|Location||Australia, Northern Territory|
|Central coordinates||136o 42.12' East 12o 50.60' South|
|Altitude||0 - 10m|
|Year of IBA assessment||2009|
Summary The Three Hummocks Islands are a group of small granite islands with very large numbers of Bridled Terns nesting on the four largest islands. Smaller numbers of Roseate Terns have also been recorded nesting on adjacent islands.
Site description The Three Hummocks Island group is south of Wanyanmera Point in north-east Arnhem Land. They are a group of partially vegetated granite island with large numbers of Bridled Terns nesting on the four largest islands. The IBA also includes the nearby rocky and sandy Dudley Island to the south and a number of unnamed rocky islets to the north. These are island refs S038, S039, S041, S104 and S105 in Chatto (2001).
Key Biodiversity Chatto (2001) made nine counts on the Three Hummocks Island group. The estimated numbers of Bridled Terns nesting in the four years between 1993-1999 when counts were made were 10,000, 5000, 7500 and 20,000-50,000. On the small islands to the north, up to 500 Roseate Terns and 450 Black-naped Terns were recorded as irregularly nesting. On Dudley Island to the south, up to 300 Black-naped, 200 Bridled and 200 Roseate Terns have been recorded nesting.
|Species||Season||Period||Population estimate||Quality of estimate||IBA Criteria||IUCN Category|
|Bridled Tern Onychoprion anaethetus||breeding||1990-2000||20,000-50,000 individuals||medium||A4i||Least Concern|
|2008||low||not assessed||not assessed|
|Poor - based on little, or potentially unreliable/unrepresentative, data|
|No known threats||no known threats||happening now||small area/few individuals (<10%)||no or imperceptible deterioration||low|
|Protected area||Designation||Area (ha)||Relationship with IBA||Overlap with IBA (ha)|
|Laynhapuy||Indigenous Protected Area||450,000||protected area overlaps with site||112|
|IUCN habitat||Habitat detail||Extent (% of site)|
|Coastline||Sea cliffs, rocky shores & rocky islets||major|
Land ownership Arnhem Land ALT
|Land-use||Extent (% of site)|
|Notes: Traditional use|
Protection status There is an overlap with the Laynhapuy Indigenous Protected Area.
Access/Land-Owner requests Traditionally-owned land.
References Chatto, R. (2001) The distribution and status of colonial breeding seabirds in the NT. Technical Report 70. Parks and Wildlife Commission of the Northern Territory, Palmerston. Harrison, L., McGuire, L., Ward, S. Fisher, A., Pavey, C., Fegan, M. and Lynch, B. (2009) An inventory of sites of international and national significance for biodiversity values in the Northern Territory. Department of Natural Resources, Environment, the Arts & Sport, Darwin, NT. Ward, S. and Harrison, L. (2009) Recognising sites of conservation significance for biodiversity values in the Northern Territory. Department of Natural Resources, Environment, the Arts & Sport, Darwin, NT.
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Recommended citation BirdLife International (2016) Important Bird and Biodiversity Area factsheet: Three Hummocks Island. Downloaded from http://www.birdlife.org on 27/08/2016
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