Distribution
In South Australia, the RAOU Atlas is still the best basis from which to assess changes in the distribution of Malleefowl in light of recent data. Historically, the species was known from the south-east comer of the state through the Murray Mallee to the South Olary Plains north of the Murray River, and westwards through a broad band of mallee and acacia shrublands into the western region of the state. This distribution was probably continuous with the exception of a gap of unsuitable habitat from the Flinders Ranges to Spencer Gulf and this may have been the only longstanding gap in the species distribution across southern Australia. Malleefowl were never known for the Nullarbor Plain in far west SA, but were recorded historically in the eastern Great Victoria Desert.
Prior to 1981, Malleefowl were recorded in 37 one-degree grid cells compared with only 15 grid cells since then. It is likely that the species still persists in some remote areas where it has not been recorded since the RAOU Atlas. Recent breeding records of the species in the Yellabinna Wilderness Area and in the northern Great Victoria Desert, suggest that the species has persisted in suitable habitat over a broad range of this remote landscape, albeit in very small numbers.
In the south-east of SA, east of Spencer Gulf, the historical range has contracted and Malleefowl no longer occur south of Naracoorte, in the vicinity of Adelaide, or on most of Yorke Peninsula (although the species still occurs at the tip of Yorke Peninsula at Innes NP). Clearing for agriculture and urbanisation are the primary reasons for these local extinctions. Within the current range south of the Murray River, Malleefowl have been recorded in numerous small areas of native vegetation that are remnant after clearing. Since 1990, Malleefowl have been recorded in 124 isolated remnants with a median size of about 250 ha, as well as in larger reserves. There has been much less clearing north of the Murray River and Malleefowl are believed to still occupy most suitable habitat at low densities.
In the arid rangelands on northern Eyre Peninsula, Malleefowl have become locally extinct from a number of areas although the reasons for this are uncertain. Much of the former habitat on Eyre Peninsula has been cleared, although the species has persisted in isolated patches of suitable habitat.
Measures of abundance
Measures of Malleefowl abundance have been obtained for eleven monitoring sites in the south east of the State, and Eyre Peninsula. These suggest breeding densities of between two and four pairs per km² in most years, and probably reflect the carrying capacity of these sites. Using the results of postal surveys and known Malleefowl densities in some areas, it is estimated that there were between three and ten thousand Malleefowl inhabiting the south-east of the state, south of the Murray River. No estimates of breeding density are available for the regions in the Great Victoria Desert. However, eight sites have been located in which Malleefowl have bred during the last few years.
Trends in Malleefowl populations
There are few data available to assess population trends in SA as most monitoring sites have been monitored for less than five years. At one site, (Bakara), Malleefowl density has increased since baiting of the general area for foxes was begun in the early 1990's.