published Thursday, June 24th, 2010

Heading off white-nose fear

In the near-midnight darkness of the Cherokee National Forest, Dr. Joy O'Keefe and three research technicians sit around a table in the middle of a fire road, waiting for bats.

Despite record-high temperatures even in the dead of night, the crew wears boots, coveralls and heavy latex gloves. It is apparel meant not to protect them, but to prevent the spread of white-nose syndrome -- a fast-spreading killer disease that is decimating nature's best pest control.

"Bats are the primary predator of nocturnal insects and an important predator of some crop pests," said Dr. O'Keefe, a research wildlife biologist with the Southern Research Station of the U.S. Department of Agriculture's National Forest Service.

Their decline could have far-reaching repercussions for humans, since the bat eats 50 percent of its body weight in insects every night, according to Dr. O'Keefe.

"We're talking about a species that's going to have a hard time repopulating after this drastic decline," she said. "They live up to 30 years and only bear one young per year, so we're probably going to see an increase in nighttime insects."

  • photo
    Staff Photo by Angela Lewis/Chattanooga Times Free Press Dr. Joy O'Keefe holds a female Indiana bat while doing research in the Cherokee National Forest in Monroe County Monday evening.

Dr. O'Keefe's original three-year research project actually was designed to look at the impact of prescribed forest burns on the federally endangered Indiana Bat. But the white-nose fungus, discovered just four years ago, has killed more than 1 million bats in the northeastern United States alone. Since its discovery, it has spread down the Appalachians, most recently to Tennessee, where it has been found in six caves in Van Buren, Carter, Fentress, Sullivan and Montgomery counties.

The fungus hasn't been found yet in Georgia, but researchers know the state line -- which is all that separates Tennessee's Cherokee National Forest from the Chattahoochee National Forest -- won't stop it.

NOCTURNAL RESEARCH

In the quiet, black Cherokee forest, researchers make flashlight runs every eight minutes to three "mist nets" strung 20 to 30 feet high and 20 feet across an open area of the fire road. Since bats travel the path of least resistance, it's the most limb-free area of the forest.

"Bat, bat" calls out Amanda Walsh, one of the technicians, when she finds one entangled in a silken mesh that Dr. O'Keefe likens to "a lunch lady's hair net."

The team swoops in to see, and Dr. O'Keefe begins the intricate process of extricating a lactating female Indiana bat, a federally endangered species.

"She's a beauty," Dr. O'Keefe said.

Luckily, the bat shows no sign or scars of the fungus, which appears on the faces, ears, wings and feet of hibernating bats. The fungus in winter causes infected bats to lose weight.

Hungry, the most-affected bats leave their caves early in search of food. Since the insects they normally eat are unavailable at that time, the bats find nothing.

ABOUT WHITE-NOSE SYNDROME

* More than 1 million bats in the northeastern United States alone have succumbed to the fungus since its discovery there in 2006. Since then, it has spread down the Appalachians, most recently to Tennessee, where to date it has been found in six caves.

* Scientists are trying to determine the cause of the fungus. They believe it can be transmitted from cave to cave on the shoes and equipment of cavers, but it also is believed to be transmitted from bat to bat.

* There is no current evidence to suggest the fungus is harmful to humans or other organisms. There have been no reported human illnesses attributed to white-nose syndrome.

Sources: U.S. Forest Service, U.S. Fish and Wildlife Service



WHY CARE ABOUT BATS?

* Bats can eat up to 1,200 mosquitoes in an hour. They also eat agricultural pests.

* The loss of half a million bats could mean 2.4 million pounds of mosquitoes and bugs that aren't eaten in a year.

* More than half the bat species in the United States are in severe decline or listed as endangered.

* Bat colonies can contain millions of bats, with young pups clustering in groups of up to 500 per square foot.

* Bat mothers bear only one pup per year and can find their babies among thousands or millions of other bats by their voices and scents.

* Forty species of bats live in the United States, 15 species live in Tennessee and 16 live in Georgia.

* With more than 900 species worldwide, bats make up one-quarter of the world's mammal population.

Sources: The Nature Conservancy, other natural resources Web sites

"They literally starve to death," said Cherokee National Forest wildlife biologist Laura Lewis.

The Cherokee National Forest is home to 15 species of bats, also including Rafinesque's big-eared bats and smallfooted bats -- both designated as threatened, she said.

Dr. O'Keefe and Ms. Lewis have confirmed a migration pattern of bats in Cherokee Forest caves to a Smoky Mountains National Park cave where the disease was found this spring.

Katrina Morris, wildlife biologist and environmental review coordinator for the Georgia Department of Natural Resources, said researchers are worried about the trail of caves that extend into the Blue Ridge, and biologists are planning a "bat blitz" of research in late July at Fort Mountain State Park.

The blitz will include three nights of mist netting at 30 to 40 sites, as well as acoustic sampling, she said.

"The more information we can get about these bats before white-nose gets here, the better," Ms. Morris said.

Other efforts

Despite efforts that began more than a year ago, researchers say bat numbers are down drastically in the Cherokee catch, study and release efforts.

Last year, Forest Service officials closed caves to cavers in hopes of stopping or slowing the spread of the disease. Now, not even researchers are going into the caves without stringent decontamination protocol.

Also, to avoid the human spread of the fungus, researchers working the mist nets now must use separate equipment for areas where the fungus has been found and for those where it hasn't been found.

Even in areas where the disease has been confirmed, they must spend hours on rigorous washing and decontamination processes for their clothing, boots, nets and other equipment.

The researchers are beginning to use transmitters to track the bats they catch for up to 21 days before the glue that attaches them dissolves and the equipment falls off.

"Unfortunately, we may not know just how important (bats) are until the decline in the populations allows us to see exactly what they were doing," Dr. O'Keefe said.

Continue reading by following these links to related stories:

Article: White-nose syndrome found in 3 more state caves

Article: 3 new caves with fatal bat syndrome spark worries

Article: State closes more caves to prevent spread of bat fungus

about Pam Sohn...

Pam Sohn has been reporting or editing Chattanooga news for 25 years. A Walden’s Ridge native, she began her journalism career with a 10-year stint at the Anniston (Ala.) Star. She came to the Chattanooga Times Free Press in 1999 after working at the Chattanooga Times for 14 years. She has been a city editor, Sunday editor, wire editor, projects team leader and assistant lifestyle editor. As a reporter, she also has covered the police, ...

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