The IBA is identical to the total area of Lake Woods in the central Northern Territory when flooded to its maximum extent (close to 100,000 ha). It includes two near-permanent waterholes (Longreach and South Newcastle) on Newcastle Creek that become broadly contiguous with Lake Woods during major floods. Lake Woods is an ephemeral freshwater lake that can hold water for more than 12 consecutive months after major floods and follow-up rains. It has been filled to capacity on at least three occasions in the past 15 years. When inundated, Lake Woods is dominated by a vast expanse of open water. However, the basin of the lake supports broad bands and zones of open Lignum shrubland and, to the north, around the delta of Newcastle Creek, mixed open woodland of Coolibah, Gutta-percha and Belalie. Coolibah occurs around most of the lake perimeter, and River Red Gum is present, in association with Coolibah and Gutta-percha, around the waterholes. Other plant species/formations present in the IBA include Annual Verbine and Ludwigia perennis when the lake bed dries; dense, seasonal thickets of Budda Pea; mats of Nardoo and, during flood events, Ipomoea; occasional specimens of Northern Bluebush amongst the Lignum shrubland; and Spiny Mudgrass on Newcastle Creek and around the waterholes after floods. The IBA overlaps a single protected area, Longreach Waterhole Protected Area (DEWHA 2007; R. Jaensch pers. comm. 2007).
The IBA supports more than 20,000 and up to 116,000 waterbirds when fully inundated (Jaensch and Bellchambers 1997; Wetlands International, unpublished data provided by R. Jaensch). Sixty-seven species of waterbird have been recorded, and 23 of these have bred, in the IBA (Jaensch and Bellchambers 1997; Australian Wetlands Database 2001). Australasian Darters, Little Black Cormorants, Great Egrets, Intermediate Egrets, Straw-necked Ibis and Royal Spoonbills breed in colonies ranging in size from several hundred to several thousand birds (Jaensch and Bellchambers 1997; R. Jaensch pers. comm. 2007). The IBA is the only known inland breeding location, and possibly the only breeding location in the Northern Territory, for Great Egret (R. Jaensch pers. comm. 2007). Australian Pelicans (8000), Oriental Pratincoles (6000+) and Little Curlews (700+) have been recorded in substantial but sub-threshold numbers (DEWHA 2007; R. Jaensch pers. comm. 2007). Grey Teal (5000), Great Egrets (3000), Intermediate Egrets (2000) and Glossy Ibis (3300) have been recorded in moderate numbers (DEWHA 2007). Small numbers of Freckled Duck (e.g. 35 birds in March 1994) occur and may breed in the IBA (Jaensch 2003b). The nationally vulnerable Australian Painted Snipe has been recorded on a single occasion (Jaensch 2003a) but could be more common than the single record indicates, based on the extent of suitable habitat and the high potential for the species to be overlooked by observers (R. Jaensch pers. comm. 2007). Yellow Chats are abundant and breed in Lignum shrubland (Jaensch and Bellchambers 1997; DEWHA 2007). The globally near threatened Australian Bustard and biome-restricted Yellow-tinted Honeyeater are occasionally recorded in the IBA (Atlas of Australian Birds database).
Non-bird biodiversity: Seven species of fish have been recorded from Lake Woods and/or Newcastle Creek. Eight species of frog have been recorded in the general region and most of these probably occur in the IBA (Fleming et al. 1983). At least 24 faunal species recorded at the site are listed under international conventions or bilateral agreements protecting migratory animals (Harrison et al. 2009).
Pressure/threats to key biodiversity
Review Longreach Waterhole management agreement to assess conservation values and contribution to reserve network. Identify possible alternative reserves where appropriate. Work in partnership with landholder to continue weed control through the Barkly Landcare and Conservation Association. In conjunction with the Northern Land Council, investigate interest, or not, of the local Aboriginal community in undertaking land management activities in the reserve including possibly establishing a community based ranger group. In the context of review of the management agreement, investigate opportunities to upgrade facilities and access at Lake Woods and Longreach Waterhole in conjuction with the landholder, Elliot Town Council, and the Northern Territory Tourist Commission (NRETA 2005). Manage livestock to minimise the impact of grazing and trampling and initiate and support research projects that assess the impact of grazing on wetland vegetation. Maintain fencing to exclude livestock from Longreach Waterhole Protected Area. Conduct a comprehensive assessment of the incidence of Parkinsonia aculeata and implement a management strategy to eradicate or reduce it or prevent further spread. Maintain fish stocks in Newcastle Creek and Longreach and Newcastle Waterholes. Monitor human disturbance of waterbirds and their habitat and regulate boating activity to minimise disturbance of waterbird breeding colonies. Conduct a comprehensive assessment of threats at the site.
Conservation responses/actions for key biodiversity
Lake Woods is listed on the Register of the National Estate and the Directory of Important Wetlands in Australia (DEWHA 2007) and is classified as a site of conservation significance by the Northern Territory Government (Harrison et al. 2009; Ward & Harrison 2009). Since 1993, Wetlands International have conducted irregular surveys of waterbirds following major flood events (R. Jaensch pers. comm. 2007). A fence was erected around Longreach Waterhole Protected Area in 1984 to exclude livestock but the fence has not been maintained in recent years. Staff from the Parks and Wildlife Service undertake regular patrols at Longreach Waterhole to ensure that stock are excluded, document weeds and fauna, and to establish fire breaks when necessary. Fire on the tropical savannas is mapped continuously under the North Australia Fire Information Project. Four tier 1 rangeland monitoring points are located in the Lake Woods region (Harrison et al. 2009).
The IBA overlaps the Longreach Waterhole Protected Area.
Two pastoral leasehold properties (Powell Creek and Newcastle Waters) managed by Consolidated Pastoral. Longreach Waterhole Protected Area is managed as a reserve by Parks and Wildlife Service Northern Territory in cooperation with the pastoral lease managers.
Roger Jaensch of Wetlands International provided review comments and interpretation on the habitat and waterbird information.