In the eastern United States, millions of bats have died over the past few years from a disease called white nose syndrome. Biologists across the country are racing to find a cure, or at least slow it down. So far there’s no evidence of white nose syndrome infecting bats in Texas, but the fungus that causes it is here. The question now is how much it’s spread.
Cypress Creek is a clear stream that runs through Wimberley in central Texas. It’s a gathering point for all kinds of wildlife – fish and turtles, birds and dragonflies. But Brittany Stamps isn’t here for them. On this bright, crisp spring morning, she and I are under a bridge that spans the creek, looking for a creature that has no interest in the sunshine.
“Right here – you see this guy up in this crack between the insulation?” Stamps says.
Stamps shines her headlamp onto a bat: a cave myotis, to be precise. It’s curled up into a fluffy ball, clinging to the underside of the bridge along with thousands of other bats. This time of day, most people only see one if it swoops down from its roost. But you can hear them, smell them and occasionally feel them – or at least, feel what they’ve left behind.
“I’m actually getting some guano on my head,” Stamps says.
Stamps is used to it though. She’s been getting up close and personal with bats all winter as a seasonal bat biologist with the Texas Parks and Wildlife Department. Her job is to search caves, culverts and bridges for bats, swab a few with what’s basically a long Q-tip, and then send those samples to a lab where they’re tested for the fungus that causes white nose syndrome. It’s been killing bats in the United States since at least 2006. In Texas, the fungus was first found in in the Panhandle in early 2017. Since then, biologists like Stamps have tracked its incremental spread, fanning out across the state each winter to swab hibernating bats and gather data – all to prepare for the day when the disease is found here.
“Once we have an understanding of the prevalence, then we’ll have a better idea of where the fungus is first of all and what to expect in the following years,” Stamps says.
After the fungus has been discovered, the disease tends to follow a few years afterward. State wildlife officials want to gather as much data as possible before that happens. Which sounds like a reasonable idea. But…
“All this special attention we’re giving to the bats is in fact probably doing a lot more harm than good,” says Merlin Tuttle. He lives in Austin and is kind of an elder statesman when it comes to bat biology.
He says we humans are doing exactly what the fungus does.
“So here we have white nose syndrome killing bats because it’s waking them up too frequently and they’re losing their fat reserve before spring,” Tuttle says. “Then we come along, well-intended, but no matter how well-intended we might be, the simple truth is we’re making them wake up extra times and that’s costing them extra energy at a time when they can least afford it.”
The bats need fat to make it through winter. Burning it by moving around when they should be sleeping makes them use up energy that they can’t spare. Some studies show that just the presence of a human can be enough to disturb a hibernating bat. And since there’s no proven cure or treatment for white nose yet, in Tuttle’s opinion…
“There just isn’t anything we’re able to do,” Tuttle says.
Tuttle would prefer Texas Parks and Wildlife take the money spent on surveys and use it to restore bat habitat. But Jonah Evans doesn’t buy the idea the state’s doing more harm than good. As the state mammalogist, much of Texas’s response to white nose falls on his shoulders. To him, it’s important to be proactive.
“The approach we’re taking is, go to the sites, make an effort to be as minimally invasive as possible, but gather the information we need so that we can have the information necessary to respond effectively to the disease,” Evans says.
He hasn’t seen any evidence that his agency’s surveys have hurt bats. And organizations around the country are conducting similar operations.
Anne Ballmann is a wildlife disease specialist for the USGS National Wildlife Health Center. She helps coordinate national surveillance efforts for white nose.
“Disease surveillance and collecting samples, looking for the pathogen, those benefits quite outweigh potential detrimental effects of the disturbance itself,” Ballmann says.
Despite the differences on what’s best for the bats, all sides agree that this a dire situation: Evans calls it a “looming disaster.”
Texas Parks and Wildlife hasn’t released any of the data collected this winter, but Evans says he expects it to show that the fungus has spread. Next year, the plan is to expand the white nose response to include testing fungicidal treatments on culverts in east Texas. It’s not a cure, but it could be a way to buy more time for bats like the ones under the bridge in Wimberley.