Harris's hawk

The Harris's hawk (Parabuteo unicinctus) formerly known as the bay-winged hawk or dusky hawk, is a medium-large bird of prey that breeds from the southwestern United States south to Chile, central Argentina, and Brazil. Birds are sometimes reported at large in Western Europe, especially Britain, but it is a popular species in falconry and these records almost certainly all refer to escapes from captivity.

The name is derived from the Greek para, meaning beside, near or like, and the Latin buteo, referring to a kind of buzzard; uni meaning once; and cinctus meaning girdled, referring to the white band at the tip of the tail.[2] John James Audubon gave this bird its English name in honor of his ornithological companion, financial supporter, and friend Edward Harris.[3]

The Harris's hawk is notable for its behavior of hunting cooperatively in packs consisting of tolerant groups, while other raptors often hunt alone. Harris hawks' social nature has been attributed to their intelligence, which makes them easy to train and have made them a popular bird for use in falconry.[4]

Harris's hawk
Harris's Hawk (Parabuteo unicinctus) 3 of 4 in set
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Accipitriformes
Family: Accipitridae
Genus: Parabuteo
P. unicinctus
Binomial name
Parabuteo unicinctus
(Temminck, 1824)

P. u. harrisi
P. u. superior
P. u. unicinctus

Parabuteo unicinctus range map
Distribution map of Parabuteo unicinctus

Falco harrisii Audubon 1839
Buteo harrisii Audubon 1840


Harris' Hawk plumage
The distinctive plumage and tail feathers clearly confirm that this is a Harris's hawk

This medium-large hawk is roughly intermediate in size between a peregrine falcon (Falco peregrinus) and a red-tailed hawk (Buteo jamaicensis). Harris's hawks range in length from 46 to 59 cm (18 to 23 in) and generally have a wingspan of about 103 to 120 cm (41 to 47 in)[5][6] These hawks have a brownish plumage, reddish shoulders and tail feathers with a white base and white tip.[7]

They exhibit sexual dimorphism with the females being larger by about 35%. In the United States, the average weight for adult males is about 701 g (1.545 lb), with a range of 546 to 850 g (1.204 to 1.874 lb), while the adult female average is 1,029 g (2.269 lb), with a range of 766 to 1,633 g (1.689 to 3.600 lb).[8][9] They have dark brown plumage with chestnut shoulders, wing linings, and thighs,[10] white on the base and tip of the tail,[11] long, yellow legs and a yellow cere.[12] The vocalizations of the Harris's hawk are very harsh sounds.[5]


Parabuteo unicinctus falconry
Juvenile in a falconry demonstration

The juvenile Harris's hawk is mostly streaked with buff, and appears much lighter than the dark adults. When in flight, the undersides of the juveniles' wings are buff-colored with brown streaking. They can look unlike adults at first glance, but the identical chestnut plumage is an aid for identification.[12]


There are three subspecies of Harris's hawk:

  • P. u. superior: found in Baja California, Arizona, Sonora, and Sinaloa. P. u. superior was believed to have longer tails and wings and to be more blackish than P. u. harrisi. However, the sample size of the original study was quite small, with only five males and six females. Later research has concluded that there is not as strong a physical difference as was originally assumed.[13] Other ecological differences, such as latitudinal cline were also brought up as arguments against the validity of the subspecies segmentation.[14]
  • P. u. harrisi: found in Texas, eastern Mexico, and much of Central America.[14]
  • P. u. unicinctus: found exclusively in South America. It is smaller than the North American subspecies.[14]

Distribution and habitat

Harris's hawks live in sparse woodland and semi-desert, as well as marshes (with some trees) in some parts of their range (Howell and Webb 1995), including mangrove swamps, as in parts of their South American range.[15] Harris's hawks are permanent residents and do not migrate.[14] Important perches and nest supports are provided by scattered larger trees or other features (e.g., power poles, woodland edges, standing dead trees, live trees, and boulders, and saguaros).[16]

The wild Harris's hawk population is declining due to habitat loss; however, under some circumstances, they have been known to move into developed areas.[17]


Aa babyharrishawks 00
At one week of age

This species occurs in relatively stable groups. A dominance hierarchy occurs in Harris's hawks, wherein the mature female is the dominant bird, followed by the adult male and then the young of previous years. Groups typically include from 2 to 7 birds. Not only do birds cooperate in hunting, they also assist in the nesting process.[18] No other bird of prey is known to hunt in groups as routinely as this species.[19]


Harriss Hawk being with chick leg (7913337978)
Eating chick's leg

The diet of the Harris's hawk consists of small creatures including birds, lizards, mammals, and large insects. Because it often hunts in groups, the Harris's hawk can also take down larger prey.[20] Although not particularly common, the Harris's hawk may take prey weighing over 2 kg (4.4 lb), such as adult jackrabbits, great blue heron (Ardea herodias) and half-grown wild turkeys (Meleagris gallapavo).[21][22][23] The desert cottontail (Syvilagus auduboni), the leading prey species in the north of the Harris's hawk range, usually weighs 800 g (1.8 lb) or less.[24] Undoubtedly because it pursues large prey often, this hawk has larger and stronger feet, with long talons, and a larger, more prominent hooked beak than most other raptors around its size.[9] Locally, other buteonine hawks, including the ferruginous hawk, the red-tailed hawk and the white-tailed hawk also hunt primarily cottontails and jackrabbits, but each are bigger, weighing about 500 g (18 oz), 300 g (11 oz) and 200 g (7.1 oz), respectively, more on average than a Harris's hawk.[25][26][27][28][29]

In the Southwestern United States, the most common prey species (in descending order of prevalence) are desert cottontail (Syvilagus auduboni), eastern cottontail (Syvilagus floridanus), black-tailed jackrabbit (Lepus californicus), ground squirrels (Ammopsermophilus spp. and Spermophilus spp.), woodrats (Neotoma spp.), kangaroo rats (Dipodomys spp.), pocket gophers (Geomys and Thomomys spp.), Gambel's quail (Callipepla gambelii), scaled quail (C. squamata), northern bobwhite (Colinus virginianus), cactus wren (Campylorhynchus brunneicapillus), northern mockingbird (Mimus polyglottos), desert spiny lizards (Sceloporus magister), and skinks (Eumeces spp.)[30][31] In the tropics, Harris's hawks have adapted to taking prey of several varieties, including those like chickens and European rabbits introduced by man.[32][33] In Chile, the common degu (Octodon degus) makes up 67.5% of the prey.[34]


Harris's hawk in flight, Southern Ontario, Canada (captive)
Harris's hawk in flight at a falconry centre

While most raptors are solitary, only coming together for breeding and migration, Harris's hawks will hunt in cooperative groups of two to six. This is believed to be an adaptation to the lack of prey in the desert climate in which they live. In one hunting technique, a small group flies ahead and scouts, then another group member flies ahead and scouts, and this continues until prey is bagged and shared. In another, all the hawks spread around the prey and one bird flushes it out.[35] Groups of Harris's hawks tend to be more successful at capturing prey than lone hawks, with groups of two to four individuals having ~10% higher success rates per extra individual.[36]


They nest in small trees, shrubby growth, or cacti. The nests are often compact, made of sticks, plant roots, and stems, and are often lined with leaves, moss, bark and plant roots. They are built mainly by the female. There are usually two to four white to blueish white eggs sometimes with a speckling of pale brown or gray. The nestlings start out light buff, but in five to six days turn a rich brown.[37]

Very often, there will be three hawks attending one nest: two males and one female.[20] Whether or not this is polyandry is debated, as it may be confused with backstanding (one bird standing on another's back).[38] The female does most of the incubation. The eggs hatch in 31 to 36 days. The young begin to explore outside the nest at 38 days, and fledge, or start to fly, at 45 to 50 days. The female sometimes breeds two or three times in a year.[37] Young may stay with their parents for up to three years, helping to raise later broods. Nests are known to be predated by coyotes (Canis latrans), golden eagles (Aquila chrysaetos), red-tailed hawks (Buteo jamaicensis), great horned owls (Bubo virginianus) and flocks of common ravens (Corvus corax), predators possibly too formidable to be fully displaced by the Harris's hawk's cooperative nest defenses.[39] In Chile, black-chested buzzard-eagles (Geranoaetus melanoleucus) are likely predators.[40]

Relationship with humans


Harris's hawk at a licensed falconry centre
Harris's hawk at a licensed falconry centre, Ontario, Canada

Since about 1980, Harris's hawks have been increasingly used in falconry and are now the most popular hawks in the West (outside of Asia) for that purpose, as they are one of the easiest to train and the most social.[41]

Trained Harris's hawks have been used to remove an unwanted pigeon population from London's Trafalgar Square.[42] and from the tennis courts at Wimbledon.[43]

In art

John James Audubon illustrated the Harris's hawk in The Birds of America (published, London 1827–38) as Plate 392 with the title "Louisiana Hawk -Buteo harrisi". The image was engraved and colored by the Robert Havell, London workshops in 1837. The original watercolor by Audubon was purchased by the New York History Society where it remains to this day (January 2009).


  1. ^ BirdLife International (2012). "Parabuteo unicinctus". IUCN Red List of Threatened Species. Version 2013.2. International Union for Conservation of Nature. Retrieved 26 November 2013.
  2. ^ Jobling, James A. (1991). A Dictionary of Scientific Bird Names. ISBN 978-0-19-854634-4.
  3. ^ National Audubon Society. "Audubon". Audubon. Retrieved 2013-04-29.
  4. ^ Beebe, Frank (1984). A Falconry Manual. Hancock House Publishers, ISBN 0-88839-978-2, page 81.
  5. ^ a b Udvardy, Miklos D. F. (2001). National Audubon Society Field Guide to North American Birds 'Western Region'. ISBN 978-0-679-42851-0.
  6. ^ Clark, W. S. and B. K. Wheeler. (1987). A Field Guide to Hawks of North America. Houghton Mifflin Co. Boston.
  7. ^ "Harris's Hawk - Appearance". 2015. Retrieved October 22, 2018.
  8. ^ Dunning, John B. Jr. (1993). CRC Handbook of Avian Masses. ISBN 978-0-8493-4258-5.
  9. ^ a b Hamerstrom, F. (1978). External sex characters of Harris' Hawks in winter. Raptor Res. 12:1–14.
  10. ^ National Geographic Society (1983). Birds of North America. ISBN 978-0-87044-472-2.
  11. ^ Sibley, David Allen (2000). National Audubon Society The Sibley Guide to Birds. ISBN 978-0-679-45122-8.
  12. ^ a b Rappole, John H. (2000). Birds of the Southwest. ISBN 978-0-89096-958-8.
  13. ^ Bednarz, J. C. (1988). "Harris' hawk subspecies: is superior larger or different than harrisi?". in Proceedings of the southwest raptor management symposium and workshop. Washington, D.C. pp. 294–300.
  14. ^ a b c d Bednarz, James C. (1995). "Harris's Hawk (Parabuteo unicinctus)".
  15. ^ (in Spanish) Olmos Fábio & Robson Silva e Silva (2003). Guará-Ambiente, Flora e Fauna dos Manguezais de Santos-Cubatão Empresa das Artes, ISBN 85-89138-06-2
  16. ^ Bednarz, J. C. and J. D. Ligon. (1988). A study of the ecological bases of cooperative breeding in the Harris' hawk. Ecology 69:1176–1187.
  17. ^ Discoll, James T. "Harris' Hawk". Retrieved 2007-11-19.
  18. ^ Dawson, J. W. and R. W. Mannan. (1991). The role of territoriality in the social organization of Harris' hawks. Auk 108:661–672.
  19. ^ Griffin, C. R. (1976). A preliminary comparison of Texas and Arizona Harris' Hawks (Parabuteo unicinctus) populations. Raptor Res. 10:50–54.
  20. ^ a b Kaufmann, Kenn (1996). Lives of North American Birds. ISBN 978-0-395-77017-7.
  21. ^ Bednarz, J. C. (1988). A comparative study of the breeding ecology of Harris's and Swainson's hawks in southeastern New Mexico. Condor 90:311–323.
  22. ^ Woodward, H.D. (2003). Lone Harris' Hawk Kills Great Blue Heron. The Raptor Research Foundation 1:85–86.
  23. ^ Houcke, H.H. (1971). Predation By a White-Tailed Hawk and a Harris' Hawk on a Wild Turkey Poult Condor 4: 475.
  24. ^ Bednarz, J. C., J. W. Dawson, and W. H. Whaley. (1988). Harris' Hawk. Pages 71–82 in Proceedings of the southwest raptor management symposium and workshop. (Glinski, R. L., B. G. Pendleton, M. B. Moss, M. N. LeFranc, Jr., B. A. Millsap, and S. W. Hoffman, Eds.) Natl. Wildl. Fed. Washington, D.C.
  25. ^ Smith, D. G. and J. R. Murphy. (1978). Biology of the Ferruginous Hawk in central Utah. Sociobiology 3:79–98.
  26. ^ Thurow, T. L., C. M. White, R. P. Howard, and J. F. Sullivan. (1980). Raptor ecology of Raft River valley, Idaho. EG&G Idaho, Inc. Idaho Falls.
  27. ^ Smith, D. G. and J. R. Murphy. (1973). Breeding ecology of raptors in the East Great Basin Desert of Utah. Brigham Young Univ. Sci. Bull., Biol. Ser. Vol. 18:1–76.
  28. ^ Farquhar, C. C. (1986). Ecology and breeding behavior of the White-tailed Hawk on the northern coastal prairies of Texas. PhD. diss. Texas A & M Univ. College Station.
  29. ^ Dunning Jr., John B. (Editor). (1992). CRC Handbook of Avian Body Masses. CRC Press. ISBN 978-0-8493-4258-5.
  30. ^ Mader, W. J. (1975). Biology of the Harris' hawk in southern Arizona. Living Bird 14:59–85.
  31. ^ Brannon, J. D. (1980). The reproductive ecology of a Texas Harris's hawk (Parabuteo unicinctus harrisi) population. Master's Thesis. Univ. of Texas, Austin.
  32. ^ Nutting, C. C. (1883). On a collection of birds from the Hacienda "La Palma," Gulf of Nicoya, Costa Rica, with critical notes by Robert Ridgway. Proc. U.S. Natl. Mus. 1982(5):382–409.
  33. ^ Johnson, A. W. (1965). The birds of Chile and adjacent regions of Argentina, Bolivia, and Peru. Platt Establecimientos Graficos, Buenos Aires.
  34. ^ Jaksic, F. M., J. L. Yanez, and R. P. Schlatter. (1980). Prey of the Harris' hawk in central Chile. Auk 97:196–198.
  35. ^ Cook, William E. (1997). Avian Desert Predators. ISBN 978-3-540-59262-4.
  36. ^ Dawson, James (1988). "The cooperative breeding system of the Harris' Hawk in Arizona". The University of Arizona. Retrieved 17 November 2017.
  37. ^ a b Baicich, Paul J.; Harrison, Colin J. O. (1997). Nests, Eggs, and Nestlings of North American Birds. ISBN 978-0-691-12295-3.
  38. ^ Ligon, J. David (1999). The Evolution of Avian Breeding Systems. Oxford Ornithology Series. 10. Oxford University Press. ISBN 978-0198549130. Retrieved 4 August 2013.
  39. ^ Dawson, J. W. and R. W. Mannan. (1991). Dominance hierarchies and helper contributions in Harris' Hawks. Auk 108:649–660.
  40. ^ Jiménez, J. E., & Jaksić, F. M. (1989). Behavioral ecology of grey eagle-buzzards, Geranoaetus melanoleucus, in central Chile. Condor 913–921.
  41. ^ "Raptors page". Users.cybercity.dk. Archived from the original on 2013-03-05. Retrieved 2013-04-29.
  42. ^ Mount, Harry (2009-10-07). "The £60,000 killer loose in Trafalgar Square". Dailymail.co.uk. Retrieved 2013-04-29.
  43. ^ Mount, Harry (2017-07-03). "Introducing Rufus the hawk: the official bird scarer of the Wimbledon Championships". Telegraph. Retrieved 2018-10-22.

External links

Historical material

  • John James Audubon. "Louisiana Hawk", Ornithological Biography volume 5 (1839). Illustration from Birds of America octavo edition, 1840.

Butastur is a genus of birds of prey in the family Accipitridae.

Cape Verde buzzard

The Cape Verde buzzard (Buteo bannermani) is a medium to large bird of prey that is sometimes considered a subspecies of the widespread common buzzard (Buteo buteo). As its name implies, it is native to Cape Verde

. Some taxonomists consider it to be a distinct species and is treated as such here.

Edward Harris (ornithologist)

Edward Harris (September 7, 1799 – June 8, 1863) was a farmer, horse breeder, philanthropist, naturalist, and ornithologist who accompanied John James Audubon on two of his expeditions to observe birds and mammals of America. Harris was commemorated by Audubon in the common names of the Harris's hawk and the Harris's sparrow, and by John Cassin in the binomial of the buff-fronted owl, Aegolius harrisii.

Edward Harris introduced the Percheron horse to America in 1839 and established the first Percheron breeding line in the United States.


Falconry is the hunting of wild animals in their natural state and habitat by means of a trained bird of prey. Small and larger animals are hunted; squirrels and rabbits often fall prey to these birds. There are two traditional terms used to describe a person involved in falconry: a falconer flies a falcon; an Austringer (German origin) flies a hawk (Accipiter, some buteos and similar) or an eagle (Aquila or similar). In modern falconry, the red-tailed hawk (Buteo jamaicensis), the Harris's hawk (Parabuteo unicinctus), and the peregrine falcon (Falco perigrinus) are some of the more commonly used birds of prey. The practice of hunting with a conditioned falconry bird is also called hawking or gamehawking, although the words hawking and hawker have become used so much to refer to petty traveling traders, that the terms falconer and falconry now apply to most use of trained birds of prey to catch game. Many contemporary practitioners still use these words in their original meaning, however.

In early English falconry literature, the word falcon referred to a female peregrine falcon only, while the word hawk or hawke referred to a female hawk. A male hawk or falcon was referred to as a tiercel (sometimes spelled "tercel") as it was roughly one third less than the female in size.

Flock (birds)

A flock is a gathering of a group of same species animals in order to forage or travel with one another. In avians flocks are typically seen in association with migration. While this is true it can also be seen that flocking is important in safety from predation and foraging benefits. However it is also important to note that living in a flock can also come at a cost to the birds living within it.The definition of flock is narrow, only focusing on a single species existing within a flock. However the existence of mixed flocks are also present in the environment and consist of at least two or more species. In avians the species that tend to flock together are typically similar in taxonomy as well as morphological characters such as size and shape. By having a flock with multiple species present, the defence against predation increases. Defence against predators is particularly important in closed habitats such as forests where early warning calls play a vital importance in the early recognition of danger. The result is the formation of many mixed-species feeding flocks.

Harris hawks optimization

The Harris hawks optimization (HHO) algorithm is a new swarm intelligence optimization paradigm proposed by Ali Asghar Heidari et al. in 2019, which is inspired by the team behaviors and chasing patterns of Harris's hawk in nature called surprise pounce.

Las Chinchillas National Reserve

Las Chinchillas National Reserve is a nature reserve located in the Choapa Province, Coquimbo Region, Chile. The reserve gives shelter to the last colonies of Long-tailed Chinchillas in the wild.


Leucopternis is a Neotropical genus of birds of prey in the Accipitridae family. They are associated with tropical forests, and are uncommon or rare. Their plumage is largely black or gray above and white below, and they have distinctive orange ceres.

Pack hunter

A pack hunter or social predator is a predatory animal which hunts its prey by working together with other members of its species. Normally animals hunting in this way are closely related, and with the exceptions of chimpanzees where only males normally hunt, all individuals in a family group contribute to hunting. When hunting cooperation is across two or more species, the broader term cooperative hunting is commonly used.

A well known pack hunter is the gray wolf; humans too can be considered pack hunters. Other pack hunting mammals include chimpanzees, dolphins, lions, dwarf and banded mongooses and spotted hyenas. Avian social predators include the Harris's hawk, butcherbirds, three of four kookaburra species and many helmetshrikes. There are a few cold-blooded pack hunters including simple arthropods such as army ants, the goldsaddle goatfish and occasionally crocodiles.Some non-avian theropod dinosaurs may have displayed pack behaviour.Pack hunting is typically associated with cooperative breeding and its concentration in the Afrotropical Region is a reflection of this. Most pack hunters are found in the southern African savannas, with a notable absence in tropical rainforests and with the exception of the wolf and coyote, higher latitudes. It is thought that either on the ancient and poor soils of the southern African savanna it is not possible for individual predators to find adequate food, or that the environment’s inherent unpredictability due to ENSO or IOD events means that in very bad conditions it will not be possible to raise the young necessary to prevent declining populations from adult mortality. It is also argued that Africa's large area of continuous flat and open country, which was even more extensive while rainforest contracted during glacial periods of the Quaternary, may have helped encourage pack hunting to become much more common than on any other continent.80-95% of carnivores are solitary and hunt alone; the others including lions, wild dogs, spotted hyenas, chimpanzees, and humans hunt cooperatively, at least some of the time. Cooperative hunting has also been documented in birds of prey and large marine vertebrates such as groupers and moray eels. Cooperative hunting has been linked to the social organization of animal species and the evolution of sociality and thus provides a unique perspective to study group behavior.

Red-necked buzzard

The red-necked buzzard (Buteo auguralis), also known as the African red-tailed buzzard, is a species of buzzard in the family Accipitridae which is found in western and northern central Africa.

Rufus the Hawk

Rufus the Hawk is a Harris's Hawk used by the All England Lawn Tennis and Croquet Club to keep pigeons away from their venue. Described as an "important member of the Wimbledon family", Rufus has been scaring away the birds for fifteen years, taking over from the previous hawk, Hamish.The All England Club employ Rufus to patrol their 42-acre grounds throughout the year, with daily visits during the two weeks of The Championships and the 2012 Summer Olympics. Pigeons are particularly attracted to the roof of the centre court. He has also been employed to scare pigeons away from Westminster Abbey, various hospitals, airfields, and landfill sites.On 28 June 2012 Rufus was stolen from the back of his owner's car while it was parked on a private drive. He would usually be driven back to his home in Corby, Northamptonshire, but his owner had chosen to stay in London. The theft caused a "global outcry" with significant coverage in the media leading to Rufus being named "the world's most notable bird" and "one of Britain's best-known birds". He was found three days later on Wimbledon Common and handed into the RSPCA. The bird was healthy with the only injury being a slightly sore leg. Rufus usually wears a radio transmitter by which he could have been tracked, but it is removed from him at night. In June 2013 it was reported that Rufus was scared by people in hoods and that he had been chased off by crows.Rufus has also been featured by Stella Artois in their advertising series 'Here's To Perfection' which can be viewed here as well as a 360 view of flying above Wimbledon.

Rufus has accounts on Twitter and Facebook and his own Wimbledon security photocard pass with the job title of "Bird Scarer". He is popular amongst Wimbledon fans who often ask to have their photograph taken with him.

Solitary eagle

The solitary eagle or montane solitary eagle (Buteogallus solitarius) is a large Neotropical eagle. It is also known as the black solitary eagle.

Upland buzzard

The upland buzzard (Buteo hemilasius) is a species of bird of prey in the family Accipitridae.

White-rumped hawk

The white-rumped hawk (Parabuteo leucorrhous) is a species of bird of prey in the family Accipitridae.

It is found in Argentina, Bolivia, Brazil, Colombia, Ecuador, Paraguay, Peru, and Venezuela.

Its natural habitat is subtropical or tropical moist montane forests.


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