Harris's Hawk
Encyclopedia
The Harris's Hawk or Harris Hawk (Parabuteo unicinctus) formerly known as the Bay-winged Hawk or Dusky Hawk, is a medium-large bird of prey
which breeds from the southwestern United States
south to Chile
and central Argentina
. 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
.
It is the only member of the genus Parabuteo. 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. John James Audubon
gave this bird its English name in honor of his ornithological companion, financial supporter, and friend Edward Harris
. The Harris Hawk is notable for its behavior of hunting cooperatively in "packs
", consisting of family groups while most other raptors hunt in solitary.
Individual Harris Hawks range in length from 46 to 76 cm (18.1 to 29.9 in) and generally have a wingspan of about 1.1 m (3.6 ft) They exhibit sexual dimorphism
with the females being larger by about 35%. In the United States, the average weight for males is about 710 g (25 oz), while the female average is 1020 g (36 oz). They have dark brown plumage
with chestnut shoulders, wing linings, and thighs, white on the base a tip of the tail, long, yellow legs and a yellow cere
. The vocalizations of the Harris's Hawk are very harsh sounds.
The juvenile Harris 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.
and semi-desert, as well as marsh
es (with some trees) in some parts of their range
(Howell and Webb 1995), including mangrove
swamps, as in parts of their South American range. Harris's Hawks are permanent residents and do not migrate
.
, the Harris's Hawk can also take down larger prey, such as jackrabbit
s.
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.
Very often, there will be three hawks attending one nest: two males and one female. Whether or not this is polyandry
is debated, as it may be confused with backstanding (one bird standing on another's back). 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. Young may stay with their parents for up to three years, helping to raise later broods.
of two to six. This is believed to be an adaptation to 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 individual flushes it.
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.
and are now the most popular hawks in the West (outside of Asia) for that purpose, as they are the easiest to train and the most social.
illustrated the Harris's Hawk in 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).
Bird of prey
Birds of prey are birds that hunt for food primarily on the wing, using their keen senses, especially vision. They are defined as birds that primarily hunt vertebrates, including other birds. Their talons and beaks tend to be relatively large, powerful and adapted for tearing and/or piercing flesh....
which breeds from the southwestern United States
Southwestern United States
The Southwestern United States is a region defined in different ways by different sources. Broad definitions include nearly a quarter of the United States, including Arizona, California, Colorado, Nevada, New Mexico, Oklahoma, Texas and Utah...
south to Chile
Chile
Chile ,officially the Republic of Chile , is a country in South America occupying a long, narrow coastal strip between the Andes mountains to the east and the Pacific Ocean to the west. It borders Peru to the north, Bolivia to the northeast, Argentina to the east, and the Drake Passage in the far...
and central Argentina
Argentina
Argentina , officially the Argentine Republic , is the second largest country in South America by land area, after Brazil. It is constituted as a federation of 23 provinces and an autonomous city, Buenos Aires...
. Birds are sometimes reported at large in Western Europe
Western Europe
Western Europe is a loose term for the collection of countries in the western most region of the European continents, though this definition is context-dependent and carries cultural and political connotations. One definition describes Western Europe as a geographic entity—the region lying in the...
, especially Britain
Great Britain
Great Britain or Britain is an island situated to the northwest of Continental Europe. It is the ninth largest island in the world, and the largest European island, as well as the largest of the British Isles...
, but it is a popular species in falconry
Falconry
Falconry is "the taking of wild quarry in its natural state and habitat by means of a trained raptor". There are two traditional terms used to describe a person involved in falconry: a falconer flies a falcon; an austringer flies a hawk or an eagle...
and these records almost certainly all refer to escapes from captivity
Captivity (animal)
Animals that live under human care are in captivity. Captivity can be used as a generalizing term to describe the keeping of either domesticated animals or wild animals. This may include for example farms, private homes and zoos...
.
It is the only member of the genus Parabuteo. The name is derived from the Greek
Greek language
Greek is an independent branch of the Indo-European family of languages. Native to the southern Balkans, it has the longest documented history of any Indo-European language, spanning 34 centuries of written records. Its writing system has been the Greek alphabet for the majority of its history;...
para, meaning beside, near or like, and the Latin
Latin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...
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. John James Audubon
John James Audubon
John James Audubon was a French-American ornithologist, naturalist, and painter. He was notable for his expansive studies to document all types of American birds and for his detailed illustrations that depicted the birds in their natural habitats...
gave this bird its English name in honor of his ornithological companion, financial supporter, and friend Edward Harris
Edward Harris (ornithologist)
Edward Harris was an American farmer and amateur naturalist.Son of a farmer, Harris grew up near to Philadelphia...
. The Harris Hawk is notable for its behavior of hunting cooperatively in "packs
Pack hunter
A pack hunter is a predator belonging to the animal kingdom, which has evolved to hunt its prey by working together with other members of its species. Normally, such animals are closely related. The most commonly known pack hunter is the Gray Wolf, the ancestor of all breeds of domesticated dogs...
", consisting of family groups while most other raptors hunt in solitary.
Description
Sexual dimorphism
Sexual dimorphism is a phenotypic difference between males and females of the same species. Examples of such differences include differences in morphology, ornamentation, and behavior.-Examples:-Ornamentation / coloration:...
with the females being larger by about 35%. In the United States, the average weight for males is about 710 g (25 oz), while the female average is 1020 g (36 oz). They have dark brown plumage
Plumage
Plumage refers both to the layer of feathers that cover a bird and the pattern, colour, and arrangement of those feathers. The pattern and colours of plumage vary between species and subspecies and can also vary between different age classes, sexes, and season. Within species there can also be a...
with chestnut shoulders, wing linings, and thighs, white on the base a tip of the tail, long, yellow legs and a yellow cere
Cère
The Cère is a long river in south-western France, left tributary of the Dordogne River. Its source is in the south-western Massif Central, near the mountain Plomb du Cantal...
. The vocalizations of the Harris's Hawk are very harsh sounds.
Juvenile
Buff
Buff may refer to:* Buff , a pale yellow-brown colour* Buff , a multifunctional article of clothing produced by Original Buff, a Catalan company* Buff * A form of Status effect, a temporary beneficial effect in some video games...
, 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
Plumage
Plumage refers both to the layer of feathers that cover a bird and the pattern, colour, and arrangement of those feathers. The pattern and colours of plumage vary between species and subspecies and can also vary between different age classes, sexes, and season. Within species there can also be a...
is an aid for identification.
Subspecies
There are three subspecies of Harris's Hawk:- P. u. superior: found in Baja CaliforniaBaja CaliforniaBaja California officially Estado Libre y Soberano de Baja California is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. It is both the northernmost and westernmost state of Mexico. Before becoming a state in 1953, the area was known as the North...
, ArizonaArizonaArizona ; is a state located in the southwestern region of the United States. It is also part of the western United States and the mountain west. The capital and largest city is Phoenix...
, SonoraSonoraSonora officially Estado Libre y Soberano de Sonora is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. It is divided into 72 municipalities; the capital city is Hermosillo....
, and SinaloaSinaloaSinaloa officially Estado Libre y Soberano de Sinaloa is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. It is divided in 18 municipalities and its capital city is Culiacán Rosales....
. 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. Other ecological differences, such as latitudinal cline were also brought up as arguments against the validity of the subspecies segmentation. - P. u. harrisi: found in TexasTexasTexas is the second largest U.S. state by both area and population, and the largest state by area in the contiguous United States.The name, based on the Caddo word "Tejas" meaning "friends" or "allies", was applied by the Spanish to the Caddo themselves and to the region of their settlement in...
, eastern MexicoMexicoThe United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
, and much of Central AmericaCentral AmericaCentral America is the central geographic region of the Americas. It is the southernmost, isthmian portion of the North American continent, which connects with South America on the southeast. When considered part of the unified continental model, it is considered a subcontinent...
. - P. u. unicinctus: found exclusively in South AmericaSouth AmericaSouth America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...
. It is smaller than the North American subspecies.
Distribution and habitat
Harris's Hawks live in sparse woodlandWoodland
Ecologically, a woodland is a low-density forest forming open habitats with plenty of sunlight and limited shade. Woodlands may support an understory of shrubs and herbaceous plants including grasses. Woodland may form a transition to shrubland under drier conditions or during early stages of...
and semi-desert, as well as marsh
Marsh
In geography, a marsh, or morass, is a type of wetland that is subject to frequent or continuous flood. Typically the water is shallow and features grasses, rushes, reeds, typhas, sedges, other herbaceous plants, and moss....
es (with some trees) in some parts of their range
Range (biology)
In biology, the range or distribution of a species is the geographical area within which that species can be found. Within that range, dispersion is variation in local density.The term is often qualified:...
(Howell and Webb 1995), including mangrove
Mangrove
Mangroves are various kinds of trees up to medium height and shrubs that grow in saline coastal sediment habitats in the tropics and subtropics – mainly between latitudes N and S...
swamps, as in parts of their South American range. Harris's Hawks are permanent residents and do not migrate
Bird migration
Bird migration is the regular seasonal journey undertaken by many species of birds. Bird movements include those made in response to changes in food availability, habitat or weather. Sometimes, journeys are not termed "true migration" because they are irregular or in only one direction...
.
Behavior
Feeding
The diet of the Harris's Hawk consists of small creatures including birds, lizards, mammals, and large insects. Because it often hunts in groupsPack hunter
A pack hunter is a predator belonging to the animal kingdom, which has evolved to hunt its prey by working together with other members of its species. Normally, such animals are closely related. The most commonly known pack hunter is the Gray Wolf, the ancestor of all breeds of domesticated dogs...
, the Harris's Hawk can also take down larger prey, such as jackrabbit
Hare
Hares and jackrabbits are leporids belonging to the genus Lepus. Hares less than one year old are called leverets. Four species commonly known as types of hare are classified outside of Lepus: the hispid hare , and three species known as red rock hares .Hares are very fast-moving...
s.
Breeding
They nest in small trees, shrubby growth, or cacti. The nestsBird nest
A bird nest is the spot in which a bird lays and incubates its eggs and raises its young. Although the term popularly refers to a specific structure made by the bird itself—such as the grassy cup nest of the American Robin or Eurasian Blackbird, or the elaborately woven hanging nest of the...
are often compact, made of sticks, plant roots, and stems, and are often lined with leaves, moss
Moss
Mosses are small, soft plants that are typically 1–10 cm tall, though some species are much larger. They commonly grow close together in clumps or mats in damp or shady locations. They do not have flowers or seeds, and their simple leaves cover the thin wiry stems...
, bark and plant roots. They are built mainly by the female. There are usually two to four white to blueish white eggs
Bird egg
Bird eggs are laid by females and incubated for a time that varies according to the species; a single young hatches from each egg. Average clutch sizes range from one to about 17...
sometimes with a speckling of pale brown
Brown
Brown is a color term, denoting a range of composite colors produced by a mixture of orange, red, rose, or yellow with black or gray. The term is from Old English brún, in origin for any dusky or dark shade of color....
or gray. The nestlings start out light buff, but in five to six days turn a rich brown.
Very often, there will be three hawks attending one nest: two males and one female. Whether or not this is polyandry
Polyandry
Polyandry refers to a form of marriage in which a woman has two or more husbands at the same time. The form of polyandry in which a woman is married to two or more brothers is known as "fraternal polyandry", and it is believed by many anthropologists to be the most frequently encountered...
is debated, as it may be confused with backstanding (one bird standing on another's back). The female does most of the incubation
Avian incubation
Incubation refers to the process by which certain oviparous animals hatch their eggs, and to the development of the embryo within the egg. The most vital factor of incubation is the constant temperature required for its development over a specific period. Especially in domestic fowl, the act of...
. The eggs hatch in 31 to 36 days. The young begin to explore outside the nest at 38 days, and fledge
Fledge
Fledge is the stage in a young bird's life when the feathers and wing muscles are sufficiently developed for flight. It also describes the act of a chick's parents raising it to a fully grown state...
, or start to fly, at 45 to 50 days. The female sometimes breeds two or three times in a year. Young may stay with their parents for up to three years, helping to raise later broods.
Relationship with humans
Hunting
While most raptors are solitary, only coming together for breeding and migration, Harris's Hawks will hunt in cooperative groupsPack hunter
A pack hunter is a predator belonging to the animal kingdom, which has evolved to hunt its prey by working together with other members of its species. Normally, such animals are closely related. The most commonly known pack hunter is the Gray Wolf, the ancestor of all breeds of domesticated dogs...
of two to six. This is believed to be an adaptation to 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 individual flushes it.
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.
Falconry
Since about 1980, Harris's Hawks have been increasingly used in falconryFalconry
Falconry is "the taking of wild quarry in its natural state and habitat by means of a trained raptor". There are two traditional terms used to describe a person involved in falconry: a falconer flies a falcon; an austringer flies a hawk or an eagle...
and are now the most popular hawks in the West (outside of Asia) for that purpose, as they are the easiest to train and the most social.
In art
John James AudubonJohn James Audubon
John James Audubon was a French-American ornithologist, naturalist, and painter. He was notable for his expansive studies to document all types of American birds and for his detailed illustrations that depicted the birds in their natural habitats...
illustrated the Harris's Hawk in Birds of America
Birds of America (book)
The Birds of America is a book by naturalist and painter John James Audubon, containing illustrations of a wide variety of birds of the United States. It was first published as a series of sections between 1827 and 1838, in Edinburgh and London....
(published, London 1827–38) as Plate 392 with the title "Louisiana Hawk -Buteo harrisi". The image was engraved
Engraving
Engraving is the practice of incising a design on to a hard, usually flat surface, by cutting grooves into it. The result may be a decorated object in itself, as when silver, gold, steel, or glass are engraved, or may provide an intaglio printing plate, of copper or another metal, for printing...
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).
General
- Steve N. G. Howell and Sophie Webb (1995) A Guide to the Birds of Mexico and Northern Central America ISBN 0-19-854012-4