For the past century the whooping crane has followed a short path to the edge of extinction. Having successfully lured the birds back on migration routes by flying ultralight planes and donning crane costumes, biologists are now acting as foster parents as they prepare to release young cranes directly into the wild this fall.
Snap! Snap! Snap! The plastic beak slammed shut in rapid succession, but each time the grasshopper narrowly escaped. Covered from head to toe in a billowing white shroud, Marianne Wellington, a biologist with the International Crane Foundation, repositioned the beak of a crane puppet she held in her hand and prepared for her next strike.
Sticking close to her rubber boots were three cinnamon-colored whooping crane chicks. Though scarcely taller than the daisies and hawkweed they waded through, the young birds were already proving better hunters than their crane-costumed “mom.” Working a remote corner of the Crane Foundation’s grounds near Baraboo, Wisconsin, the chicks consumed dozens of tadpoles, grasshoppers, crickets, and other bugs. As Wellington disappeared over a slight rise, the gangly young birds ran after her, flapping their downy wings in the early morning sunlight.
Suddenly a pair of wild sandhill cranes flew low overhead, announcing their arrival with loud trumpeting calls and slow, powerful wing flaps as they prepared for a nearby landing. Wellington, a 44-year-old with sandy blond hair and sparkling blue eyes, pointed her crane puppet skyward and began to carefully distance herself from the intruding birds. The young whooping cranes mimicked the puppet’s alert behavior and followed close behind her. Throughout their morning walk, Wellington modeled key behaviors, like searching for food and exercising caution around other animals, that the birds must learn if they are going to make it on their own. “I can’t teach them everything,” Wellington said later. “I just hope I can teach them enough so they can survive in the wild.”
The young cranes Wellington led through prairie and ponds are part of the latest efforts to rescue a species that has teetered on the brink of extinction since the World War II era, when fewer than two dozen individuals remained in the wild. Today, despite more than half a century of concerted protection and reintroduction attempts, just 360 whooping cranes fly free over North America. At first glance that may seem like a healthy population spike, but two-thirds of these birds winter together in an area long hammered by hurri-canes and chemical spills. Most of the birds are concentrated at the Aransas National Wildlife Refuge, a collection of low-lying islands and narrow spits of land on the Gulf Coast of Texas that has a major shipping channel running right through the middle of it. Now global climate change is intro-ducing another threat. “Sea-level rise is likely to devastate the wintering grounds of the whooping crane here in Aran-sas,” said Tom Stehn, whooping crane coordinator for the U.S. Fish and Wildlife Service (USFWS). “Any number of threats could wipe out the population at any time.”
The species’ future, however, is looking brighter these days, thanks to the group Operation Migration, which, since 2001, has led young whooping cranes from Wisconsin to west central Florida each fall behind ultralight airplanes. The method first gained national attention in 1996 with Canada geese in the movie Fly Away Home. The approach, which also uses costumes, puppets, audio recordings, and live adult models to ensure the birds imprint on their own species, has proven highly successful for whooping cranes as well. After six years of ultralight-led migrations, there are now 54 free-flying whooping cranes migrating on their own between Wisconsin and Florida.
But the program suffered its first major setback last February when all but one of the fledglings died in a freak storm in Florida. Although migrations behind the lightweight aircraft will continue, last winter’s tragic episode underscored the need for the program to put its eggs in more than one basket.
As a result, Wellington and other biologists are pursuing a new approach, known as the Direct Autumn Release. Instead of leading birds south behind slow-moving aircraft, biologists will release the young birds directly into the wild in the fall. The hope is that the captive-bred birds will follow older, wild cranes on their migration.
After two years of testing, the direct release program is gearing up for its first large-scale reintroduction in late October or early November. Using the same white “crane suits” and audio recordings that are part of the ultralight project to mask their human forms, Wellington and a team of interns spent the summer acting as foster parents for the birds, preparing them for release. “If it works, it’s a faster, less expensive way to get birds out there,” she said.
When John James Audubon started sketching his “double elephant” folio Birds of America, he wanted to render a lifesize portrait of each species, so he resorted to using an unprecedented 39½-inch-high page. But the whooping crane, which at five feet is the tallest bird in North America, simply would not fit. To solve this problem, Audubon posed the bird, whose majesty he likened to that of a “gallant chief,” bending forward, ready to pierce the back of a young alligator.
As imposing and graceful as adult whooping cranes appear—with crimson heads, bleach-white feathers, and jet-black wingtips—they remain particularly fussy creatures. In fact, biologists estimate that when Europeans first arrived in North America, there were only 10,000 whooping cranes, or “whoopers” as the scientists call them, on the continent.
By comparison, sandhill cranes continue to number more than half a million. The extreme discrepancy in the two closely related species can be attributed to where they live and what they eat. Put simply, “they [whooping cranes] prefer wetlands,” said Stehn. “Whooping cranes need a very different diet than sandhills to survive,” he adds. “Here at Aransas, they tend to lose energy if they aren’t eating blue crabs. And a species that relies on low-lying marshes year-round is going to have a hard time with as much wetland loss as we have had in this country.”
During Audubon’s time, whoopers migrated from the Gulf Coast to vast marshlands throughout the Midwest and Can-ada. But as Americans moved west, the swamps were drained and converted to farmland. By 1870 the whooping crane population had dropped to 1,500. “The loss of wet prairie was far and away the biggest reason for the bird’s decline,” said John Fitzpatrick, director of the Lab of Ornithol-ogy at Cornell University. “We basically removed its habitat and the bird, which wasn’t very abundant to begin with, simply vanished. It’s the same thing that happened with the ivory-bill and its virgin bottomland forest.”
Sadly, the more the birds declined, the more highly prized they became as “specimens.” The epitome of how humanity nearly preserved whooping cranes to death occurred on May 28, 1922. On that day Fred Bradshaw, a game warden in Muddy Lake, Saskatchewan, came upon a recently hatched whooper. The warden seized the chick and quickly wrung its neck. In the words of early crane biologist Robert Porter Allen, Bradshaw killed the bird to “give it immortality in the form of a tag with a number on it.” It was the last migratory nestling anyone would see in the wild for more than 30 years.
By 1941 whooping crane numbers had reached an all–time low of 21 individuals. It was about this time that Allen, the National Audubon Society’s first director of research, saw his first whooping crane on Texas’s Gulf Coast. His initial impres-sion wasn’t one of awe but of the prospect of unending labor. “I wondered idly,” he later wrote, “what poor, unsuspecting soul would some day be assigned the rugged task of making a full-scale study of them.”
Allen was fairly confident the honor would not be his, but in 1946, after serving in World War II, he was directed to study Grus americana, the whooping crane. At the time his employ-er was commissioning monographs—exhaustive life his-tories—of some of the country’s most endangered birds, in-cluding the California condor and the ivory-billed woodpecker.
During the next decade Allen learned more about the bird than anyone had ever known. Traveling more than 26,000 miles by plane and jeep from central Mexico to Point Barrow, Alaska, the scientist became captivated by the elusive bird whose study he had once hoped to avoid.
Allen’s research provided conservationists with the first accurate count of how alarmingly few whooping cranes re-mained. He also led the campaign to locate the bird’s summer breeding grounds in northern Canada—a quest that took biologists nine years to complete. In the end, Allen’s mono-graph not only shed light on the once mysterious bird but prompted an impassioned call to save it.
More than half a century later dozens of dedicated indivi-duals—including veterinarians, geneticists, refuge managers, tracking specialists, and pilots—continue Allen’s work. Wel-lington, a small-town girl from Washington, Iowa, seems to have an especially strong affinity for the birds she raises. She has been with the Crane Foundation since 1986, when she began as an intern working with recently hatched chicks for three months. For her first few years Wellington had dreams about flying with the birds in her care. “I’d go out and check on the chicks and see them flying,” she said. “I would then jump, take a few hops, and take off with them. Part of me knows if I was a crane, I’d be flying with them.”
On the walls of her home in Baraboo, Wellington keeps framed images of cranes she helped raise. Photos of other birds are also prominently displayed, on her desk, even on her refrigerator. They show Siberian cranes in India, saurus cranes from Southeast Asia, and the first nonmigratory whooping cranes released in Florida. “To be able to share in that wildness is an inspiration. There is just something about these birds that I have connected with,” she said. “Until we are successful I think people are going to continue to try different methods to see what works,” she added. “Each time we do a different project we learn from past mistakes.”
The learning curve has been steep indeed. In 1975 USFWS biologists began their first massive reintroduction effort to create a separate population of whooping cranes that didn’t winter at Aransas. During the next 14 years they placed nearly 300 whooper eggs in the nests of sandhill foster par-ents in Idaho. The sandhills raised the birds and took them on migration to New Mexico in the fall, but the whoopers imprint-ed on the species in the process. When the birds reached sexual maturity, they looked to sandhills for mates. The pro-ject was discontinued in 1989 having yielded only one off-spring—a “whoophill,” a hybrid of a whooping crane male and a sandhill female.
Likewise, the second attempt to create a population distinct from the Aransas birds could now be facing failure. Between 1993 and 2005, USFWS biologists released 289 birds in south-ern Florida in efforts to create a nonmigratory population. Today only 41 of those survive as drought and attacks by bobcats continue to take their toll.
Just six years into the current reintroduction effort, 54 free-flying whooping cranes are making annual migrations between Wisconsin and Florida. The goal of the federal recovery effort is to establish a self-sustaining population of 120 individuals, including 30 breeding pairs. “If we can get 20 or more birds out a year with a good survival rate, we should be up around 120 birds in five years,” Stehn said.
But as the birds mature, a couple of concerns are beginning to arise. The first involves the return migrations of both the direct release and ultralight-led birds. Each spring a few birds wander off course on their way back to Wisconsin. If they veer too far to the east, they end up on the wrong side of Lake Michigan—a 118-mile-wide barrier dividing Wisconsin and Michigan. Older, more experienced birds would likely cross the water or find their way around it. But those that end up east of the lake on their first spring migration typically stay there through the summer and then return to the same spot year after year.
“Twenty years from now, if we have a pair nesting in Michigan, it will be no problem,” said Sara Zimorski, a tracking specialist with the Crane Foundation. “But for now we have to work really hard to concentrate the population to maximize the chances of reproduction.” To Zimorski and USFWS biologist Richard Urbanek, “concentrating the population” means repatriating misguided birds.
During the past five years the two biologists have captured a total of 10 whooping cranes in Michigan, Ohio, New York, and South Dakota and returned them to Wisconsin’s Necedah National Wildlife Refuge. Once the birds are returned, they generally stay put. But catching them is no mean feat. While no two roundups are the same, they typically begin with Zimorski and Urbanek flying out of Wisconsin in the early morning in a donated plane. A couple of hours later they land at a small-town airport near where they’ve picked up recent satellite or radio signals from transmitters on the bird’s legs. A local biologist or landowner with whom they’ve coordinated the capture usually greets them. Their guide then drives them, along with their crane costumes, some ears of corn, and a large refrigerator box, to the place the bird was last seen. There the costumed biologists approach the whooper and, using the corn as bait, try to coax it into the cardboard box. If all goes well, they’re back in the plane with the bird in time to release it at the Necedah refuge before sunset.
“We obviously can’t keep doing this forever,” Zimorski said of the resource-intensive repatriations. But she thinks that if the birds can be brought back to Wisconsin now, the problem will likely diminish in a generation or two. This is because, with both the ultralight and the direct release approaches, young birds have to find their own way back to Wisconsin the first time they make the spring migration. Once the birds have young of their own, however, they typically lead their off-spring back home on their first northern migration.
Another, potentially graver, problem that could still jeopardize the direct release program is one of imprinting. Cranes that don’t spend enough time with their parents or other members of their species when they are young may try to mate with members of other species when they get older. But no one knows exactly how much time is enough. The problem is of special concern for whooping cranes, since once they are in the wild they are surrounded by sandhill cranes but very few other whooping cranes.
“We have to see them reach sexual maturity and start pairing up with each other and breeding,” Stehn said. “Until that happens, it’s still an experiment.” He and others worry that by setting the direct release birds free so early—in their first fall instead of keeping them together through their first winter, as is the case with the ultralight birds—they may not fully imprint on their fellow whooping cranes. “A significant number of the direct release whooping cranes are spending just about all their time with sandhill cranes,” Stehn said. “That may turn out to be a problem come breeding time.”
But if the direct release method proves successful, it offers certain advantages. Despite the ultralight’s winning track record (last winter’s tragedy notwithstanding), the migrations are slow, laborious, and expensive. Fall migrations take about two months to complete, require a support staff of roughly a dozen individuals, and cost half a million dollars. Last year four direct release birds in a pilot study made it south in less than half the time at a fraction of the cost. “Both projects are largely privately funded, but if you figure in all expenses, from egg to released bird one year later, the ultralight pro-gram costs about four times as much as the direct release approach,” Stehn said.
It will be an additional three to five years before this year’s direct release birds start mating. Meanwhile, older birds, re-introduced via ultralight, have already started. In June 2006 biologists found a pair of whooping crane chicks at a nest inside the Necedah refuge, marking the first time in more than 100 years that wild, migrating whooping cranes had hatched in the eastern United States. One of the chicks died last summer, most likely killed by a raccoon or other pre-dator. The other, however, arrived back on the refuge this spring with its parents leading the way.
As the July sun begins to set over central Wisconsin’s rolling hills and marshland, Wellington made a final check on each of the young whoopers. She walked down a dark hall-way inside the Crane Foundation’s rearing facility, where a pair of speakers plays recordings of prairie birds and insects to drown out the scuffling of her feet. Panels of one-way glass mirrors line the hallway’s far wall. On the other side of each panel, just inches from her nose, a whooping crane chick nestles into its enclosure. Some of the older birds strut around their pens, oblivious to her observations. Others, including a chick that hatched that afternoon, snooze under low-hanging heat lamps.
Twenty-one years after first dreaming of flying with the birds she cares for, Wellington’s rubber boots remain firmly planted on the rearing facility’s cement floor. But watching the freshly hatched chicks that will soon take flight, she can’t help but smile. “If we can take captive birds and get them back into the wild, I guess I’m kind of fulfilling that dream,” she said. So far the most recent efforts with ultralights and direct re-leases seem to be on target. “We know we can get birds to migrate, and we know at least some will reproduce. Now we just need to get more birds out there.”
Phil McKenna is a freelance science writer based in Boston.
WHAT YOU CAN DO
The whooping crane reintroduction programs are privately funded by nongovernmental organizations. To learn more and to find out how to support them, visit the International Crane Foundation, Operation Migration, and the Whooping Crane Eastern Partnership (a consortium of all groups working with the Wisconsin–Florida population, including the International Crane Foundation and Operation Migration).
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