Crane tragedy threatens site
After the birds' deaths, a report suggests cranes could winter elsewhere.
By BARBARA BEHRENDT
Published June 19, 2007
CHASSAHOWITZKA - The devastating loss of 17 rare whooping cranes in a freak storm last year may force the birds to head somewhere else for their winter migration.
A report by the Whooping Crane Eastern Partnership, a coalition of private and government groups supporting the reintroduction of the cranes, calls for changes in the innovative program that has seen flocks of cranes led by humans in an ultralight aircraft trek from Wisconsin to Florida each winter for the past six years.
As successful as this experiment has been, the report focused on a tragic reversal last year, the loss of 17 of the 18 juvenile whooping cranes that comprised the Class of 2006.
The birds died during a strong storm that hit the coast overnight in February. The cranes were inside a top-netted pen, a protection from predators and from older whooping cranes from previous year migrations that had been harassing the youngsters.
Necropsy results showed that the young cranes were likely shocked by a nearby lightning strike and drowned in rising waters.
The report concludes that new measures are needed at Chassahowitzka to reduce the danger of another mass mortality event.
One alternative is to find another site for the final winter destination for either some or all of the cranes in future years.
The report states that the partners in the project considered a mass mortality with elements of lightning and flooding only a remote danger.
"But the unthinkable did happen and it is appropriate to re-evaluate our protocols, procedures and facilities to see what could be added or changed to help reduce the risk of a future catastrophic loss as was experienced in February," the report concludes.
Last year was the sixth year that cranes hatched in Maryland and trained to follow ultralight aircraft in Wisconsin were led to central Florida to teach them a migration route. In the spring, the birds return to Wisconsin on their own.
Currently there are 58 adult birds in that reintroduced migratory population. That doesn't count the 23 chicks hatched this year, the largest group ever.
The first group of those chicks is due to be flown from the Patuxent Wildlife Research Center in Maryland to the Necedah National Wildlife Refuge in Wisconsin today, according to Liz Condie, executive director for Operation Migration.
Condie said she would be surprised if this year's cranes don't land in Chassahowitzka despite the report's conclusions. Still, she said that considering moving the final destination is just a smart discussion after last year's loss.
"Everyone is obviously nervous and doesn't want to make any mistakes," she said. "This project from day one, from the first time someone took a flock of geese up behind ultralights, it's been, 'Let's try this.' But you've got to remember, we're dealing with wild things and Mother Nature."
According to the partnership's report, the crane handlers should consider changes at Chassahowitzka including:
-Releasing the cranes into the large open-top pen if there is any danger of severe thunderstorms or tornadoes.
-Reducing the use of top-netted pens by finding other ways to keep the older birds from harassing the juvenile cranes.
-Considering moving or extending the top-netted pen to higher ground or add a raised mound where the birds can escape rising water.
-Installing an automatic system for opening the top-netted pen if water levels rise.
The report also suggests that splitting the flock into two destinations would reduce the chance of losing another entire class of cranes. But it also notes that other sites might hold greater threats from predators or other dangers.
The partnership has looked at alternative sites in the Lower Suwannee National Wildlife Refuge and the St. Marks National Wildlife Refuge and others are suggesting sites in Tennessee, Georgia, South Carolina and Alabama.
Condie noted that the same conditions that make Chassahowitzka a good location also make it a bad location.
It is remote and keeps the birds away from people. But that means the cranes are remote from their human handlers as well.
The site is also not preferred habitat by the birds, which means that after the older birds find out they can't get free food there, they tend to move on to better habitat.
But finding good habitat is difficult, according to Jim Kraus, manager of the Chassahowitzka National Wildlife Refuge complex.
And while losing the whooping crane project to another area might be a disappointment to area residents who have come to follow their story, Kraus said people must keep the bigger picture of the reintroduction process.
"Everyone involved in this project is committed to its long-term success," he said.
To view the report by the partnership, visit www.bringbackthecranes.org/.
Barbara Behrendt can be reached at behrendt@sptimes.com or (352) 848-1434.