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Illinois Department of Natural Resources
February 2020
February 1, 2020
Indiana bats. Photo by Dan Kirk, IDNR.

The Minds They Are A-Changin’

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By Patty Gillespie

Despite being a creature whose mug shot once adorned many a wanted poster for an alleged affiliation with Dracula or for attempted invasion of one’s hair, the bat has recently gained a new respected position in our imaginations.

Joe Kath, who serves as the endangered species program manager for the Illinois Department of Natural Resources (IDNR), speaks about his observation of people’s views about bats.

“The public’s perception of bats has basically done a 180,” Kath said. “During the last 10 years, there’s been a shift toward the positive. Now when I receive a call alerting me to a bat as a nuisance (for example, a bat having entered an attic), the first thing I hear is that the homeowner wishes not to harm the bat.”

Kath tells of being surprised by the number of enthusiastic individuals who attend outreach events.

A scientist examines a bat.
Joe Kath examining a bat. Photo by Steve Taylor, INHS.

“Once approximately 200 people watched as I demonstrated and explained research procedures,” he explained.

 “On a winter day, fellow scientists and I might enter a known hibernaculum and count the number of bats present, and on a summer evening we may set up mist nets and capture bats for examination.” Kath says of the research takes place year-round.

Kath mentions the use of radio telemetry. When researchers wish to find sites being utilized as maternity roosts, they capture bats using mist nets set at sunset in late spring or early summer. They examine the females, checking gently for rounded bellies indicating pregnancy or lactating mammary glands indicating motherhood. The female bats are fitted with radio transmitters and released quickly. The tiny transmitters, which are attached with a short-lived surgical glue to the backs of the captured bats, emit faint radio pulses at regular intervals. Receiving antennas pick up the signals coming from the transmitters, and researchers track the bats to a location, often a tree, during daylight hours. As night falls, the bats exit hollows and crevices in the located tree. Observers count the emerging bats as they fly off to forage. Thereby, a site can be classified as a maternity roost.

A cluster of bats roosting in a cave.
A cluster of Indiana bats. Photo by Tim Carter, Ball State University.

Tara Hohoff, a scientist with the University of Illinois Prairie Research Institute (Illinois Natural History Survey, INHS) and the Illinois Bat Conservation Program (IBCP), comments about another use of technology in bat research: “If bats are out exercising their echolocation abilities, scientists can use ultrasonic acoustic monitors (or bioacoustics recorders) to detect the bats’ emanations of high frequency sound waves (inaudible to the human ear).” Recordings of the bats’ vocalizations undergo computer analyses. The audio files are converted into spectrograms, also called sonograms, which are graph-like pictures showing frequency (kHz) in relation to time (ms). A signature sonogram points to the presence of that bat species. Data gathered through many acoustic monitoring events help scientists gain insights into diversity.

Kath and Hohoff agree that the work of researchers in surveying bats is driven by the need to track fluctuations in bat populations. Thirteen species of bats reside in Illinois, making Illinois a state with one of the highest diversities of bat species in the Midwest; however, six of those are listed as endangered or threatened by the state of Illinois and/or the U.S. Fish and Wildlife Service. Additionally, white-nose syndrome (WNS) is killing North American bats at an alarming rate. The fungal causative agent of WNS is known to be present in bats’ hibernacula in 14 counties in Illinois.

Perhaps, national news coverage about WNS and the plight of bats has served to stir people’s curiosity about the nature of bats. Illinois state agencies are working to help individuals satisfy that curiosity. IDNR and INHS have terrific educational pages. A picture of a sonogram of a bat’s vocalization appears on the IBCP website along with other great photos and much information. Educators across Illinois flock to the IDNR’s ENTICE programs designed to enhance effectiveness in teaching about nature; “Illinois Bats” is one of the topics. Illinois scientists, including Hohoff and Kath, make themselves accessible to the public via phone and internet and through presentations at outreach events.

A scientist leads a group of people of all ages during an outreach event about bats.
Tara Hohoff leading a group at an outreach event at Lincoln Memorial Garden in Springfield, IL. Photo by Dr. Colin Lieberman.

One evening this past summer, during a public event at Lincoln Memorial Garden in Springfield, Hohoff discovered the way to wow an audience. Holding a tall pole upon which a microphone was attached, she recorded the ultrasonic vocalizations of the bats overhead and noted the sonograms appearing on her iPad. Then, like a mystery writer offering the final clue, she named the species of bats present. When she handed the pole off to a child to hold, a greater number of bats were discovered, and the crowd was delighted.

The minds they are a-changin’. Illinois bats, once those lurking-in-the-dark, blind-as-a-bat, predatory animals, are now nocturnal, sighted-by-vision-and-echolocation, helping-to-control-pests, insectivorous mammals. Bats are being recognized as the amazing and ecologically significant creatures that they really are. We are envisioning bats as a species of the future, flourishing and diverse. Let us hope that that image is not just a figment of our imaginations.


For years, Patty Gillespie shared her enthusiasm for language and nature and got paid for it at a public school and at a nature center. Now she plays outdoors as often as she can and writes for the sheer joy of it.

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