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After Long Struggle, Whooping Crane Population Hits Milestone
U.S. scientists also developed a technique in the 1980s for raising whoopers in captivity by using crane handlers -- humans dressed in costumes that resemble cranes -- to raise chicks in isolation from actual human contact, so they grow up to be wild. Starting in 1993, many of those captive cranes have been released yearly in central Florida, where they have stayed because they never learned how to migrate, behavior that would normally be passed on by their parents.
In 2001, the Whooping Crane Eastern Partnership, an American-Canadian partnership of governments, nonprofit organizations, citizens and corporations, developed a method to teach captive-raised whoopers how to migrate so they could be introduced to the wild. Since then, young cranes have been led in migration every fall by gliders flying from the Necedah National Wildlife Refuge in Wisconsin to the Chassahowitzka National Wildlife Refuge in Florida, 1,200 miles away. The cranes return on their own in the spring.
  A family of whooping cranes heads to the water near the Aransas National Wildlife Refuge in Texas. Conservation efforts have saved the birds, once nearly extinct. (By Ron Heflin -- Associated Press) |
These efforts involve the Canadian and U.S. governments; federal agencies such as the Fish and Wildlife Service and the Geological Survey; state agencies; conservation groups such as the Whooping Crane Eastern Partnership and the International Crane Foundation of Baraboo, Wis.; and local zoos.
"For all of us, this is exactly what we are all about: trying to get animals reproduced and back out in the wild," said San Antonio Zoo bird curator Josef San Miguel. His staff specializes in costume-rearing whooping crane chicks, some of which are donated yearly to the International Crane Foundation for the glider migration project.
"It's a group effort, and when you hear the birds are doing what we need for them to do, it makes us all feel good," San Miguel said.
Extremely good nest production this summer in Wood Buffalo National Park is credited with producing this winter's record flock at the Aransas refuge. Stuart Macmillan, a biologist at Wood Buffalo, cited favorable breeding conditions such as adequate water levels in ponds where cranes build their nests, an ample food supply and fewer natural predators.
Today's threats to the species are power lines, which cranes crash into during migration; loss of stopover habitat; a lack of genetic diversity; disease; and a decline in habitat conditions at the Aransas refuge because less freshwater is flowing into the salt marsh.
"There are a lot of threats out there on the horizon, and that's what worries us," Stehn said. The whooping crane is likely to remain on the endangered species list until the migratory flock numbers more than 5,000, he said.
Staff writer Matthew C. Wright contributed to this report from Austin.
