Current view: Data table and detailed info
Taxonomic source(s)
Christidis, L. and Boles, W.E. 2008. Systematics and Taxonomy of Australian Birds. CSIRO Publishing, Collingwood, Australia.
del Hoyo, J., Collar, N.J., Christie, D.A., Elliott, A. and Fishpool, L.D.C. 2014. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Volume 1: Non-passerines. Lynx Edicions BirdLife International, Barcelona, Spain and Cambridge, UK.
IUCN Red List criteria met and history
Red List criteria met
Red List history
| Migratory status |
not a migrant |
Forest dependency |
does not normally occur in forest |
| Land-mass type |
Australia
|
Average mass |
- |
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).
Country/territory distribution
Important Bird and Biodiversity Areas (IBA)
Recommended citation
BirdLife International (2024) Species factsheet: Plains-wanderer Pedionomus torquatus. Downloaded from
https://datazone.birdlife.org/species/factsheet/plains-wanderer-pedionomus-torquatus on 23/12/2024.
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 23/12/2024.
