The Saipan reed warbler (''Acrocephalus hiwae'') is a critically endangered songbird of the

Northern Mariana Islands The Northern Mariana Islands, officially the Commonwealth of the Northern Mariana Islands (CNMI; ch, Sankattan Siha Na Islas Mariånas; cal, Commonwealth Téél Falúw kka Efáng llól Marianas), is an unincorporated territory and commonw ...

. It is considered a subspecies of the

nightingale reed warbler The nightingale reed warbler (''Acrocephalus luscinius''), or Guam reed-warbler, was a songbird endemic to Guam. It has not been seen since 1969. Taxonomy and systematics The nightingale reed warbler was described by the French zoologists ...

by some taxonomists. It occurs on two islands:

Saipan Saipan ( ch, Sa’ipan, cal, Seipél, formerly in es, Saipán, and in ja, 彩帆島, Saipan-tō) is the largest island of the Northern Mariana Islands, a Commonwealth (U.S. insular area), commonwealth of the United States in the western Pa ...

and

Alamagan Alamagan is an island in the Northern Mariana Islands in the Pacific Ocean, north of Guguan, north of Saipan, and south of Pagan. It is currently uninhabited. History Alamagan was once settled by the Chamorros, who left behind archaeological ...

. An estimated population of 2700 birds was reported in 2009 on Saipan, and on Alamagan 950 birds were reported in 2010. The Saipan reed warbler is approximately long, and is greyish olive-brown above with a pale-yellow underside. It inhabits

wetlands A wetland is a distinct ecosystem that is flooded or saturated by water, either permanently (for years or decades) or seasonally (for weeks or months). Flooding results in oxygen-free (anoxic) processes prevailing, especially in the soils. The ...

, thickets and the margins of forests. The female is slightly smaller than the male. Both sexes have a long bill compared to other

reed warbler The ''Acrocephalus'' warblers are small, insectivorous passerine birds belonging to the genus ''Acrocephalus''. Formerly in the paraphyletic Old World warbler assemblage, they are now separated as the namesake of the marsh and tree warbler famil ...

species. Threats to the survival of the Saipan reed warbler include

habitat destruction Habitat destruction (also termed habitat loss and habitat reduction) is the process by which a natural habitat becomes incapable of supporting its native species. The organisms that previously inhabited the site are displaced or dead, thereby ...

resulting from urban development and agriculture, the introduction of invasive species, and volcanic eruptions.

References

Saipan reed warbler The Saipan reed warbler (''Acrocephalus hiwae'') is a critically endangered songbird of the Northern Mariana Islands. It is considered a subspecies of the nightingale reed warbler by some taxonomists. It occurs on two islands: Saipan and Alama ...

Birds of the Northern Mariana Islands

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