Justification of Red List Category
Although this species may have a restricted range, it is not believed to 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). The population trend appears to be increasing, and hence the species does not approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size has not been quantified, but it is not believed to 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.
The global population size has not been quantified, but the population size for the nominate subspecies has been estimated as c.3,000 individuals (Garnett and Crowley 2000).
The population is suspected to be increasing as ongoing habitat degradation is creating new areas of suitable habitat.
This species is endemic to Australia. Subspecies pastinator is found in most of south-west Australia, south of Perth from the Swan and Avon rivers in the north, to Augusta in the west and Broome in the east. Subspecies derbyi is found in the northern wheatbelt of Western Australia.
Subspecies pastinator declined significantly in range and numbers early in the 20th century, as it was considered an agricultural pest. Extensive shooting and poisoning by farmers caused the population to plummet to c.100 birds in the 1940s. However, both the expansion of agriculture and prohibition of poisoning and shooting has allowed a recovery in numbers (Garnett and Crowley 2000). Clearance for agriculture has reduced the area of breeding habitat for subspecies derbyi, and may be favouring the Short-billed Corella C. sanguinea. Nevertheless, despite a low reproductive rate, the range of this subspecies has expanded in recent decades (Garnett 1992).
Text account compilers
Ekstrom, J., Butchart, S., Harding, M.
BirdLife International (2020) Species factsheet: Cacatua pastinator. Downloaded from http://www.birdlife.org on 30/09/2020. Recommended citation for factsheets for more than one species: BirdLife International (2020) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 30/09/2020.