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| − | [[Image: | + | [[Image:Variable Hawk male, Falklands.jpg|thumb|550px|right|Male light morph ''G. p. polyosoma'' with [[Upland Goose]] prey<br />Photo by {{user|w32aphex|w32aphex}}<br /> [[Falkland Islands]], April 2010]] |
'''Alternative name: Red-backed Hawk''' | '''Alternative name: Red-backed Hawk''' | ||
;[[:Category:Geranoaetus|Geranoaetus]] polyosoma | ;[[:Category:Geranoaetus|Geranoaetus]] polyosoma | ||
'''Includes Puna Hawk''' | '''Includes Puna Hawk''' | ||
==Identification== | ==Identification== | ||
| − | + | Length 46-61 cm, wingspan 110-150 cm, weight ''c''. 950-1000 g | |
*White tail with black sub-terminal band but otherwise very variable in plumage | *White tail with black sub-terminal band but otherwise very variable in plumage | ||
| − | *Lacks black commas or larger black marks seen on wing underside at the wrist of most similar species <br /> | + | *Lacks black commas or larger black marks seen on wing underside at the wrist of most similar species |
| − | [[Image: | + | *Legs yellow; bill with yellow base and blackish tip<br /> |
| + | [[Image:VARIABLE HAWK2 copy.jpg|thumb|350px|right|Female light morph ''G. p. polyosoma''<br />Photo by {{user|lior+kislev|lior kislev}}<br /> Puno to Cusco road, [[Peru]], December 2009]] | ||
'''Male''' | '''Male''' | ||
| − | *Grey back (mantle can be reddish on some individuals) | + | *Grey back (mantle can be reddish on some individuals; see also Subspecies, below); light grey in light morph, dark grey in dark morph |
| − | *White | + | *White underparts in light morph, dark grey underparts in dark morph<br /> |
| − | '''Female''' | + | '''Female''' |
| + | *Usually has a rufous mantle but may have either white or rufous or rufous-and-black underparts.<br /> | ||
| + | '''Juvenile''' | ||
| + | *Mottled brown | ||
| − | The wings fall short of the tip of the tail on the sitting bird in the "Red-backed" form while the "Puna" form (formerly a separate species) has wingtips that reach the tip of the tail; this seems to be the best separator of the two | + | The wings fall short of the tip of the tail on the sitting bird in the "Red-backed" form while the "Puna" form (formerly a separate species) has wingtips that reach the tip of the tail; this seems to be the best separator of the two subspecies. |
| + | [[Image:Puna_Hawk.jpg|thumb|350px|right|Puna Hawk ''G. p. poecilochrous'' male<br />Photo by {{user|tf1044x|tf1044x}} in Peru]] | ||
| − | |||
==Distribution== | ==Distribution== | ||
[[South America]]: found in [[Colombia]], [[Ecuador]], [[Peru]], [[Bolivia]], [[Chile]], [[Argentina]], and [[Falkland Islands]];vagrant to [[Uruguay]], [[Brazil]]. | [[South America]]: found in [[Colombia]], [[Ecuador]], [[Peru]], [[Bolivia]], [[Chile]], [[Argentina]], and [[Falkland Islands]];vagrant to [[Uruguay]], [[Brazil]]. | ||
| + | |||
==Taxonomy== | ==Taxonomy== | ||
Formerly placed in genus ''[[:Category:Buteo|Buteo]]'' | Formerly placed in genus ''[[:Category:Buteo|Buteo]]'' | ||
====Subspecies<sup>[[#References|[1]]]</sup>==== | ====Subspecies<sup>[[#References|[1]]]</sup>==== | ||
| − | Two subspecies are | + | Two to subspecies are accepted by different authorities: |
| − | * ''G. p. polyosoma'' - Andes of | + | * ''G. p. polyosoma'' - Andes of western [[Colombia]] south to Tierra del Fuego, and [[Falkland Islands]] ('''Red-backed Hawk''') |
| − | * ''G. p. exsul'' - Juan Fernadez Islands, [[Chile]] | + | :* Smaller; 46-56 cm, wingspan 110-120 cm; light morph males mostly grey-backed, white below, females rufous-backed, white below; dark morph males dark grey above and below, females rufous-backed and rufous breasted |
| + | * ''G. p. exsul'' - Juan Fernadez Islands, [[Chile]] ('''Juan Fernadez Hawk''') | ||
| + | :* Slightly larger; both sexes grey-backed | ||
| + | * ''G. p. poecilochrous'' - High Andes from s Colombia to s Ecuador ('''Puna Hawk''') | ||
| + | :* Larger; 51-61 cm, wingspan 125-150 cm | ||
| + | * ''G. p. fjeldsai'' - Andes from n Peru to nw Argentina (described 2009, as a split from Puna Hawk) | ||
| − | There is an active debate as to whether Red-backed Hawk and Puna Hawk are | + | There is an active debate as to whether Red-backed Hawk, Juan Fernadez Hawk, and Puna Hawk are three species or one. Opus follows a consensus according to which it is one, Variable Hawk. |
==Habitat== | ==Habitat== | ||
| + | [[Image:10884IMG 9491 Buteo polyosoma.jpg|thumb|350px|right|Female dark morph ''G. p. polyosoma''<br />Photo by {{user|BirdsPeru|BirdsPeru}}<br />High Andes, Lima, [[Peru]], November 2006 ]] | ||
Open areas to open forest, but most likely in areas with scrub and some trees in steep terrain. Observed at heights up to around 3000 meters in the north of its range, lower down further south. Where overlapping with Puna Hawk, the form Red-backed Hawk is normally seen at lower elevation. | Open areas to open forest, but most likely in areas with scrub and some trees in steep terrain. Observed at heights up to around 3000 meters in the north of its range, lower down further south. Where overlapping with Puna Hawk, the form Red-backed Hawk is normally seen at lower elevation. | ||
==Behaviour== | ==Behaviour== | ||
====Diet==== | ====Diet==== | ||
| − | + | Eats primarily mammals but with a significant amount of insects and some birds. Pairs sometime hunts co-operatively, taking birds in flight as large as [[Upland Goose]] (3 kg, 50% more than the combined weight of the hunting pair). | |
| − | Eats primarily mammals but with a significant amount of insects and some birds. | ||
====Breeding==== | ====Breeding==== | ||
It nests in treetops. The nest is large and made of dry sticks. The clutch generally consists of 2 white eggs with light reddish spots. | It nests in treetops. The nest is large and made of dry sticks. The clutch generally consists of 2 white eggs with light reddish spots. | ||
| + | [[Image:18681YoungRedBack.jpg|thumb|300px|right|Juvenile<br />Photo by {{user|zweiblumen|zweiblumen}}<br />Cape Pembroke, [[Falkland Islands]], April 2004]] | ||
| + | |||
==References== | ==References== | ||
#{{Ref-GillDonsker14V4.3}}#Avibase | #{{Ref-GillDonsker14V4.3}}#Avibase | ||
| Line 39: | Line 51: | ||
# Restall et al. 2006. Birds of Northern South America. Yale University Press. ISBN 9780300124156 | # Restall et al. 2006. Birds of Northern South America. Yale University Press. ISBN 9780300124156 | ||
# [http://www.birdforum.net/showthread.php?t=177760 Birdforum thread] mentioning several taxonomic proposals, of which 460 is relevant here | # [http://www.birdforum.net/showthread.php?t=177760 Birdforum thread] mentioning several taxonomic proposals, of which 460 is relevant here | ||
| + | # [http://www.birdforum.net/showthread.php?t=330330 Birdforum thread] with details of feeding ecology | ||
{{ref}} | {{ref}} | ||
==External Links== | ==External Links== | ||
Revision as of 13:40, 27 August 2016
Male light morph G. p. polyosoma with Upland Goose prey
Photo by w32aphex
Falkland Islands, April 2010
Photo by w32aphex
Falkland Islands, April 2010
Alternative name: Red-backed Hawk
- Geranoaetus polyosoma
Includes Puna Hawk
Identification
Length 46-61 cm, wingspan 110-150 cm, weight c. 950-1000 g
- White tail with black sub-terminal band but otherwise very variable in plumage
- Lacks black commas or larger black marks seen on wing underside at the wrist of most similar species
- Legs yellow; bill with yellow base and blackish tip
Male
- Grey back (mantle can be reddish on some individuals; see also Subspecies, below); light grey in light morph, dark grey in dark morph
- White underparts in light morph, dark grey underparts in dark morph
Female
- Usually has a rufous mantle but may have either white or rufous or rufous-and-black underparts.
Juvenile
- Mottled brown
The wings fall short of the tip of the tail on the sitting bird in the "Red-backed" form while the "Puna" form (formerly a separate species) has wingtips that reach the tip of the tail; this seems to be the best separator of the two subspecies.
Distribution
South America: found in Colombia, Ecuador, Peru, Bolivia, Chile, Argentina, and Falkland Islands;vagrant to Uruguay, Brazil.
Taxonomy
Formerly placed in genus Buteo
Subspecies[1]
Two to subspecies are accepted by different authorities:
- G. p. polyosoma - Andes of western Colombia south to Tierra del Fuego, and Falkland Islands (Red-backed Hawk)
- Smaller; 46-56 cm, wingspan 110-120 cm; light morph males mostly grey-backed, white below, females rufous-backed, white below; dark morph males dark grey above and below, females rufous-backed and rufous breasted
- G. p. exsul - Juan Fernadez Islands, Chile (Juan Fernadez Hawk)
- Slightly larger; both sexes grey-backed
- G. p. poecilochrous - High Andes from s Colombia to s Ecuador (Puna Hawk)
- Larger; 51-61 cm, wingspan 125-150 cm
- G. p. fjeldsai - Andes from n Peru to nw Argentina (described 2009, as a split from Puna Hawk)
There is an active debate as to whether Red-backed Hawk, Juan Fernadez Hawk, and Puna Hawk are three species or one. Opus follows a consensus according to which it is one, Variable Hawk.
Habitat
Open areas to open forest, but most likely in areas with scrub and some trees in steep terrain. Observed at heights up to around 3000 meters in the north of its range, lower down further south. Where overlapping with Puna Hawk, the form Red-backed Hawk is normally seen at lower elevation.
Behaviour
Diet
Eats primarily mammals but with a significant amount of insects and some birds. Pairs sometime hunts co-operatively, taking birds in flight as large as Upland Goose (3 kg, 50% more than the combined weight of the hunting pair).
Breeding
It nests in treetops. The nest is large and made of dry sticks. The clutch generally consists of 2 white eggs with light reddish spots.
References
- Gill, F and D Donsker (Eds). 2014. IOC World Bird Names (version 4.3). Available at http://www.worldbirdnames.org/.
- Avibase
- BF Member observations
- Restall et al. 2006. Birds of Northern South America. Yale University Press. ISBN 9780300124156
- Birdforum thread mentioning several taxonomic proposals, of which 460 is relevant here
- Birdforum thread with details of feeding ecology
Recommended Citation
- BirdForum Opus contributors. (2024) Variable Hawk. In: BirdForum, the forum for wild birds and birding. Retrieved 25 April 2024 from https://www.birdforum.net/opus/Variable_Hawk
