Fall is the prime season for birding on the Vineyard, and while October is generally past the peak of migration, it’s our best month for viewing transient hawks. The month brings us only a subset of the region’s birds of prey. Buteos %u2014 broad-winged, broad-tailed soaring hawks %u2014 prefer not to cross water and rarely visit the Vineyard (though we have a resident red-tailed hawk population of perhaps two dozen pairs). Ospreys have all headed south, and some other species either rarely range this far south (gyrfalcons and goshawks) or have grown so scarce in our region (American kestrels) that they don’t often turn up on the Vineyard.
But two falcons, notable for their pointed wings and swift flight, grow common in October. The peregrine falcon, roughly crow-sized, is gray-backed and sports a distinctive “sideburn” mark on the face; adults are finely barred in black underneath, while young birds show much heavier dark streaking. The peregrine’s cousin, the merlin, about the size of a grackle, varies with both sex and age: Adult males are gray above, while young birds and females are browner. All are more or less heavily streaked beneath. Merlins, quite famously in local birding circles, have nested in Chappaquiddick each of the past three years, hundreds of miles south of this species’ typical breeding range.
And two accipiters, with rounded wings and long tails, may become even more common than falcons. The compact, jay-sized sharp-shinned hawk and the lankier Cooper’s hawk resemble each other closely in plumage and are best separated by size and structure. Adults are grayish-brown above and washed with orange barring underneath; much more common here are young birds, browner and heavily streaked underneath. Cooper’s hawks have resumed nesting on the Vineyard after an absence of many decades. And indeed all four of these hawks appear to be growing in numbers, their populations rebounding from indiscriminate shooting that persisted into the middle decades of the 20th century.
What these four species have in common is a taste for smaller birds %u2014 or, in the case of merlins and “sharpies,” even birds that approach the predator in size. They tend to follow the same coastal migration route used by their songbird targets, and they gravitate to places where migrant songbirds concentrate, like the Vineyard. Typically, they peak in numbers sometime during the first half of this month, and this past weekend may have seen their highest numbers. But they will remain common into November, and a few individuals of all four species are likely to linger into and even through the winter.
Supreme aerialists, the “bird hawks” are icons of grace and ferocity. All four species soar or cruise in search of prey, but they differ in their preferred manner of attack. Their victim spotted, falcons strive to climb above it, then fold their wings and plunge like stones. Often, the target saves itself by jinking at the last moment and dodging the plunging hawk’s talons. But often enough, the falcon connects, striking its prey in passing and then circling back to snatch the injured victim out of the air. Peregrines will even eat while aloft, holding a small bird in one foot and plucking it while riding the wind.
Slower but more maneuverable, the accipiters are low-level attackers. Spotting a careless bird, or even just noting promising habitat that may hold birds that can be startled into flight, these hawks swoop in just above the vegetation; generally, they either catch their prey wholly by surprise, or not at all.
The best place to observe these birds on the Vineyard is unquestionably in Aquinnah, around the Gay Head Cliffs. Their prey is abundant here, as the geography of the Island funnels songbirds moving south along the coast into the Vineyard’s western tip. The low, scrubby vegetation of this part of the Island provides hunting hawks with long vistas. And constant winds, hitting the cliffs, produce updrafts that lift hawks into effortless, soaring flight. Numbers of hawks here vary from day to day, depending on the wind strength and direction. But it is rare that one needs to wait long before spotting a sharp-shin or a merlin, and at times multiple peregrines hang like kites in the breeze.
But there’s no need to drive up-Island to find October hawks. Except for the wary peregrine, which avoids settled areas and human activity, the bird hawks are nonchalant around people and even exploit yard features like bird-feeders that attract songbirds. Speedy and stealthy on the attack, bird hawks often escape the notice of the unobservant. And even for birders tuned in to avian activity, falcons and accipiters often register in the past tense: a dusky streak is there and gone again before the brain knows what to call it. But aloft or low, these birds are here now, and worth watching for.