Ecology

The versatility of Red-Tailed Hawks

Anne Gageby
Environmental Education Manager
Strawberry Hill

(10/2022) Few species can claim they have benefited from human actions like the red-tailed hawks. These large, stocky buteos have adapted in ways most other animals never could. The expansion of human civilization has created landscapes dotted with small woodlots and isolated trees where expansive forests once stood. For most animals, this means fewer resources and tougher competition for basic necessities like food and shelter. But for red-tailed hawks, it has created opportunities.

Unlike most animal species living so close to humans, redtails haven’t felt the pinch of limited space and resources. They haven’t had to contend with expanding roads and the dangers of traffic like Eastern box turtles or white-tailed deer. Nor have they dealt with the loss of nesting areas like the Great egret, which have a total of two nesting sites remaining for the entire state of Pennsylvania. Great egret numbers have further dwindled because of dams causing flooding in shallow feeding areas, a problem red-tailed hawks don’t face. Instead, red-tailed hawks are thriving by taking advantage of human ingenuity and adapting where other species fail.

In the Eastern half of the United States thinning forests and the Interstate Highway System have proved to be a boon for redtails, providing both prime real estate for nesting and hunting grounds. Where mankind has built infrastructure, the redtails adapt and flourish. At the opposite end of this spectrum sits the elusive long-eared owl. The reduction in wooded habitats is only part of the problem. Over the years, our forests have converted from primarily softwoods to hardwoods, a problem for the long-eared owl who nests in dense conifers. Their preferred habitat is a perfect mix of forest, wetland, and open fields, yet areas that meet this description have greatly diminished. Other raptors have been even less fortunate. The northern harrier, for example, has been listed as ‘threatened’ due to its loss of wetlands and riparian woodland.

Red-tailed hawks haven’t suffered from a lack of forest. This thick, broad-winged raptor prefers to perch high above the open ground, so power lines and telephone poles are a prized addition to the usual tree branches, especially along wide stretches of road flanked by open fields. These specific perches are also innumerable in today’s modern landscape. This is one of the reasons redtails have become one of the most recognizable birds, regularly spotted along roads and flying over fields. They are often referred to as ‘roadside hawks’ because of their preference for this environment.

Redtails haven’t been limited to smaller and smaller ranges like other animal species. The Florida panther, for example, now roams only five percent of its native territory. Similarly, the Mississippi gopher frog has been restricted to only three small breeding ponds in the state with a total population count of less than 250 in the wild. The roseate tern has become endangered as its territory along the Eastern seaboard has diminished. Even still, other species have fared worse. The red wolf, for example, has less than two dozen wolves remaining in the wild. Red-tailed hawks haven’t been dealt the same blow. Their territory still stretches from Panama to central Alaska and Canada and their numbers are in the millions.

Similar to other members of their family, red-tailed hawks are partial migrants. Those living in the northernmost territories typically migrate south for winter. Redtails living along the mid-latitudes tend to stay put though individuals may migrate south for a few weeks during the deepest part of winter. The autumn migration runs from mid-August to mid-December, though late October is when birdwatchers will be able to see the most diversity in the skies. The average red-tailed hawk usually migrates alone but will sometimes migrate in small flocks.

Red-tailed hawks are members of the family Accipitridae which includes nearly 250 species of eagles, hawks, kites, harriers, and more. Red-tailed hawks have a wingspan that averages between three and a half to four feet, and they typically weigh two to three pounds. They have dark patagial marks on the undersides of their wings and tend to be light in color though they can range from brown to black on their upper body. Coloring differences depend on age and race though adults usually have reddish tails with a dark, narrow band along the tip. At a distance, large females appear so similar to young eagles that they’re often confused for one another.

Unlike many of their kin, red-tailed hawks are primarily perch-hunters who only occasionally hunt via flight. This is an interesting contrast to their image as elegant fliers best known for their ability to kite – appearing to fly in place. Remarkably, researchers have found that red-tailed hawks prefer hunting locations with high perches even if the prey density in those areas is low. They are also piratical in their hunting. Redtails frequently steal prey from other raptors, especially in winter or if the prey quantity is slim. They have even been known to hunt in pairs with each individual scanning distinctly separate angles of the same space and working in tandem to finish the task.

Red-tailed hawks are known as generalist predators because they tend to prey on many different types of animals. Diets vary by location but generally include everything from rabbits and squirrels to reptiles such as snakes, bats, frogs, and even other birds. Carrion, including roadkill, are a regular addition to their diets. Despite preying upon a wide variety of animals, most focus on hunting abundant species which are easily caught like field mice, rats, and chipmunks. Not every species is fortunate enough to have a varied diet. The black-footed ferret, the only ferret native to North America, mainly feasts on prairie dogs and has suffered greatly because of prairie dog eradication programs.

This flexibility in diet and habitat has made red-tailed hawks uniquely able to tolerate human development. They are one of the few species that have been able to do so. These traits have allowed redtails to become the most abundant hawk in North America, pushing out red-shouldered hawks for prominence as well as the most visible. It’s clear that red-tailed hawks have the upper hand in this evolutionary game and aren’t afraid to play.