LAUREL CAVE — Dave Waldien stretches, shining his helmet’s light into a limestone crevice.

“I’ve got two,” he says. “One’s a big brown ... and I’m not sure what that one is.” Stepping across a few of the cave’s boulders, Jim Kennedy takes a look.

It’s a northern myotis, he says, making a tick in his notebook — and it’s one of thousands of bats the Bat Conservation International researchers will count during this weekend’s Crawlathon.

While the annual Carter Caves event attracts some 700 cavers and thrill-seekers for three days of wild cave tours, these guys have come to descend into darkness on a different mission.

“We’re doing science,” said Kennedy, a BCI biologist. “Not big science ... but we go to some of the bigger caves that have the endangered Indiana bat and count in those caves every two years so we can get an idea of what the populations are doing, whether they’re increasing, decreasing or remaining stable.”

That data then gives scientists a lot of information for better management of the species, he said.

In fact, Kennedy and BCI, a global member- and scientist-driven organization in Austin, Texas, devoted to bat conservation and research, have been studying Indiana bats at Carter Caves since 1998. The state park in western Carter County harbors some of its best habitat — complex cold-air caves with a steady climate.

The bat has been on the federal endangered species list for decades, with less than 500,000 individuals and declining. Many thousands hibernate in Bat Cave here, listed by U.S. Fish and Wildlife authorities as one of two “critical habitats” in Kentucky.

The Indiana bat, as well as all bats, are important to the environment because they control insect populations, researchers say. (A single bat can eat up to 2,000 insects a night, on average.)

The difficulty in helping the species recover deals with how sensitive it is to environmental change.

In Laurel Cave, for instance, the temperature is not steady or in the range the Indiana bat likes while hibernating during winter, Kennedy said.

Plus, Indiana bats are extremely susceptible to disturbance, he said, and if awakened will expend too much of the energy they have stored, and die. In other caves, flooding, mineral extraction and commercialization have likely contributed to the bats' decline.

That’s why biologists have taken measures to not only close caves during the hibernation season — both Bat Cave and Saltpetre Cave are gated and off limits in winter — but also to redirect airflow and take other measures in the species’ more historic homes, Kennedy said.

“In Saltpetre, they’ve been steadily increasing,” he said. “It’s almost doubling every two years, as we’re doing the counts.”

And it’s that counting, the not-so-big science Kennedy does, that, with other studies, allows such success.

“It’s been a hypothesis of ours, just looking at Bat Cave is not giving us the full picture,” he said. “There are at least eight to 10 caves in the immediate vicinity they also use. By not counting (those) we’re not getting a true picture of health.”

In other words, the more information about how many spend the winter in all the caves means “more pieces of the puzzle,” Kennedy says.

That is, the puzzle of how to repopulate an endangered species, of how to manage current and past Indiana bat caves the right way.

As BCI puts it: Restoration of appropriate temperatures in key roosting caves of the past, not just protection of caves with the largest current populations, is critical.

“Bat counts are the only way we have to really gauge our success,” Kennedy said. “It’s definitely working here ... It’s very neat, and very exciting.”

ALLEN BLAIR can be reached at ablair@dailyindependent.com or (606) 326-2657.