SCIENCE

It’s Hawk Watch Season

October 13, 2010

It's the most wonderful time of the year—fall bird migration.

Spring migration is nice, too, when birds are in their brightest breeding plumage (see the difference between spring and fall colors in a chestnut-sided warbler). But birds flying from their wintering grounds to their breeding grounds are on a mission. They've got to get to their summer range, establish a breeding territory, defend it from other birds, attract and choose a mate and start pushing out eggs.

By the time birds head back south in the fall, they have already fledged their brood of chicks. There's no rush. They can meander on their way to their wintering grounds, loitering in parks and backyards where they fill up on food for the long journey. (If you're birdwatching in the East, you can use this handy timetable to find out which migratory birds to expect when.)

Birdwatching has a reputation, not entirely unjustified, for causing a certain amount of discomfort. Birders wake up before sunrise to catch the dawn chorus; they skulk through tick-infested fields; they get neck cramps from aiming their binoculars at the tree-tops. But fall migration is the perfect season for the easiest, most novice-friendly and (some say) thrilling type of birdwatching: hawk watching.

You don't have to wake up early to see hawks. They like hot, windy afternoons when they can soar on thermals. They're big and easy to see; they gather by the dozens in "kettles" of circling birds riding a thermal; and there are many places where you're pretty much guaranteed to get great views of migrating raptors.

One of the most famous is Hawk Mountain in Pennsylvania. Hundreds of hawks stream past this Appalachian ridge every day during migration. It's not really a place to contemplate nature in peace and solitude—it's more like going to a theater, or maybe fireworks on the Fourth of July (complete with oohs and aahs). You sit at observation stations with guides and official counters who point out distant hawks as they approach. It may be cheating, but Hawk Mountain guides put up tall stakes topped with owl decoys. The hawks buy the disguise, and they zoom right over the observation stations (everybody duck!) to attack their owl arch-nemeses.