Aguiguan Island and Naftan Rock (24516)
Northern Mariana Islands (to USA), Oceania
Site overview
KBA status: confirmed
Global KBA criteria: A1a, A1c, B1, B2
Year of last assessment: 2007
National site name: Aguiguan Island and Naftan Rock
Central coordinates: Latitude: 14.8500, Longitude: 145.5667
System: marine, terrestrial
Elevation (m): 0 to 150
Area of KBA (km2): 39.06187
KBA classification: Global
Legacy site: Yes
Site details
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.
Rationale for qualifying as KBA: This site qualifies as a Key Biodiversity Area of international significance that meets the thresholds for at least one criterion described in the Global Standard for the Identification of KBAs.
Additional 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
Delineation rationale: 2012-12-17 (BL Secretariat): original polygon clipped to hi-res coastline following identification in October 2012 of new marine IBA offshore this site; site area consequently changed from 7500 ha to 3906 ha.
Habitats
Summary of habitats in KBA: Aguiguan Island is an uninhabited island with patches of native forest.
| IUCN Habitat | Coverage % | Habitat detail |
|---|---|---|
| Forest | 100 |
Threats
Summary of threats to biodiversity at KBA: There is a large population of feral goats that disturb native flora and fauna. Rats and monitor lizards also pose a threat. Invasive weeds cover open fields on the island and may prevent the return of forest cover. Craig (1999) wrote that birds on Aguiguan are vulnerable to destruction of habitat caused by typhoons, given Aguiguan’s small size. However, typhoons are a regular occurrence in the CNMI, and birds have presumably adapted to the current typhoon regime. Changing typhoon frequency and intensity as predicted by some climate change models (Chowdhury et al., 2007) may change this balance.
| Threat level 1 | Threat level 2 | Threat level 3 | Timing |
|---|---|---|---|
| Invasive & other problematic species, genes & diseases | Invasive non-native/alien species/diseases | Named species | Ongoing |