• Summary
• Text account
• Data table and detailed info
• Distribution map
• Reference and further resources

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.

Red List criteria met

Critically Endangered	Endangered	Vulnerable
-	-	D1

Red List history

Year	Category	Criteria
2022	Vulnerable	D1
2016	Vulnerable	D1
2012	Vulnerable	D1
2008	Near Threatened	C2a(ii)
2004	Near Threatened
2000	Lower Risk/Near Threatened
1996	Vulnerable
1994	Vulnerable
1988	Threatened

Migratory status	nomadic	Forest dependency	does not normally occur in forest
Land-mass type	Australia	Average mass	-

	Estimate	Data quality
Extent of Occurrence (breeding/resident)	4,450,000 km2	medium
Severely fragmented?	no	-

	Estimate	Data quality	Derivation	Year of estimate
Population size	500-10000, 1000 mature individuals	poor	estimated	2020
Population trend	stable	medium	suspected	-
Generation length	4.57 years	-	-	-
Number of subpopulations	1	-	-	-
Percentage of mature individuals in largest subpopulation	100%	-	-	-

Population justification:

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).

Country/Territory	Presence	Origin	Resident	Breeding visitor	Non-breeding visitor	Passage migrant
Australia	extant	native	yes
Papua New Guinea	extant	vagrant

Country/Territory	IBA Name
Australia	Boodjamulla
Australia	Fortescue Marshes
Australia	Mornington Sanctuary
Australia	Simpson Desert

Habitat (level 1)	Habitat (level 2)	Importance	Occurrence
Grassland	Subtropical/Tropical Dry	suitable	resident
Shrubland	Subtropical/Tropical Dry	suitable	resident
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
		Stresses Ecosystem degradation, Ecosystem conversion
Biological resource use	Hunting & trapping terrestrial animals - Intentional use (species is the target)	Timing		Scope		Severity		Impact
		Ongoing		Unknown		Unknown		Unknown
		Stresses Reduced reproductive success, Species mortality
Climate change & severe weather	Habitat shifting & alteration	Timing		Scope		Severity		Impact
		Future		Whole (>90%)		Unknown		Unknown
		Stresses Indirect ecosystem effects, Ecosystem degradation
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Felis catus	Timing		Scope		Severity		Impact
		Ongoing		Unknown		Unknown		Unknown
		Stresses Species mortality
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Unspecified species	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Unknown		Unknown
		Stresses Ecosystem degradation
Invasive and other problematic species, genes & diseases	Problematic native species/diseases - Unspecified species	Timing		Scope		Severity		Impact
		Future		Minority (<50%)		Unknown		Unknown
		Stresses Competition
Pollution	Agricultural & forestry effluents - Type Unknown/Unrecorded	Timing		Scope		Severity		Impact
		Past, Unlikely to Return		Minority (<50%)		Slow, Significant Declines		Past Impact
		Stresses Ecosystem degradation, Reduced reproductive success

Purpose	Scale
Pets/display animals, horticulture	international
Sport hunting/specimen collecting	subsistence, national

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Recommended citation
BirdLife International (2024) Species factsheet: Grey Falcon Falco hypoleucos. Downloaded from https://datazone.birdlife.org/species/factsheet/grey-falcon-falco-hypoleucos on 22/12/2024.
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 22/12/2024.