The failed experiments in surrogate parenting sparked researchers at the International Crane Foundation (ICF) in Baraboo, Wis., to develop elaborate techniques to prevent future chicks from identifying with their human handlers. In 1986, ICF ethologist Robert Horwich created full-body, white-hooded costumes that handlers wore while working with the birds, and they played crane calls from recorders hidden beneath the costumes. Attached to one arm, handlers also wore a realistic hand puppet of a crane head — the part of the crane that chicks identify with most — to feed and prod the chicks as crane parents would. And, as often as possible, the young birds were penned near older whooping cranes so they could imitate them.
Other Migratory Techniques: Scientists are trying two other methods for teaching chicks reared in captivity the migration route south. Both rely on the chicks experiencing it for the first time by following their elders.
Status: Endangered in the U.S. since 1970
Life Span: Up to 25 years in the wild; 50 years in captivity
Height: 5 feet
Weight: 14 to 16 pounds
Behavior: Mates for life
Reproduction: The first eggs are laid when the whooping cranes are between 4 and 5 years old. The usual clutch size is two eggs, of which one chick typically survives.In an effort to save one of the world’s most endangered birds, scientists are, quite literally, taking them under their (costumed) wings.
Gradually, in this more natural environment, the distinction between the whooping crane’s instinctual and learned behaviors became clearer, says George Archibald, an acclaimed ornithologist and co-founder of ICF. Archibald was awarded the National Audubon Society’s prestigious Dan W. Lufkin Prize for Environmental Leadership in 2103 for his more than 40 years of work to save cranes worldwide. “We now know there are things that are absolutely instinctive, such as how they make calls and certain postures, that are as good as an anatomical feature from a genetics basis in understanding the relations among different species,” he says. “Whooping cranes have at least 16 different calls that the birds innately recognize.”
What also became apparent is that migration is a combination of genetics and experience. Archibald says that each fall, the captive birds would get agitated and fly around their nesting grounds as if preparing to migrate, yet they would not. “They’d lost the cultural knowledge to migrate,” Archibald says. “Whatever internal GPS is set for the direction to fly gets set through the first migration. After that, they refine it through experience.”
In 2001, to reinstill this ancient migration ritual, Canada’s nonprofit Operation Migration, working alongside the Whooping Crane Eastern Partnership, a consortium of government and nonprofit experts, began teaching chicks to migrate by substituting for the whooper parent an ultralight plane, flown by a costumed pilot. The chicks were shown the route south and, after that, like their counterparts in the wild, the whoopers were on their own for the return trip north.