EN
Grey-backed Hawk Pseudastur occidentalis



Taxonomy

Taxonomic note
Pseudastur occidentalis (del Hoyo and Collar 2014) was previously placed in the genus Leucopternis.

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.
del Hoyo, J.; Collar, N. J.; Christie, D. A.; Elliott, A.; Fishpool, L. D. C. 2014. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Barcelona, Spain and Cambridge UK: Lynx Edicions and BirdLife International.
SACC. 2006. A classification of the bird species of South America. Available at: #http://www.museum.lsu.edu/~Remsen/SACCBaseline.html#.
SACC. 2006. A classification of the bird species of South America. Available at: #http://www.museum.lsu.edu/~Remsen/SACCBaseline.htm#.

IUCN Red list criteria met and history
Red List criteria met
Critically Endangered Endangered Vulnerable
- C2a(i) C2a(i); D1

Red List history
Year Category Criteria
2016 Endangered C2a(i)
2012 Endangered C2a(i)
2008 Endangered C2a(i)
2004 Endangered
2000 Endangered
1996 Endangered
1994 Endangered
1988 Threatened
Species attributes

Migratory status not a migrant Forest dependency High
Land mass type Land-mass type - continent
Average mass -
Extent of occurrence (EOO)

Estimate Data quality
Extent of Occurrence breeding/resident (km2) 64,400 medium
Number of locations 11-100 -
Fragmentation -
Population and trend
Estimate Data quality Derivation Year of estimate
No. of mature individuals 250-999 poor estimated 2000
Population trend Decreasing poor suspected -
Decline (3 years/1 generation past) - - -
Decline (5 years/1 generation past) - - -
Decline (10 years/1 generation past) - - -
Decline (10 years/3 generation future) 20-29 - - -
Decline (10 years/3 generation past and future) - - -
Number of subpopulations 2-100 - - -
Largest subpopulations - - -
Generation length (yrs) 6 - - -

Population justification: The population density in the Northwest Peru Biosphere Reserve was calculated to be 0.65 individuals per km2, with the population of the study area estimated at 136 individuals (Piana 2016). The population is estimated to number 250-999 mature individuals based on an assessment of known records, descriptions of abundance and range size. This is consistent with recorded population density estimates for congeners or close relatives with a similar body size, and the fact that only a proportion of the estimated Extent of Occurrence is likely to be occupied. This estimate is equivalent to 375-1,499 individuals in total, rounded here to 350-1,500 individuals.

Trend justification: A moderately rapid and ongoing population decline is suspected to be occurring in response to continuing habitat destruction and fragmentation over the period of the last three generations.


Country/territory distribution
Country/Territory Occurrence status Presence Resident Breeding Non-breeding Passage
Ecuador N Extant Yes
Peru N Extant Yes

Important Bird and Biodiversity Areas (IBA)
Country/Territory IBA Name
Ecuador Abras de Mantequilla
Ecuador Alamor-Celica
Ecuador Bosque Protector Cerro Blanco
Ecuador Bosque Protector Cerro Pata de Pájaro
Ecuador Bosque Protector Chongón-Colonche
Ecuador Bosque Protector Jatumpamba-Jorupe
Ecuador Cañón del río Catamayo
Ecuador Cazaderos-Mangaurquillo
Ecuador Centro Científico Río Palenque
Ecuador Cerro de Hayas-Naranjal
Ecuador Cerro Mutiles
Ecuador Daucay
Ecuador Reserva Biológica Tito Santos
Ecuador Hacienda Camarones
Ecuador La Tagua
Ecuador Bosque Protector Molleturo Mullopungo
Ecuador Parque Nacional Machalilla y alrededores
Ecuador Reserva Buenaventura
Ecuador Reserva Ecológica Comunal Loma Alta
Ecuador Mache Chindul Ecological Reserve and surrouding areas (Reserva Ecológica Mache-Chindul IBA)
Ecuador Reserva Ecológica Manglares-Churute
Ecuador Reserva Natural Tumbesia-La Ceiba-Zapotillo
Ecuador Verde-Ónzole-Cayapas-Canandé
Peru Zona Reservada de Tumbes
Peru Parque Nacional Cerros de Amotape

Habitats & altitude
Habitat (level 1) Habitat (level 2) Importance Occurrence
Forest Subtropical/Tropical Dry major resident
Forest Subtropical/Tropical Moist Lowland major resident
Altitude 100 - 2900 m Occasional altitudinal limits  

Threats & impact
Threat (level 1) Threat (level 2) Impact and Stresses
Agriculture & aquaculture Annual & perennial non-timber crops - Scale Unknown/Unrecorded Timing Scope Severity Impact
Ongoing Majority (50-90%) Rapid Declines Medium Impact: 7
Stresses
Ecosystem degradation, Ecosystem conversion
Agriculture & aquaculture Livestock farming & ranching - Small-holder grazing, ranching or farming Timing Scope Severity Impact
Ongoing Majority (50-90%) Rapid Declines Medium Impact: 7
Stresses
Ecosystem degradation, Ecosystem conversion
Biological resource use Logging & wood harvesting - Unintentional effects: (subsistence/small scale) [harvest] Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Declines Low Impact: 5
Stresses
Ecosystem degradation
Residential & commercial development Housing & urban areas Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Declines Low Impact: 5
Stresses
Ecosystem degradation, Ecosystem conversion

Recommended citation
BirdLife International (2020) Species factsheet: Pseudastur occidentalis. Downloaded from http://www.birdlife.org on 21/09/2020. Recommended citation for factsheets for more than one species: BirdLife International (2020) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 21/09/2020.