By Katie Koerten Gazette Contributing Writer
When I first became interested in birds and their identification in the wild, I was daunted by the prospect of identifying raptors (birds of prey) in flight.
Sure, field guides are helpful when it comes to looking for coloring and field marks, but when you’re standing on the ground and the bird is flying across the sky, these characteristics can be hard to detect. From a distance you can’t determine size with much certainty, let alone any markings. Often you can just make out the shape of the bird, and maybe catch a few wing flaps before it soars out of sight.
With more than 20 species of birds of prey found in western Massachusetts, it’s helpful to have a few more tools in your raptor ID toolbox beyond the field guide. My own frustration lessened when I learned how to distinguish a few main groups of these birds of prey. There are three major genera of raptors: Buteo, Falco and Accipiter. With a few exceptions, such as the Northern harrier and osprey, most of our common diurnal (daytime) raptors in Massachusetts belong to one of these genera.
After I got the hang of these categories, I discovered it was much easier to narrow down the raptors I spotted in the sky. Does the raptor soar in large circles with few wingbeats? Members of the genus Buteo are characterized by their long, broad wings and fan-shaped tails. They use their vast surface area to ride on thermals rising up from the earth and rarely need to flap their wings. Buteo species found locally are red-tailed hawks, rough-legged hawks, broad-winged hawks and red-shouldered hawks. (It’s tempting to put bald eagles in this category because of their similar body shape and flight pattern, but they belong to the genus Haliaeetus. When you see one soaring above with its magnificent 7-foot wingspan I think you’ll agree they are a world apart.)
Does the bird plunge off skyscrapers in pursuit of a pigeon? Built for speed, genus Falco species have long, tapered wings and long narrow tails. In Massachusetts, these are the merlin, American kestrel and the fastest animal on record, the peregrine falcon. Our falcons can be found in a variety of habitats. Look for kestrels perched on telephone wires near an open field, scanning for mice and crickets. Peregrines prefer high cliffs, or tall buildings where pigeons are abundant.
Does the raptor dart in and out of trees in the forest, chasing after smaller birds? If so, you’re probably observing a member of the genus Accipiter at work. Accipiters may be less familiar than the other two groups of hawks, but you’ll find they are quite common once you know what to look for. Birds of this genus have broad wings like the buteos, but they are shorter and stouter. And like the falcons, accipiters’ tails are narrow, but longer relative to their bodies. This shape allows them to be the jet fighters of the raptor world and enables them to be exceptionally agile. Accipiters are built for the pursuit of their favorite prey: birds on the wing.
If you have seen a raptor circling your feeder in hot pursuit of a bird, chances are it was an accipiter. You can find three species of accipiters in Massachusetts: Cooper’s hawk, sharp-shinned hawk and the Northern goshawk. Cooper’s hawks and “sharpies” are virtually identical in coloration. Both have the same slate-gray wings, orange barring on the breast and banded tails. The main difference between the two species to look for is size: Sharp-shinned hawks are about the size of a blue jay (11 inches long) while Cooper’s hawks are larger (16.5 inches). Northern goshawks are our largest local accipiter at 21 inches in length and are a paler gray with fine gray and white barring on the breast.
When they are not maneuvering around the forest at breakneck speeds, accipiters can be seen flying through the air with a distinctive “flap-flap-flap-glide” flight pattern. Whenever I see a bird flapping like this, I look at the tail: Is it long and narrow like an accipiter’s?
I’m no professional, but slowly I’m building my birding toolbox. Sometimes it’s more fun to put down the field guide and solve the bird mystery in front of (or above) you by looking for clues such as habitat, flight and silhouette.
Katie Koerten is an environmental educator and coordinator of child and family programs at the Hitchcock Center for the Environment.
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