- The Washington Times - Wednesday, December 26, 2001

WARRENTON, Va. A strange sight will soon cross the Virginia sky: a caged gaggle of geese hanging from a huge helium balloon, flying low from Northern Virginia down to the Tidewater.
The 10 Canada geese are the stars in a serious scientific experiment to determine if migratory birds can learn migration passively that is, without actually flapping their wings.
The experiment is an extension of research done eight years ago by William J.L. Sladen, director of Environmental Studies at Airlie, near Warrenton, and Canadian pilot William Lishman. The two demonstrated that geese could be taught to migrate by following an ultralight aircraft that served as a surrogate mother.
The experiment was the basis for the 1996 film "Fly Away Home." The technique also was used earlier this year to lead six endangered whooping cranes on a 1,200-mile migration from Wisconsin to Florida.
But using ultralight aircraft to teach migration presents problems. To begin with, it is time consuming. The young birds have to "imprint" onto the aircraft; they must be fooled into thinking the aircraft is their mother, a process that takes several months.
Birds also can be injured by the aircraft, said Amy Harney, the experiment's project manager. In addition, ultralight aircraft are not permitted to fly at night, and birds are known to use the stars to help with navigation.
"We need to know whether this can or cannot work," Mr. Sladen said. "If they can learn passively, then we can teach many more birds."
When Mr. Sladen and Harry Darlington IV, founder of the Sky Calypso Society, which is Mr. Sladen's partner on the project, first discussed the experiment, both were skeptical. But they have grown optimistic as the birds have trained the past few months, suspended from a flag pole to simulate the balloon ride.
"They're comfortable in the cages," Mr. Darlington said. "They're going to be excited; they're going to be looking around."
Mr. Sladen pointed out that it seemed unlikely to many eight years ago that birds learn to migrate by following an aircraft, so there's reason for optimism this time as well.
The researchers won't know until the spring if the experiment is a success. That's when they hope the 10 tagged geese will have returned to Airlie.
Miss Harney said she'll consider the experiment a success if just one goose can find its way back to Fauquier County.
The geese will be dropped in a rural area of Southampton County where hunting is not permitted, but they still face natural predators and danger from humans who consider the birds a nuisance. The researchers hope an outreach program to let area residents know about the project will help ensure the birds are left alone.
It's expected the birds will be released somewhere near Franklin, but the helium balloon that will carry the birds has limited steering ability, so the exact location is uncertain.
The balloonists plan to take off as soon as they can catch favorable wind and weather. The flight has been delayed several times, but Miss Harney said the balloonists are hoping to take off as soon as today. The wind needs to blow to the south or southeast to carry the balloon where they want to go.
Once launched, the balloon will fly relatively low, about 1,000 to 3,000 feet, to mimic geese's natural migration, Miss Harney said.
Thomas Wood, an assistant professor of conservation studies at George Mason University and a research associate with the Smithsonian Institution, said the experiment could help researchers learn more about how birds migrate.
"We don't know much about the mechanisms that are involved" in birds' migration patterns, Mr. Wood said. "It is certainly a unique experiment."
Although Canada geese are being used in the experiment, the ultimate goal is to use passive migration to teach migration routes to rare trumpeter swans and endangered whooping cranes.
Mr. Sladen is particularly fond of the swans, calling them "the most magnificent of all waterfowl," graceful yet massive with an eight-foot wingspan. The birds were once common in the East, but hunting led to their disappearance from this region more than a century ago.
About 16,000 birds remain, but 14,000 are in Alaska.
Initial trumpeter swan populations would have to be taught how to migrate, though. Otherwise, the birds would become resident.
"We need them to migrate so the food resource can replenish itself," said Brooke Pennypacker, a team leader on the experiment. Otherwise, "they would deplete the food reserve. They would become a nuisance like the resident geese in this area."
Mr. Sladen said the swans would be a welcome addition to the region.
"It is such a magnificent bird," he said. "They were a part of an ecosystem we completely destroyed."

LOAD COMMENTS ()

 

Click to Read More

Click to Hide