This week for Flora and Fauna Friday we’re investigating a duo of agile aerial assassins, the Hawks of Genus Accipiter.
We have two species of Accipter Hawk here in South Carolina, the Cooper’s Hawk (A. cooperii) and the Sharp-shinned Hawk (A. striatus). Here on the Sea Islands, both wander our way come winter, with the Cooper’s Hawk being the more abundant. They are inhabitants of woodlands of all forest types and rarely a guarantee to see here so close to the coast.
Cooper’s Hawk: (1) Adult | (2) Immature | (3) In flight
Sharp-shinned Hawk: (1) Adult | (2) Immature | (3) In fight
Both our Accipiter Hawks are lean framed and, when full grown, have a back coated in gunmetal-gray, a breast of rust-orange finely checkered by white, a white rump, a long barred tail, yolk-yellow legs, piercing scarlet eyes, and a dark slate-gray cap on their head. Juveniles instead have yellow eyes and coat themselves in a mantle of walnut-brown with a white chest streaked in a lighter chestnut-brown. In flight, their wings are light with many fine, dark bands. Both these birds, as adults and as juveniles, look very similar to one another and can be difficult for even seasoned birders to tell apart without careful consideration. The Cooper’s Hawk has a heavier bill, thicker legs, and a larger head. Sharp-shinned Hawks tend to have a squared off tail tip, a short neck, and more of a dark hood than a cap on their head. There are many other minute difference between the two but the big one I’ve yet to mention is size. Cooper’s Hawks can be twice the size of a Sharp-shinned Hawk, or they can be nearly the same size. In raptors, the females are larger than the males. So a small male Cooper’s Hawk can look practically the same size as a big female Sharp-shinned Hawk. But on the opposite extreme, the two are strikingly different, with a small male Sharp-shinned about the size of a Blue Jay and a big female Cooper’s as big as some Red-shouldered Hawks. The male Sharp-shinned hawk is, in fact, our smallest hawk, but not our smallest raptor.
A streak of gray, a cloud of feathers, and the forest falls silent in a moment in memorial for a songbird. An aerial assassin has silenced an unsuspecting soul. Songbird snacking is the modus operandi of the assassin-like Accipiter Hawks. The Sharp-shinned Hawk lives on a diet of almost entirely songbirds. Cooper’s Hawks eat much the same but make use of their heavier frame to diversify a bit by including squirrels, bats, and mice. Our Accipter Hawks are masters of aerial agility and arboreal acrobatics. The Sharp-shinned Hawk takes the gold between these two sister species. Sharpies can fly at break neck speed while they glide, dive, pitch, and yaw between branches amidst the densest of brush. They use this unmatched agility with their keen vision to blindside birds buried between bushes. In suburban settings, Cooper’s Hawks are notorious for watching bird feeders from afar, diving down to skim the surface of the grass, then popping up over a bush or hedge to pluck a panicked feeder bird out of midair.
