Order Falconiformes, Family Accipitridae. The family
Accipitridae includes most birds of prey except falcons, owls, and American
vultures. Buteo hawks are moderately large soaring hawks that inhabit open or
semi-open areas. They are the most common daytime avian predators on
ground-dwelling vertebrates, particularly rodents and other small mammals.
They range in size from the broad-winged hawk (41 cm bill tip
to tail tip) to the ferruginous hawk (58 cm). Hawks egest pellets that
contain undigestible parts of their prey, such as hair and feathers, that can
be useful in identifying the types of prey eaten (bones usually are digested
completely).
Where Does Red-tailed Hawk Live?
The red-tailed hawk “Buteo jamaicensis” is the most common
Buteo species in the United States. Breeding populations are distributed
throughout most wooded and semi-wooded regions of the United States and
Canada south of the tundra, although some populations are found in deserts
and prairie habitats. Six subspecies are recognized. Nesting primarily in
woodlands, red-tails feed in open country on a wide variety of
small-to-medium-sized prey.
Body Size
Males of this medium-sized buteo (46 cm) weigh about 1 kg, and
females are approximately 20 percent heavier than the males. Otherwise, the sexes
look alike.
Habitat
Red-tails are found in habitats ranging from woodlands,
wetlands, pastures, and prairies to deserts. They appear to prefer a mixed
landscape containing old fields, wetlands, and pastures for foraging
interspersed with groves of woodlands and bluffs and streamside trees for
perching and nesting. Red-tails build their nests close to the tops of trees
in low-density forests and often in trees that are on a slope.
In areas where trees are scarce, nests are built on other
structures, occasionally in cactus, on rock pinnacles or ledges, or man-made
structures. In winter, night roosts usually are in thick conifers if
available and in other types of trees otherwise.
What Does Red-Tailed Hawk Eat?
The Red-tails hunt mainly from an elevated perch, often near
woodland edges. Small mammals, including mice, shrews, voles, rabbits, and
squirrels, are important prey, particularly during winter. Red-tails also eat
a wide variety of foods depending on availability, including birds, lizards,
snakes, and large insects.
In general, red-tails are opportunistic and will feed on
whatever species are most abundant Winter food choices vary with snow cover;
when small mammals such as voles become unavailable (under the snow),
red-tails may concentrate on larger prey, such as pheasants.
Juvenile Red-tailed Hawk
Juveniles molt into adult plumage in a gradual process from
the spring (age about 14 months) to summer or early fall.
Migration.
The more northerly red-tailed hawk populations are migratory
while the more southerly is year-round residents.
Red-tailed Hawk Life Cycle
Red-tails lay one clutch per year consisting of one to three
eggs, although a replacement clutch is possible if the initial clutch is lost
early in the breeding season. Their nests are large and built of twigs. Both
sexes incubate, but the male provides food for the female during incubation
and the entire family following hatching. The parents continue to feed their
young after fledging while they are learning to hunt.
Red-tailed Hawk Lifespan
The average life span of a wild red hawk is around 20 to 25
years.
Re-tailed Hawk Behavior
Red-tailed hawks are territorial throughout the year,
including winter. Trees or other sites for nesting and perching are important
requirements for breeding territories and can determine which habitats are
used in an area.
Home range size can vary from a few hundred hectares to over
1,500 hectares, depending on the habitat. The size of red-tail territories
and the location of boundaries between territories varied little from year to
year, even though individual birds or pairs died and were replaced.
Population density.
Population densities normally do not exceed 0.03 pairs per
hectare, and habitually are lower than 0.005 pairs per hectare. Populations
in southern areas such as Florida can increase substantially in the winter
with the influx of migrants from the more northerly populations.
Population dynamics.
Beginning at 2 years of age, most red-tailed hawks attempt to
breed, although the proportion of breeding can vary by population and
environmental conditions. Average clutch size varies regionally, tending to
increase from east to west and from south to north. The density of their main
prey, the snowshoe hare, over the years.
The mean clutch size for the red-tail population, however,
appeared to vary with prey density, from 1.7 to 2.6 eggs/nest. Over the
course of the study, about 50 percent of observed nestling losses occurred
within 3 to 4 weeks after hatching due to starvation.
Most of the variance in yearly mortality of nestlings could be
attributed to the amount of food supplied and the frequency of rain. Large
raptors such as horned owls also can be important sources of mortality for red-tail
nestlings in some areas.
Similar species
1. The
ferruginous hawk (Buteo regalis), one of the larger buteos (58 cm), inhabits
the dry open country of the western United States.
2. The
red-shouldered hawk (Buteo lineatus) is slightly smaller (53 cm) and feeds on
snakes, frogs, crayfish, mice, and some small birds. Its range is east of the
Rocky Mountains and in California, with moist mixed woodlands preferred.
3. Swainson's
hawk (Buteo swainsoni) is restricted to the open plains of the western United
States. Although it is as large (53 cm) as the red-tail, it preys mostly on
insects.
4. The
broad-winged hawk (Buteo platypterus) is one of the smaller buteos (41 cm)
and preys on mice, frogs, snakes, and insects. It prefers woodlands and is
found almost exclusively east of the Mississippi River.
5. Harris'
hawk (Parabuteo unicinctus) is similar in size (53 cm) to the red-tailed hawk
but is restricted to the semiarid wood and brushlands of the southwest. This
bird nests in saguaro, mesquite, and yucca and preys on rodents, lizards, and
small birds.
6. The
rough-legged hawk (Buteo lagopus) is one of the larger buteos (56 cm). It
winters throughout most of the United States in open country but breeds only
in the high arctic of North America.
7. The
zone-tailed hawk (Buteo albonotatus) is slightly smaller (51 cm) than most
buteos and feeds on rodents, lizards, fish, frogs, and small birds. It can be
found in mesa and mountain country within its limited range between the
southwest United States and Mexico.
8. The
short-tailed hawk (Buteo brachyurus) is the smallest buteo (39 cm) and can
only be found in the southern tip of Florida in mixed woodland and grassland
habitats.
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Tuesday, 17 September 2019
The Red-tailed Hawk Facts
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Birds
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