Bill Sladen kneels on the lawn, honking like a goose. Pride is not an option in dealing with birds, especially movie stars.

"C'mon, geese!" he commands, British diction intact even after three decades as a U.S. citizen. The geese are a few feet away on a lawn 60 miles west of Washington's urban grit.

The plump Canada geese lift their ink-black heads from grazing to gaze at the rumpled scientist. They stay put. Sladen tries bribery, tossing a handful of corn near his feet. One bird waddles his way. Then two more.

Sladen points: "That's the one that guanoed my car."

The story of Sladen and his geese stands at the rare intersection of ornithology and Hollywood, where the true story of this crusty scientist and an artist friend who taught birds how to migrate behind an ultralight plane turned into a screenplay about a young girl and her father who taught birds to migrate behind an ultralight plane. The geese that Sladen used in his fieldwork were cast as extras in the movie.

These birds, now retired from cinema work, roost on a pond near Sladen's house at the Airlie Conference Center in Virginia's horse country. They range the countryside by day. They don't fear humans because they were raised by them.

Their ultralight training won them roles in the movie "Fly Away Home," in which a young girl (played by Anna Paquin) pilots the plane that leads a flock of geese from Canada to North Carolina, out of the clutches of government wildlife officials. She is helped by her father (Jeff Daniels) in this project, which repairs their estranged relationship. The movie is filled with images of goslings cuddling with the girl, as well as spectacular flying scenes.

But there is serious science behind the movie, which was based on a series of flight experiments, called Operation Migration, staged by Sladen and Canadian sculptor Bill Lishman. The key to both the scientific work and the movie is a peculiarity of some birds called imprinting. Geese and many other species form a psychological attachment to the first thing they see after hatching. Normally, that is one of their parents, but in this case it was Lishman. Then Lishman, piloting an ultralight, led a flock of geese from his home in Ontario to Airlie in October 1993. It was the first time birds had been led on a migratory route by a plane.

Why bother? Don't geese know how to fly?

Yes, but geese (as well as cranes and swans) don't know their migratory routes instinctively. They learn from their parents. Or, as other scientists have shown, a boat. A car. A plane.

Sladen and Lishman trained the geese that appeared in the film and helped with wildlife scenes. Lishman was a flying double for Jeff Daniels. Both are fuzzy-haired hang-loose kinda guys. There also is a scientist named Dr. Killian in the movie, roughly modeled after Sladen.

The six geese now pecking at Airlie's lawn were shown flying alongside Paquin's plane, honking and gliding. (Paquin was not allowed to fly, so a double was used). They've spent the summer wandering the hedgerows, thistle and expansive lawns of Fauquier County. Sometime in the coming weeks, they are due to leave for South Carolina.

Also in residence at Airlie, but not headed anywhere, is a flock of a dozen geese including Igor, the movie's lovable runt. Igor's band are "truck geese," raised in Canada (by Lishman's daughter, who played tapes of Paquin's voice so the geese would take to the actress) and trucked to the movie site at Niagara Falls for filming intimate shots of Paquin bonding with the birds. They trotted after Paquin. Nuzzled her. Napped with her.

The movie Igor had a limp and couldn't fly. To save him, Paquin tucks him into the plane for the flight.

In reality, Igor favors his left leg but he can fly fine. He and his flock lift off from Sladen's pond each morning and return at night. Now, they're nibbling peaceably on an Airlie neighbor's lawn. Igor pecks at the grass, then lifts his left leg to scratch his ear.

"Igor is not the bottom of the totem pole," explains Airlie biologist Kevin Richards, wearing an Operation Migration sweat shirt. "He's probably third to last. He's not the one that gets beaten up all the time. Igor is just one of the guys." The truck geese grunt softly to each other. A few lie down to doze, curling their necks so they can rest their heads on their backs.

"You can't help but get fond of them," Sladen says, "even though they do poop up your porch."

Every day, Sladen the scientist jots details about the geese in a small beige field notebook. Where they feed. Where they assemble.

Every night after dark, he heads to the pond with a flashlight and a handful of corn. He counts to make sure everyone is back. "We're going to get some fantastic data from these birds," he says.

But Sladen -- William J.L. Sladen, MD, PhD -- wants people to know that he is not, ultimately, interested in the common Branta canadensis, even if it does sound more impressive in Latin. He's concerned with more exotic game.

After all, this is a man whose resume includes having two mountains named after him for his work in Antarctica. Whose pioneering work on penguins won him British honors twice. A professor emeritus of ecology at Johns Hopkins University. He is 75, and his retirement job is as co-director of environmental studies at Airlie, the country estate used for a variety of meetings.

The trumpeter swan -- now that's a bird. Among the largest waterfowl -- five feet long -- with a remarkable cry. They once wintered near Chesapeake Bay, but hunting took care of that. Now they're no closer than the Great Lakes. Sladen wants to bring them back.

So he and the environmental group Defenders of Wildlife have teamed up to do it. Assuming they obtain needed permits and raise several hundred thousand dollars, they want to hatch trumpeter eggs at Airlie next spring and fly the swans to an Eastern Shore farm in the fall. (More information on this project is available at the Airlie and Defenders Web sites: http://www.airlie.com and http://www.defenders.org)

They may try ultralights; two Airlie biologists have learned to fly them. But trumpeters are two or three times the size of geese, and could disrupt the air pattern needed to give lift to the ultralight. So they also are thinking about boats. Or other options.

"Gorgeous birds," Sladen says. "Very gentle birds."

He has seven of them on his property. A pair on the upper pond near his house. Another pair -- Sasha and Natalia -- on the lower pond, along with their brood of five. By now, the young are nearly the size of their parents, but with pale brown feathers. To keep the birds legally, he had to clip the tip off one wing so they could not fly with wild flocks and possibly spread disease.

Sladen loves going to look at them. He drops a few kernels of corn into the pond. One by one, the birds dip their heads into the water to feed.

"It's nice to have birds trusting you, isn't it?" Sladen says. CAPTION: Biologist Kevin Richards, above, uses a scope to get a look at an injured goose's identification tag number while Bill Sladen adjusts an antenna that picks up signals from transmitters attached to some of the birds. Right, Sladen feeds the animals. Below, trumpeter swans at Airlie, part of a project to reintroduce the species to the Chesapeake Bay region. CAPTION: Working with flightly Hollywood types, Jeff Daniels stars as Thomas Alden, who helps his daughter teach geese to migrate in "Fly Away Home."