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Location Australia, Western Australia
Central coordinates 121o 9.09' East  19o 41.44' South
IBA criteria A1, A2, A4i
Area 333,723 ha
Altitude 0 - 15m
Year of IBA assessment 2009

BirdLife Australia

Summary When flooded, the IBA supports more than 1% of the global populations of Plumed Whistling-Duck, Hardhead, White-necked Heron, Glossy Ibis, Straw-necked Ibis, Brolga, Little Curlew, Banded Stilt, Black-winged Stilt, Red-necked Avocet, Oriental Plover, Oriental Pratincole, Gull-billed Tern and Whiskered Tern. It also supports populations of the near threatened Australian Bustard and Bush Thick-knee and the restricted-range Dusky Gerygone.

Site description The IBA is a periodically flooded marshland that extends approximately 60 km inland from the coastal sand dunes of Eighty Mile Beach in the southern Kimberley. The IBA is defined as the maximum extent of flooded land inland of Eighty Mile Beach (which extends for 220 km between Cape Missiessy and Cape Keraudren), extrapolated from maps in Halse et al. (2005). Only a few species of shorebird move regularly between this and the intertidal Eighty Mile Beach IBA, so these are kept as separate IBAs. Most of Mandora Marsh and Anna Plains consists of grazed samphire and grassland, and includes a permanent saline creek, permanent fresh to brackish springs and a large saline basin that is bare when dry. Low-lying sections of the western marshland support introduced Buffel Grass, with a mixture of shrubs and trees present in more elevated areas. The climate is tropical with hot summers, warm winters and mean annual rainfall of 341 mm. The west end is crossed by the Great Northern Highway. Part of the IBA is included within the Eighty-mile Beach Ramsar site.

Key Biodiversity Notable sub-threshold counts from the IBA include 16,500 Grey Teal, 2650 Hoary-headed Grebe and 43,290 Eurasian Coot in August 1999, 7530 Australian Pelican in June 2000 and 19,190 Grey Teal and 160 Black-fronted Dotterel in August 2000 (Halse et al. 2005). Three near threatened species, Black-necked Stork, Letter-winged Kite and Grey Falcon, have been recorded in the IBA but not in significant numbers; the nationally threatened Australian Painted Snipe has been recorded breeding (Atlas of Australian Birds database; Hassell and Rogers 2002). The biome-restricted Black Honeyeater, Pied Honeyeater, Yellow-tinted Honeyeater, Long-tailed Finch and Grey-headed Honeyeater have rarely been recorded and are probably not present in sufficient numbers to justify inclusion as IBA trigger species (Atlas of Australian Birds database; C. Hassell in litt. 2008). Australian Yellow White-eye has rarely been recorded (Atlas of Australian Birds database) but is potentially relatively common in mangroves.

Populations of IBA trigger species

Species Season Period Population estimate Quality of estimate IBA Criteria IUCN Category
Plumed Whistling-duck Dendrocygna eytoni resident  1999-2000  740-14,070 individuals  A4i  Least Concern 
Hardhead Aythya australis resident  1999-2000  1,940-98,750 individuals  A4i  Least Concern 
Straw-necked Ibis Threskiornis spinicollis resident  1999-2000  31,860-48,630 individuals  A4i  Least Concern 
Glossy Ibis Plegadis falcinellus unknown  1999-2000  880-26,140 individuals  A4i  Least Concern 
White-necked Heron Ardea pacifica resident  1999-2000  1,120-1,760 individuals  A4i  Least Concern 
Australian Bustard Ardeotis australis resident  1998-2008  common  A1  Least Concern 
Brolga Antigone rubicunda unknown  1999-2000  20-3,620 individuals  A4i  Least Concern 
Bush Thick-knee Burhinus grallarius resident  1998-2008  frequent  A1  Least Concern 
Himantopus leucocephalus resident  1999-2000  101,760-219,520 individuals  A4i  Not Recognised 
Banded Stilt Cladorhynchus leucocephalus unknown  1999-2000  2,670 individuals  A4i  Least Concern 
Red-necked Avocet Recurvirostra novaehollandiae unknown  1999-2000  180-3,740 individuals  A4i  Least Concern 
Oriental Plover Charadrius veredus non-breeding  1988-2006  29,000-60,000 individuals  A4i  Least Concern 
Little Curlew Numenius minutus non-breeding  1988-2006  12,000 individuals  A4i  Least Concern 
Oriental Pratincole Glareola maldivarum non-breeding  1998-2006  20,000-2,880,000 individuals  A4i  Least Concern 
Sterna nilotica breeding  1999-2000  70-6,590 individuals  A4i  Not Recognised 
Whiskered Tern Chlidonias hybrida breeding  1999-2000  4,920-27,360 individuals  A4i  Least Concern 
Dusky Gerygone Gerygone tenebrosa resident  1998-2008  common  A2  Least Concern 

IBA Monitoring

2008 low not assessed not assessed
Medium - based upon reliable but incomplete / partially representative data

Agriculture and aquaculture livestock farming and ranching (includes forest grazing) - agro-industry grazing, ranching or farmin happening now majority/most of area/population (50-90%) no or imperceptible deterioration low
Invasive & other problematic species, genes & diseases invasive non-native/alien species/diseases - named species happening now majority/most of area/population (50-90%) no or imperceptible deterioration low


IUCN habitat Habitat detail Extent (% of site)
Grassland Tussock grasslands  major
Wetlands (inland) Ephemeral; Salt marshes  major
Coastline Mangrove wetlands  minor

Land ownership Crown Land including Mandora, Anna Plains and Wallal pastoral leases.

Land use

Land-use Extent (% of site)
energy production and mining minor
rangeland/pastureland major

Protection status None.

Access/Land-Owner requests Access to the IBA must be granted by managers of the pastoral leases.

Acknowledgements The owners of Anna Plains Station have supported the Australasian Wader Studies Group and Broome Bird Observatory to undertake bird research at the site. Thanks to Chris Hassell as compiler.

References Collins, P. (1995) The Birds of Broome – An Annotated List. Broome, Western Australia: Broome Bird Observatory.

DEWHA (2008) A Directory of Important Wetlands in Australia. Mandora Salt Marsh-WA042. Downloaded from accessed November 2008.

Halse, S.A., Pearson, G.B., Hassell, C., Collins, P., Scanlon, M.D. and Minton, C.D.T. (2005) Mandora Marsh, north-western Australia, an arid-zone wetland maintaining continental populations of waterbirds. Emu 105: 115-125.

Hassell, C.J. and Rogers, D.I. (2002) Painted Snipe nesting at Taylor’s Lagoon near Broome, North-western Australia. Stilt 41: 14-21.

Lane, B.A. (1987) Shorebirds in Australia. Melbourne: Nelson Publishers.

Minton, C., Jessop, R., Collins, P. and Hassell, C. (2005) NWA 2005 wader and tern expedition, 12 February to 6 March 2005. Stilt 47: 58-64.

Sitters, K., Minton, C., Collins, P., Etheridge, B., Hassell, C. and O’Connor, F. (2004) Extraordinary numbers of Oriental Pratincoles in NW Australia. Stilt 45: 43-49.

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Recommended citation  BirdLife International (2016) Important Bird and Biodiversity Area factsheet: Mandora Marsh and Anna Plains. Downloaded from on 27/10/2016

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