TERRE HAUTE —
In the quickening darkness, black nets, stretched across gravel paths, melted into the night while overhead plane engines roared as they throttled back for touchdown at the Indianapolis International Airport’s runways.
“Got a second one,” Candace Naughton, an Indiana State University senior, said as she walked up the path to the table and camp chairs that marked the center of the night’s operations. “It’s a northern.”
She carefully clipped the mesh bag, with the northern long-eared bat inside, to the scale. After figuring for the weight of the bag, the female bat weighed in at 6 grams, or about six paperclips.
“You’re so tiny,” Naughton said as she began her inspection of the bat. “You’re so chill.”
As Naughton checked the bat’s wings and body, she discovered a small band clamped around the bat’s forearm. “IN ISU A05504,” she read off. “The number sounds familiar. We may have caught her last week.”
Each bat caught during a night of netting gets banded. The band number and bat’s information goes into a database that researchers can reference in the future.
After the last measurements, Naughton released the bat and it fluttered back into the night.
“Where there are northern, there may also be Indiana bats,” said Joy O’Keefe, Indiana State assistant professor of biology. “They like the same habitat.”
The Indiana bat, a federally endangered species since 1967, set in motion mitigation efforts by the Indianapolis Airport Authority and brought the Indiana State University research team to Plainfield. When the airport began to expand about two decades ago, federal officials required the authority to mitigate for the bats’ habitat loss. Now, southwest of Indianapolis International Airport sits a pocket of green space, hundreds of acres through which the East Fork of White Lick Creek wanders and which is surrounded by a growing suburbia. Indiana bats call this green space their summer home.
In the bats’ home sits a park named for the Indiana bat: the Sodalis Nature Park. The Indiana bat’s Latin name is Myotis sodalis: Myotis because it’s a mouse-eared bat and sodalis because it’s a social bat living in large colonies. By day, people walk and jog the park’s paths or fish in its pond. But at night, the park becomes the bat’s hunting zone as it swoops around the trees along the paths.
On one of the park’s trails, O’Keefe and the students set up mist nets. For 10 years, students with Indiana State and the Center for North American Bat Research and Conservation have netted the bats to see what species use the area and to outfit Indiana bats with transmitters. Students then track the transmittered bats to see where they’re eating at night and roosting during the day. While Indiana bats prefer to roost under the bark of dead trees, they also roost in bat boxes attached to trees. At dusk, students watch the trees and boxes and count the number of bats leaving for a night of foraging. One night students counted 163 Indiana bats leaving one tree.
“It’s really critical for students to get out and do research so that they can understand ecological concepts,” O’Keefe said. “Field work takes the classroom concepts and makes them more relevant.”
Naughton has worked netting bats, counting bats as they emerged from roosting trees and tracking bats to their roosts during the day. A class with O’Keefe opened the biology student to studying bats.
“It is really neat to get to experience what a biologist really does out in the field because I really had no idea before I got out here,” she said. “I am a very hands-on person so I love catching bats and doing that kind of thing…This is my office. I don’t have to sit in a room all day at a computer. This, definitely, is the best job I’ve ever had.”
Devin Howard, a junior information technology major from Newport, has spent two summers working on the airport project.
“I just love animals honestly and just getting the experience in doing something different outside of my field as well,” he said. “Learning outside the classroom is just a lot more hands on and I learn a lot better that way.”
Zach Kaiser, a graduate student in biology, became interested in studying bats while doing work with the wind energy industry. Wind turbines that generate electricity also are decimating populations of migratory bats.
“Bat populations are struggling, especially out east, so I felt like should put my efforts toward conserving these animals and at the same time I find bats really intriguing ‘cause there is not a whole lot known about certain species,” he said. “They’re nocturnal. It’s an animal that is often overlooked. People don’t see it so it is kind of shrouded in mystery.”
To help unveil some of the mystery, Kaiser has been setting out acoustic detectors that record bats’ echolocation calls as they use the East Fork of White Lick Creek as a highway.
“We are trying to create a statistical model that could be used to determine if the federally endangered Indiana bat is present,” he said about expanding to areas where it is unknown if the Indiana bat lives. “It is important because acoustics is an up-and-coming technique for studying bats. It’s a lot more hands off so you can deploy these detectors out in the field and take part in several other field techniques and still collect data even though you are not present. At the same time, it just gives us a lot of information about species, their relative abundance, where they are going, what they are doing in these areas and that can help us make inferences about habitat quality, what these bats need in order to survive.”
As researchers have learned more about bats they have discovered the importance of habitat. O’Keefe said several factors led to the Indiana bats becoming endangered, such as disturbances in the caves where bats hibernate. Indiana bats, being social, hibernate with hundreds to thousands of its brethren in caves.
“Indiana bats have a pretty narrow temperature range that they like to hibernate in,” O’Keefe said.
Humans by entering caves or altering air flow through caves or by building structures that block cave entrances have had a devastating impact on the bat population. People prejudiced against bats and who have persecuted them have also helped lead to their decline.
“Ultimately, now what we think is just as critical is habitat loss,” O’Keefe said, noting that the bats return year after year to the same forests (and sometimes the same trees) and caves. “These bats rely on caves in the winter and then they rely on the forests in the summer. Of course, with increasing human population and urbanization, we’re losing some of our forested landscape and so we’re losing some of the critical habitat for species.”
Habitat has become even more important since the 2007 discovery of white nose syndrome, which has decimated bat populations in the northeast. A cold-loving white fungus called Geomyces destructans eats away bats’ wing tissue and causes the bats to wake during hibernation. The bats burn through their fat reserves and are forced into fruitless ventures onto the barren, winter landscape in search of meals. Millions of bats have died from the disease, which has spread north into Canada, south into Alabama and as far west as Iowa.
White nose syndrome reached Indiana in 2011 and has been found in nine counties.
“We haven’t seen a major decline in the number of bats that are hibernating in our caves, but it can take a few years for that decline to be evident,” O’Keefe said.
So far scientists have been unable to find a solution to stopping the spread of White Nose Syndrome, but one thing remains true to help bats: habitat.
“By providing them with a good habitat, that allows them to build up their energy reserves so that when fall rolls around and they go into hibernation, they have a good base to build off for winter,” O’Keefe said. “Actually what the airport authority has done here is really important, just setting aside habitat for bats. Even though White Nose Syndrome has killed millions of bats, still the greatest threat to bats is habitat loss and that’s the greatest threat to any wildlife on this planet.”
Scott Bergeson, a doctoral student in biology, has set a goal for himself of figuring out what habitat Indiana bats need.
“Just what specifically do they need to succeed in an area? With that information, I hope to help managers identify potential habitat and secure that habitat for the future,” he said.
The future of bats is important to Bergeson, who finds bats “awesome” and grows animated in discussing why he likes them.
“Bats are really unique because they are the only true flying mammals. There are some flying squirrels, quote unquote, but they got nothing on bats,” he said. “Bats are the only ones that can actually produce lift. The cool thing that I absolutely love about bats is that they have wings but all the bones in their arms are exactly the same as ours. If we just elongated our fingers and had some skin here, we could fly, too.”
He also pointed out the ecological benefit of bats eating insects. O’Keefe noted that a bat can eat its weight in insects each night.
“That is great because a whole colony of bats can consume thousands of pounds of insects in the summer and so bats are really great to have around,” O’Keefe said. “In fact, we know that bats eat a lot of moths and beetles, and moths and beetles tend to be our crop and forest pests.”
Bergeson protested against the notion that bats are “rats with wings.” Bats can live up to 30 years and have only one or two pups per year. Plus, there are other differences.
“They fly around. They eat nasty bugs, and I think they are actually pretty adorable,” he said.