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The IUCN Red List of Threatened Species™
ISSN 2307-8235 (online)
IUCN 2008: T22696479A93566768
Scope: Global
Language: English
Falco hypoleucos, Grey Falcon
Assessment by: BirdLife International
View on www.iucnredlist.org
Citation: BirdLife International. 2016. Falco hypoleucos. The IUCN Red List of Threatened Species
2016: e.T22696479A93566768. http://dx.doi.org/10.2305/IUCN.UK.20163.RLTS.T22696479A93566768.en
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THE IUCN RED LIST OF THREATENED SPECIES™
Taxonomy
Kingdom
Phylum
Class
Order
Family
Animalia
Chordata
Aves
Falconiformes
Falconidae
Taxon Name: Falco hypoleucos Gould, 1841
Common Name(s):
• English:
• Spanish:
Grey Falcon
Halcón Gris, Halcón Gris de Australia
Taxonomic Source(s):
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. Lynx Edicions BirdLife International,
Barcelona, Spain and Cambridge, UK.
Identification Information:
Typical falcon intermediate in size between Peregrine Falcon Falco peregrinus and Australian Kestrel
Falco cenchroides and with loud repeated 'kek' call. Overall coloration grey with black primaries.
Secondaries grey with 10 dark brown wavy bars. Small black moustachial stripe, with black streaking
often around eye. Throat whitish. Underparts may be greyish white. Iris brown; bill bluish and yellow at
base; cere orange; legs yellow or yellow-orange.
Assessment Information
Red List Category & Criteria:
Vulnerable D1 ver 3.1
Year Published:
2016
Date Assessed:
October 1, 2016
Justification:
This species has been uplisted to Vulnerable because although it has an extremely large range, and
historical populations declines and range contractions are believed to have ceased, it occurs at very low
densities and its population has been precautionarily estimated to number fewer than 1,000 mature
individuals. If the population size is eventually found to be larger than currently feared it may be eligible
for downlisting.
Previously Published Red List Assessments
2012 – Vulnerable (VU) – http://dx.doi.org/10.2305/IUCN.UK.2012-1.RLTS.T22696479A40323445.en
2008 – Near Threatened (NT)
2004 – Near Threatened (NT)
2000 – Lower Risk/near threatened (LR/nt)
1996 – Vulnerable (VU)
© The IUCN Red List of Threatened Species: Falco hypoleucos – published in 2016.
http://dx.doi.org/10.2305/IUCN.UK.2016-3.RLTS.T22696479A93566768.en
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1994 – Vulnerable (VU)
1988 – Threatened (T)
Geographic Range
Range Description:
Falco hypoleucos is distributed sparsely over Australia's arid and semi-arid zones. It is absent from Cape
York Peninsula, south of the Great Dividing Range in Queensland and New South Wales, south of the
Great Dividing Range in Victoria, and south of 26oS in Western (Barrett et al. 2003). Occurrence records
from these uninhabited areas are likely the result of misidentification, particularly records from New
Guinea and islands off the Queensland coast. The breeding distribution now covers areas of the highest
annual average temperatures (Schoenjahn 2013). The present range is believed to be stable. There is
evidence of regular seasonal movements between the arid zone and northern Australia, and from west
to east in Queensland. The species may have been eliminated from some breeding areas early in the
20th century (Olsen 1998) but this perception is questionable because it was based on data that include
observations and materials in specimen collections (including eggs) that may not pertain to the species
(Schoenjahn 2010). The species is always found at very low densities, and its population is believed to
be less than 1,000 mature individuals in total (Schoenjahn 2011, Garnett et al. 2011). This estimate is
based on limited information about the species and comparison with data for the Peregrine Falcon Falco
peregrinus (J. Schoenjahn in litt. 2007). There is no evidence of a decline of the population of F.
hypoleucos.
Country Occurrence:
Native: Australia
Vagrant: Papua New Guinea
© The IUCN Red List of Threatened Species: Falco hypoleucos – published in 2016.
http://dx.doi.org/10.2305/IUCN.UK.2016-3.RLTS.T22696479A93566768.en
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Distribution Map
Falco hypoleucos
© The IUCN Red List of Threatened Species: Falco hypoleucos – published in 2016.
http://dx.doi.org/10.2305/IUCN.UK.2016-3.RLTS.T22696479A93566768.en
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Population
The species always occurs at low densities and other grey raptors are often misreported as Grey Falcons;
the AOO is nominally estimated at 0.1% of the EOO as the species has been encountered very infre­
quently during extensive dedicated searching in many parts of arid Australia over the last decade
(Schoenjahn 2011). 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), thus the population is estimated here at 999 mature individuals.
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). The population is now suspected to be stable
(Garnett and Crowley 2000, Garnett et al. 2011).
Current Population Trend: Stable
Habitat and Ecology (see Appendix for additional information)
The distribution of this species is restricted largely to areas of the highest annual average temperatures
where there is an average annual rainfall of less than 500 mm. It favours lightly timbered and
untimbered lowland plains that are crossed by tree-lined watercourses (Schoenjah in litt. 2016), but
frequents other habitats including grassland and sand dune habitats (J. Schoenjahn in litt. 2016). It hunts
almost exclusively birds ≤300 g throughout the year, including doves, pigeons, small cockatoos, and
finches (Schoenjahn 2013). It uses the abandoned nests of other bird species, particularly corvids
(Schoenjahn 2013), and lays one to four eggs in July or August (Johnstone and Storr 1998). Until
recently, little was known about its breeding ecology. A continent-wide study from 2003-2011 recorded
37 breeding attempts, with between 1-4 nestlings observed in nests (an average of 2.2 nestlings)
(Schoenjahn 2013). A nesting attempt was observed and documented at a site 40 km north-west of Alice
Springs in 2010, though this nest failed (Watson 2011).
Systems: Terrestrial, Freshwater
Threats (see Appendix for additional information)
The 20th century decline and range contraction was caused by overgrazing in arid zone rangelands and
clearance of open woodland in the semi-arid zone for marginal farming, which degraded habitat and
affected prey abundance and nest site availability (Garnett 1993). Localised DDT-related eggshell
thinning of up to 15% was detected when this pesticide was legal, but is no longer considered a
© The IUCN Red List of Threatened Species: Falco hypoleucos – published in 2016.
http://dx.doi.org/10.2305/IUCN.UK.2016-3.RLTS.T22696479A93566768.en
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problem. Nest-site availability, particularly in sparsely-treed inland areas, may eventually become a
limiting factor, especially where grazing by introduced herbivores is preventing tree regeneration.
Competition by the more mesic Peregrine Falcon F. peregrinus in the wetter margins of the species's
range could be a problem. All threats that have been suggested are speculative (Garnett and Crowley
2000). Egg-collecting may not be a threat any more since this practice became illegal in all of Australia. A
threat from international falconry may exist but has not been quantified. The species' extremely low
population size may pose a threat to the species as a whole.
Conservation Actions (see Appendix for additional information)
Conservation Actions Underway
CITES Appendix II. Research on the species was underway in 2007 (J. Schoenjahn in litt. 2007).
Conservation Actions Proposed
Develop methods for assessing population trends. Survey and record regeneration status of nesting
habitat. Carry out regular monitoring of the species in selected parts of range, including both arid and
semi-arid zones. Study its biology, ecology, and conservation status and needs (Garnett 1993, Olsen
1998). Document nest-sites and encourage protection by volunteers (Garnett 1993).
Credits
Assessor(s):
BirdLife International
Reviewer(s):
Butchart, S. & Symes, A.
Contributor(s):
Olsen, P., Schoenjahn, J. & Watson, C.
Facilitators(s) and
Compiler(s):
Dutson, G., Garnett, S., McClellan, R., North, A., O'Brien, A., Symes, A., Taylor, J.
© The IUCN Red List of Threatened Species: Falco hypoleucos – published in 2016.
http://dx.doi.org/10.2305/IUCN.UK.2016-3.RLTS.T22696479A93566768.en
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Bibliography
Barrett, G.; Silcocks, A.; Barry, S.; Cunningham, R.; Poulter, R. 2003. The new atlas of Australian birds.
Royal Australasian Ornithologists Union, Victoria, Australia.
Blakers, M.; Davies, S. J. J. F.; Reilly, P. N. 1984. The atlas of Australian birds. Royal Australasian
Ornithologists' Union, Victoria.
Garnett, S. 1992. Threatened and extinct birds of Australia. Royal Australasian Ornithologists' Union and
Australian National Parks and Wildlife Service, Moonee Ponds, Australia.
Garnett, S. T.; Crowley, G. M. 2000. The action plan for Australian birds 2000. Environment Australia,
Canberra.
Garnett, S. T.; Szabo, J. K.; Dutson, G. 2011. The Action Plan for Australian Birds 2010. CSIRO Publishing,
Collingwood.
IUCN. 2016. The IUCN Red List of Threatened Species. Version 2016-3. Available at: www.iucnredlist.org.
(Accessed: 07 December 2016).
Johnstone, R. E.; Storr, G. M. 1998. Handbook of Western Australian birds, volume I: non-passerines
(emu to dollarbird). Western Australian Museum, Perth, Australia.
Olsen, P. 1998. Australia's raptors: diurnal birds of prey and owls.
Schoenjahn, J. 2011. How scarce is the Grey Falcon? Boobook 29(1): 24-25.
Watson, C. 2011. A Failed Breeding Attempt by the Grey Falcon Falco hypoleucos near Alice Springs,
Northern Territory. Australian Field Ornithology 28: 167–179.
Citation
BirdLife International. 2016. Falco hypoleucos. The IUCN Red List of Threatened Species 2016:
e.T22696479A93566768. http://dx.doi.org/10.2305/IUCN.UK.2016-3.RLTS.T22696479A93566768.en
Disclaimer
To make use of this information, please check the Terms of Use.
External Resources
For Images and External Links to Additional Information, please see the Red List website.
© The IUCN Red List of Threatened Species: Falco hypoleucos – published in 2016.
http://dx.doi.org/10.2305/IUCN.UK.2016-3.RLTS.T22696479A93566768.en
6
Appendix
Habitats
(http://www.iucnredlist.org/technical-documents/classification-schemes)
Habitat
Season
Suitability
Major
Importance?
3. Shrubland -> 3.5. Shrubland - Subtropical/Tropical Dry
Resident
Suitable
No
4. Grassland -> 4.5. Grassland - Subtropical/Tropical Dry
Resident
Suitable
No
5. Wetlands (inland) -> 5.4. Wetlands (inland) - Bogs, Marshes, Swamps,
Fens, Peatlands
Resident
Suitable
No
Threats
(http://www.iucnredlist.org/technical-documents/classification-schemes)
Threat
Timing
Scope
Severity
Impact Score
2. Agriculture & aquaculture -> 2.3. Livestock farming
& ranching -> 2.3.3. Agro-industry grazing, ranching
or farming
Past,
unlikely to
return
Majority (5090%)
Slow, significant
declines
Past impact
Stresses:
1. Ecosystem stresses -> 1.1. Ecosystem conversion
1. Ecosystem stresses -> 1.2. Ecosystem degradation
Ongoing
Minority (50%)
Stresses:
2. Species Stresses -> 2.1. Species mortality
2. Species Stresses -> 2.3. Indirect species effects ->
2.3.7. Reduced reproductive success
Ongoing
Minority (50%)
Stresses:
1. Ecosystem stresses -> 1.2. Ecosystem degradation
Future
Minority (50%)
Stresses:
2. Species Stresses -> 2.3. Indirect species effects ->
2.3.2. Competition
Past,
unlikely to
return
Minority (50%)
Stresses:
1. Ecosystem stresses -> 1.2. Ecosystem degradation
2. Species Stresses -> 2.3. Indirect species effects ->
2.3.7. Reduced reproductive success
5. Biological resource use -> 5.1. Hunting & trapping
terrestrial animals -> 5.1.1. Intentional use (species is
the target)
8. Invasive and other problematic species, genes &
diseases -> 8.1. Invasive non-native/alien
species/diseases -> 8.1.1. Unspecified species
8. Invasive and other problematic species, genes &
diseases -> 8.2. Problematic native species/diseases
-> 8.2.1. Unspecified species
9. Pollution -> 9.3. Agricultural & forestry effluents ->
9.3.4. Type Unknown/Unrecorded
Negligible declines
Unknown
Unknown
Slow, significant
declines
Low impact: 4
Unknown
Unknown
Past impact
Conservation Actions in Place
(http://www.iucnredlist.org/technical-documents/classification-schemes)
© The IUCN Red List of Threatened Species: Falco hypoleucos – published in 2016.
http://dx.doi.org/10.2305/IUCN.UK.2016-3.RLTS.T22696479A93566768.en
7
Conservation Actions in Place
In-Place Research, Monitoring and Planning
Action Recovery plan: Yes
Systematic monitoring scheme: No
In-Place Land/Water Protection and Management
Conservation sites identified: Yes, over entire range
Occur in at least one PA: Yes
Invasive species control or prevention: No
In-Place Species Management
Successfully reintroduced or introduced beningly: No
Subject to ex-situ conservation: No
In-Place Education
Subject to recent education and awareness programmes: No
Included in international legislation: No
Subject to any international management/trade controls: Yes
Conservation Actions Needed
(http://www.iucnredlist.org/technical-documents/classification-schemes)
Conservation Actions Needed
1. Land/water protection -> 1.1. Site/area protection
Research Needed
(http://www.iucnredlist.org/technical-documents/classification-schemes)
Research Needed
1. Research -> 1.2. Population size, distribution & trends
1. Research -> 1.3. Life history & ecology
3. Monitoring -> 3.1. Population trends
3. Monitoring -> 3.4. Habitat trends
Additional Data Fields
Distribution
Continuing decline in area of occupancy (AOO): Unknown
© The IUCN Red List of Threatened Species: Falco hypoleucos – published in 2016.
http://dx.doi.org/10.2305/IUCN.UK.2016-3.RLTS.T22696479A93566768.en
8
Distribution
Extreme fluctuations in area of occupancy (AOO): No
Estimated extent of occurrence (EOO) (km²): 7760000
Continuing decline in extent of occurrence (EOO): Unknown
Extreme fluctuations in extent of occurrence (EOO): No
Continuing decline in number of locations: Unknown
Extreme fluctuations in the number of locations: No
Upper elevation limit (m): 500
Population
Number of mature individuals: 999
Continuing decline of mature individuals: Unknown
Extreme fluctuations: No
Population severely fragmented: No
No. of subpopulations: 1
Continuing decline in subpopulations: Unknown
Extreme fluctuations in subpopulations: No
All individuals in one subpopulation: Yes
No. of individuals in largest subpopulation: 100
Habitats and Ecology
Continuing decline in area, extent and/or quality of habitat: Unknown
Generation Length (years): 6.2
Movement patterns: Nomadic
© The IUCN Red List of Threatened Species: Falco hypoleucos – published in 2016.
http://dx.doi.org/10.2305/IUCN.UK.2016-3.RLTS.T22696479A93566768.en
9
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The IUCN Red List of Threatened Species™ is produced and managed by the IUCN Global Species
Programme, the IUCN Species Survival Commission (SSC) and The IUCN Red List Partnership.
The IUCN Red List Partners are: Arizona State University; BirdLife International; Botanic Gardens
Conservation International; Conservation International; NatureServe; Royal Botanic Gardens, Kew;
Sapienza University of Rome; Texas A&M University; and Zoological Society of London.
THE IUCN RED LIST OF THREATENED SPECIES™