For the Birds Radio Program: Whooping Crane Ultralight Migration
Today’s the day the Whooping Cranes could be taking off from Wisconsin, following an ultralight plane to Florida.
When one of the wildest and most endangered species on the planet comes in contact with high technology and hundreds of humans, sometimes the result can be bad, but sometimes the result can bring new hope for the future. Whooping Cranes were never an abundant bird—in 1860, after facing decades of unregulated hunting, there were only about 1400 remaining on the planet. And just 80 years later, in 1941, the species had diminished to a mere 15 wild migrants. The situation was dire.
1941 was a frightening time for the world, but even with the horrific events unfolding in Europe and Asia, or perhaps because of them, Americans were desperate to protect this magnificent piece of our nation’s history—a symbol of America’s wilderness and rich natural resources. The last wild birds in Louisiana’s non-migratory flock were dying out, but the migratory flock was protected on its wintering grounds in the Aransas National Wildlife Refuge near Corpus Christi, Texas. The protection afforded these birds here and on their breeding grounds in Wood Buffalo National Park, straddling the border between Alberta and the Northwest Territories in Canada, allowed the flock to slowly increase until by 1999 they were up to 180 birds.
Unfortunately, the Texas coast is not exactly pristine and secure from environmental assaults. A single oil spill could wipe out every one of the birds in this flock. And the rivers flowing into the estuary where the cranes winter are critical. The primary food the cranes eat in winter are blue crabs, and the more crabs they feed on in winter, the better their bodies are prepared to reproduce the following spring. In years when crabs are abundant, the cranes have excellent breeding success. In years when the crabs do poorly, the cranes have very low reproduction rates. Blue crabs do terribly when the salinity of the estuary is high. In drought years and years when people withdraw too much water from the rivers, crane reproduction drops dramatically. With Texas’s burgeoning population and dramatically increasing water usage, humans are directly competing for the fresh water so critical to crane survival. To ensure the species’ future, researchers decided they simply could no longer keep their eggs in one basket, and figured the most important thing they could do for long-term crane conservation was to get some new flocks established in places other than Texas.
So in 1993, scientists started a new non-migratory flock in the Kissimmee Prairie region of central Florida. This area, close to all the environmental assaults of Disney World, isn’t exactly perfect for Whoopers, but it was a start. This flock has grown to 80 birds, all introduced from captivity. One pair finally hatched chicks, the first wild Whooping Crane chicks hatched in the United States in 60 years, in 2000, but the babies were lost to predators. Last summer another pair of chicks hatched. A Bald Eagle killed one of them, but when it returned to kill the sibling, the parent cranes beat it up. Rescuers had to take the eagle to a rehabilitation center, and the baby, Lucky, is still alive.
But Florida is not the best place to raise baby cranes. Golf courses, theme parks, and ever-increasing acres of houses and shopping malls are about as different from the Canadian wilderness as you can get. So although this flock may, indeed, become self-sustaining eventually, a better possibility would be to establish a flock in a wilder, more natural environment for breeding, and teach them to migrate to a wild and safe place for the winter. But how would that be possible?
When people developed techniques for training Canada Geese to follow an ultralight airplane to learn their migration route, suddenly there was a new possibility. In 2000, they tested the plan by raising Sandhill Cranes in the Necedah National Wildlife Refuge in Wisconsin, and trained them to follow an ultralight airplane to the Chassahowitzka National Wildlife Refuge in Florida for the winter. The experiment was a rousing success—the following spring the cranes made it back to Wisconsin on their own, and then returned to Florida on their own the following winter.
So in 2001, they tried the experiment on Whooping Cranes. That year 5 Whooping Cranes followed the ultralight from Wisconsin to Florida, and all of them made their way back to Wisconsin the next spring. In 2002, 16 baby cranes followed the ultralight down, and 15 of them and the five older birds made it back to Wisconsin on their own this year. And if the weather permits, today is the day another 16 birds will set off behind an ultralight to boost the population of migrating cranes even more. For several more years, each fall a new batch of babies will follow an ultralight on this migratory pathway. In another year or two, the oldest birds in this experiment will start reproducing, and within 10 or 15 years, the birds may well become a self-sustaining flock that no longer requires human intervention.
Every cool morning when it isn’t raining and there isn’t too much wind, the cranes will take off behind the ultralight and fly between 30 and 60 miles. By November or early December, they should be in Florida. Every day you can follow their progress on the Internet. I’ll have links to the best sites for following them on my webpage, www.lauraerickson.com .