Document ID: chunk:federal_register_of_legislation:F2016L01082:reg:1:p6
Version: federal_register_of_legislation:F2016L01082
Segment Type: reg
Provision Reference: reg 1 (pt 6/30)
Character Range: 19976–22872

Radford et al., 2013) have shown that the species is likely to be more scarce now than it was in the 1990s.
Within the Patho Plains of Victoria the plains-wanderer population was estimated to have undergone a reduction in numbers of greater than 90% between 2010 and 2012 (Radford et al., 2013) and by 2014 the population on ten private paddocks on the Patho Plains are estimated to have declined by approximately 95% since 2010 (Baker-Gabb, 2014). Declines in numbers also appear to be similar for populations in Terrick Terrick National Park (Antos, 2014) and Avoca Plains (Baker-Gabb, 2012). Following several surveys during which there were no records of birds breeding on the Patho Plains or Avoca Plains (Baker-Gabb, 2014), a sub-adult pair was observed in late 2014, a male with four chicks was observed in early 2015 and a nest with eggs was recorded in late 2015, indicating that limited breeding has again been occurring in these areas (Antos, 2015). Two possible hypotheses are proposed to explain the reduction in numbers in Victoria; either the Victorian population has undergone a mass migration or it has experienced mass mortality (Radford et al., 2013). While there may be suitable habitat within inland Australia into which the Victorian plains-wanderer population could have migrated, there is no evidence for this (Antos, 2013b; Radford et al., 2013).
Within the Riverina region of New South Wales the plains-wanderer population was estimated to have undergone a reduction in numbers of approximately 75% during the 2002 drought, after which time there was only minor, staged increases in numbers between 2004 to 2010 (Parker & Baker-Gabb, 2013). Further population declines in the Riverina population of plains-wanderer subsequently occurred following the increased rainfalls experienced from late 2010 to 2012 (Parker & Baker-Gabb, 2013). Recent analysis of monitoring data collected between 2001 and 2014 indicates that there was an overall decline in numbers of 93% across sites in the Riverina region over this time period (Wilson et al., 2014).
The size of the plains-wanderer population is likely to vary with seasonal conditions. Studies by Baker-Gabb et al (1990) indicated that the Riverina population of plains-wanderer could vary by up to 80% from year to year in times of drought. Previously, plains-wanderer populations have been shown to recover from population declines associated with drought conditions and localised overgrazing (Baker-Gabb et al., 1990, Maher, 1997). However, Parker and Baker-Gabb (2013) noted that plains-wanderer numbers have now remained historically low for more than a decade.

3.4 Biology and ecology

3.4.1 Longevity
The life expectancy of plains-wanderers in the wild is unknown (Baker-Gabb, 2002a), but in captivity they are capable of surviving for at least eight years (Baker-Gabb, 1993b).

3.4.2 Diet
The plains-wanderer feeds