Hunga Ha'apai, Hunga Tonga Islands

Year of compilation: 2007

Site description
The Hungas IBA comprises both the islands of Hunga Ha’apai and Hunga Tonga, two isolated volcanic islands of the Ha’apai Group with a combined area of just over one square kilometre. The islands are uninhabited and are very rarely visited by people. The Hungas are renowned for their seabird colonies, although these are poorly documented they probably exceed over 10,000 pairs of several species. A breeding record of the globally threatened Phoenix petrel from the Hungas is doubted, but the threatened friendly ground-dove Gallicolumba stairi occurs on both islands as well as four other ‘central Polynesian’ restricted range species.

Key biodiversity
Ornithological information There are very few published ornithological observations for the Hungas. The Whitney South Seas Expedition visited the islands in July 23,24 1925 but not all their observations or collections have been published. Information from journal accounts of the Expedition’s collectors was extracted for seabirds by Jenkins (1980). Rinke et al. (1992) records some of DRs previous observations on a visit to the Hungas in April 1991. Two globally threatened species (A1) have been recorded although the record of the Phoenix Petrel is doubted; and, five ‘central polynesian’ restricted range species (A2). It is considered probable that there are more than 10,000 pairs of seabirds of mixed species on the islands (A4iii).

Non-bird biodiversity: No records.

Pressure/threats to key biodiversity
The Hungas are difficult to land on, very isolated and have no agricultural potential. They are rarely visited by people, and when visits are made they are generally to harvest seabirds or their eggs.

Conservation responses/actions for key biodiversity
There are no research or conservation projects on the Hungas at the present time (Prescott & Folaumoetu’i (2004).

Habitat and land use
Hunga Ha’apai and Hunga Tonga (the Hungas) are a pair of isolated volcanic islands, 55 km west of the Ha’apai group. The two linear andesitic islands are about 2 km long. They have inwardfacing cliffs that represent the western and northern remnants of the rim of a largely submarine caldera lying east and south of the islands. A rocky shoal is visible 3.2 km SE of Hunga Ha'apai and 3 km south of Hunga Tonga and marks the most prominent historically active vent (Taylor and Ewart, 1997). Submarine eruptions were reported here in 1912 and 1937 and from a fissure 1 km SSE of Hunga Ha'apai in 1988 (Smithsonian 2007). The islands are uninhabited and rarely visited. There are no records or accounts of the vegetation or flora or of the fauna other than some observations on the avifauna. Jenkins (1980) describes the islands as ‘rocky and steep, with sheer cliffs and thin vegetation'.

Recommended citation
BirdLife International (2020) Important Bird Areas factsheet: Hunga Ha'apai, Hunga Tonga Islands. Downloaded from on 10/08/2020.