The Nauru reed warbler (itsirir), Acrocephalus rehsei, is a passerine bird endemic to the island of Nauru in the Pacific Ocean. It is one of only two native breeding land-birds on Nauru, the other being the Micronesian pigeon, and it is the only passerine found on the island. It is related to other Micronesian reed warblers, all of which evolved f...