Data Zone
Justification of Red List category
The species is considered to have become extinct prior to the 1981 volcanic eruption on Pagan, though this event destroyed hopes of the species persisting to the present day. Surveys in the 1970s, 1980s, in 2000 and in 2010 all failed to find any trace of the species, its disappearance primarily a result of severe habitat modification.
Population justification
None remain.
Trend justification
This species is historically known from Pagan in the Northern Mariana Islands (to USA).
It was almost exclusively found in freshwater wetland and wetland edge vegetation (Engbring et al. 1982, Reichel et al. 1992, USFWS 1998).
On Pagan virtually all vegetative ground cover was effectively removed at certain periods during the 20th century through a variety of agents including human development, introduced feral ungulates and finally a volcanic eruption in 1981 (Reichel et al. 1992, Hume 2017). However, there had not been any records for some time prior to this, with reports of reed-warblers being present by D. Aldan and J. Sablan into at least the 1960s (Reichel et al. 1992) appearing to be the last observations. The primary threat is thought to have been severe habitat modification through wetland drainage for agriculture and grazing by feral livestock (Hume 2017). Predation by rats and cats is also thought to have driven declines (Hume 2017). The volcanic eruptions in 1981 appear to mark a full stop to the possibility of the species persisting, as all herbaceous and virtually all woody vegetation was destroyed in the last known site, around the upper lake (Reichel et al. 1992).
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: Pagan Reed-warbler Acrocephalus yamashinae. Downloaded from
https://datazone.birdlife.org/species/factsheet/pagan-reed-warbler-acrocephalus-yamashinae on 22/11/2024.
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 22/11/2024.