Red-tailed hawks—the versatile raptors
THEY SIT on posts or poles, eying the ground below. Perched in trees along highways, one can spot their characteristic white breast patch while driving by. Look to the sky on warm, sunny afternoons and you often see red-tailed hawks gliding and wheeling, soaring on rising air masses called thermals.
But when a red-tailed hawk drops in for a chicken dinner, there’s a ruckus. “You’d better get over here to catch a big hawk that’s in the barn before Dad gets home,” announced the voice on the phone. “He’ll shoot it.” I caught Bernadine’s hawk before her Dad returned. But how to stop it from coming back? Another scary human encounter might do the trick! I drove to the Lands and Forests office with the bird in a box and showed it to the staff over coffee break. Then I drove back and released it. It never returned to commit a fowl deed. Red-tails are smart.
Common across North America, this large hawk is aptly named. Adults sport tail feathers with an upper side that is trademark reddish brown—that distinguishes mature red-tailed hawks from other birds of prey. Juveniles under two years lack this colour distinction and are mostly brown streaked with white, but they do have the white breast spot. Dark, intermediate and light colour phases of this species are common.
From Nova Scotia to Alaska, and south to Florida and Central America, red-tails make a living in a variety of habitats (but are absent in Newfoundland). They like open country, woodlands with scattered clearings, prairies, mountains and roadsides. They prefer to watch open ground from a high perch. Once prey materialize, the hawk swoops down with piercing talons.
Red-tailed hawks are versatile, opportunistic predators. Females are larger than males. Their hunting focus varies by location and season, and includes small mammals like mice, voles, snowshoe hares, rabbits and squirrels. Birds as large as pheasants are taken. Snakes are another favourite. They have the gastronomic propensity to attack and consume almost any catchable small to medium-sized animal, from bugs to weasels, and bats to woodpeckers. Carrion is scavenged occasionally. They have difficulty raising their two or three nestlings if snowshoe hare (rabbit) populations are abundant.
Nesting and the problem with owls
In Saltscapes country, red-tails usually share their field and woodland hunting grounds with great horned owls. Red-tails carefully construct large nests of sticks and twigs, lined with finer materials like shredded bark. Up to a metre wide, with a slight depression in the centre, these nests represent a valuable real estate investment not only for the hawks, but also for great horned owls, who don’t build their own nests.
Red-tails and great horns compete for the same prey. The owls spend winters here and when rabbit populations crash, many owls starve. Few may survive in sufficiently healthy condition to raise young in the spring. Migrating red-tails, on the other hand, hunt rodents, snakes and birds as far south as along the Gulf Coast and Costa Rica. They return north in early April in reasonably good health to reoccupy an empty nest. With rabbits scarce, they turn to other prey.
When rabbit populations have been plentiful, some red-tails may over-winter in southern parts of the Maritimes rather than migrate further south. Returning in the spring, migrants may find their nest already occupied by early-nesting, rabbit-fed great horned owls. Three quarters of nests seized by great horned owls are constructed by red-tails. Savage night fighters, great horned owls also commandeer bald eagle, osprey and crow nests. Ousted red-tail pairs are forced to build a new nest within their breeding territory. If that nest is too near to the owls, two-thirds of their nestlings are likely to become owl food. So an abundance of rabbits creates an abundance of owls, and that means nest and nestling losses for red-tails.
My first experiences with red-tailed hawks began as a regional biologist when interested landowners reported large nests in their woodlands. Often located in tall trees, nesting pairs seem to favour white and yellow birch, although nests have been found well hidden in large spruces. Two to four eggs are laid. Both male and female will incubate them for about 30 days until hatching occurs. Then some serious hunting begins to feed the voracious nestlings.
A month later the nestlings are fully feathered and ready to fly. After a great deal of practice flapping on the rim of the nest, the young become airborne. They learn to hunt by their parents’ example. At first the fledglings are brought mice and squirrels. Soon they begin to follow their parents on hunts and watch from a distance. Teaching is important. The mortality rate for first-year red-tails is as high as 80 per cent.
Of mice and ham sandwiches
Occasionally an injured adult red-tail would be delivered to me for rehabilitation. I had pens and a permit. After a visit to a veterinary clinic, I tended to each bird’s needs until it was ready to release. One couldn’t help but notice that some birds spent time studying me while I was helping them.
One summer a weak juvenile red-tail was delivered. The bird regained its strength with time and feeding. I let it go, while continuing to place food outside on top of the pen. This process is called a gentle release. The idea was to gradually wean it off the food and let it return to hunt again in the wild.
That weaning process did not unfold as planned. A set of hot-air solar collectors outside my bedroom window became a dawn perch for the hawk. It waited there to be fed, staring at me until I felt compelled to get up. Retrieving a bag of mice from the freezer, I’d nuke a mouse and deliver it outside on a dish to my waiting “wild” friend. Then it would disappear for the day. This routine gradually diminished with time. Good, I thought.
One Sunday in late August the phone rang. It was a neighbour a half kilometre away. “Do you have a hawk around?” he enquired. “Yes”, I answered. “I wondered,” he replied, “We’re having a family picnic. A large hawk just joined us. It’s eating my ham sandwich!”