Wild Side : Red-tailed hawks have year-round homes on Martha's Vineyard
File photo by Tim Johnson
Aptly named and hard to overlook, the red-tailed hawk ranks among the most prominent birds on Martha's Vineyard, a common sight perched on a snag or soaring overhead. And March may be the month when this impressive predator is most active and obvious, courting, nest-building, and even hunting to feed an early clutch of young. If you're outdoors these days and spend some time looking up, you're almost sure to see one.
As a species, the red-tail occupies a vast range, spanning the continent and nesting north nearly to the tundra. And across this range, this bird displays a bewildering range of variation, from all-black birds (which are fairly common in the west) to our pale eastern race, mostly brown above and white below with a dark band across the belly. The eponymous tail, orange-red, is a trait of adult birds; on youngsters, the tail is brown and finely banded.
Perched, a red-tail looks stout, large-headed, and short-tailed; overhead, where it can hang for hours on rising air currents, this hawk shows broad wings and a wide, fan-shaped tail. Because of its size and variability, the red-tail is often misidentified as a different hawk or even an eagle by casual observers (and sometimes by veteran birders). But given how common red-tails are on the Vineyard, and how rare other hawks of similar size and build are here, you need a good reason to assign a big, chunky hawk to anything other than this species.
While the red-tailed hawk is, in general, a strongly migratory species, it doesn't appear that the Island population migrates, or that it receives much augmentation from migrants arriving from elsewhere. Certainly I've never seen a red-tail arriving on or departing from the Vineyard, though I've often seen other hawks doing so. And there is little indication that red-tail numbers vary much during the year. A likely reason is the water that separates the Island from the mainland. Though a red-tail certainly could cross it, they don't. This species is designed more for soaring than for direct flight, and crossing a water barrier that would require sustained, flapping flight to traverse evidently strikes this species as more trouble than it's worth.
A typical count of red-tails on the Vineyard's annual Christmas Bird Count is about 50 individuals; because these birds fly high and range widely, the red-tail is one species I can imagine gets counted in its entirety, or even over-counted, during that event. In any case, that figure translates to about two dozen pairs resident on the Island, which sounds about right to me. It is a rare day that passes without my spotting at least one of these birds.
Oddly, in an account of this hawk published in 1937, ornithologist Arthur Cleveland Bent describes the red-tail as "one of the shiest of our birds; a man on foot can seldom approach one to within 100 yards." There is no reason to doubt the observation, and given that hawks of all kinds were considered fair game for gunners until about that time, the red-tails Bent was familiar with may indeed have been wary of humans. But red-tails are smart birds and highly adaptable, and the ones on the Vineyard, at least, have grown used to humans. One red-tail hunts routinely around the hospital, often resting or digesting on a telephone pole along the road; another pair frequents the fields and barnyards of the FARM Institute; and Islandwide, these hawks perch nonchalantly as humans pass quite close by.
And while a perched red-tail may look somnolent, in fact it is likely working: keen-eyed like other birds of prey, red-tails often hunt from exposed perches, conserving energy until a promising prey item comes into view. Then...WHAM! Dropping off the perch, the hawk zeroes in like a guided missile. Small rodents, such as voles and mice, probably make up the bulk of this hawk's diet. But a red-tail has no trouble handling prey as large as an adult rabbit. They're also deft enough to catch small birds, and will settle for cold-blooded prey like snakes or even large insects if a good opportunity comes up. This versatility probably accounts for the wide range and abundance of the species.
At this season, red-tails are strengthening their pair bonds, engaging in playful aerial chases or sitting companionably on perches. This species builds an impressive nest of sticks, large and solidly constructed; on the Island, at least, it seems like pitch pines provide the most favored nest sites, and these hawks are surprisingly good at concealing their bulky nest in a tree's canopy. By late spring or early summer, fledged young will be shrieking incessantly for parental attention — one more easily observed stage in the life cycle of this wild but tolerant predator.