tail has a broad, blackish band with a paler tip. Adults possess white irises, whilst juveniles have dark eyes. The buff-rumped thornbill is one of 14 species within the genus Acanthiza genus, which are recognisable by their thin, pointed bill. Species are unique in their plumage and distribution. Despite their shared name, the genus is not related to hummingbirds.