The Zone-tailed Hawk is found from the southwestern United States to Central and South America (Johnson et al. 2000).
Biogeographic Regions: nearctic (Native ); neotropical (Native )
Regularity: Regularly occurring
Type of Residency: Breeding
Global Range: RESIDENT: northern Baja California, central Arizona, southern New Mexico, and western Texas south locally to Panama (including Pearl Islands), eastern Colombia (Santa Marta region south to Magdalena; east of the Andes in Meta, Caqueta, and Amazonas), northern and southeastern Venezuela (Zulia to Anzoategui, northeastern Bolivar), Trinidad, Guyana, Surinam, eastern Brazil (Isla Marajo, Ceara, Pernambuco, Alagoas, Parana), Paraguay, northern and eastern Bolivia (Beni, Santa Cruz), western Ecuador, and west-central Peru (near Lima) (Sibley and Monroe 1990). Center of abundance in U.S. is in central Arizona, with about a dozen known pairs in both New Mexico and southwestern Texas and a few recent sightings in California (Snyder and Glinski 1998).
- Clements, J. F., T. S. Schulenberg, M. J. Iliff, D. Roberson, T. A. Fredericks, B. L. Sullivan, and C. L. Wood. 2014. The eBird/Clements checklist of birds of the world: Version 6.9. Downloaded from http://www.birds.cornell.edu/clementschecklist/download/
The Zone-tailed Hawk is a dark hawk (black with brown cast) lacking the light morphology commonly found in many Buteo species. The tail has 2 to 3 light bands that are white when viewed from below. The under-wing is two-toned with black wing tips. The legs and beak of the Zone-tailed Hawk are yellow. The female is slightly larger than the males of this species. The immature hawk is a little darker with white spots around head and on under parts. The immature hawk has many narrow blackish bands on tail. (Johnson et al. 2000)
Range mass: 610 to 940 g.
Range length: 45 to 56 cm.
Range wingspan: 119 to 140 cm.
Other Physical Features: endothermic ; bilateral symmetry
Length: 51 cm
Weight: 886 grams
Riparian forest and woodland, desert uplands, and mixed conifer forests (Johnson et al. 2000).
Range elevation: 0 to 2200 m.
Habitat Regions: temperate ; tropical
Terrestrial Biomes: desert or dune ; forest
Other Habitat Features: riparian
Habitat and Ecology
Comments: Arid open country, especially open deciduous or pine-oak woodland (AOU 1983). Mesa and mountain country, often near watercouses (NGS 1983). Wooded canyons and tree-lined rivers along middle slopes of desert mountains. Open country with scattered trees or thickets, especially near marshes or streams (Costa Rica, Stiles and Skutch 1989).
Nests in various habitats and sites, ranging from small trees in lower desert, giant cottonwoods in riparian areas and mature conifers in high mountain regions; often selects nest site close to cliff or steep hillside (which may provide some shading part of day) adapts well to regular low-level human activity (if not too close to nest) (Snyder and Glinski 1988). Nests usually in large tree in U.S., often in cottonwood along canyon stream (Terres 1980). In Costa Rica, nests high in tree, often in gallery woodland (Stiles and Skutch 1989). Often uses same nest tree for many years (Snyder and Glinski 1988).
Non-Migrant: Yes. At least some populations of this species do not make significant seasonal migrations. Juvenile dispersal is not considered a migration.
Locally Migrant: Yes. At least some populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).
Locally Migrant: Yes. At least some populations of this species make annual migrations of over 200 km.
Partially migratory in northern part of breeding range. A few winter in mountains "west" [east?] of San Diego with occasional winter records from desert areas of Arizona, New Mexico, and southern Texas. Arrives on breeding grounds in U.S. mid-March to early April (Snyder and Glinski 1988).
The diet of the Zone-tailed Hawk includes many small vertebrates (birds, especially passerines; mammals, especially ground squirrels and chipmunks; amphibians and reptiles, particularly the common collared lizard and crevice spiny lizard; rarely fish) (Sherrod 1978). Prey that is exposed and becomes conditioned to the harmless presence of Turkey Vultures is likely prey of the Zone-tailed Hawk (Willis 1963, Zimmerman 1976, Synder and Synder 1991). The hawk is believed to mimic the Turkey Vulture in flight to take advantage of prey that is desensitized to the presence of vultures. Alternatively, dihedral wing shape may simply help stabilize low flight over rough terrain (Mueller 1972, 1976).
The Zone-tailed Hawk circles 40-105m above ground with wings in dihedral position before stooping on prey (McLaran and MacInnis 1977). Also circles at altitude of 15-60m; after sighting prey, continues to circle, dropping behind cover, turning swiftly and, when possible, approaching behind cover to within 0.5-2m of prey before striking (Snyder in Palmer 1988).
Primary Diet: carnivore (Eats terrestrial vertebrates)
Comments: Eats various small vertebrates (especially birds and lizards in U.S., also rodents, frogs, snakes, centipedes); pounces from low glide (Terres 1980, NGS 1983). In Arizona, observed foraging up to 26 km from nest (Palmer 1988). Usual hunting method: soars rapidly and widely over ground at altitude of about 50-500 ft (usually at lower end of this range).
Life History and Behavior
Perception Channels: visual ; tactile ; acoustic ; chemical
Believed to be monogamous.
Mating System: monogamous
The Zone-tailed Hawk engages in spectacular courtship displays. During these displays aerial loops, dives, and rolls are performed. Heights of up to 500 m are achieved during these ritualized interactions between male and females. Female Zone-tailed Hawks lay one or two eggs per clutch. While in the southwestern United States these hawks breed only once, not much is known about their breeding habits in South America except that year-round residents breed only once.(Johnson et al. 2000)
Breeding season: March to May
Range eggs per season: 1 to 3.
Range time to hatching: 28 to 34 days.
Range fledging age: 28 to 35 days.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization (Internal ); oviparous
Young are semi-altricial at hatching, with grey down. Female parent incubates, while male parent collects food for the female and young. (Baicich and Harrison 1997; Johnson et al. 2000)
Growth is gradual to slow during first 7 days; between days 7-21, growth is rapid. Cases of siblicide have been documented. (Johnson et al. 2000)
Parental Investment: altricial ; male parental care ; female parental care
Egg dates: mid-April to mid-May in Arizona; late March to mid-May in Texas. Nesting begins November-December in Central America. Breeds February-March in Trinidad (Palmer 1988). Eggs laid mostly in latter half of April in north (U.S.). Clutch size 1-3 (usually 2). Incubation about 35 days, primarily by female. Young attain flight in 6-7 weeks (July-August in north).
Molecular Biology and Genetics
Barcode data: Buteo albonotatus
Below is a sequence of the barcode region Cytochrome oxidase subunit 1 (COI or COX1) from a member of the species.
See the BOLD taxonomy browser for more complete information about this specimen and other sequences.
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Download FASTA File
Statistics of barcoding coverage: Buteo albonotatus
Public Records: 5
Specimens with Barcodes: 6
Species With Barcodes: 1
Not federally or state Threatened or Endangered except Threatened in Texas (Johnson et al 2000).
US Migratory Bird Act: protected
US Federal List: no special status
CITES: no special status
IUCN Red List of Threatened Species: least concern
IUCN Red List Assessment
Red List Category
Red List Criteria
National NatureServe Conservation Status
Rounded National Status Rank: N4B - Apparently Secure
NatureServe Conservation Status
Rounded Global Status Rank: G4 - Apparently Secure
Comments: Greatest threat in U.S. is loss of riparian nesting habitat; presence of DDT in several river systems is a concern in southwestern Texas (where contamination of lizard prey is documented) (Palmer 1988).
Management Requirements: Primary desireable management action in U.S. is protection of all known nest trees, especially those in vulnerable riparian areas (Snyder and Glinski 1988, which see for research needs).
Relevance to Humans and Ecosystems
Believed by some to be a pest, viewed as a "chicken hawk". (Johnson et al 2000)
The zone-tailed hawk (Buteo albonotatus) is a medium-sized hawk of warm, dry parts of the Americas. It is somewhat similar in plumage and flight style to a common scavenger, the turkey vulture, and may benefit from being able to blend into groups of vultures. It feeds on small vertebrates of all kinds (other than fish), including various small mammals and birds.
Zone-tailed hawks range from parts of southern Arizona, New Mexico, and western Texas almost throughout inland Mexico and the central portions of Central America down into eastern Colombia, Ecuador and, more sporadically, into Peru, southern Brazil, Paraguay, Bolivia, and northern Argentina. In winter they generally withdraw from the U.S. and northernmost Mexico, with these populations wintering mostly in Oaxaca and the Yucatán Peninsula. The hawks of Central America may be seasonally migratory, although their movements are not well known. Zone-tails sometimes wander out of their normal range, and the bird was once recorded in Nova Scotia.
Zone-tailed hawks can adapt to various habitats across their broad range, including both closed and open ones and wet and dry ones. Often, the largest numbers are found in rocky areas with access to water. They often reside in coniferous or pine-oak forests as well as timbered canyonland, hilly riverine woods, dry open boscage and scrub, humid forests and overgrown marshes. They may forage over ranches and even semi-desert, but always need at least scattered tree thickets for nesting. They may be distributed in elevation from sea-level to 3,000 m (9,800 ft), though are mainly found below 1,500 m (4,900 ft) in the north and below 500 m (1,600 ft) in the southern reaches of the breeding range.
The zone-tailed hawk is a fairly large but slender Buteo hawk. Grown birds are 46 to 56 cm (18 to 22 in) in length with a wingspan of about 117–140 cm (46–55 in). The zone-tailed is comparable in length and wingspan to common large Buteos found to the north such as Swainson's and red-tailed hawk, but may weigh considerably less. Their body mass can range from 565–1,080 g (1.246–2.381 lb). In measurements, the sexes are close in size, but the female, at an average of 900 g (2.0 lb), is much heavier and bulkier than the male, at an average of 637 g (1.404 lb). Among standard measurements, the wing chord is 36.5–46 cm (14.4–18.1 in), the fairly long tail is 19.4–23.5 cm (7.6–9.3 in) and the tarsus is 6.7–7.8 cm (2.6–3.1 in).
The adult plumage is mostly blackish. The notable exception is that the flight feathers are barred with lighter gray, which can appear solid silver-gray from a distance. The tail has three or four bands (the "zones" of the common name), white from below and light gray from above, of which the one second from the tip is particularly broad and conspicuous. The cere and legs are yellow, the lores are light gray and a light touch of white may be seen on the face. Immatures are similar except for small white spots on the breast and tails with narrow gray and black bands and a broad dark tip. The zone-tailed hawk adults resemble the common black hawk but are distinctly more slender in flight and overall small, and they have more white bars on the tail. Other Buteo hawks in their dark phase, especially the broad-winged hawk, may appear similar but often have more silvery coloration on the wings and are broader-winged.
The call is a loud scream, a somewhat typical Buteo call, dropping in pitch at the end, kra kree-kree-kree-kree. In at least some birds, there is an abrupt rise in pitch (like a break to a falsetto voice) in the middle and an equally abrupt drop back down. They are most often heard vocalizing when engaging in breeding displays at the beginning of the mating season. When disturbed at the nest, they may utter a long, lower-pitched raaaaauu.
The bird's flight feathers closely resembles those of the turkey vulture. Zone-tailed hawks soar with their wings held in a dihedral position (pointing slightly upwards), rocking from side to side, a flight style that parallels that of turkey vultures. Bird guides caution against confusing them with the much more common turkey vulture, but at a reasonable distance one can distinguish them from vultures by their smaller size, the typical hawk shape of the wings and head, and the pale stripe on the tail. Since vultures frequently can be seen flying in numbers (groups are called "kettles"), zone-tailed hawks can mingle with them and are perhaps most often missed by the human eye in such kettles.
Turkey vultures do not normally prey on live animals, but zone-tailed hawks are active predators. Therefore, some ornithologists believe that this mimicry tricks potential prey animals into not being alarmed when a zone-tail flies overhead (Clark 2004). This hawk mainly preys on small birds and mammals, but reptiles can be locally favored, including virtually any type of lizard. In the north, California quail, along with possibly other quail species, and chipmunks seemed to be the favorite prey. Zone-tails also eat various young birds, having been observed preying on nestlings and fledgings of species as varied as herons and passerines. Zone-tailed hawks snatch young birds from trees or the ground without landing. Second-hand reports of predation on frogs and fishes may be cases of misidentification of common black-hawks. Zone-tailed hawks are very active foragers, hunting almost exclusively by transects and random quartering in low flight at around 10–30 m (33–98 ft) over the ground. When approaching the prey, the hawk may try to use obstructing cover such as trees until it is within 0.5–2 m (1.6–6.6 ft) of the prey, easy striking distance. Outside the breeding pair bond, these hawks are wholly solitary and are not known to hunt in pairs.
The mating season of the species varies geographically but is almost always in the first half of the year. In the northern reaches of the range, the breeding season is mid-April through July, whereas in Trinidad and Ecuador, it is February through June. Eggs have been found as late as August in Colombia, implying an only loose breeding season in the true tropics. The mating pair perform a courtship display, which may include engaging in aerial loops, dives and rolls with each other. The nest is typical of hawks: a big, bulky assemblage of sticks, lined with green leaves, usually built in the top or in the main fork of a tree, in this case at 7.5 to 30 m (25 to 98 ft) above the ground. Typically, tall trees such as a cottonwood or pine tree are selected, and the nest may be in the open or concealed by foliage. Occasionally, nests are found on cliffs.
The clutch comprises one to three, typically two, white eggs, often marked with brown. Incubation lasts for around 28 to 35 days and typically the female incubates, while being fed by the male, although the male may occasionally incubate. The young are semi-altricial at hatching and are covered in gray down. They grow slowly for the first 7 days of life and then considerably faster from 7 to 21 days old. As is common in raptors the older sibling often kills the younger one or outcompetes it for food; only occasionally do both survive to adulthood. The younger hatchling is sometimes referred to as the "spare" one since it may be tended to more directly if the first dies. The young fledge at 42 to 50 days, though are not typically self-assured fliers until around a week later. They may remain in their parents' care until the following breeding season, though in migratory populations, the young and adults often separate. There have been no extensive reports on longevity and mortality in the species.