Researchers Remotely Peek Into the World of Bats

In north-central Wyoming, the Bureau of Land Management (BLM) wanted to learn more about how caves were used by bats. They were working on developing a cave management plan to manage visitation while protecting bats and wildlife, and reducing human-wildlife conflict. To do this, they needed to find out when the bats were using the caves and when they were hibernating.

It wasn’t practical to send someone to sit outside each cave for weeks on end hoping to glimpse a bat. Instead, BLM and Bat Conservation International (BCI) partnered with Wildlife Imaging Systems (WIS), which created a system to automate the task and capture bat activity using cameras and infrared technology.

The cameras use invisible infrared light to illuminate the cave interior without causing disturbance. The cameras record for several hours each night, and specialized software created by WIS cut the hours of video into small segments, which were then collapsed into a series of thumbnail images each representing 15 minutes of time. This creates time lapse images of bats flying across the screen, with multiple imprints showing their paths. Or, if no bats fly across the area during the 15-minute window, the image is simply black. This saves humans from hours of trudging through the recordings.

“It allows us to look at these images and get a quick snapshot of what happened across hours of time at night,” BCI Subterranean Team Lead Shawn Thomas says. “It’s a pretty amazing and novel approach to doing continuous monitoring.”

In fall of 2021, the team deployed three of these camera systems at three different caves and recorded 70 nights of footage before running out of power. In the spring of 2022, the team redeployed the cameras in hopes of capturing the bats’ emergence from hibernation.

“The technology is the most exciting aspect,” Thomas says. “It’s the first time we’ve tried anything like that. It was pretty successful,” he says, noting the technology is now being further refined for use in other projects.