A deadly disease called white nose syndrome has killed millions of North American bats, which normally serve as voracious eaters of farm, garden and human pests. It usually hits when the bats are hibernating in caves and mines for the winter.
Ohio’s first finding of the disease was in 2011, in hibernating bats in an abandoned mine in southern Ohio’s Lawrence County. Experts now consider the disease present in all 88 of the state’s counties.
“It’s one of the worst wildlife diseases of the past century,” said Marne Titchenell, wildlife program specialist in the College of Food, Agricultural, and Environmental Sciences (CFAES) at The Ohio State University.
Bat disease spreads fast, kills most
That’s because of its rapid spread — to more than 30 U.S. states and five Canadian provinces in 10 years — and high mortality rates, which range from 70 percent to 100 percent in infected caves and mines, she said.
For example, the number of bats hibernating in Ohio’s ground zero, the Lawrence County mine, has plummeted 99 percent, she said.
There’s no known treatment for white nose syndrome, which is caused by a fungus. Scientists are continuing to try to develop remedies. It doesn’t infect humans.
Titchenell, who works in CFAES’s School of Environment and Natural Resources, will give an update on the disease during the Ohio Community Wildlife Cooperative’s annual conference on Nov. 8 at Ohio State. The event is for city officials, community planners and others who manage conflicts between humans and wildlife, such as deer and feral cats.
Bats eat bugs, benefit people
Titchenell said that while bats help people a great deal by eating flying insect pests, they do sometimes get into houses and other buildings — a nuisance to homeowners and less than ideal for the bats. Another of the conference’s speakers will cover the best ways to keep bats out of those places.
Overall, however, bats are great to have around, Titchenell said. Just one little brown bat, for example, an Ohio species, can eat up to half its weight in moths, flying beetles and other insects every night, even more if the bat is a pregnant female. That’s equal to up to a half dozen grams of pesky bugs every night, or about the same weight as a U.S. nickel.
Multiply that by a summer of nights and the millions of bats that live in Ohio, and that’s — a batload of nickels.
Bats’ key roles in nature
“Bats play critical roles in our ecosystems, serving as predators and prey in many food webs,” Titchenell said. “They’re the primary predators of night-flying insects, some of which are pests in our residential areas and agricultural crops.”
She said other bat facts include:
- Bats aren’t blind. But they can locate objects extremely well by sound, a skill called echolocation. It lets them detect something as small as a human hair — or, say, a mosquito — on the darkest nights. “It’s this same ability that makes it very unlikely a bat will get stuck in your hair,” Titchenell said.
- A blood-thinning compound found in the saliva of vampire bats, which live in Central and South America, not Ohio, is being tested as a drug to help heart attack and stroke patients. Researchers have named it, yes, Draculin.
- Ohio has 10 bat species, according to the Ohio Division of Wildlife. They include the aforementioned little brown bat, big brown bat, evening bat and northern long-eared bat.
White nose syndrome or not, Ohioans probably won’t see any bats on Halloween night, at least none that aren’t wearing capes. Cold fall temperatures mean the departure of Ohio’s bats, the start of their long winter’s nap, or both.
“Depending on the species, Ohio’s bats either migrate to southern states, or migrate to caves and mines within the state, and spend the winter hibernating,” Titchenell said.
Low temperatures around Ohio could dip below freezing on Halloween night, according to the National Weather Service.
That means no insects, and as a result, no bat food.
Hibernation lets bats “slow things down in order to get through the winter” without food, Titchenell said — provided white nose syndrome doesn’t strike.
Bat fact sheet
Titchenell has written a fact sheet about white nose syndrome. It’s available online at go.osu.edu/wns.
Details about the Ohio Community Wildlife Cooperative conference are at go.osu.edu/2017OCWC.