Alamagan Island

Country/territory: Northern Mariana Islands (to USA)

IBA Criteria met: A1, A2 (2007)
For more information about IBA criteria please click here

Area: 1,520 ha

Most recent IBA monitoring assessment
Year of assessment Threat score (pressure) Condition score (state) Action score (response)
2007 medium not assessed not assessed
For more information about IBA monitoring please click here

Site description
The proposed Alamagan Island IBA is one of only two islands with extant populations of Nightingale Reed Warblers. The interior of the island has steep slopes cut by steep ravines; other areas are grassland or bare lava flows.

Key biodiversity
The entire island of Alamagan (Figure 18) is proposed as an IBA under A1 and A2 criteria, specifically for its population of Nightingale Reed Warblers. The island is also home to Micronesian Megapodes, White-throated Ground-Doves, Collared Kingfishers, Micronesian Starlings, and Micronesian Honeyeaters. Currently, populations of Nightingale Reed Warblers are found only on Saipan and Alamagan (DFW, 2007a), with approximately 100 pairs residing on Alamagan. Although Micronesian Megapodes and Nightingale Reed-Warblers prefer to use forested areas, the entire island is proposed as an IBA due to its small size.

Recommended citation
BirdLife International (2023) Important Bird Areas factsheet: Alamagan Island. Downloaded from on 08/02/2023.