|Most recent IBA monitoring assessment|
|Year of assessment||Threat score (pressure)||Condition score (state)||Action score (response)|
|2008||medium||not assessed||not assessed|
|For more information about IBA monitoring please click here|
The IBA is comprised of Tarrabool Lake and an unnamed swamp to the north-west of Tarrabool Lake on Eva Downs Station (unofficially titled Eva Downs Swamp). In wetter years, these two water bodies become broadly connected to form a single massive freshwater wetland of up to 275,000 ha. Tarrabool Lake and Eva Downs Swamp are seasonally inundated, but may retain water for 12 consecutive months (or more in the case of Tarrabool Lake) after major flood events. Tarrabool Lake is dominated by low sparse to open Coolibah woodland, with extensive open Lignum shrubland (often under Coolibah woodland) in the centre-east, large areas devoid of trees in the centre-north and centre-south, and smaller open areas elsewhere, and some patches of open Northern Bluebush shrubland. The heart of Eva Downs Swamp is dominated by open Belalie woodland, mostly in association with open Lignum shrubland, and is surrounded by open Northern Bluebush shrubland; and there is tall tussock grassland to the south-east, with some open Coolibah woodland on the southern margin. Ground-cover plants such as Schoenoplectus dissachanthus can grow prolifically on drying or marshy areas of the system, and Nardoo is common (DEWHA 2007; R. Jaensch pers. comm. 2007).
The IBA supports large numbers of waterbirds when conditions are suitable, e.g. up to 269,000 waterbirds may have been present during a major flood event in 2001-2002. At least 50 species of waterbird have been recorded, and 17 of these species are known to breed, in the IBA (Jaensch & Bellchambers 1997; Wetlands International, unpublished data provided by R. Jaensch). Species recorded in notable but sub-threshold numbers are Freckled Duck (84 on 29 March 2006), Great Egret (several thousand in 2001-2002 and 2006), Glossy Ibis (possibly more than 10,000 in March 2006) and Gull-billed Tern (1300 in 1995) (Jaensch & Bellchambers 1997; Wetlands International, unpublished data provided by R. Jaensch). Species observed in many thousands, but not confirmed to exceed thesholds, include the Magpie Goose, Plumed Whistling-Duck, Grey Teal, Hardhead and Intermediate Egret (R. Jaensch pers. comm. 2007). The nationally vulnerable Australian Painted Snipe bred at Tarabool Lake in 1993 (Jaensch 2003a), this representing the first breeding record for the species in the Northern Territory (R. Jaensch pers. comm. 2007). A breeding event involving 1500 pairs of Great Egret at Eva Downs Swamp in 2001 (Jaensch & Bellchambers 1997; Wetlands International, unpublished data provided by R. Jaensch) may be the largest documented breeding effort by this species in inland tropical Australia (R. Jaensch pers. comm. 2007).
Non-bird biodiversity: At least seven faunal species recorded in the Tarabool Lake-Eva Downs region are listed under international conventions or bilateral agreements protecting migratory animals .
BirdLife International (2020) Important Bird Areas factsheet: Tarrabool Lake-Eva Downs Swamp System. Downloaded from http://www.birdlife.org on 05/07/2020.