Trumpeter swan lured to Shore is missing, but the explanation could be quite natural 2 other birds remain at Dorchester site

March 21, 1998|By Frank D. Roylance | Frank D. Roylance,SUN STAFF

Yo Yo is a no-show.

The 10-month-old trumpeter swan, one of three taught to migrate to Maryland's Eastern Shore in December behind an ultralight airplane, has been missing from her Dorchester County wintering grounds for two weeks.

"Although we don't like to think about it, there is a possibility she has been killed," said Gavin Shire, a biologist and ultralight pilot with Environmental Studies at Airlie, in Virginia. Yo Yo's two companion swans, also raised at Airlie, are fine.

"It's unlikely anyone would have shot her; the hunting season is over," Shire said.

Dogs, foxes and power-line collisions are also dangers. But Dr. William Sladen, who has led swan research at Airlie, said he is confident that Yo Yo will return.

"I'm not particularly concerned," he said. "This is the time when we expect them to be exploring."

Bob Farris, director of species conservation for the Defenders of Wildlife, which is co-sponsoring the research, said big, noisy flocks of tundra swans have been gathering on the Honga River in Dorchester County preparing for their migration north.

"It excites the trumpeter swans," he said. "For them, it's a precursor to migration or moving. It's possible Yo Yo heard the cue, although it was not the right cue, and might have flown a little north and left the area."

Yo Yo's loss would be sad, Shire said. But "the fact that we actually pulled together a migration of three birds was a real triumph. If only two came back, it would still be a real success."

As soon as the weather improves, Shire and the birds' caretakers want to take their radio tracking gear up in a small airplane to determine whether they can make contact with Yo Yo.

"If anyone is interested in flying us for free, that would be great," Sladen said.

The transmitter Yo Yo wears has not been heard since she disappeared. But the receiver's range on the ground is small.

"If we don't pick up a signal from the air, either the transmitter has failed, or she's out of range, or she is dead. and the transmitter has been destroyed," Shire said.

"The strongest possibility is she'll turn up in a few days and rejoin the group," he said.

It's unlikely she has run away to join the tundra swans. "It's a different species, and she's a hand-raised bird," Shire said. "They become independent eventually, but at this stage they're still probably more likely to land next to a human and seek direction than another swan."

The Airlie center and the Defenders of Wildlife are trying to re-establish a migratory population of trumpeters on the Eastern Shore. Native trumpeters were wiped out by the 19th century by hunting and habitat destruction.

Yo Yo and two other females -- Isabelle and Sydney -- were raised at Airlie to regard Shire and his ultralight as their mother. When he took off from a cornfield near Warrenton, Va., in December, the birds followed him to Lakes Cove, in Dorchester County.

Similar experiments with Canada geese inspired the 1995 movie "Fly Away Home."

Yo Yo is white with gray shading. She has an 8-foot wingspan, weighs about 25 pounds and wears a large yellow neck band. Anyone who sights her is urged to call toll-free 1-888-2MIGRATE.

Pub Date: 3/21/98

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