OKA STATE NATURE RESERVE, Russia - Lean, light and hawk-profiled, hang-glider Angelo d'Arrigo twitches with a birdlike intensity and tends to push himself higher, ever higher, unsatisfied by the bounds of gravity.
So it is no coincidence that d'Arrigo wants to become a bird. Or, at least as close to one as is humanly possible.
He calls it his five-year "Metamorphosis" project. And as part of it, he is embarking on one of the most ambitious - and unusual - wildlife rescue plans ever devised. Russian scientists and the U.S.-based International Crane Foundation have called on d'Arrigo to help them rescue the western Siberian crane from extinction.
This elegant, long-limbed and long-lived bird has been ravaged by a shrinking habitat and hunting, especially among a subgroup of the tiny crane population that has been risking the combat zone of Afghanistan on its annual migration from north of the Arctic Circle to its wintering place in a national park in India.
In the wild, fewer than 20 of the western Siberian cranes are left. The scientists believe that d'Arrigo may prove the cranes' salvation by steering them instead to the highlands of Iran near the Caspian Sea.
Late last month, at the onset of the Arctic winter, d'Arrigo came from Italy to begin leading 10 cranes bred in captivity on a new migration route. Flying like a bird - without an engine - he will take them on a 3,400-mile journey following several Russian rivers that provide wetlands where the cranes can feed.
The two-time world champion hang glider, retired from active competition, has devoted himself to studying birds - mostly raptors - trying to learn from them the secrets of unassisted flight.
Like the mythological Icarus, he intends to soar on the winds over mountain, sea and valley using the sun and the air currents as his engine. If he succeeds, it will be the longest human flight in the history of free flying.
And in the process, scientists plan for him to teach his charges, the Siberian cranes, a new, safer migration route that avoids Afghanistan and Pakistan - where they fall victim to the abundant guns in the hands of tribal fighters - and which would then, scientists hope, be passed on from parent to fledgling for generations of cranes to come.
"The attempt to change the migration route is truly an innovation," says Russian ornithologist Tatyana Zhuchkova, who is helping to raise the cranes bred in captivity at this nature reserve 230 miles southeast of Moscow. "It has never been done before."
At the reserve, the hatchling cranes - at about 110 days old - were "imprinted" to view d'Arrigo, wraparound sunglasses and all, as their parent. They were raised under the wings of his hang glider and received their food from him and other white-suited keepers.
Each day they saw him flying like an adult crane, riding on the thermal currents about them, and then landing with the same easy grace as a real crane. They were also taught to be at home with the sound of his 12-pound motor, which he requires only to take off or in an emergency when he cannot find the needed currents to keep him aloft.
Working with d'Arrigo is a small corps of dedicated Russian naturalists such as Zhuchkova, who can't help admiring the species.
"These are very intelligent birds," she says. "Each has its own character and cast of mind and its own behavioral patterns. They have their own tastes, preferences, likes and dislikes. They know where they want to walk, what they want to eat and what they don't want to do.
"When they are little they are funny and their intellectual level is not that high. When they grow up they become totally, absolutely independent individuals."
The young birds raised at the breeding center are far from that stage. For now, they need d'Arrigo to lead them on their migratory quest, and the benefit for him, he says, is to learn to live and think like a bird.
Most of the time on the migration, d'Arrigo says, his motor will be hauled back into his harness and his propellers folded back to look like black tail feathers. The setup leaves him to glide only with his nylon and aluminum wings that have been crafted to mimic the flying profile of the cranes.
For the past decade, Russian scientists have been raising the birds in captivity and then in the fall taking them to live in the wilds of Siberia. But the short Arctic summer means that the birds hardly have time to mature before they face the difficult test of survival in making the lengthy journey.
"The birds [raised in captivity] learn to survive and start to migrate, but then there is a very, very low rate of seeing the birds again," says Claire Mirande, director of the International Crane Foundation, based in Baraboo, Wis. "Our success rate is lower than we need to sustain the population, and that is why we are trying something so crazy." To make it, she says, "they just need that extra parental supervision."