This site has some information on breeding territories. These nothern breeding territories provide an abundant amount of food and nesting sites. They also minimize competition and allows successful reproduction. This site talks about Operation Migration. This was the first aircraft led migration in 1993.
Most waterfowl learn the route and their destination or wintering area from their parents.
However, captive birds need to be shown the way. The Operation Migration team acts as surrogate parents and then fly with the aircraft leading the captive birds. This site talks about the endangered Whooping Cranes. There are only 150 birds left in the wild. The whooping Crane Recovery Team established a second flock independent from the others in habitat and migration route.