Hawks Are on the Move
September 19, 2020
By Steve Grinley

     September is the month to look skyward as hawks begin their flight south. Tens, and sometimes hundreds, of hawks can be seen migrating overhead on a crisp fall day in New England when the winds turn out of the northwest. On cooler autumn days, as the sun warms the earth, warm air rises into thermals which hawks use to glide their way south. River valleys and ridges of hills and mountains provide thermal paths along which hawks migrate. If you can find a high vantage point with a clear view of the northern sky, you may catch “kettles” of hawks traveling south in the midday thermals.

     Popular hawk watching sites include Mt. Wachusett, Mt. Watatic, Mt. Tom and Pack Manadnock in New Hampshire and Mt. Agamenticus in Maine. In this area, the Merrimack Valley provides good thermals for migrating raptors. Behind the Page School in West Newbury is one of the more popular spots for hawk watchers in this area. It provides a panoramic view of the Merrimack Valley and you can watch hawks as they approach from the north.

     Most hawks can be identified into one of three groups: buteos, accipiters and falcons. Buteos are large hawks with broad wings and short rounded tails. Accipiters are generally smaller than buteos with rounded wings and long tails. Falcons have pointed wings and long tails.

     The red-tailed hawk is probably the most familiar buteo. They are the common roadside hawk that you see along highways or on the telephone poles on the way to Plum Island. They have a white chest with a dark band across the belly. Its red tail is present in adult birds, but juvenile red-tails have brown tails

     Broad-winged hawks are smaller that red-tails with wide light and dark bands across the tail. Broadwings migrate by the thousands through Massachusetts and “kettles” of them circling in the sky can be spotted on a good autumn day. Red-shouldered hawks and the larger rough-legged hawk sometimes make appearances among the other buteos.

     The wing beat pattern of “flap, flap, sail” is characteristic of accipiters (though other hawks do that occasionally too). The Cooper’s and sharp-shinned hawks are nearly identical in color patterns with the “sharpy” usually the smaller of the two. These are the two common hawks that feed on birds at the backyard feeders. The goshawk is the largest accipiter – crow size and much less common here.

     Of the three eastern falcons, the largest and fastest is the peregrine falcon which can reach speeds in excess of 60 mph with a strong tail wind or when diving for a shorebird or pigeon. The American kestrel is the most plentiful of the falcons during migration. Adult kestrels are identified by their small size, rusty coloration on their back and tail and light color underneath. Both the peregrine and the kestrel sport black sideburns and the merlin has a hint of them as well. The merlin is small like the kestrel but heavily striped underneath with a noticeable white tip to the tail, and a white line over the eye.

     Harriers, turkey vultures, and ospreys are among the other large raptors you might see. You may also be lucky enough to catch sight of a bald eagle, soaring on flat wings they glide overhead. So keep your eyes skyward on these autumn days!