Data Zone
Justification of Red List category
In poor years (which appear to be getting more frequent and less recovered from), this species has a small population size comprising fewer than 1,000 mature individuals. The loss and degradation of its grassland habitat is ongoing with birds abandoning sites that are no longer suitable. For these reasons it is assessed as Endangered.
Population justification
Population estimates of this species vary widely and there is much uncertainty. The occurrence of P. torquatus is highly dynamic, spatially and temporally, with fluctuations in habitat suitability seemingly directly linked to population size both locally and globally. If habitat suitability is maintained, birds can remain in the same area for years, only to disperse (or migrate) suddenly if it becomes unsuitable. When breeding, birds also appear to form loose aggregations that extend over a few adjacent paddocks (with nearby areas of suitable habitat unoccupied), making quantification using species density multiplied by the area of suitable habitat and occupancy challenging. These factors make population size determination extremely difficult but in poor years population maxima appear to be constrained by the area of drought refuge habitat.
Previously, the population was estimated to vary between 5,500–7,000 individuals in good years to around 2,000 individuals during periods of widespread drought (Baker-Gabb 2002, Garnett et al. 2011) but regular monitoring has indicated that the species has declined since these estimates were made, with comparatively poor recovery from good years (TSSC 2015, Wilson et al. 2014, Parker et al. 2021). In 2015, the total number of mature individuals was estimated to be <1,000 birds (TSSC 2015) while in 2020, the population was more pessimistically suspected to number as few as 100-500 individuals (Parker et al. 2021). Based on annual monitoring (including the recent use of thermal imaging cameras), the population in Victoria is unlikely to exceed more than a few hundred mature individuals even in good years (D. Nugent in litt. 2021), with potentially far fewer in poor ones. In New South Wales, the Riverina population is thought capable of hosting a maximum of c.3,100 individuals however recently, despite above-average rainfall, continues to sit at 350-400 individuals (D. Parker in litt. 2022). Sightings from elsewhere in New South Wales (in the far north-west and south-west) appear to refer to birds that do not linger for any extended periods of time; for example, despite claims of them being common when recorded at Nariearra Station, east of Tibooburra, in 2020, no birds have been recorded since (D. Parker in litt. 2021). There have also been recent sightings in western Queensland and north-east South Australia (mostly encountered during thermal camera monitoring for other species) however it is unclear whether these populations are temporary (and present in only good years). Based on surveys in 1984 and 2002, carrying capacity in western Queensland is markedly lower than in New South Wales/Victoria and any population here is therefore not considered to be substantial; survey encounter rates in South Australia are even lower (D. Baker-Gabb in litt. 2021). Consequently, it is considered prudent to set a population estimate based on data from the two strongholds (Victoria and the NSW Riverina). Overall, the population is broadly estimated to number 251-5,000 mature individuals (encompassing minimum and maximum values that encompass annual variation), with a best estimate of 251-999 at population minima.
Trend justification
The trend of this species is difficult to determine owing to its fluctuations both in abundance and occupancy. In northern Victoria, a 90% fall in detection rates from 2010 and 2012 (Baker-Gabb et al. 2016) was followed by a partial recovery in 2018 (Baker-Gabb 2018), but numbers fell again by 2019 (D. Nugent unpublished): in protected grasslands at Terrick Terrick National Park, Plains-wanderers were encountered at a rate of 0.11 birds/km (0.025–0.18) in 2018–2020, down from 0.45–1.1 in 2010 (Antos 2019; M. Antos unpublished, in Parker et al. 2021). In New South Wales, survey results from 2001 and 2014 suggested a substantial decline in the Riverina (Wilson et al. 2014). While numbers increased from 2017 to mid-2018, there had been another substantial decline by the end of 2018, and none were detected in standard monitoring in early 2019, for the first time since it began, with < 10% of habitat in good condition. Plains-wanderers were encountered at a rate of 0.03 birds/km (0.01–0.05) in 2018, decreasing to 0.005 birds/km (0–0.004) in 2019 (D. Parker unpublished). The species appeared to be recovering in 2020 and 2021, with breeding recorded in most months in Victoria and a return of the species to the Avoca Plains after an apparent absence of over five years (M. Antos in litt. 2022). However, despite effective, landscape-scale fox control on predominant sheep farms detection rates have remained low in New South Wales (M. Antos in litt. 2022) and in Victoria grassland destruction is ongoing with more patches lost each year with birds permanently abandoning sites that are converted, the maximum size of this population shrinking permanently with each patch lost (D. Nugent and D. Parker in litt. 2022). Consequently, while short-term trends may show partial recovery, the longer-term trend over the past three generations, and for the next, is that of decline with increasingly constrained recovery from population minima (Parker et al. 2021).
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).
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, 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, Parker et al. 2021). 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). 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 shooting them in error; 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’ 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
Berryman, A., Garnett, S.
Contributors
Allinson, T, Antos, M., Baker-Gabb, D., Dutson, G., Garnett, S., Gregory, P., McClellan, R., Nugent, D., Parker, D., Pilgrim, J., Shutes, S., Stattersfield, A., Symes, A., Taylor, J., Westrip, J.R.S. & Wheatley, H.
Recommended citation
BirdLife International (2024) Species factsheet: Plains-wanderer Pedionomus torquatus. Downloaded from
https://datazone.birdlife.org/species/factsheet/plains-wanderer-pedionomus-torquatus on 23/11/2024.
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 23/11/2024.