So far, what is being called the the eastern migratory population now has 96 birds, including two chicks that were hatched in the wild. One chick has already been taught the migration route by its parents, an important step that shows promise for the future of the newly established wild migrating flock.

"We call them the first family," said Duff. "The chick is migrating back and forth on its own. Its parents have passed this on to their offspring."

The restored flock is now regularly migrating between Necedah and Florida, and at a pace much faster than the young birds learning to migrate behind the ultralight airplanes. That assisted migration often lasts into January because of delays such as that now being endured in Illinois. The older birds migrating on their own get there in days.

"It's rather embarrassing for us," said Duff. "In the wild these are soaring birds. They get a free ride by getting up in the wind currents. They can certainly fly on days we can't."

If things go well, there may only be two or three more of the assisted migration flights, Duff said. He added it would be strange not to be with the birds in the fall as they fly. Being in the air with the huge birds as they wing their way south is humbling, he added.