Formerly placed in the "Old World warbler" assemblage (Sylviidae), it is now in the newly recognized marsh-warbler family Acrocephalidae.

It is endemic to Pitcairn Island in the southern Pacific.

Locally known as the "sparrow" (true sparrows are not found on Pitcairn), it used to be common throughout the island, where it is the only land bird.

It was formerly classified as a vulnerable species by the IUCN due to its small range.

You can help Wikipedia by expanding it.This Pitcairn-related article is a stub.