The IBA is the maximum extent of the ephemeral Lake Mackay, the fourth largest lake in Australia, which spans the Western Australia and Northern Territory border. Lake Mackay is a vast salt lake with numerous islands and smaller freshwater swamps and pans in the surrounding sandplains and dunes. Inundation is infrequent but can persist for more than six months. The water and islands of the lake provide important breeding habitat for waterbirds (Duguid et al. 2005). There are numerous mineral exploration licences and projects around the lake.
There has been only one comprehensive survey of waterbirds at Lake Mackay: an aerial survey of two hours duration in 2001 counted 40,344 waterbirds of at least 21 different species (subsequent ground surveys recorded an additional six species). Actual waterbird numbers were probably greater than the total counted because the survey covered only part of the lake and was undertaken some months after water levels had begun to recede. The count of 40,344 waterbirds included globally significant numbers of Black-winged Stilt, Banded Stilt and Red-necked Avocet as well as 4653 Grey Teal, 8460 unidentified ducks and 4600 Whiskered and/or White-winged Black Terns. Although conditions at Lake Mackay may only infrequently be suitable for the Banded Stilt to breed, the low number of Silver Gulls present at the site might enable the stilts to breed with greater success than at other locations (Duguid et al. 2005). The near threatened Australian Bustard has been recorded at Lake Mackay (Ward et al., in prep.) but numbers have not been quantified.
Non-bird biodiversity: One plant species, Stackhousia sp. Lake Mackay, is endemic to the site, and another, Swainsonea cyclocarpa, which occurs at the site, has a restricted range in the Northern Territory.
Pressure/threats to key biodiversity
Establish a survey program as part of the Bioregion Natural Resource Assessment to assess conservation and cultural values and develop appropriate conservation management programs (NRETA 2005).
Aboriginal freehold title held by Lake Mackay Aboriginal Land Trust. The Northern Territory component of Lake Mackay is part of the proposed Southern Tanami Indigenous Protected Area.
Site access / Land-owner requests
Permission is required to access tribal land.
The nomination was prepared by Birds Australia. Thanks to Louise Harrison and Ray Chatto for providing information.
BirdLife International (2022) Important Bird Areas factsheet: Lake Mackay. Downloaded from
http://www.birdlife.org on 27/11/2022.