Hawks Get the Urge for Going

By Scott Fitzpatrick on Friday, September 12, 2008.

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We often think of hawks and other raptors as lone rangers, but as Scott explains now is the time of year when you might see them in droves.

The Broad-wing hawk is heading south, and he does it without much flapping. (Courtesy Peter Manship)

Come mid-September, right now in fact, it's eyes-to-the-sky time. Mid-September is when one hawk species in particular deserts New Hampshire forests in waves sweeping south and picking up others along the way. For migrating species the seasonal urge to go is strong – often triggered by shifting daylight levels – and for New Hampshire's Broad-winged Hawks, the urge to go is focused on mid-September.

Anyone in the right place and right time to witness these swirling crowds is in for a treat. And the right place is just about any backyard, schoolyard or street corner. All you have to do is look up when conditions are right.

Broad-winged Hawks are solar powered, so the right conditions require sun. Because they hunt from a perch, they lack the stamina for sustained flight. Instead they hitch a ride on heat rising from the earth's surface. They circle high in groups called kettles. When thermal lift weakens, the highest birds set their wings for a glide south. The others follow in an orderly fashion that's surprisingly easy to count. These elevating rides and southern glides, are repeated all the way to Central and South America.

For a few sunny days in mid-September, some kettles will top 50 birds and a day's count can top a thousand. So keep an eye to the sky, especially after a storm front clears this time of year and the first sunny, clear sky returns. A caution though: hawkwatching can be addictive.