Data Zone
Justification of Red List category
There have been no records of the species since the mid-1990s despite extensive surveys in 2000, 2001, 2008 and 2009, its disappearance likely primarily due to large-scale vegetation clearance. It is therefore classified as Extinct.
Population justification
A tiny population was reported to remain on the uninhabited island, but has not been observed since the mid-1990s despite extensive surveys in 2000, 2001, 2008, and 2009 (USFWS 1998, Esselstyn et al. 2003, Camp et al. 2009, Amidon et al. 2014), and the species is now considered to be Extinct.
Trend justification
This species is historically known only from Aguijan in the Northern Mariana Islands (to USA).
It inhabited formerly disturbed areas vegetated by groves of trees and thickets (Engbring et al. 1982, Reichel et al. 1992, USFWS 1998).
Habitat destruction as a result of intensive farming is likely responsible for this species' disappearance (Reichel et al. 1992). Goats (Capra hircus) introduced in the 1950s may have also been a contributing factor (Hume 2017).
18 cm. Large, lanky, scruffy-looking warbler with long bill and often dishevelled feathers and erect head feathers when singing. Dingy olive-yellow above, with dull yellow eyebrow and underparts. Voice Call was a loud chuck or tchack. Males sang long, loud, varied and complex song.
Text account compilers
Vine, J.
Contributors
Amidon, F.A., Camp, R., Dutson, G., Freifeld, H., Gourley, J., Mosher, S., Radley, P. & Saunders, A.
Recommended citation
BirdLife International (2024) Species factsheet: Aguijan Reed-warbler Acrocephalus nijoi. Downloaded from
https://datazone.birdlife.org/species/factsheet/aguijan-reed-warbler-acrocephalus-nijoi on 24/11/2024.
Recommended citation for factsheets for more than one species: BirdLife International (2024) IUCN Red List for birds. Downloaded from
https://datazone.birdlife.org/species/search on 24/11/2024.