The Eastern flock of whooping cranes train for migration by following an ultralight. Photo courtesy of Operation Migration, Inc.
Some of the three dozen whooping cranes that winter in Florida have begun their spring migration to the Great Lakes region. More cranes are expected to fly north within the next few weeks. Wildlife officials put together that experimental migrating flock for the Eastern U.S., in case something happens to the only other migrating flock of whoopers, which winters in Texas and spends summers in western Canada. Scientists say there are several potential threats to the western birds. The Great Lakes Radio Consortium’s Chuck Quirmbach reports from the Texas Gulf Coast:
Transcript
Some of the three dozen whooping cranes that winter in Florida have begun their spring
migration to the Great Lakes region. More cranes are expected to fly north within the next few
weeks. Wildlife officials put together that experimental migrating flock for the Eastern U.S. in
case something happens to the only other migrating flock of whoopers, which winters in Texas
and spends summers in western Canada. Scientists say there are several potential threats to the
western birds. The Great Lakes Radio Consortium’s Chuck Quirmbach reports from the Texas
Gulf Coast:
The sight of a five foot tall adult whooping crane is awe-inspiring to many people. A Minnesota
man named Gary, who lives in Texas during the winter, says he loves to see the brilliantly white
whoopers and their amazing wing span.
“They’re pretty – huge and beautiful, pretty bird. Something we don’t have in Minnesota.”
The birds winter here at the Aransas National Wildlife Refuge. It’s a fifteen mile long by seven
mile wide peninsula north of the city of Corpus Christi. Aransas was the wintertime home for the
whoopers when the population of the endangered cranes dwindled to just 15 birds in the 1940s.
Today there are 194 whooping cranes in the Western flock.
“There’s a family out there.”
Crane Researcher Colleen Satyshur crouches down in a remote area of the refuge. she points at
three cranes.
“They’re just on the other side of the waterway that runs on the far side of the levy there. Two
parents on the outside and one baby in the middle”
The birds come to within about 100 yards.
It seems like a perfect place for the cranes. But because there is such a small number of birds, the
flock is at risk.
U.S. Fish and Wildlife Service whooping crane Coordinator Tom Stehn says 194 whoopers in one
site is just not that many.
“That’s just not much genetics in the population and there’s big threats to the population whenever
there’s concentrated in such low numbers.”
And a small gene pool is just the beginning of problems for the western flock of whoopers.
A few miles south of the Aransas refuge an earth mover loads dirt and rock into dump trucks.
Development along the Gulf of Mexico is taking up land. The human population here is expected
to double within forty years. Tom Stehn says that’ll increase demand for freshwater. He says
Texas is looking at diverting river water that currently flows into the Aransas refuge, where it
sustains crabs, a major food source for the whooping cranes.
“The crabs need the fresh water coming down the rivers, so if we dam up those rivers, prevent those inflows, the cranes
are gonna suffer.”
The refuge managers also worry about maritime accidents.
(sound of boat)
Boats like this one that travel the Gulf Intracoastal Waterway on the border of the Aransas refuge
sometimes carry toxic chemicals that could wipe out the birds with one spill.
Stehn says the list of potential risks to cranes is extensive – it includes things such as flying into
power lines along the cranes 2,400 mile migration route. He says there are new concerns, such as
global warming and West Nile virus.
Barring any disasters from those threats, Stehn says he’s pretty confident that generations of
whooping cranes will continue to winter in Texas for another 50 to 100 years. But Stehn says
even the crane’s longevity is in some ways a weakness.
“It’s a long lived bird with slow reproductive potential, so it’s gonna struggle to adjust if change
happens too rapidly.”
Stehn says the wildlife agencies can’t protect the birds from everything. But researchers can learn
more about the whooping cranes’ habits and hopefully that will help figure out the best ways
to aid the birds.
(sound of whooping cranes)
Help may come by tracking the cranes. This winter, Colleen
Satyshur recorded some of the birds’ calls. Some scientists believe
every crane has its own unique voiceprint that can be measured
through soundwaves run through a computer. Satyshur says they
think they might be able to use the voiceprinting as a way to
see which cranes are doing what.
“Which pairs are bringing down chicks, how many years, might tell us something new we can use to help us conserve the birds.”
Many people see the whoopers comeback as an inspiring symbol of wildlife preservation.
Keeping an eye on the birds is not just about the safety of the whooping cranes. Even with the
eastern flock becoming established and flying between Florida and the Great Lakes. Losing the
western flock of whooping cranes for any reason would be a blow to the entire wildlife
preservation movement.
For the Great Lakes Radio Consortium, this is Chuck Quirmbach in Southeast Texas.