Accidental tourist

Martha's Vineyard is bracing today for an onslaught of tourists who are coming not for the beaches, but for a single bird.

A red-footed falcon, a bird of prey never before recorded in the Western Hemisphere, was spotted on the island earlier this week, thousands of miles from its normal summer home in Eastern Europe. The juvenile male is, perhaps fittingly, at an airport. An estimated 100-120 people flocked to Edgartown's Katama Airfield yesterday to watch the bird sit on sign posts, circle overhead, and, a crowd-pleaser, swoop after dragonflies and grasshoppers.

When well-known birder E. Vernon Laux spotted the slate-gray falcon on Sunday, he first thought it was a different bird, a Mississippi kite. But something about it didn't sit right, so on Tuesday he forwarded a picture of the bird to Harvard ornithologist Jeremiah Trimble.

''My heart started beating faster when I saw it," Trimble said. He caught the next ferry to the Vineyard.

Yesterday, as the falcon's sighting triggered rare-bird alerts across the country, birders scrambled to make plans to visit the airport, a bus ride from Edgartown. The bird was described by one observer as ''cooperative," and Laux said that every person who came to see the bird yesterday did.

''It's like a pet that is lost thousands of miles from its brothers and sisters," said Peter Alden, a Concord ornithologist who rushed to the Vineyard two days ago to see the falcon. Researchers believe that the bird was blown off course on its way from Africa, where it would normally spend the winter.

''It's fine, but it's just on the wrong continent," Alden said.

BETH DALEY