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Location Tonga, Tongatapu Group
Central coordinates 176o 17.00' West  22o 58.00' South
IBA criteria A2, A4ii, A4iii
Area 184 ha
Altitude 0 - 355m
Year of IBA assessment 2012

Site description The ‘Ata IBA comprises the whole of the 2.3 volcanic island of ‘Ata, the southernmost island of the Tongan archipelago. The island is mostly forested and is currently uninhabited and very rarely visited by people. ’Ata has some of the largest seabird colonies in Tonga especially wedge-tailed shearwaters, masked, red-footed and brown booby, and black and brown boobies. Together these are believed to number over 50,000 birds.

Key Biodiversity ‘Ata is renowned for its seabird colonies but these remain very poorly documented. Apart from the collectors of the Whitney South Sea Expedition who visited the island 13-14 July 1925, only Rinke (1991) has published ornithological observations. The apparent loss of the Pacific harrier and the exotic European starling between the visits of the WSSE and Dieter Rinke’s visit is of great interest. The island indubitably supports over 10,000 pairs of seabirds (A4iii), probably comprising 15 species. Whilst the breeding populations of the three species of booby and the two species of noddy both fulfill IBA criteria (A4ii). In addition, the Polynesian starling is a ‘central polynesian’ restricted range species (A2).

Non-bird biodiversity: Rinke (1991) records the abundance of Ficus the forest on the plateau, as well as the presence of Inocarpus edulis and coconuts and pawpaw. Other species noted include Wedelia biflora thickets, Pisonia grandis, Hibiscus tiliaceus and Casuarina equisetifolia. He confirmed the presence of the Polynesian rat Rattus exulans and three skinks. Emoia cyanura, E.pheonura and Cryptoblepharus eximius.

Populations of IBA trigger species

Species Season Period Population estimate Quality of estimate IBA Criteria IUCN Category
Wedge-tailed Shearwater Ardenna pacifica breeding  1990  20,000-50,000 individuals  good  A4ii  Least Concern 
Red-footed Booby Sula sula breeding  1990  10,000 individuals  poor  A4ii  Least Concern 
Brown Booby Sula leucogaster breeding  1990  1,000-10,000 individuals  poor  A4ii  Least Concern 
Polynesian Starling Aplonis tabuensis breeding  1990  abundant  A2  Least Concern 
A4iii Species group - waterbirds breeding  1990  20,000 individuals  good  A4iii   
A4iii Species group - seabirds breeding  1990  31,000-61,000 individuals  good  A4iii   


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

References Jenkins, J.A.F. 1980. Seabird records from Tonga-an account based on the literature and recent observations. Notornis 27:205-235. Prescott, N. and P. S. Folaumoetu’i (Editors). 2004. Tonga Biodiversity Stocktaking. Technical Report 1 for the National Biodiversity Strategy and Action Plan. Dept. of Environment, Nuku’alofa. Rinke, D. 1986. The status of wildlife in Tonga. Oryx 20:146-151. 1991. Birds of ‘Ata and Late, and additional notes on the avifauna of Niuafo’ou Island, Kingdom of Tonga. Notornis 38: 131-151. Stattersfield, A.J., M.J. Crosby, A.J. Long, and D.C. Wege. 1998. Endemic Bird Areas of the World: Priorities for biodiversity conservation. BirdLife Conservation Series no. 7, BirdLife International, Cambridge, UK. 846 pp. WWF 2001.

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Recommended citation  BirdLife International (2016) Important Bird and Biodiversity Area factsheet: 'Ata Island. Downloaded from on 21/10/2016

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