journey behind a very special guide. for the last ten years "operation migration" has been leading the cranes south behind this special tiny aircraft known as an ultralight. >> they're just learning their wings. they're just on their first big adventure. sometimes they're very insecure. sometimes they're overly confident. >> reporter: whooping cranes, the largest north american bird at five feet tall with a seven-foot wing span, all but disappeared from the planet. there were as few as 15. 15 in the 1940s. but through conservation efforts like this their numbers have grown to several hundred. but their migration routes have been erased from memory. they need to be taught where to go. the long route from wisconsin to florida. from the time the birds are hatched they're introduced to the planes on the ground, around a track, to get used to the sound. and then -- they take flight. but this year the migration hit a bureaucratic snag. "operation migration" pays its