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.
|2000||Lower Risk/Near Threatened|
|Migratory status||nomadic||Forest dependency||Does not normally occur in forest|
|Land mass type||
Land-mass type - Australia
|Extent of Occurrence breeding/resident (km2)||4,450,000||medium|
|Number of locations||-|
|Value||Data quality||Derivation||Year of estimate|
|No. of mature individuals||500-10000, 1000||poor||estimated||2020|
|Decline (3 years/1 generation past)||-||-||-|
|Decline (5 years/1 generation past)||-||-||-|
|Decline (10 years/1 generation past)||-||-||-|
|Decline (10 years/3 generation future)||-||-||-|
|Decline (10 years/3 generation past and future)||-||-||-|
|Number of subpopulations||1||-||-||-|
|Percentage in largest subpopulation||100||-||-||-|
|Generation length (yrs)||4.57||-||-||-|
The species is always found at very low densities. The population size is estimated from observations at about 1,000 mature individuals (Schoenjahn 2011, 2013; Mullin et al. 2020b; Schoenjahn et al. 2020). By comparing the range and number of sightings per 1 degree block in the first Atlas (Blakers et al. 1984), it is estimated that the Grey Falcon occupies about 0.27× the area occupied by the Peregrine Falcon F. peregrinus (99 compared to 365 grid blocks) at an average of one-quarter its density. Given an estimated 3,000–5,000 pairs of Peregrines in Australia (Olsen and Olsen 1988, in Garnett et al. 2011), this suggests a total of 200 to 350 pairs of Grey Falcon (Schoenjahn 2011). The second Atlas (Barrett et al. 2003) reports sightings in 118 (14%) compared with 384 (47%) of grid blocks, for the Grey Falcon and Peregrine Falcon respectively. At one-third the distribution and a little over half the density, the estimated population is 550–915 pairs. The average of the mid-point of these ranges, about 500 pairs, is considered appropriately precautionary, especially considering the uncertainty and historical declines (Garnett et al. 2011). While genetic analysis of feathers suggests an effective population size of 4,068 individuals (682–10 322), there is great uncertainty around this estimate, and observational data is currently thought to be more accurate.
Trend justification: It may have been eliminated from some breeding areas early in the 20th century, particularly those with more than 500 mm of annual rainfall in New South Wales, where its eastern limit has also shifted further inland since the 1950s (Olsen 1998). This contraction in its breeding distribution (Garnett 1993) was attributed to habitat degradation, which reduced the suitability of some semi-arid habitat and restricted the species to the arid zone (Olsen 1998). However, the population always appears to have been small and currently shows no evidence of decline (Mullin et al. 2020b).
|Papua New Guinea||V||Extant|
|Australia||Sturt National Park|
|Habitat (level 1)||Habitat (level 2)||Importance||Occurrence|
|Wetlands (inland)||Bogs, Marshes, Swamps, Fens, Peatlands||suitable||resident|
|Altitude||0 - 500 m||Occasional altitudinal limits|
|Threat (level 1)||Threat (level 2)||Impact and Stresses|
|Agriculture & aquaculture||Livestock farming & ranching - Agro-industry grazing, ranching or farming||Timing||Scope||Severity||Impact|
|Past, Unlikely to Return||Majority (50-90%)||Slow, Significant Declines||Past Impact|
|Biological resource use||Hunting & trapping terrestrial animals - Intentional use (species is the target)||Timing||Scope||Severity||Impact|
|Climate change & severe weather||Habitat shifting & alteration||Timing||Scope||Severity||Impact|
|Invasive and other problematic species, genes & diseases||Invasive non-native/alien species/diseases - Felis catus||Timing||Scope||Severity||Impact|
|Invasive and other problematic species, genes & diseases||Invasive non-native/alien species/diseases - Unspecified species||Timing||Scope||Severity||Impact|
|Invasive and other problematic species, genes & diseases||Problematic native species/diseases - Unspecified species||Timing||Scope||Severity||Impact|
|Pollution||Agricultural & forestry effluents - Type Unknown/Unrecorded||Timing||Scope||Severity||Impact|
|Past, Unlikely to Return||Minority (<50%)||Slow, Significant Declines||Past Impact|
|Purpose||Primary form used||Life stage used||Source||Scale||Level||Timing|
|Pets/display animals, horticulture||-||-||International||Non-trivial||Recent|
|Sport hunting/specimen collecting||-||-||Non-trivial||Recent|
BirdLife International (2022) Species factsheet: Falco hypoleucos. Downloaded from http://www.birdlife.org on 10/08/2022. Recommended citation for factsheets for more than one species: BirdLife International (2022) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 10/08/2022.