Alligator Rivers Floodplains


IBA Justification

The site was identified as important in 2009 because it was regularly supporting significant populations of the species listed below, meeting ('triggering') IBA criteria.

Populations meeting IBA criteria ('trigger species'):
Species Current IUCN Red List Category Season Year(s) Population estimate at site IBA criteria met
Magpie Goose Anseranas semipalmata LC resident 1981-1994 1,600,000 individuals A4i
Plumed Whistling-duck Dendrocygna eytoni LC resident 1981-1994 50,000 individuals A4i
Wandering Whistling-duck Dendrocygna arcuata LC resident 1981-1994 400,000 individuals A4i
Radjah Shelduck Radjah radjah LC resident 1981-1994 20,000 individuals A4i
Green Pygmy-goose Nettapus pulchellus LC resident 1981-1994 50,000 individuals A4i
Pacific Black Duck Anas superciliosa LC resident 1981-1994 60,000 individuals A4i
Grey Teal Anas gracilis LC resident 1981-1994 50,000 individuals A4i
Brolga Grus rubicunda LC resident 1981-1994 24,000 individuals A4i
Australian Bustard Ardeotis australis LC resident 1998-2008 212 individuals A1
Black-necked Stork Ephippiorhynchus asiaticus NT resident 1981-1984 1,800 individuals A1, A4i
Royal Spoonbill Platalea regia LC resident 1981-1994 35,000 individuals A4i
Australian Ibis Threskiornis moluccus LC non-breeding 1981-1994 15,000 individuals A4i
Straw-necked Ibis Threskiornis spinicollis LC resident 1981-1994 80,000 individuals A4i
Glossy Ibis Plegadis falcinellus LC resident 1981-1994 60,000 individuals A4i
Plumed Egret Ardea plumifera LC resident 1981-1994 200,000 individuals A4i
Pied Heron Egretta picata LC breeding 1981-1994 50,000 individuals A4i
Australian Pelican Pelecanus conspicillatus LC resident 1981-1994 50,000 individuals A4i
Bush Thick-knee Burhinus grallarius LC resident 1998-2008 frequent A1
Black-winged Stilt Himantopus himantopus LC resident 1981-1994 100,000 individuals A4i
Masked Lapwing Vanellus miles LC resident 1981-1994 80,000 individuals A4i
Comb-crested Jacana Irediparra gallinacea LC resident 1981-1994 25,000 individuals A4i
Little Curlew Numenius minutus LC non-breeding 1981-1994 300,000 individuals A4i
Sharp-tailed Sandpiper Calidris acuminata VU non-breeding 1990-2002 4,900 individuals A4i
Australian Pratincole Stiltia isabella LC non-breeding 1981-1994 30,000 individuals A4i
Whiskered Tern Chlidonias hybrida LC non-breeding 1981-1994 45,000 individuals A4i
Northern Rosella Platycercus venustus LC resident 1998-2008 uncommon A3
Varied Lorikeet Psitteuteles versicolor LC resident 1998-2008 uncommon A3
Rainbow Pitta Pitta iris LC resident 1998-2008 uncommon A2, A3
Banded Honeyeater Cissomela pectoralis LC resident 1998-2008 uncommon A3
Silver-crowned Friarbird Philemon argenticeps LC resident 1998-2008 uncommon A3
Bar-breasted Honeyeater Ramsayornis fasciatus LC resident 1998-2008 uncommon A3
White-gaped Honeyeater Stomiopera unicolor LC resident 1998-2008 abundant A3
Buff-sided Robin Poecilodryas cerviniventris LC resident 1998-2008 uncommon A3
Australian Yellow White-eye Zosterops luteus LC resident 1998-2008 uncommon A3
Masked Finch Poephila personata LC resident 1998-2008 uncommon A3
Long-tailed Finch Poephila acuticauda LC resident 1998-2008 frequent A3

The current IUCN Red List category may differ from that which was valid at the time of IBA criteria assessment (2009).


IBA Conservation

IBA conservation assessment
Year of assessment (most recent) State (condition) Pressure (threat) Response (action)
2008 not assessed high not assessed
Was the whole site assessed? State assessed by Accuracy of information
yes unset good

Pressure (threats to the trigger species and/or their habitats)
Threat level 1 Threat level 2 Timing Scope Severity Result
Climate change and severe weather storms and floods likely in long term (beyond 4 years) some of area/population (10-49%) slow but significant deterioration medium
Energy production and mining mining and quarrying happening now small area/few individuals (<10%) slow but significant deterioration low
Invasive and other problematic species and genes invasive non-native/alien species/diseases - named species happening now majority/most of area/population (50-90%) slow but significant deterioration high

Response (conservation actions taken for the trigger species and/or their habitats)
Protected-area designation Management planning Other conservation action Result
Not assessed Not assessed Not assessed not assessed
For more information about IBA conservation status, please click here

IBA Protection

Protected area (PA) PA designation PA area (ha) Relationship of PA with IBA Overlap of PA with IBA (ha)
Mary River National Park 121,525 protected area is adjacent to site 0
Kakadu National Park World Heritage Site (natural or mixed) 1,980,994 protected area overlaps with site 240,333
Kakadu National Park Ramsar Site, Wetland of International Importance 1,902,510 protected area overlaps with site 0
Kakadu National Park (Commonwealth) 1,911,167 protected area overlaps with site 0
Kakadu National Park 1,980,400 protected area overlaps with site 248,294

Habitats

Habitat (IUCN level 1) Habitat detail Extent (% of site)
Forest Melaleuca forests & woodlands, Mangroves -
Shrubland Chenopod shrubs, samphire shrubs and forblands -
Wetlands (inland) Riverine floodplains -
Marine Intertidal -
For more information about the IUCN Habitat classification, please click here.

Land use

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

Land ownership
Kakadu NP owned by Traditional Owners and managed in partnership with National Parks; wetlands to east owned by Arnhemland ALT.


Recommended citation
BirdLife International (2024) Important Bird Area factsheet: Alligator Rivers Floodplains. Downloaded from https://datazone.birdlife.org/site/factsheet/alligator-rivers-floodplains-iba-australia on 21/02/2024.