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Location Australia, Commonwealth
Central coordinates 123o 5.60' East  12o 14.43' South
IBA criteria A4i, A4ii
Area 58,343 ha
Altitude 0 - 3m
Year of IBA assessment 2009

BirdLife Australia

Summary The IBA is a staging area for >1% of the global population of Grey-tailed Tattler and has supported breeding colonies comprised of >1% of the global populations of Brown Booby and Lesser Frigatebird.

Site description The IBA is identical to Ashmore Reef National Nature Reserve, which lies approximately 840 km west of Darwin and 610 km north of Broome in the Timor Sea. The IBA captures three islands - West Island, Middle Island and East Island - and surrounding rocky reefs, tidal sand flats and inshore waters which are important for seabirds. The IBA excludes Cartier and Scott Reefs and Browse Island. Ashmore Reef is a shelf-edge platform reef consisting of three islets surrounded by intertidal reef and sand flats and deeper subtidal reef and sand flats. The southern and windward side of the reef has developed a robust algal ridge, which extends unbroken around to the eastern rim. The reef flat is well defined and up to two kilometres wide behind this algal ridge. The islands support herbs and grasses with fringing bands and/or remnant patches of shrubland, and West Island also has some coconut trees. The climate is dry tropical with prominent cloud, rain and thunderstorm activity with most of the mean annual 950 mm of rainfall occurring in the monsoon season between December and May. Cyclones can occur between November and May. The south-easterly trade winds blow strongly, regularly at 20-25 knots, from May to September. Fresh water lenses develop in the sand during the monsoon season; a fresh water pump installed near the beach on West Island is maintained by Environment Australia for use by visiting Indonesian fishermen.

Key Biodiversity Ninety-five species of bird have been recorded from the islands and waters around Ashmore Reef Nature Reserve. This figure includes 42 species listed under the Japan-Australia Migratory Bird Agreement (JAMBA) and/or China-Australia Migratory Bird Agreement (CAMBA). Twenty species are known to breed in the reserve (DEWHA 2008). The islands of Ashmore Reef provide breeding sites for large but sub-threshold numbers of Sooty Tern (estimated 40,020 birds from 23-29 January 2002, 15,002 birds from 24 January-3 February 2003 and 10,000 birds on 26 October 2006). Large colonies of Crested Tern, Bridled Tern and Common Noddy (4,515 birds from 23-29 January 2002, 2060 birds from 24 January-3 February 2003, 15,000 birds on 28 October 2004 and 5010 birds on 27 October 2006), and smaller breeding colonies of Black Noddy (1600 birds from 23-29 January 2002), Red-tailed Tropicbirds, White-tailed Tropicbirds, Roseate Terns and Wedge-tailed Shearwaters breed on the islands (Australian National Parks and Wildlife Service 1989; Stokes and Hinchey 1990; Swann 2005a, 2005b; Kimberley Birdwatching unpublished data). Other species recorded in notable but sub-threshold numbers on the islands include Bar-tailed Godwit (2,536 birds on 28 January 2002, 2785 birds on 2 February 2003, 2500 birds on 28 October 2004 and 4560 birds on 28 January 2005), Ruddy Turnstone (1700 birds on 4-5 November 2001, 1708 birds on 2 February 2003 and 1515 birds on 29 January 2005), Great Knot (1592 birds on 28 January 2002 and 1090 birds on 29 January 2005), Sanderling (1132 birds on 2 February 2003), Red-necked Stint (975 birds on 28 January 2002, 1128 birds on 2 February 2003 and 1530 birds on 29 January 2005), Pacific Golden Plover (562 birds on 2 February 2003 and 669 birds on 29 January 2005), Grey Plover (1475 birds on 2 February 2003 and 1511 birds on 29 January 2005), Greater Sand Plover (1196 birds on 28 January 2002, 1295 birds on 2 February 2003 and 2490 birds on 28 January 2005) (Swann 2005a, 2005b; Kimberley Birdwatching unpublished data).

Non-bird biodiversity: Ashmore Reef is reported to have the highest diversity and number of sea snakes for any reef system: 14 species have been identified but as many as 19 species may be present. Marine turtles nest on all the islands. Green Turtle Chelonia mydas are the most common nesting turtle, with an estimated population of approximately 10,000 (Guinea 1995). There is a small population of Loggerhead turtles Caretta caretta nesting on the islands and a smaller population of Hawksbill turtles Eretmochelys imbricata that utilise the waters of Ashmore Reef. Regular sightings of Dugong Dugong dugon, sometimes with calves. The islands also support a limited variety of plant species (Pike & Leach 1997) and a suite of terrestrial invertebrates including hermit crabs, 127 species of insect, seven species of spider and a single species each of millipede, centipede and pseudoscorpion (Brown 1999). The Asian House Gecko is common on the islands (Commonwealth of Australia 2002).

Populations of IBA trigger species

Species Season Period Population estimate Quality of estimate IBA Criteria IUCN Category
Lesser Frigatebird Fregata ariel resident  2001-2006  2,300 individuals  unknown  A4ii  Least Concern 
Brown Booby Sula leucogaster resident  2001-2006  4,800 individuals  unknown  A4ii  Least Concern 
Grey-tailed Tattler Tringa brevipes non-breeding  1998-2006  85-1,706 individuals  medium  A4i  Near Threatened 

IBA Monitoring

2008 high not assessed not assessed
Good - based on reliable and complete / representative data

Climate change and severe weather storms and floods likely in long term (beyond 4 years) whole area/population (>90%) slow but significant deterioration medium
Human intrusions and disturbance work and other activities happening now majority/most of area/population (50-90%) slow but significant deterioration high
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

Protected areas

Protected area Designation Area (ha) Relationship with IBA Overlap with IBA (ha)  
Ashmore Reef National Nature Reserve 58,337 is identical to site 58,343  
Ashmore Reef National Nature Reserve Wetlands of International Importance (Ramsar) 58,300 is identical to site 58,300  


IUCN habitat Habitat detail Extent (% of site)
Coastline Intertidal mud, sand & salt flats; Sand cays, islets & bars; Sea cliffs, rocky shores & rocky islets  major
Shrubland   minor

Land ownership Federal Government - managed by Department of the Environment and Water Resources.

Land use

Land-use Extent (% of site)
nature conservation and research 100%

Protection status Ashmore Reef National Nature Reserve

Access/Land-Owner requests The only permitted point of public access is the eastern beach of Western Island. Public access to Middle and East Islands is prohibited.

Acknowledgements George Swann, Susan Forbes and Amelia Tandy kindly provided or facilitated bird count data. The nomination was prepared by Scott Chambers in consultation with George Swann.

References Brown, G.R. (1999). A Preliminary Report on the Insects of Ashmore Reef National Nature Reserve. Unpublished report of the Northern Territory Museum: Darwin.

Commonwealth of Australia (2002). Ashmore Reef National Nature Reserve and Cartier Island Marine Reserve (Commonwealth Waters) Management Plans. (Environment Australia: Canberra.)Commonwealth of Australia (2005) Ashmore Reef and Cartier Island Reserves brochure. (Environment Australia: Canberra.)

DEWHA (2008) Directory of Important Wetlands in Australia. accessed 2008.

Lavering, I.H. (1993)Quaternary and modern environments of the Van Diemen Rise, Timor Sea, and potential effects of additional petroleum exploration activity. Journal of Australian Geology and Geophysics 13: 281-292.

Milton, D. (1999)Occasional Count No. 2: Ashmore Reef, north-western Australia. Stilt 34: 35.

Milton, D.A.(1999)Birds of Ashmore Reef National Nature Reserve. Unpub rpt.

Pielke, R.A. (1990)The Hurricane. (Routledge: London.)

Pike, G.D. (1993)Birds of Ashmore Reef. Wingspan 11: 12-14.

Pike, G.D., & Leach, G.J. (1997)Handbook of the Vascular Plants of Ashmore and Cartier Islands. (Parks Australia: Canberra.)

Swann, G. (2005a)Occasional Count No. 7 - Ashmore Reef, 21 to 30 January 2002. Stilt 47: 26-33.

Stokes, T. & Hinchey, M. (1990) Which Small Noddies Breed at Ashmore Reef in the Eastern Indian Ocean? Emu 90:269-71.

Swann, G. (2001)Ornithological Report of Ashmore Reef - November 2001, Unpub rpt to Env Aust.

Swann, G. (2003)Ornithological Report: Ashmore Reef, 23 January to 4 February 2003. Unpublished report.

Swann, G. (2005b)Occasional Count No. 8 - Ashmore Reef, 23 January to 4 February 2003. Stilt 47: 34-39.

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Recommended citation  BirdLife International (2016) Important Bird and Biodiversity Area factsheet: Ashmore Reef. Downloaded from on 25/10/2016

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