For the first time in two centuries, a group of trumpeter swans - the largest waterfowl in North America - touched down on the Eastern Shore in late December, the first step in an innovative project to bring the birds back to the Bay region.

The swans made their 103-mile experimental migration from Virginia to a farm in Crapo, MD, where they will spend the winter. The three female swans - YoYo, Sid and Isabelle - made the flight Dec. 19 behind an ultralight plane, which they had been trained to follow as if it were a "parent swan," in four-and-a-half hours.

"We had the wind at our backs and were able to make good time as soon as the birds clued into the fact that we were on migration," said lead pilot Gavin Shire. "They stuck with me all the way. They were great and the weather was perfect. It was clear visibility and you could see the whole expanse of the Chesapeake Bay below us. The Coast Guard followed below us.

It was an incredible sight."

The birds were reared by Environmental Studies in Airlie Center, near Warrenton, VA, and had been trained to follow the ultralight since they were in their eggs. Scientists played recordings of an ultralight engine to "imprint" the noise on the unhatched birds, in the same manner that they would learn to identify their own mother's trumpet-like call.

Of seven birds hatched last spring, five were ultimately selected to make the flight. Two males were expected to make the trip later.

The return of the swans was carried out by the Migratory Bird Project, a partnership between Environmental Studies at Airlie and Defenders of Wildlife. After spending the winter on the Eastern Shore, the birds are expected to return to their takeoff point in Airlie, VA this spring.

"I've studied trumpeter swans and tundra swans for more than 30 years, and this is the realization of a dream for the restoration of migratory trumpeters on the Eastern Shore," said William Sladen, director of Environmental Studies at Airlie, a swan expert.

In 1989, Sladen teamed up with ultralight enthusiast William Lishman to teach the more compliant Canada geese to migrate. In 1993, they completed the first ultralight-led goose migration from Ontario, Canada, to the Airlie Center, a trip depicted in the 1996 movie, Fly Away Home.

If all goes well, scientists will repeat the trumpeter swam experiment on a larger scale next fall with more swans in a migration from New York to Maryland. The ultimate goal is to reestablish a migration route between upstate New York and the Eastern Shore.

The birds were considered unlikely to return to the Bay region on their own because because migration routes are passed from one generation to the next, and none of the giant birds have lived along the East Coast for decades.

Migration is considered important because birds take advantage of food supplies in different regions at different times of the year. If the birds do not learn to migrate, their year-round presence could result in their becoming a nuisance species, as is the case of the large flocks of "resident" Canada geese that inhabit the region.

Trumpeter swans once lived in nearly all of North America. About 100,000 wintered in the Chesapeake Bay area about 200 years ago, but were an early victim of European settlement. By 1932, overhunting had left only 69 trumpeters in the lower 48 states.

There are now about 19,000 trumpeter swans in North America, 16,000 of them in a migratory flock that breeds in Alaska and winters in the Pacific Northwest. The remaining 3,000 are in a few small, non-migratory flocks in Iowa and around the Great Lakes.

Restoring an eastern population will help to ensure the long-term survival of the species because remaining populations in the lower 48 states are vulnerable to such perils as continued loss of wintering habitat. The concentration of wintering flocks at relatively few sites also make them vulnerable to disease.

The birds, white with a black beak, weigh up to 30 pounds, have an 8-foot wing span and can stand 6 feet tall with neck outstretched.

They have a long, convoluted trachea that produces the resonant trumpeting sound.

People can learn more about the project and view photos of the birds at the Defenders of Wildlife's World Wide Web site at www.defenders.org