Sweet Briar ‘Cave Women’ Encounter Bat Epidemic

| February 17, 2012

For those who like dark places and clambering between rocks, caves are pretty exciting already. But if there’s one thing that can up their wow-factor, it’s bats. Recently, Sweet Briar students saw both during SWEBOP’s spelunking trip to Island Ford Cave in Covington.

The group was led by director of outdoor programs Tasha Purcell and instructors Jordanne Ryan ’13 and Victoria Litos ’13. They were joined by Sweet Briar’s naturalist-in-residence, Mike Hayslett, and bat educator Bonnie Miles, who was recently recognized for her work by Bat Conservation International (BCI) in the winter issue of BATS magazine.

Bonnie Miles and Mike Hayslett.

Miles and Hayslett have been working together for several months to install “bat boxes” on campus. The project is sponsored by Central Virginia Master Naturalists, which has donated around $1,500. In March, Miles and Hayslett will erect the boxes on campus. In addition to providing housing for the bats, they hope that the boxes will also draw bats away from older campus buildings, such as Dew and Reid.

Hayslett said he invited Miles on the caving trip to show his appreciation for her efforts, and to give her an opportunity to apply her extensive knowledge to a “real wildlife scenario.” (After the trip, Miles, whose research usually doesn’t involve on-the-ground experience, joked that she was glad to have emerged from the cave alive.)

One of the first things students learned was how to safely explore a cave. Dressed in white Tyvek coveralls, the group spent several hours exploring passages and the stream channel inside the cave.

“Caving provides physical and mental challenges,” Litos said, adding that she enjoys watching participants master these difficulties.

“We get into different and sometimes odd positions [as we] venture through the cave. This process involves trial and error, as well as some patience with yourself and your immediate environment.”

The group also hiked through Peanut Butter Alley (aptly named for its muddiness) and took a break in the “Buddha Room,” writes Ryan in SWEBOP’s blog post “Cave Women.”

But it was the bats that got everyone’s attention. The students discovered 21 of them, 19 tri-colored bats and two little brown bats. One was clearly sick.

“Unfortunately, one of the little browns had white-nose syndrome,” Miles said.

White-nose syndrome, or WNS, is named for the white fungus evident on the muzzles and wings of affected bats. To prevent the spread of WNS, the BCI decontamination protocol requires cavers to wear disposable coveralls.

“This is the first disease ever known to target a hibernating animal,” Miles added.

Little brown bats with white-nose syndrome, New York. Photo courtesy of Nancy Heaslip, New York Department of Environmental Conservation.

The fungus, she said, enters their internal system and irritates them, which causes the bats to wake up more frequently during hibernation. Some of them start flying around the cave, others venture outside, possibly in search of insects.

The cause of death is complicated.

“Using up stored body fat and starving is one problem, but there is also dehydration and electrolyte imbalance to consider,” Miles explained.

“The bats that leave the cave either freeze to death or are picked off by waiting predators, such as hawks.”

The U.S. Fish and Wildlife Service reports that the disease was first documented at four sites in eastern New York in the winter of 2006 and 2007. Since then, WNS has spread rapidly to multiple sites throughout the Northeast, affecting 19 U.S. states and five Canadian provinces. 19 species of bats have been infected with the disease, and more than six million bats have died from it so far.

Little brown bat; close-up of nose with fungus, New York, Oct. 2008. Photo courtesy of Ryan von Linden/New York Department of Environmental Conservation.

“That equates to between seven hundred and thirteen hundred metric tons of insects not eaten each summer,” Miles said.

After the disease first occurred, many caves across the country were closed for several months, but are now opening back up. Unfortunately, this doesn’t mean that the problem has been resolved.

“I believe that caves have been reopened because the closures did not significantly slow the spread of the disease,” Miles said.

“There are so many caves that it was impossible to enforce the closures. There is also no way to control the disease if it is spreading bat to bat, as is probable.”

Most caves are already infected, she added, so closures seem pointless. While the 2012 federal budget has allocated 4 million dollars toward research into stopping WNS, researchers struggle to find a solution.

“This is a complicated disease, and there are still many questions and unknowns,” Miles said.

While the caving trip was not intended to focus entirely on WNS, students learned a lot about it. Litos said that they had talked about the disease before, but experiencing it first-hand was a different matter.

“Actually seeing a cute little hibernating bat with [WNS] spoke worlds to me in comparison to seeing it on Google images,” she said.

If you didn’t get a chance to attend the caving trip, there’s another one coming up soon. Until March 23, students can sign up for the fourth-quarter “Introduction to Caving”-class, which counts as half of a physical education credit and will culminate in a three-day weekend caving trip to Island Ford, Crossroads and Porter’s caves.


Contact: Janika Carey

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