Crows are not the only birds affected by West Nile virus. Some Bald Eagles have come down with the virus as well. (Photo courtesy of the USFWS)
A wild bird sanctuary is using high-tech tracking devices to keep track of bald eagles recovering from West Nile virus. There’s no medicinal cure for the disease. But volunteers have nursed some bald eagles back to health. They’ve recently released a few of the birds and are watching to see if the disease affects their long term behavior. The Great Lakes Radio Consortium’s Patty Murray has more:
Transcript
A wild bird sanctuary is using high-tech tracking devices to keep track of
bald eagles recovering from West Nile Virus. There’s no medicinal cure for
the disease. But volunteers have nursed some bald eagles back to health. They’ve recently
released a few of the birds and are watching to see if the disease affects their long term behavior.
The Great Lakes Radio Consortium’s Patty Murray has more:
Marge Gibson is crunching through the snow on the grounds of the Raptor Education Group
Incorporated. Several big brown buildings stand stark against the gray Wisconsin winter. They
make up a hospital campus for injured or sick raptors.
(bird chirping)
Gibson approaches a screened in gazebo.
Inside is a very talkative young female bald eagle who’s hopping around on a perch and giving
Gibson a knowing look.
“She’s very vocal and she likes to chat…She’s doing her rendition of ‘poor me, get over here and
pay attention to me’ in bald eagle.”
West Nile Virus began showing up in birds here about two years ago. It’s not known if a bird can
ever fully be cured of it. But in January the sanctuary released three bald eagles that had
sufficiently recovered.
Gibson says it would have been irresponsible to let them go without first observing the lingering
effects of the disease. She’s studying West Nile Virus in eagles with the help of Nick Derene.
He’s a graduate student from the University of Wisconsin, Stevens Point.
Derene logs onto a special website and tracks down one recently released bald eagle that’s been
tagged with a satellite transmitter.
A topographical map shows the region where the bird has settled. A red “x” marks the spot
within 100 yards of where the bird is at that moment.
“And he’s found a nice place on a bluff alongside a stream outside of Black earth About 3 miles
off the highway that runs from Madison to Blackearth.
“Very nice secluded spot atop a hill.”
The satellite transmitters are more accurate than traditional radio monitoring. And they’re a lot
more expensive. Since the Raptor Education Group doesn’t get state or federal funding, Marge
Gibson foots most of the bills herself. The monitoring project could cost as much as 60-thousand
dollars.
Just getting birds to the sanctuary is an involved process. Volunteers pick up birds they think
need help and drive them here. Then Nick Derene keeps an eye on the birds to see if they exhibit
any tell-tale signs of West Nile Virus.
“They’re usually convulsing, they have poor balance, head tremors. Usually
eye problems, sometimes they can’t fly-usually they can’t fly.”
West Nile Virus can also affect an eagle’s voice. That’s a problem because its mate might not
recognize its call.
When the sanctuary staff suspects a bald eagle has West Nile Virus they draw
a blood sample and send it to a local clinic for testing. Once the virus is confirmed, the only way
to treat it is with some tender loving care.
“Hi…lookit”
The birds are kept in cardboard boxes so they don’t expend energy flapping around. And they’re
fed baby food so they don’t waste energy in digestion. When the birds feel up to it they’re put in
an indoor flight room.
It looks like a warehouse-150 feet long and almost three stories high. It’s essentially a rehab ward
for birds who need to test their wings. An immature eagle flies overhead, but he hasn’t perfected
flight yet. He misses his perch, hits the wall and falls to the gravelly floor.
“Flapping, hits wall….is he okay?”
He’s okay but almost looks a little embarrassed.
On the floor of this flight room is a pile of fish, a deer carcass, and the ribcage of an animal that
became eagle chow.
Marge Gibson says she wants the eagles to stick to their wild diet. That’s why the satellite
monitoring program is so important because the birds’ behavior in the wild will indicate the
lasting effects of West Nile Virus.
“We can judge certain things in captivity, in a flight building. Whether the bird is flying well.
But one of the things we can’t judge is his visual acuity, his mental acuity and those things we
have to rely on once they’re released. And the satellite transmitter can follow them to see how
they’re reacting with their own species and other species once they’re in the
wild.”
So far, West Nile Virus is fairly rare in wild bald eagles. In Wisconsin, more bald eagles die
from being hit by cars than they do from West Nile virus.
Nationwide the birds have made a remarkable recovery since being nearly wiped in the 1970’s by
the pesticide DDT. It’s now banned.
It doesn’t look as though West Nile virus will reverse that upward trend.
Marge Gibson hopes to keep tabs on just a few of the eagles infected by the virus to help shed
light on a still mysterious disease.
For the Great Lakes Radio Consortium, I’m Patty Murray.