Justification of Red List Category
The species is listed as Critically Endangered because it has a very small population which, in the past decade, has experienced a decline of >90% in both of its strongholds, the Riverina of New South Wales and north-central Victoria, due to cultivation, and inappropriate grazing of natural grassland and climatic events.
The population is estimated to vary from between 5,500–7,000 in good years to around 2,000 birds during periods of widespread drought (Baker-Gabb 2002, Garnett et al. 2011). Regular monitoring has recorded a >90% decline in the species’s Victorian stronghold between 2010 and 2015 (Baker-Gabb et al. 2016), and a 93% decline between 2001 and 2014 in its other stronghold in NSW (Wilson et al. 2014). The TSSC (2015) estimated the total number of mature individuals of Plains-wanderers to be < 1,000 birds in 2015, and so the population size is placed here in the range 250-999 mature individuals.
A decline of >90% has been detected in the past decade in both of its strongholds, the Riverina of New South Wales and north-central Victoria, due to cultivation and inappropriate grazing of natural grassland and climatic events (TSSC 2015). The total decline over the past 3 generations (c.22 years) is not known, and as the species will move away from unsuitable areas, part of these reported declines could represent the species moving to new, as yet unfound, sites. However, in the absence of any evidence for this species moving to new areas, the rate of decline may be conservatively suspected to be >80% over the past 3 generations and so is placed here in the range 80-99%.
Pedionomus torquatus is endemic to Australia. It is recorded from north-central Victoria, north-eastern South Australia, southern New South Wales (NSW) around the Riverina and west-central Queensland (Barrett et al. 2003, Commonwealth of Australia 2016). Garnett et al. (2011) estimated the total number of mature individuals to be c.2000 and decreasing. Since that time, significant declines in Plains-wanderer numbers have been reported in the species’s two strongholds in Victoria and NSW. Monitoring and annual surveys conducted across the Northern Plains of Victoria between 2010 and 2015 indicated a decline in numbers of > 90% during this period (Baker-Gabb et al. 2016). Monitoring across the NSW Riverina detected a decline in numbers of 93% across the region over the period from 2001 to 2014 (Wilson et al. 2014). Whether the smaller populations in west-central Queensland and north-east South Australia have experienced similar declines is not known. The status of the species in native grasslands of the basalt plains of south-western Victoria is unknown. There is no regular survey effort in this region and recent records are sparse and sporadic.
Plains-wanderers inhabit sparse grasslands with c.50% bare ground, with most vegetation 5-15cm in height and some widely spaced plants up to 30 cm high (Baker-Gabb et al. 1990, Baker-Gabb et al. 2016). The species may occasionally use lower-quality habitat including cereal stubble, but cannot persist in a cropped landscape (Garnett et al. 2011). Plains-wanderers are sedentary for as long as the habitat remains suitable (Garnett et al. 2011). They are capable of breeding in their first year, breeding in solitary pairs (Baker-Gabb et al. 1990). Evidence suggests that the species may have a polyandrous mating system in which individual females may mate with more than one male (Baker-Gabb et al. 1990). The nest is a hollow or 'scrape' that is scratched into the ground and lined with grass (Harrington et al. 1988). The nests are usually placed in native grasses and herbs, and in some instances, nearby grasses may be pulled over the nest to form a concealing cone or tent (Harrington et al. 1988, Marchant and Higgins 1993). Clutch-size is usually four eggs, but can range from two to five (Bennett 1983). The male does most of the incubation during the 23 day incubation period (Bennett 1983, Baker-Gabb et al. 1990). The young are primarily attended by the male and become independent at about two months of age (Baker-Gabb 1990).
The cultivation of native grassland has virtually extinguished the species from southern South Australia and Victoria, and is increasing across Northern Victoria and the Riverina (Garnett et al. 2011). Even if left to recover, habitat remains unsuitable for decades; however, with appropriate management Plains-wanderers can sometimes return within 20 years of cropping (Antos 2014). Where patches survive, they are often too few and dispersed to be suitable. High levels of grazing cause the desertion of an area, possibly because birds become vulnerable to predators (Baker-Gabb et al. 1990). Insufficient grazing following widespread rainfall and prolific grass growth will also cause the abandonment of grasslands that become too dense for Plains-wanderers (Baker-Gabb et al. 2016). Pesticides for locust control may kill birds, directly or indirectly through the food chain (Commonwealth of Australia 2016). Plains-wanderers may be exposed to increased extinction risk due to their historically low population size. Other potential threats to Plains-wanderers include: depredation by foxes and native species; lack of appropriate burning regimes; planting of trees in or near grasslands; wildfires; quail hunters; and climate change, including extreme climatic events such as drought (which appear to have impacted the species heavily [P. Gregory in litt. 2017]) and floods, which make habitat management difficult and can hamper population recovery (TSSC 2015).
Conservation Actions Underway
Management actions completed or underway include extensive surveys in New South Wales, Victoria and south-east South Australia, detailed research on habitat requirements, recovery planning in New South Wales and Victoria, and incorporation of habitat in the protected areas estate in New South Wales, Queensland and Victoria. Locust control spraying is now regulated in the species's habitat. Habitat is being managed for conservation outcomes within protected areas in NSW and Victoria primarily through grazing and, to a lesser extent, ecological burning. Ongoing localised community education and engagement programmes have resulted in a significant portion of local communities in north central Victoria being aware of and valuing Plains-wanderers (Johnstone et al. 2015). A small captive colony has now been established (S. Garnett in litt. 2017).
Maintain long term monitoring programmes in the species’s strongholds in the Riverina region of NSW and the Northern Plains of Victoria. Undertake regular monitoring at other known Plains-wanderer sites. Closely monitor grazing impacts on public and private reserves where grazing regimes are being managed for Plains-wanderers, to ensure grassland structure remains within acceptable limits for the species. Increase understanding of population dynamics (e.g. population size, age/size class structure, dispersal rates). Study the effects of season, grazing and burning on the type and availability of food in Plains-wanderer habitat. Measure the impacts of feral species on Plains-wanderers. Study the roles of burning and slashing in maintaining and improving habitat conditions in National Parks, Reserves and other lands managed for Plains-wanderer conservation. Measure the impacts of wildfires, quail hunting and pesticide use on Plains-wanderers. Develop a Population Response Model for Plains-wanderers.
15-19 cm. Distinctive, quail-like ground bird. Adult male light brown above with brown rosette and white streak patterning. Fawn-white underparts with black crescents. Adult female has distinctive, white-spotted black collar and broad rufous gorget on upper breast. Juvenile similar to adult male. Similar spp. Similar to buttonquails Turnix spp. but with longer legs. Distinguished in flight from quails and buttonquails by upperwing pattern of white primary patch and broad pale trailing edge, and on ground, by diagnostic female plumage, characteristic upright posture and longer legs. Voice Repeated, low-pitched resonant oo by day and night, in spring. Hints Usually detected at night by spotlighting lightly-grazed grasslands.
Text account compilers
Taylor, J., Allinson, T, Symes, A., Wheatley, H., Pilgrim, J., Westrip, J., Shutes, S., McClellan, R., Garnett, S., Dutson, G., Stattersfield, A.
Antos, M., Baker-Gabb, D., Dutson, G., Garnett, S. & Gregory, P.
BirdLife International (2020) Species factsheet: Pedionomus torquatus. Downloaded from http://www.birdlife.org on 06/08/2020. Recommended citation for factsheets for more than one species: BirdLife International (2020) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 06/08/2020.