Leader of the Flock - using ultralight aircraft to start a whooping crane flock

Training endangered cranes to follow a man in an ultralight means risks as well as rewards

Ultralight-aircraft enthusiast Kent Clegg and a contingent of young sandhill and whooping cranes were riding a thermal over a Colorado plateau last October when a golden eagle, drifting at 10,000 feet on the same bubble of hot air, folded its wings, homed in on one of the cranes like a missile--and missed!

Clegg is an independent wildlife biologist who has worked with cranes for 20 years and has a dream of using ultralights to start a whooping crane flock in the Rocky Mountain area. This was his third trip leading a flock of cranes on an experimental migration from his ranch in Grace, Idaho, to Bosque del Apache National Wildlife Refuge in New Mexico. The 800-mile route follows the spine of the southern Rocky Mountains before crossing roadless canyon lands--all prime golden eagle country--and attacks on his charges were nothing new. The day before, one of the powerful raptors had smashed a whooper to the ground, ripping a bloody wound in a drumstick, before being scared off by Clegg's support team. Stitched up by a veterinarian and dosed with antibiotics, the crane finished its journey in a trailer.

But this time, with the eagle circling for another try, it was Clegg who had a close call. He had trained the crane chicks to think of him as their parent from the day they hatched at Patuxent Wildlife Research Center in Maryland. And as the birds jostled to get close to the plane for safety, a sandhill became snagged on the emergency parachute canister. To keep the bird from going through the rear-mounted propeller, Clegg cut the throttle, nosed the plane downward and landed in a hay field with his panicked flock close behind.

"What Kent did was extremely dangerous," says biologist Tom Stehn of Aransas National Wildlife Refuge on the Texas coast, who watched the flight with the ground crew. It wasn't the only near-accident during the 1997 migration lesson. Errol Spaulding, pilot of the second ultralight on the nine-day trip to Bosque del Apache, was chasing an eagle away from the cranes when his engine quit during a sharp turn because of a fuel problem. Spaulding was only 200 feet from the ground and barely had time to level out and find a flat spot to land, stopping at the brink of a gully.

Those incidents, together with another crane-ultralight entanglement in Canada that wrecked the plane and injured its pilot, add safety concerns to a list of scientific, logistical and political questions about the popular idea of using the fragile aircraft to start a new migratory whooper flock. "I'm not convinced we should push full-bore forward with the ultralight plan," says Stehn, who is the U.S. Fish and Wildlife Service coordinator of the international Whooping Crane Recovery Team. Still, for now ultralights remain part of a grand plan to ensure the species' survival.

The whooping crane may be the most famous bird on the North American if not the worldwide list of rare wildlife, and the recovery team's goal is to upgrade the species' official status from endangered to threatened by the year 2020. At the historic low point in 1942, only 16 whoopers returned to their winter home at the Aransas refuge from their then-unknown breeding grounds in the muskeg wilderness of northern Canada's Wood Buffalo National Park. Last winter a record 182 whooping cranes, including an all-time high count of 30 juveniles, arrived in Texas. Despite those heartening numbers, the species remains at considerable risk. As Stehn points out, the Aransas marshes lie along a crowded shipping lane for petroleum and chemicals. A spill could devastate the habitat and kill dozens of cranes.

The recovery team's plan, then, calls for supplementing the Aransas- Wood Buffalo whoopers with two other self-sustaining populations, each with at least 25 breeding pairs. One would be a nonmigratory flock on the pasturelands of central Florida, where dozens of captive-raised cranes have been released over the past seven years, although none have mated and produced young. Cranes living in the South where there is a year-round food supply have no need to migrate, and there was a sedentary flock of whoopers in Louisiana until it was devastated by a hurricane in 1940.

A new migratory flock, meanwhile, would nest and winter at locations well east of the historic flight corridor between Texas and the Canadian province of Manitoba so there would be no commingling of the two populations. And therein lies a big problem as well as the potential role of ultralight aircraft, because whooping cranes, unlike many small birds, need to be shown the way home.

While the phenomenon defies full scientific understanding, biologists know that songbirds like orioles and warblers, as well as plovers and other shorebirds, are genetically programmed to use celestial and magnetic cues to navigate at night between their breeding and wintering grounds. Young of the year of those species, moreover, migrate thousands of miles without help of any kind from their parents.