Fall migration season is a great time to see North American raptors.
My husband invested considerable energy into choosing the right magical name. He eventually settled on the Gaelic Seabhag Fionn, literally (we think) "white falcon" or "fair hawk." It is a fitting totem, I think, for someone who aspires to be a Warrior and a Naturalist. Raptors symbolize not only the power, skill and grace needed by the warrior as well as the hunter, but they also remind us that even in environmental crises, trend is not destiny': most hawk species have enjoyed remarkable recovery in the years since DDT- induced eggshell thinning threatened to wipe out avian predators.
Autumn is a good time to think about hawks because many of our species are on the move in migration, and you may be able to see birds that spend most of the year in deep forests or on the tundra. Of course, any time of the year is good for thinking about hawks, and spring migrations are equally popular among captor enthusiasts.
Catching a glimpse of a migrating hawk is less haphazard than it may seem. Many hawks tend to fly along "leading lines" which influence their direction of flight (Dunne, et al. 1988). Leading lines may take the form of a cold front that pushes birds southward in front of bad weather. Large bodies of water, which raptors are reluctant to cross, form permanent leading lines, and many of the best hawk watching sites, including Cape May, N], Derby Hill, NY, and Hawk Ridge, MN, are located along oceans or the Great Lakes, where birds "bottleneck", changing direction to avoid crossing the water. Mountain ridges also form leading lines as hawks catch and glide on upwelling warm air.
To identify flying raptors with precision, you will need a good identification book (see references), many years' practice, and ideally, an informal mentor at a hawk counting station at a popular hawk-watching site. Contact your local parks to find out if anyone is counting hawks in your area. This guide, however, may help you start to distinguish between hawk species.
Most North American raptors fall into one of five categories: eagles, kites, accipiters, buteos, and falcons. In most species, females are larger than the males, and both parents usually hunt and care for young.
Bald eagles are probably the most easily recognizable raptor, and while the golden eagle is still rare in the east, the bald eagle had made a remarkable recovery and can be seen near waterways (where it predominantly hunts fish and waterfowl in many eastern states. I have seen bald eagles in Maine, Michigan, Pennsylvania, and Virginia. The turkey and black vulture are commonly mistaken for eagles. Turkey vultures hold their wings in a V-shape during flight, and frequently tip unsteadily. To identify an eagle, look for a very large bird. with wings held flat in a soaring glide, with occasional deliberate wing beats.
Kites are agile southern raptors that prey predominantly on invertebrates. The Swallow-tailed kite is easily distinguished by its long, forked tail. These birds breed in the Southern US, but can be seen as far north as Cape May, NJ, during migration.
The third category of NOM American rapt or is the accipiter. Accipiters frequent forests, darting between branches to capture smaller birds. These hawks also frequent backyard birdfeeders, earning them a bad reputation among passerine lovers. Our three species share long rudder-like tails and relatively short wings that aid in the navigation of dense forest cover. Males of the three species also share a slate grey plumage. The sharp-shinned hawk and the slightly larger Cooper's hawk are found over most of the continental US, while the largest accipiter, the northern goshawk, occurs mainly in Canada and across the Western states.
Buteos are the most diverse group of North American raptors, and are probably the most frequently sighted, as most are known for their soaring flight. The most common buteo is the red-tailed hawk.
The red tail is not obvious when the bird is seen in flight from below or head-on when the bird is perched on telephone poles or tree branches, from which it preys on rodents. Look for a pale breast with a belt of tan streaking; in flight, note the lack of banding on the tail. The red-shouldered hawk and broad-winged hawk are also common in the East. The red-shoulder is identified by a crescent-shaped "window" near the tip of each wing where light actually passes through the outer flight feathers. Broad-winged hawks are the smallest of the eastern buteos, but are spectacular in that they migrate in large groups, frequently forming "kettles" over the Appalachians as dozens of birds take advantage of upwellings of air. Other North American buteos include the Swainson's and Ferruginous hawks, found in the Western states, the southwestern Harris' hawk, which hunts in packs and nests on cacti, and the boreal rough-legged hawk, which winters across most of the US. A few other species are restricted to Florida and the extreme Southwest.
Most hawk species have enjoyed remarkable recovery since DDC-induced eggshell thinning threatened to wipe them out.
And now we come to the falcons, the group which most captures the imagination. Falconry has rightly been the sport of kings for countless centuries, and this group includes some of the fastest animals on the planet. Like accipiters, falcons prey mainly on other birds, but their method is a high-speed chase over open ground rather than a dodge among branches. The American kestrel is our smallest and most common falcon. They commonly perch on power lines and are frequently seen hovering in flight along roadsides, looking for prey. Merlins and peregrines, both familiar to falconers, are larger and less common than the kestrel. The eastern subspecies of the peregrine was actually extirpated by pesticide use, but captive breeding of western birds has precipitated a recovery that rivals that of the bald eagle. In fact, several eastern cities now boast pairs which nest on the cliff-like skyscrapers and feed on the endless supply of pigeons. Prairie falcons and gyrfalcons round out our falcon species, living in western states and Northern Canada, respectively.
There are two final species of note, which do not fall neatly into the categories listed above. These are the osprey and the northern harrier, both relatively large hawks found near wetlands. Ospreys feed almost exclusively on fish and build large nests over water in dead trees or on platforms built by wildlife conservationists. Harriers are smaller than ospreys and are distinguished by an owl-like face, a white patch on the rump and a slight dihedral to the wing while in flight. Female harriers have brown backs and wings, males are predominantly grey.
Dunne, Pete, David Sibley, and Clay Sutton. 1988. Hawks in Flight. Boston: Houghton-Mifflin.
National Geographic Society. 1987. Field Guide to the Birds of North America.