Operation Migration
http://www.operationmigration.org/index.html
The pioneering migration pilots featured in NATURE’s “Flight School.” Get updates on the birds, watch video clips, and find out how you can get involved.

National Wildlife Federation: Whooping Cranes
http://www.nwf.org/wildlife/whoopingcrane/
Learn amazing whooper facts, see how a baby whooper changes as it grows, and tour the migration patterns of cranes in North America.

Whooping Crane Eastern Partnership
http://www.bringbackthecranes.org/
Working to bring back the cranes! Track the cranes’ migration from Wisconsin to Florida.

International Crane Foundation
http://www.savingcranes.org/
Learn more about other endangered cranes from an organization dedicated to protecting them.

Konrad Lorenz
http://www.age-of-the-sage.org/scientist/konrad_lorenz.html
Read a brief biography of the scientist who first formally described “imprinting” and gave it its name.

Books

Jonathan Elphick, ed. ATLAS OF BIRD MIGRATION: TRACING THE GREAT JOURNEYS OF THE WORLD’S BIRDS. New York: Random House, 1995.

Hermes, Patricia. FLY AWAY HOME: THE NOVELIZATION AND STORY BEHIND THE FILM. New York: Newmarket Press, 2000.

Lishman, Bill. FATHER GOOSE: ONE MAN, A GAGGLE OF GEESE, AND THEIR REAL LIFE INCREDIBLE JOURNEY SOUTH. New York: Crown, 1996.

Lorenz, Konrad. HERE I AM — WHERE ARE YOU?: A LIFETIME’S STUDY OF THE UNCANNILY HUMAN BEHAVIOUR OF GREYLAG GEESE. New York: Harper Collins, 1990.

Matheisson, Peter. THE BIRDS OF HEAVEN: TRAVELS WITH CRANES. New York: North Point Press, 2003.

McCoy, J.J. THE HUNT FOR THE WHOOPING CRANES: A NATURAL HISTORY
DETECTIVE STORY. New York: Paul S. Eriksson, 1996.

As a young boy, Canadian sculptor William Lishman wanted to be a military pilot. Vision problems grounded that dream, but he did eventually take up flying ultralight aircraft. And in 1988, he made ornithological and aviation history by leading a flock of 12 Canada geese that had imprinted on him; bonding to his plane as if it was a mother goose. Then, in 1994, he and partner Joseph Duff together led the first aircraft migration of 18 geese from Ontario to Virginia — a trip that later became the basis for the Hollywood film Fly Away Home.

Today, the two men help lead Operation Migration, a nonprofit organization that conducts migration studies and — as NATURE’s Flight School shows — is using ultralight aircraft to help restore migrating populations of whooping cranes to Florida. It’s a tricky business: In order to survive in the wild, cranes can not become imprinted on people, yet they must learn to follow an aircraft. piloted by a human.

NATURE caught up with Duff in Canada, as the group was tracking the Spring 2004 return of more than a dozen hand-reared whooping cranes it had led to Florida in late 2003.

How’s the migration going?

It’s looking very good so far. We’ve got birds moving north, with some in Wisconsin, Indiana, and Illinois. It’s a lot of work keeping track of them all, but we’re happy (for an update, see the Operation Migration Web site.

How did you get involved in this?

Well, I’m a commercial photographer, and back in 1988 my friend Bill Lishman met a guy on a local lake here who was teaching geese to follow his boat, using the boat as a photography platform. Bill wondered if you could get the geese to follow an ultralight too. It took him a while to figure it out, but he finally did it. Later, we realized that this could be useful for endangered species. We’ve been pushing the idea ever since. We did our first crane study with sandhills in 1998.

How do you make sure that the cranes don’t imprint on you?

We work hard to minimize human contact and give the bird as natural an experience as possible. Only people in costumes get near the birds, which are raised in very isolated areas. So by the time they arrive in Florida they have never seen an uncostumed human. It’s a very strict protocol and very difficult to do — it complicates everything.

Many other kinds of cranes around the world besides whooping cranes are endangered. Is there any talk of using the aircraft approach with any of these other cranes?

There is a discussion using powered hang gliders with Siberian cranes (in Asia). That’s because all cranes are soaring birds — they don’t flap very often. Our birds have to learn to follow the eddies off the wing, and you can only do that when the air is calm. Once midday comes, it is far too bumpy for them. But with a hang glider, you can soar on the thermals, just like the birds do. But it would be very difficult. The Siberian crane’s migration route is very long, and hasn’t even been identified yet.

What’s the next landmark for the flock you are working to establish in Florida?

One thing is that we’re only in our third year so our birds haven’t started breeding yet. They start to pair bond at around three years old and may mate in their fifth year. So we’re waiting to see what is going to happen and hoping for the best.

What are some of the problems you face in keeping your flock safe?

Well, we’re always scrambling to raise funds. But beside that maybe the worst thing that can happen is that people start feeding the birds. Then they start ending up in the McDonald’s parking lot, or not migrating. So we always preach that people should just leave them alone. After all these are wild birds that were once known as the “white ghost of the wetlands.” They deserve to be left in peace.

Rural children have who raised ducks or geese have long known about “imprinting” — or socially bonding to a parent figure. They learned that if they were the first moving object seen by newborn chicks, the young birds would soon follow them around devotedly. Many a delighted young farmer has paraded around the garden followed by “their” waddling brood.

But it wasn’t until the 1930s that a young Austrian scientist named Konrad Zacharias Lorenz formally documented the imprinting process — and gave it its name. Lorenz, who died in 1989 at the age of 86, ultimately won a Nobel Prize for his work.

Lorenz became interested in birds and bird behavior as a child. At one point, he recalled in an autobiography, “I yearned to become a wild goose and, on realizing that this was impossible, I desperately wanted to have one and, when this also proved impossible, I settled for having domestic ducks.” Soon, a neighbor gave him a one-day old duckling, which immediately began to follow Lorenz around, “to my intense joy.”

In college, Lorenz studied medicine and anatomy, but continued to keep and study birds and other animals. Then, in 1935, he published one of his most famous studies. In it, he showed that young ducks and geese could be “imprinted” on virtually anything — from people to colored balls — during their first days of life. Such “programming” probably evolved to help young birds recognize and stick close to their parents for safety.

Soon, university officials had set up a special institute where Lorenz and several other scientists could study animal behavior full time. But the work was interrupted by World War II. Lorenz became a military doctor, and was eventually captured by the Russian Army. After years as a prisoner, he returned to Austria in 1948, and was offered funds to resume his work. “We had money to support our animals, no salaries but plenty of enthusiasm and enough to eat,” he recalled. He eventually moved to Germany, where he was offered the chance to create a small research station.

For the next several decades, Lorenz helped pioneer the study of animal behavior, or “ethology.” He wrote several popular books, and soon became known to the public as “the man who walked with geese.” Magazines featured pictures of Lorenz leading, and even swimming with, his imprinted flocks. In 1973 Lorenz, together with two other scientists, was awarded the Nobel Prize for Physiology.

Today, Lorenz’s theory of imprinting is still being fine-tuned by scientists. Among other things, they’ve found that the imprinting window may not be as narrow as once thought. But, in general, Lorenz’s work has stood the test of time. And, as NATURE’s Flight School illustrates, an understanding of imprinting has important implications for conservation.

In the show, for instance, viewers meet Chewy, a gangly young sandhill crane whose parents were killed by a coyote. As a result, he was raised by people, and is imprinted on a woman named Mia. While Mia’s a great mom, Chewy never learned to behave as a normal, well-adjusted crane. As a result, he doesn’t know how to migrate and there’s little chance he’ll ever mate.

For biologists trying to raise and reintroduce endangered birds such as whooping cranes back into the wild, such imprinting gone awry would be a disaster. Conservationists thus go to great lengths to prevent newborn whoopers from imprinting on people. They wear crane costumes whenever they are around the birds, use puppets to feed the chicks, and raise the birds in isolated areas away from people.

So far, the strategy seems to work pretty well. And, eventually, researchers hope that there will be plenty of wild cranes to raise their own young — and biologists won’t have to worry about the behavioral quirk that Konrad Lorenz studied so long ago.

They are the superhighways of the sky. Biologists call them “flyways,” and each spring and fall billions of birds hit these atmospheric roads for their annual migrations, which can stretch thousands of miles. The sandhill and whooping cranes seen on NATURE’s Flight School, for instance, travel up to 2,500 miles each way on their migrations, following the same flyways first pioneered thousands of years ago by their ancestors.

In general, flyways follow major landforms, such as mountain ridges, coastlines, or river valleys that act as natural funnels. And while every type of bird may have their own route, many birds use the same general channels. In North America, for instance, scientists recognize four major flyways: the Atlantic, the Mississippi, the Central, and the Pacific. Birds typically move north and south along these routes between their breeding grounds in Canada and the northern United States, and their wintering grounds in South and Central America.

Overall, about 80 percent of the some 650 species of birds that nest in North America migrate along these flyways — and the few remaining whooping cranes are part of the seasonal traffic jam. Each spring, the small flock of wild whoopers that nests in Canada’s Northwest Territories embarks on its 2,500-mile flight south to the Aransas National Wildlife Refuge in Texas. The journey takes up to 3 weeks. Now, as seen in NATURE’s Flight School, conservationists are using ultralight aircraft to help establish a new migrating flock that will travel between Florida and the upper Midwest. There is also a non-migrating flock of whooping cranes in Florida.

Operation Migration’s whooping cranes migrated from the Midwest to Florida.

While it might seem like the cranes fly a long way, their trip is nothing compared to the annual migration undertaken by the arctic tern. Each year, the small seabird takes a round trip that can top out at more than 20,000 miles, from the Arctic to the Antarctic and back again. Other sea birds routinely fly more than 10,000 miles on their migrations.

Each species handles their annual trips a bit differently. Some cut the journey up into short hops, flying low, and stopping frequently to rest or feed. Others, like many cranes, are able to use wind currents or “thermals” of hot air to soar vast distances. Some may fly as high as 30,000 feet to get the best breezes or to cross mountains. While some fly during the day, many others travel only by night.

In recent years, scientists have perfected the art of using radar and tags that transmit signals to satellites as they track birds on their remarkable journeys. This technology allows the researchers to see exactly where the birds are going, and how long it takes them. It also helps conservationists identify key resting and feeding grounds in need of protection.

The tracking studies even provide opportunities for the public to have a bit of fun by following specific birds through Web sites. Scientists studying satellite-tagged albatrosses in the Pacific, for instance, recently sponsored the “Big Bird Race,” which allowed gamblers to place bets on which bird would reach the destination first — with the profits going to albatross conservation. “Who knows, if enough money is raised with the “Big Bird Race” then maybe albatrosses may one day outnumber horses,” says Gemma Brass of Ladbrokes, the U.K.-based betting company that sponsored the race.

Whooping cranes learn survival lessons from human surrogate parents on NATURE’s Flight School.

At five-feet tall, with a wing span of nearly 8 feet, whooping cranes are among the largest and most beautiful birds of North America. But hunting and other forms of human encroachment drove them to the very edge of extinction in the mid-20th century, when the head count for the last known flock plummeted to an all-time low of just 15. Legal protection, conservation measures, and artificial breeding programs have slowly lifted the number of whoopers to more than 400 today, of which nearly 300 are in the wild. But those are still dangerously low figures.

Enter Operation Migration — a group of scientists from the Patuxent Wildlife Research Center in Maryland, the International Crane Foundation in Wisconsin, and other conservation groups. To help ensure the survival of these endangered birds, Operation Migration maintains an artificial breeding program that prepares chicks for adulthood. Disguising their human appearance with whooping crane costumes, researchers meticulously train the chicks for flight. Using ultralight aircrafts, the scientists then lead them on their inaugural migration — covering more than 1,200 miles. The scientists are hoping that their experiment will enable the birds to grow up as normal adult cranes and successfully breed.

Follow the whooping cranes’ migration and share the excitement, perils and, in some cases, the heartbreak of the scientists of Operation Migration in Flight School.

To order a copy of Flight School, please visit the NATURE Shop.

Online content for Flight School was originally posted April 2004.