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Location Northern Mariana Islands (to USA), Aguiguan Island
Central coordinates 145o 34.00' East  14o 51.00' North
IBA criteria A1, A2
Area 3,906 ha
Altitude 0 - 150m
Year of IBA assessment 2007

Site description Aguiguan Island is an uninhabited island with patches of native forest. The island is difficult to access due to steep cliffs and visitors to the island should have permission. Naftan Rock is a small islet 1 km off the southwest coast of Aguiguan and is home to several thousand seabirds.

Key Biodiversity In 1982 Engbring et al. (1986) found that all of the CNMI’s native birds, with the exception of the Tinian Monarch, Mariana Crow, and Rota White-eye, used the small uninhabited island of Aguiguan. Craig (1999) wrote that Aguiguan was important to the Critically Endangered Golden White-Eye, which was threatened on Saipan due to the establishment of the Brown Treesnake. The entire complex of Aguiguan Island and Naftan Rock(Figure 8) is proposed as an IBA because of the presence of the Golden White-Eye and the Mariana Swiftlet (found only on Saipan and Aguiguan) and the small but consistent population of Micronesian Megapodes. Naftan Rock is a small islet 1 km off the southwest coast of Aguiguan and is home to several thousand seabirds (Table 11). Reichel (1991) reported over 600 pairs of breeding seabirds for Aguiguan, including 120 pairs of Brown Boobies and 450 pairs of Brown Noddies.

Non-bird biodiversity: Other rare, endemic, and threatened species occurring in the proposed IBA are: • Sheath-tailed Bats • Mariana Fruit Bat • Langford’s Tree Snail

Populations of IBA trigger species

Species Season Period Population estimate Quality of estimate IBA Criteria IUCN Category
Micronesian Scrubfowl Megapodius laperouse resident  1982  11 individuals  unknown  A1, A2  Endangered 
Mariana Fruit-dove Ptilinopus roseicapilla resident  1982  292 individuals  unknown  A1, A2  Endangered 
White-throated Ground-dove Alopecoenas xanthonurus resident  1982  34 individuals  unknown  A1, A2  Near Threatened 
Mariana Swiftlet Aerodramus bartschi resident  1982  1,022 individuals  unknown  A1, A2  Endangered 
Micronesian Myzomela Myzomela rubratra resident  1982  2,195 individuals  unknown  A2  Least Concern 
Rufous Fantail Rhipidura rufifrons resident  1982  1,472 individuals  unknown  A2  Least Concern 
Bridled White-eye Zosterops conspicillatus resident  1982  7,431 individuals  unknown  A1, A2  Endangered 
Golden White-eye Cleptornis marchei resident  1982  2,366 individuals  unknown  A1, A2  Critically Endangered 
Micronesian Starling Aplonis opaca resident  1982  428 individuals  unknown  A2  Least Concern 

IBA Monitoring

2007 high not assessed not assessed

Invasive & other problematic species, genes & diseases invasive non-native/alien species/diseases - named species happening now majority/most of area/population (50-90%) slow but significant deterioration high


IUCN habitat Habitat detail Extent (% of site)
Forest Lowland evergreen rain forest (tropical)  -

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Recommended citation  BirdLife International (2016) Important Bird and Biodiversity Area factsheet: Aguiguan Island and Naftan Rock. Downloaded from on 26/10/2016

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