New tenants wanted: must be quiet during the day, must enjoy bugs.
It might not sound like your kind of real estate, but the architects of a new manmade cave near Clarksville, Tennessee are hoping it will attract bats. The bats need a haven because they are threatened by a devastating and mysterious fungus that grows like white fuzz on their faces and wings as they hibernate. The fungal infection is called white-nose syndrome.
The key difference between the manmade cave in Clarksville and a natural one is—the manmade cave can be disinfected. The idea is to build bats a cleanable winter home where white-nose syndrome can’t run wild.
The construction is a concrete box about as long as a basketball court, but only half as wide. For insulation, earthmovers have been dumping four feet of dirt on top. The unique features inside include surveillance cameras that detect heat without getting warm, or making any noise. Even ultrasonic sound could be a deal-breaker for house-hunting bats.
White-nose was first found in New England six years ago. Since then it has spread from Canada to Alabama, leaving millions of dead bats in its wake. Early stages of the disease have already been spotted in a natural cave next door to the manmade one in Clarksville. It often takes just a few winters to ravage a sleeping population.
“It’s kind of terrifying,” said Ann Froschauer who works for the U.S. Fish and Wildlife Service in Massachusetts and witnessed firsthand one of the worst die-offs there. She says the cave floor was strewn with long, skinny bones. In her mind they were like pine needles.
“I knew that, that’s not what it was, but it was just really impossible for me to sort of understand—there’s an inch, inch and a half, to two-inch thick carpet of just bones on the floor here, and skulls, and if you crouch down and look, you can see there’s little clumps of fur and decaying tissue.”
Froschauer cried when she got home. Bats often live decades, and she’d just seen whole generations undone, and when bats die they’re not easy to replace.
“They’re very slow reproducers – one pup a year. They’re very labor-intensive babies, just sort of like human babies. They’re breast-fed milk by their mothers and take a lot of work. So even if this disease were to stop in its tracks today, and we were to stop seeing the mortality that we’ve been seeing with the disease, it would take hundreds and hundreds of years to repopulate,” Froshchauer said.
Biologists fear regional extinction and they say that could be unpleasant and expensive. If you don’t enjoy mosquitoes feasting on your flesh, or walking through swarms of insects, and if you don’t want to see pests devastate crops, then you don’t want to live in a country without bats. Bats provide a kind of insect control service, eating crop pests and other bugs. Some have pegged the agricultural value of eating so many insects in the billions, if not tens of billions.
That’s part of what’s driving the artificial cave project in Clarksville. Aside from efforts to fence caves off so humans don’t spread white-nose, biologist for The Nature Conservancy Cory Holliday says there hasn’t been much people could do to stem the disease. Some have pondered treating or vaccinating bats, but Holliday thinks the manmade cave could save more bats, faster.
“We would’ve liked to have had more time… but with white-nose syndrome moving as rapidly as it is, we just didn’t feel like we had that time.”
That’s why The Nature Conservancy fronted a big part of the $300,000 to build the manmade cave. If it succeeds, Holliday hopes similar artificial caves will follow, and leave enough bats with enough time to move in.