For the Birds Radio Program: Whooping Crane Ultralight Experiment
Imagine flying in the sky, mile after mile, somehow knowing deep in your bones where you’re headed. Last year 8 Whooping Cranes were raised by humans dressed in billowing white costumes so their human form wouldn’t be recognizable, armed with hand puppets that were shaped like Whooping Crane heads, that could provide food.
These puppets also had digital recordings of several wild crane vocalizations which the people operating could play in the right contexts. When the baby cranes were ready to fly, they followed the costumed people as they went up in an ultralight airplane. To ensure that the cranes never saw a human-like form, even the pilots were required to wear the costume, and no one was allowed to speak in the cranes’ presence.
Cranes following an ultralight must flap much more than they would if flying with adult cranes, who take advantage of thermals to soar, minimizing the energy they expend. So the birds could only fly a maximum of 60 or so miles a day, and only on days with virtually no wind. They left the Necedah National Wildlife Refuge on October 17, but it took them until December 3 to make it all the way to the Chassahowitzka National Wildhfe Refuge in Florida. Of the 8 cranes that started on the voyage, only 7 made it all the way, and two more were lost during the course of the winter. But every one of those five flew back to Wisconsin in a few days this spring with no ultralight to guide them.
And they took a different route, with different resting stops along the way, so they were clearly not navigating by familiar landmarks. Somehow deep in their bones, or at least in their brains, they apparently have a Global Positioning System that shows them the way. And now four of last years birds are back in Florida again-they made it without the plane, and two of them even made the trip entirely on their own, without even a sibling to keep them company. The fifth bird from last year has hooked up with a flock of Sandhill Cranes that last I heard were in Tennessee.
This year the researchers made a few changes to their program, and they started out with more birds. From eighteen eggs, seventeen young cranes followed the ultralight down to Florida. Thanks to long stretches of bad weather, including tornadoes and blizzards, they were frequently grounded, and to make up for lost time made a few trips of a hundred miles. But sixteen cranes completed the long journey and are now safely on the refuge in Florida. The seventeenth had a minor injury early in the journey, when the wind shifted and it collided with the ultralight. It was recovering at the International Crane Foundation.
Next spring the survivors of these two flocks will return to Wisconsin on their own. But they will all be too young to pair off and nest for a few years more. Meanwhile, more birds will be introduced for a few more autumns, in hopes that eventually as these birds mature they will form pairs, raise babies, and teach them how to migrate without human assistance anymore. It’s a gamble, but all the care and love and solid knowledge make it a gamble worth the risk. This project has been time consuming and expensive, yet such a wonderful testament to both human ingenuity and the commitment that some people still feel toward the wildlife with whom we are so deeply connected on this little planet that we share.