The beginning birder doesn’t need a field guide to know that raptors are cool. Meat-eating birds—hawks, falcons, kites, eagles, and others—are the “rebels” of the birding world, presiding boldly and without care over their territories while smaller creatures tremble and flee in their presence.
However, though all raptors share a trait of self-evident coolness (I think so, anyway), they go about their business of finding food in very different ways. Indeed, each of these birds has evolved to become specially designed to exploit their chosen prey, and learning how the various groups of raptors are different from each other will help you learn to find and identify them in the field.
I want to focus on a certain set of raptors here: diurnal birds of prey with hooked bills, strong talons, and good eyesight. There are other meat-eating birds out there: insect-eating nighthawks, fish-eating pelicans and herons, and of course owls, but I want to focus on the birds in the families Accipitradae and Falconidae, birds that a non-birder might look at and say, “Oh look, a hawk.”
In the United States, these birds fall into a bunch of different groups: the buteos, accipiters, harriers, kites, eagles, falcons, vultures, caracaras, and the Osprey. Each of these birds eats meat, but they all go after prey in a different way that requires specialized bodies to be as successful as possible. This isn’t meant to be a comprehensive list, but it’s helpful to understand how the bodies of different raptors aid them on the hunt.
Built for Speed. Falcons are the fastest flying birds on the planet, and arguably our most spectacular hunters. If you’ve ever seen a Peregrine Falcon on the chase you know what I’m talking about. Peregrines are feathered fighter jets. Every flap should be accompanied by a screaming guitar solo.
Peregrines and other large falcons feed frequently on open-country birds, such as ducks and pigeons. Birds, in other words, that have lots of room to escape. To capture their prey, falcons need to be very fast while also keeping the element of surprise. Built for speed, falcons have long, pointed wings and plenty of power. Sometimes they’ll fly low and fast, hoping to surprise their target before it has a chance to escape. But the most spectacular of the falcon’s hunting techniques is the “stoop,” where they dive-bomb flying prey from above, often with the sun directly behind them. Peregrine Falcon stoops have been recorded at 200 mph and above, faster than any other animal in the world.
Built with Super Senses. The element of surprise is important for all hunting birds, and some raptors rely on heightened senses to detect concealed prey. Buteos, the group that many consider to be “classic” hawks—including Red-tailed Hawks, Red-shouldered Hawks, and Swainson’s Hawks—have a particular taste for small mammals. While buteos actually have a fairly varied diet that can include smaller birds, insects, and carrion, they are built to pounce down on unsuspecting mice, squirrels, voles, and other little mammalian critters on the ground.
While buteos don’t need to be particularly fast, they do need to have strong talons to grip squirmy mammals. But the real challenge for these birds is spotting their prey, which scurries around hidden in the grass. And for that, they need excellent vision.
To find their next meal, buteos watch. They use their incredible eyesight and a nice perch to watch the ground until they see movement. This is why you see Red-tailed Hawks and other buteos so often perched on a fence or a tree along the roadside. They’re not lazy—they’re just hunting and need a steady place from which to survey. Some buteos, like Swainson’s and Short-tailed Hawks, will hunt in flight, using their long, broad wings to steady themselves over a hunting patch.
The Northern Harrier also hunts for small mammals, but unlike buteos, it searches over large fields, marshes, and other places without convenient perches for scanning. To help them stay low and steady while in flight, harriers have evolved long wings and tails. They’ve also developed special, owl-like facial disks that help collect the tiny sounds of creatures in the grass.
Finally, no discussion of super senses would be complete without mentioning vultures. Carrion can be hard to find—it doesn’t move or make noise, after all. But vultures still need to eat. So they use their long wings to steady themselves high in the air where they can survey huge areas for dead creatures. What’s more, Turkey Vultures are one of the few birds with a well-developed sense of smell, allowing them to seek out dead and rotting (a.k.a. delicious) meat even when it’s hidden from sight.
Built for Agility. Some raptors need to be exceptionally nimble if they’re going to catch their prey. Accipiter hawks—Sharp-shinned Hawks, Cooper’s Hawks, and Northern Goshawks—are great examples. Unlike their big buteo cousins, who are typically out hunting over open ground, accipiters choose to go after prey in the forests and shrubby areas. To ambush the birds and small mammals in the woods, these hawks need to be able to move quickly between trees and through dense foliage.
Accipiters have developed short, rounded wings and long tails that act as rudders to help them navigate through tight areas. It all works really well: Check out this awesome video of a European accipiter, the sparrowhawk, tucking through a gap in a fence. Now picture some beefy Red-tailed Hawk trying that same maneuver. He’d just plug himself right in there!
Some species of kite are also built for agility. The Mississippi Kite has evolved narrow, pointed wings that allow for the maximum aeronautics they need to catch their favored prey: flying insects. Meanwhile, the Swallow-tailed Kite, a bird often referred to as our most graceful flier, uses its agility not just for flying insects but also to quickly pluck reptiles and snakes out of the treetops, eatings them on the wing like some kind of champion gymnast.
Built for Power. Eagles, of course, are huge. Golden Eagles are especially fearsome, and their size allows them to go after prey that few other raptors would even attempt. I’m not talking about, like, a bigger-than-average mouse here; I’m talking about freaking wolves. A wolf! I don’t think they go after them naturally, but man are Golden Eagles powerful. They knock goats off cliffs! Insanity.
Ospreys are also built for strength, though they’re only after fish. Because Ospreys can’t just lounge in the water eating their catch, their power is really useful for launching themselves back into the air while holding onto a wriggling fish. Eagles and Ospreys both have massive talons that allow them to get a death grip on their prey and not let go. Against such powerful and strong birds, big prey rarely stands a chance.
Alright, that covers the raptors I wanted to talk about here. Next time you see a hawk on a perch or a vulture soaring overhead, take a moment to think about how it’s built to hunt. Understanding how raptors are built for specific prey will help you become a better better bird and observer of the natural world.