Researchers Explore Declining Bat Population In North America

Transcript

AUDIE CORNISH, HOST:

North American bats have been disappearing for decades, and scientists are still sorting out why. Georgia Public Broadcasting's Grant Blankenship takes us to a swamp in the middle of Georgia where researchers are working to find answers.

GRANT BLANKENSHIP, BYLINE: The sun sets on a large wetland as two women string a huge net, 27 feet wide, across a fast-moving creek.

UNIDENTIFIED WOMAN #1: How's that look?

UNIDENTIFIED WOMAN #2: It looks right from over here. Is it real tight? I think it looks all right.

UNIDENTIFIED WOMAN #3: It looks great. It looks better.

UNIDENTIFIED WOMAN #2: Awesome.

BLANKENSHIP: This is a bat trap in the first-ever bat survey in the middle of Georgia. State Department of Natural Resources researchers are trying to do here what others are starting to do across North America - get a good look at what bats we have left and in what numbers. Georgia researchers began paying more attention to bats when a disease called white-nose syndrome started wiping out whole caves of them in the Northeast.

JACLYN BECK: You know, we knew that white-nose was coming, like, for a couple of years. It's sad. You could just watch it spread south.

BLANKENSHIP: That's Jaclyn Beck, coordinator of this survey at the Ocmulgee National Monument. Beck says the fungal disease did hit southern caves. Since then...

BECK: Our populations have gone down 82 percent since we found white-nose in Georgia.

BLANKENSHIP: It's not just in Georgia where bat numbers are declining, and it's not just due to white-nose syndrome.

LAURA ELLISON: Or there's been a sense that they've been declining for decades.

BLANKENSHIP: Laura Ellison is a bat expert with the U.S. Geological Survey.

ELLISON: Back in the '70s, bat biologists were concerned about places that they were going to that they had been to for long periods of time.

BLANKENSHIP: Ellison says that gut feeling that something has been wrong with bats for a while has never been fully explored.

ELLISON: In the past, they haven't really been on people's radar unless you were a bad researcher or had them roosting in your house or saw them outside during the daytime. But now they're more in the public eye.

BLANKENSHIP: That might be the only upshot to white-nose syndrome. Taking advantage of the new visibility, Ellison's coordinating the North American Bat Monitoring Program. Ellison and others have authored guidelines for scientists and wildlife agencies to collect data uniformly.

ELLISON: And now we're trying to figure out a way to quantify that and make it so that we can actually say something about bat populations across a large scale like the continent.

BLANKENSHIP: So that going forward, numbers from, say, Kentucky make sense in Canada. This has never been attempted before. This summer is the pilot project. This Georgia survey takes a three-pronged approach. Researchers are catching bats in nets, inspecting areas where they roost during the day and recording their calls in the evening.

Tonight, it looks like an owl has scared the bats off the nest site. After a couple trips to the creek, Jaclyn Beck and her team are successful. They've caught an evening bat. Clad in waders despite the heat, wildlife techs Sarah Sherburne and Rebekah Tuck jump in the creek to free the bat.

SARAH SHERBURNE: I mean, it's going to take me a little bit. He's pretty bad.

BLANKENSHIP: Sherburne doesn't mean the bat is injured, just really wrapped up in the net. Catching bats is tricky. Hoping they fly into a well-placed net is about the only way to do it. Rebekah Tuck explains what's at stake as they untangle the animal.

REBEKAH TUCK: Their little toes are so tiny that you can dislocate them.

BLANKENSHIP: Later at their workstation, they look the bat over, all joints intact.

TUCK: So you can hear him chirping away.

SHERBURNE: She's lactating right now.

BLANKENSHIP: Which means there's a pup in a tree somewhere. Overall, this evening bat is in good health.

BECK: Her wings are lovely.

BLANKENSHIP: After a month of netting and searching, the researchers caught just three bats. They didn't find any in daytime inspections of hollow trees either. While bats are hard to catch, their calls are easier to record. Analyzing the sounds of bats they never captured might change the survey bottom line, but that will take months. Jaclyn Beck says many everyday people are noticing something is wrong even without hard numbers.

BECK: They're like, you know, I used to always see bats by my pond, or, I used to always see them around the light outside my house; I don't see them anymore.

BLANKENSHIP: By next year, Georgia is expected to be among the states adding numbers to the larger North American bat database to help researchers sort out what's happening and why. For NPR News, I'm Grant Blankenship. Transcript provided by NPR, Copyright NPR.