Data Zone
Justification of Red List category
This species has a very large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (extent of occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). Despite the fact that the population trend appears to be decreasing, the decline is not believed to be sufficiently rapid to approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size is very large, and hence does not approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.
Population justification
The size of the eastern population estimated from published sources (Garnett et al. 2011; NSW OEH 2016, 2019) to have been 5,700 (5,200–8,300) after fires in 2019–2020 killed an estimated 18% of birds (13–24% depending on the mortality scenario) based on maps of fire severity in 2019–2020 within the pre-fire range and initial assumptions about mortality at different fire severity classes (fire severity low: 10%; medium: 30%; high: 80%; very high: 100%). A true estimate of the western population has never been possible given the density of the habitat and cryptic nature of the bird (Burbidge et al. 2007; DPaW 2014), but an estimated population of 100 seems likely given recent losses (S Comer unpublished; in Comer et al. 2021). The population on Tasmania is the stronghold and suspected to exceed 100,000 birds (Collar and Boesman 2020).
Trend justification
Although the western population is declining, the global population is suspected to be stable overall given the stronghold on Tasmania and, to a lesser extent, the eastern mainland. Monitoring of the eastern population suggests all populations have survived fires and are likely to recover, but only if the future fire regime is suitable and habitat recovers in the way it has historically (Oliver et al. 2021). The western population is thought to be declining rapidly, although represents a small proportion of the global population - severe fires have reduced the population by >80%, and there is a high risk that further population reductions of the same order will occur in the next three generations (Comer et al. 2021).
The most important current threat is extensive and intense fires that temporarily remove habitat and can potentially extirpate isolated subpopulations, although there is proven resilience to a range of fire regimes (Baker et al. 2010). In some places habitat rapidly becomes suitable again after good rains: at Yuragir National Park birds were present at two sites a year after a severe fire in numbers similar to those detected before the fire (M. Andren unpublished). Extreme fire weather is likely to increase in frequency (Di Virgilio et al. 2019, Dowdy et al. 2019), driven by increases in the frequency and severity of drought and heat waves (Evans et al. 2017, Herold et al. 2018). Conversely, a lack of fire leading to succession by tall shrubby vegetation appears to have caused extirpation of the Otway Ranges population (G. Dutson unpublished). As a ground nester, Ground Parrots may be susceptible to predation by cats Felis catus and foxes Vulpes vulpes, particularly immediately after a fire (Lindenmayer et al. 2009, Woinarski et al. 2017). Most subpopulations are in relatively intact protected areas but south of the Noosa River in Queensland, the cumulative effects of urban development, stormwater run-off, sewage discharge and an unsuitable fire regime is thought to be leading to a gradual replacement of the nutrient poor-heathland habitat needed by the parrots with taller native and introduced weeds (K.A. land unpublished). Also, relatively high rate of hatching failure in the subpopulation in south-east Queensland (McFarland 1991c) may be related to a particularly low rate of genetic variability (Chan et al. 2008) but has not been investigated.
Text account compilers
Vine, J.
Contributors
Garnett, S.
Recommended citation
BirdLife International (2024) Species factsheet: Ground Parrot Pezoporus wallicus. Downloaded from
https://datazone.birdlife.org/species/factsheet/ground-parrot-pezoporus-wallicus on 30/11/2024.
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 30/11/2024.