Indiana State University
When the state of Missouri wanted to determine how forest management practices affect the federally endangered Indiana bat in northeast Missouri, they called on Indiana State University researchers.
This spring, Joy O'Keefe, associate professor of biology, and Diana Hews, professor of biology, will start an eight-year project working on state-owned lands to assess the effects of the timber harvest on Indiana bats.
The scope of their projects begins with three years of pre-treatment data collection looking at the population numbers and demographics, as well as bat health. During the upcoming 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.
"This project 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 and it's gone, they have no habitat."
In preparation for the research, a Ph.D. student was hired in August to help Hews run tests. When fieldwork begins this spring, the Ph.D. student will begin gathering data on Indiana bats and other species that coexist in the Missouri forests.
"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 prepare for demands the animal may have that take energy, like flying, fighting immune infection and reproduction.
"Our hypothesis is that if the Indiana bat is being adversely impacted by the forest management practices, we will see that bats have higher baseline levels of the stress hormone," Hews said.
Because the Indiana bat is federally protected and large blood samples can't be taken, they will examine other tissues as 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.
"We're going to collect fecal samples, which is a procedure that has really taken off in wildlife biology in the last 15 years," Hews said. "This method has a lot of ifs, ands and buts. The time course is a problem because the moment the fecal pellet is deposited, then bacteria in the fecal pellet begins to chew apart the molecule you're looking at. Many bats will provide a fecal sample while in the hand, so we'll know that the sample is fresh."
O'Keefe is using the fall and winter to hire a crew of students, including a post-doctoral student for the entire period of the project. Later on, another Ph.D. student and two master's degree students will be added. Each summer, she 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. Since we first discovered Indiana bats roosting in trees back in the 70s, we've had questions about how harvest affects the bats. But there's not been the opportunity to have such a long-term project like this with Indiana bats until now."