The breeding range of the Red-tailed Hawk is likely the largest of all, diurnal North American raptors. It is very close, if not equal, to that of the American Kestrel. It extends from western Alaska eastward across the forested belt of northern Canada to about the middle latitudes of Quebec and onwards to include the Maritime provinces, excluding Newfoundland. Breeding continues in most habitats throughout the entire United States into south central Mexico and disjunctly into Costa Rica and Panama. On the east coast, breeding occurs south through the Bahamas to the Greater and Lesser Antilles.
Wintering birds can be found from the southern portions of the Canadian breeding range south throughout the remainder of the north and central American range.
Year-round, the Red-tailed Hawk is found from extreme southern British Columbia (about 50 degrees of latitude), southern Ontario, Quebec, and Nova Scotia with very low winter populations across the Canadian prairies. Whether these birds are truly resident or are winter replacements from northern migrant populations is not known, but from parts of southern Canada and the north-central United States south, the Red-tailed Hawk is usually considered a resident species. Southern numbers are altered by incoming wintering birds. Winter densities are quite low in Montana, the Dakotas, Minnesota, and Wyoming but numbers increase dramatically in the winter as one proceeds south, east, or west, from these states.
Twelve to 16 subspecies are listed for the world, all of which occur in North or Central America. Again, depending upon taxonomic philosophy, five to seven subspecies occur in North America. The distribution for this subspecies is as follows.
"Western" Red-tailed Hawk (B. j. calurus)
- breeds from northeastern Yukon, southwestern Mackenzie, northern Saskatchewan, and west-central Manitoba south through central Saskatchewan, southeastern Alberta, western Montana, southern Wyoming, southwest South Dakota, western Nebraska, eastern Colorado, most of New Mexico, and probably extreme southeastern Arizona.
The remaining subspecies occur in Mexico, Central America, and the Antilles.
MIGRATION
Migration can be grouped into several patterns related to the geographic origins of the individuals. These are:
1. Northern breeders that migrate south to winter essentially within the North American range of southern residents.
2. Interior birds between latitudes 43 to 48 degrees that vacate their breeding territories for shorter periods of time and move varying distances.
3. Resident coastal birds along the British Columbia coast to Alaska.
4. Southern residents that do not migrate but young birds are displaced into areas not held by territorial birds.
In the north, fall migration begins in some areas with post-nesting dispersal and some wandering before southern movements are consistent. Southern migration is underway throughout Canada during August and continues through the northern United States until mid December. The peak movements at these latitudes for northern birds are from mid September through mid November with more immatures moving during the first two months than during the last month. At Hawk Mountain, Pennsylvania, the peak movement of the Red-tailed Hawk is from October 20 to November 10, but migrants can be seen from early September to mid December.
Although the Red-tailed Hawk moves over a wide front, thousands per day can pass key topographic features that concentrate them, particularly in eastern North America. Large water bodies, such as the Great Lakes, concentrate birds and funnel them along the shore towards suitable terrestrial bypass routes or narrow water crossings. Ridges that trend in a beneficial direction such as the Appalachian Mountains, create air currents and concentrate migrant birds that can be viewed by the hundreds or thousands per day as they pass. South trending winds and storm fronts push birds ahead of them as migrants take advantage of the improved flying conditions. Over grasslands, birds take advantage of small topographic features to gain lift and they utilize thermals to gain altitude as the heat of the day progresses. Thermals are also used to great advantage over a variety of other terrain's. In general, the Red-tailed Hawk seems to attempt to fly directly to their migration goals.
The fall dispersal of mid-latitude immatures occurs in a variety of directions with some birds even moving north. The distances traveled vary from less than 50 to over 1,000 miles (80 to 1,600 kilometers). Fledglings from these areas may return to within five miles (8 kilometers) of their nest to set up new territories.
Spring migration through the northern United States and southern Canada occurs from March through May as some migrants overfly residents already involved in their breeding cycle. Movement out of Mexico occurs during February and some migrants have arrived in southern New York state by mid February. The origins of such early migrants are uncertain and may be birds that wintered not far to the south.
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