A better understanding

Two state-funded initiatives — in North Carolina and Missouri — are arming Indiana State biologists with the resources to study and protect the endangered gray bat and Indiana bat.




North Carolina and Missouri may be in different time zones, but they have Indiana State University researchers in common. Sycamore biologists are working to protect federally endangered bats — gray bats in North Carolina and Indiana bats in Missouri — through separate years-long studies of the species, their behaviors and habitat.

Gray bats roost in the mountains of Asheville, N.C., but a team of will be ready to track their every move when they take flight ahead of winter.

The three-year study is being funded by the North Carolina Department of Transportation to look at the distribution, preferred habitats and migration habits of gray bats. Although gray bats live mostly in Tennessee, Alabama, Arkansas, Kentucky and Missouri, hundreds of gray bats were recently found in state transportation structures in western North Carolina.

Since NCDOT routinely conducts maintenance and replaces bridges, state officials need a better understanding of where the bats are located and when they are there. To gain that understanding, they chose a proposal from Joy O’Keefe, associate professor of biology and director of the Center for Bat Research, Outreach and Conservation at Indiana State.

Researchers examine the wing of a gray bat in North Carolina.

“It’s a pretty large-scale project covering the French Broad River Basin in North Carolina, looking at the distribution of the gray bat, and it’s gone really well,” O’Keefe said. “We’ve captured a lot of bats and know some distinct roosting areas where we can catch the bats, put radio tags on them and follow them.

“They are difficult to catch, though, because they’re fast-moving, and they move long distances each night, but we’ve put up telemetry towers to track their moves. So if they pass by one of our towers, we can pinpoint a bat’s location.”

In July, the crew began putting acoustic stations around the basin to record bat calls, indicating when and where the creatures are active. Once all the stations are installed, they will be up year-round to see when the bats arrive in the spring and leave in the fall.

Moving into fall migration, O’Keefe said a consulting firm has been hired to track the bats by plane to determine where the bats move to in winter. She has her own hypothesis.

“Gray bats are roosting in relatively open areas on the landscape around Asheville, N.C., and it doesn’t seem possible they would spend the winter there. It’s likely they’re going to a cave somewhere, maybe Tennessee,” she said. “We don’t know of any hibernacula in North Carolina, so we are hoping to find something new or make a connection between a known hibernaculum and the site where the bats are, so that we can say this is the pathway they take and this is how they move.”

If anyone can figure out where the gray bats go, it’s O’Keefe’s dynamic crew with deep Indiana State ties, including State alumni Joey Weber, ’15, who is leading the team, and Jordan Holmes, ’15. The group has also collaborated with the University of North Carolina-Asheville, which has provided assistance with undergraduate students.

Sean Caslery works with a harp trap in North Carolina.

The team already discovered two locations where gray bats roost with big brown bats and Mexican free-tailed bats, which O’Keefe said is a species that is expanding its range.

“It’s a really Southern bat, at home in Texas but now moving north,” she said. “The fact that it’s established in the mountains of western North Carolina suggests that it could move further north.”

With their findings, O’Keefe aims to get a better sense of the distribution of gray bats throughout the basin and provide pertinent information to help NCDOT.

“Asheville is a fast-growing area with approximately a half a million people in the vicinity who rely on that urban area, and with increased growth there is more need for new or improved transportation corridors. By understanding where the bats are, the North Carolina Department of Transportation can plan better for projects,” she said. “From the bat perspective, we have hundreds of gray bats, possibly thousands, in that area consuming thousands of insects each night. If we can learn more about their location, then maybe we can do more to manage for better habitats for these bats, which will also affect the people of Asheville, who also need clean water and healthy forests.”

Helping Missouri forest managers understand the Indiana Bat

O’Keefe was in North Carolina capturing bats last spring, returned for a bit this summer and plans to help with this fall’s migration telemetry effort while she is on sabbatical. She will have to begin splitting her time between North Carolina and northeast Missouri, where she and biology professor Diana Hews will start an eight-year project working on state-owned lands to determine how forest management practices affect the federally endangered Indiana bat.

Researchers examine a bat in North Carolina.

“This stems from a larger question that many agencies in many states have, which is if we harvest timber, are we negatively impacting these bats that rely on trees in the summer?” O’Keefe said. “The presence of the bat can sometimes impede or halt timber harvest operations, because they use trees to raise their pups in the summer. There’s concern that if you cut the trees down during the summer, you might harm bats. Or, if you cut trees down in the winter, you might be taking away valuable habitat the bats need and when the bats come back the next summer.”

The project will assess the effects of the timber harvest on Indiana bats, beginning with three years of pre-treatment data collection looking at the population numbers and demographics, as well as bat health.

During the next two years, the state of Missouri will harvest trees in three of the six sites where research will be conducted. The final three years of the project will involve assessment of bat population size and health to determine the impact of the forest clearing on the Indiana bat.

In preparation for the research, a Ph.D. student was hired in August to help Hews run tests. Work in the field will begin in the spring.

“This is my first time working with bats, and I am coming at it from a health angle, because my major research area is broadly defined as hormones and behavior,” Hews said. “I mostly work on reproductive hormones, such as testosterone and estrogen, but I also work on the stress hormone cortisol. When mammals get stressed, they get a surge of cortisol, which helps preparing for demands the animal may have that take energy, like flying, fighting immune infection and reproduction.”

Researcher Sean Casler examines a gray bat.

Because the Indiana bat is federally protected and blood samples can’t be taken, they will examine other tissues to look at indicators of the bats’ stress levels. Specifically, the team will analyze stress hormones in feces and in hair samples. Fecal samples will provide a quick snapshot of current hormone levels over the last few hours; hair samples record hormones levels over the time that the fur has been growing. Hair from young of the year, born in June, will let the researchers know how stressful life was both before and after birth.

O’Keefe is using the fall and winter to hire a crew of students, including a post-doctoral fellow for the entire period of the project, and later, another Ph.D. student and two master’s students. Each summer, she also plans to hire a crew of workers to help in the field — about 10 students per summer on average to help manage the six areas.

“Those undergrads will get to work with me, the post-doc and graduate students and get a lot of hands-on experience, a lot of really important training. They’ll get experience working with an endangered species and with state agency biologists,” she said. “Working on a large-scale project such as this will facilitate undergraduate research during the school year working in concert with Dr. Hews or me. It’s just a tremendous opportunity, because it will be a boost to our undergrads who are interested in wildlife.”

O’Keefe expects challenges with a project of this magnitude, but the knowledge that could be created is even greater.

“I think for the state of Missouri we’re going to demonstrate more solidly than anyone has done before how timber harvest affects Indiana bats. There hasn’t been a before-after control experiment like this, so we have measurements before and after, control sites that will never be harvested and then we have these experimental sites that will be harvested. There’s not been the opportunity to have such a long-term forest management project like this with Indiana bats. Since we first discovered them roosting in trees back in the ’70s we’ve had questions about how harvest affects the bats,” O’Keefe said.

“I think we’ll also learn a lot about how to study bat health, which is a major part of the project. What’s nice about the Missouri project is that the control sites are many miles away from the harvest sites, so the idea is that the bats aren’t going to use both. There will be different populations of bats, so you’ll more distinctly be able to see the effects of harvest, if there are any. It’s a well-designed, long-term experiment.”



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