A small reed warbler found on Rimatara. Its plumage is not limited to brown above and a pale underside; all-yellow and olive-green individuals are also described.
The upperparts are brown, while the underside may be white to pale yellow; some birds are entirely yellow or olive green. The crown feathers can be raised slightly.
It uses ravines, horticultural areas, and raised fossil-coral terrain, feeding on insects, other invertebrates, and flower nectar.
An extinction-risk assessment has not been added yet.