We had all our eggs in one very shaky basket. She realized that the next step in effectively managing the birds was to disperse them. Swans once migrated to many other wintering areas, after all, but those that went farther south had been hunted, and those that stayed had been fed. The population no longer knew where else to go. Teaching swans to migrate, however, is trickier than merely cutting off their food supply.
Swans learn migration routes from their parents.
Juveniles, or cygnets, stay with their parents the first winter, fly with them to feeding sites, then join them on the flight home. Soon afterward, the parents drive the young away. Trumpeters begin breeding at age two to six years and may live 20 years or more, returning to the same wintering sites each year. The latter technique, in which captures occurred at night in an icy river, has been deemed unnecessary because hazing has met with success. Some swans relearn migration routes to historic wintering areas, while others return to familiar ground near Yellowstone.