Data Zone
Justification of Red List category
Although this species has an extremely large range, reporting rates suggest recent rapid declines that are suspected to continue. As a result, the species is assessed as Vulnerable.
Population justification
The population of each subspecies has been quantified separately. Both were estimated by estimating the area of occupied habitat by three measures: the minimum is the number of 2x2 km squares with records since 1990, the best estimate is double this value to account for unsurveyed area, and the maximum is four times this. Within each square, 4 ha of suitable habitat was assumed. The densities used of the two subspecies is that recorded in 2-ha 20-minute surveys (A. l. castaneiventris 3.36±SD 2.50; A. l. leucopsis 3.42± SD 2.75; Birdata).
The population of A. l. castaneiventris is therefore estimated at 36,000-134,000 mature individuals, with a best estimate of 67,000; A. l. leucopsis was estimated ad 200,000-820,000 with a best estimate of 410,000. Combined, these give an estimated population size of 236,000-954,000 mature individuals, with a best estimate of 477,000 (Ehmke et al. 2021).
Trend justification
Trends in range-wide reporting rates for both subspecies since 2000 have been strongly negative with a high level of significance. For A. l. castaneiventris, reporting rates in 2-ha 20-min counts and 500-m radius area searches from 2000–2020 declined by 86% and 46%, respectively (2000–2009: -35% and -35%; 2010–2019: -49%, +3%). For A. l. leucopsis, the equivalent figures were 64% and 72% from 1999–2000 (2000–2009: -49% and -20%; 2010–2019: -57% and -65%). A. l. leucopsis are one of a suite of taxa often considered to be declining at a local level, including around Adelaide, western New South Wales and northern Victoria (Paton et al. 1994, Reid 1999, Olsen et al. 2005) and they disappeared after the millennium drought in central New South Wales (Ellis and Taylor 2014). There are no comparable regional data for A. l. castaneiventris. However, not all trend data are negative. Reporting rates were stable between the first Australian Bird Atlas (1977–1981) and the second (1998–2001) for the whole species (Barrett et al. 2002). In New South Wales, reporting rates in less wooded bioregions increased between Atlases (Barrett et al. 2007) and there was no significant change in reporting rates from 2-ha 20 min surveys for 1999–2013 for the Arid Zone and Mallee regions (BirdLife Australia 2015) or in surveys during 2000–2015 at over 165 sites in southern New South Wales (Lindenmayer et al. 2018). Reporting rates in the Australian Capital Territory show a four-fold fluctuation, with peaks around 1989 and 2009 and troughs in 2000 and 2017 (Canberra Ornithologists Group 2020). Combining these analyses and evaluating the global trend, Ehmke et al. (2021) concluded that the species has probably declined by 30-49% over the past three generations. The threats enacting to have caused this rate of population reduction aren't well understood and so precautionarily, a similar rate of decline is suspected to occur in the future.
Southern Whitefaces occur across most of mainland Australia south of the tropics from the north-eastern edge of the Western Australian wheatbelt east to the Great Dividing Range. There is a broad hybrid zone between the two subspecies extending north from the western edge of the Nullarbor Plain. The northern boundary extends to about Carnarvon in the west, to the southern Northern Territory in central Australia, but is slightly further south in Queensland, where the species is largely confined to the south-west of the Mitchell Grass Downs and along the southern state border (Schodde and Mason 1999). They were extirpated from the Cumberland Plain before 1970 (Saunders 2018) and at least temporarily from central western New South Wales between 2005–2008 during a drought to 2010–2012 after the rain had fallen (Ellis and Taylor 2014). They are generally considered sedentary but may move in response to drought (Higgins and Peter 2002).
Southern Whitefaces live in a wide range of sparsely treed woodlands and shrublands where there is an understorey of grasses or shrubs or both, usually in habitats dominated by acacias or eucalypts on ranges, foothills and lowlands and plains. They feed on insects and seeds, largely gleaned from the bare ground or leaf litter (Higgins and Peter 2002, Antos and Bennett 2006, Antos et al. 2008) and build a bulky domed nest in a hollow or crevice, although sometimes in low bushes, where they usually lay 3–4 eggs (Higgins and Peter 2002).
There is no clear reason for declines in either Southern Whiteface subspecies, except in that part of the range where there has been complete removal of habitat for intensive agriculture. A study in Victoria found no effect of habitat fragment area, isolation, fragmentation, quality or complexity (Maron and Lill 2005). A. l. castaneiventris is largely absent from areas with intensive agriculture, but declines have occurred both there and in extensive use rangelands in the east as well as intensive use areas. Droughts may have local impacts (Ellis and Taylor 2014) and are likely to become more frequent and severe (Evans et al. 2017). Modelling suggests optimal climatic conditions for the species will retract to the south (Garnett and Franklin 2014) because of rainfall reductions (Garnett et al. 2013). However, whitefaces live in some of the driest and hottest parts of the country, yet they have declined in places that are generally far wetter.
Conservation Actions Underway
Some parts of the range are in public and private protected areas.
Conservation Actions Proposed
Determine reasons for population declines. Understand demography and movement ecology with respect to climate variables. Develop appropriate management interventions for key parts of the range. Secure key occupied habitat patches in areas with a patchy distribution from degradation and loss.
Text account compilers
Vine, J., Berryman, A.
Contributors
Dahal, P.R.
Recommended citation
BirdLife International (2024) Species factsheet: Southern Whiteface Aphelocephala leucopsis. Downloaded from
https://datazone.birdlife.org/species/factsheet/southern-whiteface-aphelocephala-leucopsis on 22/12/2024.
Recommended citation for factsheets for more than one species: BirdLife International (2024) IUCN Red List for birds. Downloaded from
https://datazone.birdlife.org/species/search on 22/12/2024.