|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|
Lake Argyle varies in size from less than 750 km² to over 2000 km². The maximum depth is about 50 m over the original channel of the Ord River but the southern and eastern slopes are very shallow with gradients less than 1 in 500. Water levels fluctuate about 4 m every year, preventing the growth of extensive fringing vegetation, but allowing floating weeds to develop extensive mats up to hundreds of metres wide. The IBA includes the maximum extent of the lake, which includes large areas of mud flats and flat grasslands when the lake is not in full flood.
Lake Argyle supported around 181,400 waterbirds in 1986 (Jaensch and Vervest 1990), 150,000 in 2005 (Hassell et al. 2006), which could be extrapolated to 200,000, and 245,000 in 2007 (Bennelongia 2007). Other waterbirds with high numbers estimated in these surveys (note that the 2005 survey was better timed for shorebirds) include: 50,800, 54,327 and 9659 Eurasian Coot (in 1986, 2005 and 2007 respectively), 17,200, 11,602 and 4300 Grey Teal, 972, 4558 and 4082 Glossy Ibis, 60, 5091 and 99 Marsh Sandpiper, 150, 3732 and 119 Australasian Grebe, 3362, 510 and 1725 Plumed Whistling-Duck, 90, 2308 and 30 Wood Sandpiper, 657, 369 and 1133 Radjah Shelduck, 460, 646 and 517 Australasian Darter, 398, 52 and 4 Brolga and, in 2005, 6264 Pink-eared Duck, 1687 Little Curlew and 159 Freckled Duck. Few waterbirds breed, max 245 pairs of Pied Cormorant in 1986. A flock of 3000 Flock Bronzewings was seen in December 2005. Yellow Chats breed, and more than 100 were counted in 1986. Six Australian Painted Snipe were seen in August 2007 (G. Dutson pers. obs.; http://www.birdswa.com.au/sightings/sightings_124.htm). Terrestrial restricted-range or biome-restricted species which have been recorded in small numbers around the margin of the IBA include Banded Honeyeater, Bar-breasted Honeyeater, Bush Stone-curlew, Long-tailed Finch, Masked Finch, Northern Rosella, Purple-crowned Fairy-wren (probably now extirpated; G. Dutson pers. obs.), Sandstone Shrike-thrush, Silver-crowned Friarbird, Star Finch, White-gaped Honeyeater, White-quilled Rock-Pigeon and Yellow-tinted Honeyeater (Atlas of Australian Birds database).
BirdLife International (2021) Important Bird Areas factsheet: Lake Argyle. Downloaded from http://www.birdlife.org on 16/01/2021.