Ultra-Light Plane Charts Course for Birds : Wildlife: Craft teaches 11 sandhill cranes migratory route from Idaho to New Mexico. The technique may be used to save endangered whooping cranes.

Is it a bird? A plane? It’s an ultra-light plane painted to look like a bird--a good enough disguise to get a small flock of sandhill cranes to migrate 800 miles in 11 days.

“I suppose it’s like mom and dad,” said Jim Lewis, a biologist with the U.S. Fish and Wildlife Service, which helps fund the migration experiment.

Because cranes learn their migration routes from their parents, scientists trained 11 sandhill cranes bred in captivity to follow the ultra-light plane south.

After leaving Idaho on Oct. 16 and making overnight stops in Utah, Colorado and New Mexico, seven of the birds made it to Bosque del Apache National Wildlife Refuge, 80 miles south of Albuquerque.

If the seven birds fly back to Idaho in the spring with other cranes, scientists hope to repeat the migration experiment next year to help save young captive-bred whooping cranes, which are endangered. Sandhill cranes are not endangered.

Kent Clegg, an independent researcher, piloted the one-person ultra-light, whose wings were painted white with black tips to match those of a crane. The 17-foot wingspan is extra long to slow its speed to about 35 m.p.h., matching the bird’s normal flight.

A second, faster ultra-light plane flew in front of the flock to guard it against golden eagles, which killed one of the original 11 and are suspected of killing a second. A third sandhill flew back to Idaho and a fourth developed an infection and was rescued on the ground.

“There definitely were birds saved from eagles by the second aircraft,” Lewis said.

The cranes fear any other aircraft but the ultra-lights, he said.

The seven birds, all bearing a yellow numbered leg tag and a radio transmitter, didn’t immediately mingle with the thousands of other sandhills that spend the winter at the refuge, instead staying in a field near the other flocks.

Clegg led them to the various wetlands and other feeding areas in an effort to start the process of weaning them from human supervision.

The refuge expects to eventually have as many as 20,000 wild sandhill cranes, as well as 20,000 to 30,000 Canadian snow geese.

Four whooping cranes are expected to winter among the sandhills this year, Lewis said. There are only 178 whooping cranes in the wild and 145 in captivity, the Fish and Wildlife Service says.

Ultra-lights are already being used to lead Canada geese down the East Coast.