This article first appeared in the November 2004 issue of the San Antonio
If any bird typifies the generic "hawk", the Red-tail (Buteo jamacensis) is probably it. Its likeness and call are commonly employed whenever a touch of "wilderness" is desired in movies and commercials such that most Americans would probably recognize its call from TV. This is the most common and widespread of all our hawks. In this case familiarity does breed, if not actual contempt, perhaps a touch of indifference. I cannot remember all the times I have raised binoculars to look at a distant hawk only to lower them a moment later thinking "darn, just a Red-tail".
Solidly-built with broad wings and tail, Red-Tails are typical of the hawks
of their genus, most of the nearly thirty species in this cosmopolitan group
feeding primarily upon vertebrate prey taken on the ground. Across our continent,
the adaptable Red-tail occurs in a wide variety of open and semi-open habitats
from Alaska south to Panama and the Caribbean, the chief habitat requirements
being the presence of potential prey and the availability of perches from which
to hunt. Red-tails can and do hunt from the air, especially in windy conditions,
but most often do so from a perch. Likely this species has benefited greatly
in modern times from the fragmentation of forests, as well as the spread of
trees and utility poles across the plains.
Small rodents are the most usual prey. Reptiles and birds are also taken. Prey as small as crickets may not be overlooked and creatures up to the size of rattlesnakes and jackrabbits may be taken. Individual Red-tails have been observed taking such unorthodox prey as house cats and even an escaped parrot. Young peregrines have been snatched off cliff ledges and in some areas Red-tails commonly take pheasants. Red-tails have been observed plunging though bat swarms with outstretched talons and one famous resident of Manhattan (see www.palemale.com) has become similarly adept at diving though flocks of pigeons. Carrion and road kills may be scavenged and it is believed that some cases of West Nile virus reported in Red-tails were the result of hawks taking dead or dying crows afflicted with the disease.
The breeding biology is typical of raptors. A bulky nest of sticks and twigs is built upon some elevated place, originally in a tree or on a cliff ledge but nowadays also upon utility towers and buildings. The female hawk is larger than her mate and remains at the nest throughout incubation and the first days after hatching, fed at the nest by her mate. Two to four eggs are laid and incubation commences with the first egg so that hatching is asynchronous, the older nestlings being larger then their younger siblings. These smallest nestlings frequently perish and in some years only a single nestling may survive. Of those that survive to fledge, more than half will not survive their first year, many succumbing to starvation.
Adult Red-tails are often sedentary, remaining on their territory all year round. Many young birds, and all of those Red-tails from the northern parts of the breeding range, exhibit varying degrees of migratory behavior, the result being a general southward shift in the distribution of the North American population each autumn. At least twelve different races occur across the Red-tail's extensive range and much variation in plumage exists between and within these separate races. Many Red-tails of different races arrive in Texas in the fall, such that a ghostly pale Krider's Hawk from the Great Plains may occur in the same field as the darkest Harlan's examples from Alaska. The red tail of the adult is acquired during the second year. This red tail along with the dark patagial marks on the underwings and at least a hint of a dark belly band are useful field marks common to most of the wide range of possible plumages. First-year birds of all races and adult birds of the Harlan's race lack the red tail, and the patagial marks and belly band may not be apparent in the darkest individuals. Perhaps the best field mark is the shape; the stocky build, broad wings and long secondaries lend this species a familiar flight silhouette that becomes recognizable with practice.
Sources and More Info:
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