PELLSTON, Mich. — The University of Michigan Biological Station welcomed a new researcher to the campus in northern Michigan this year.
Dr. Amanda Koltz, an assistant professor in the Department of Integrative Biology at the University of Texas at Austin, started a project that enlists undergraduate students in the UMBS Field Mammalogy course to collect data in the forests along Douglas Lake, about 20 miles south of the Mackinac Bridge.
Koltz and her collaborating researchers at Yale, Texas A&M and U-M are assessing disease ecology in the wild at UMBS.
Founded in 1909, the historic field station is where students and scientists from around the world live and learn from the place.
How Disease Shapes Ecosystems
On Tuesday, July 2, in what are called the “Burn Plots” at UMBS, Koltz held a white-footed mouse whose scientific name is Peromyscus leucopus — one of the most abundant mammal species in North America and “very important players within the forest ecosystem,” Koltz explained.
“Most free-living animals are infected with parasites like gastrointestinal worms,” Koltz said. “If parasites influence what mice eat, how they behave, or their reproduction, that could have cascading effects on the ecosystem. We’re trying to understand the role of parasites within these forest ecosystems.”
Her parasite removal experiment in white-footed mice in Michigan is funded by the Wild Animal Initiative and the Stockard Fellowship, which is supported by UMBS donors.
Students Gather Research Data
One of Koltz’s collaborators is Dr. Jessica Light, a professor at Texas A&M University and the instructor of the UMBS Field Mammalogy course. Light said her students already participate in gathering data for long-term research at UMBS that tracks species diversity over time as part of the four-week summer course curriculum. For example, they captured the majesty of northern Michigan wildlife on video this summer. A black bear meandered in front of a trail cam July 17. (Watch the bear video.)
But this new mouse parasite project gave them a different research goal.
“In order to do the research, we have to get our hands on the rodents. And that’s where the class comes into play,” Light said.
On July 2, Light examined the body condition of the mouse that Koltz held before setting it free.
In advance of the arrival of the Field Mammalogy students at the U-M campus in northern Michigan, the two scientists from Texas and the Field Mammalogy teaching assistant went through the process of setting live traps, holding mice, examining their body condition, recording measurements, collecting fecal samples and releasing the animals.
“We want students to get skills using various field mammalogy techniques,” Light said. “And we have this research goal — this broader picture that the students get to participate in and hopefully appreciate that thanks to their help setting traps, picking up traps, seeing what we capture, and handling the animals, that they’re contributing to an ongoing research project that has really important implications for the ecosystem around us.”
Research Collaborators Across the Country
Additional collaborators include Dr. Aimée Classen, director of UMBS and a professor in the University of Michigan Department of Ecology and Evolutionary Biology, and Dr. Vanessa Ezenwa, a professor of ecology and evolutionary biology at Yale University. In 2023 Ezenwa visited UMBS to give the Pettingill Lecture in Natural History about her work uncovering the long-term evolutionary interaction playing out between worms and TB in buffalo in South Africa.
In northern Michigan, the team is looking at helminths, or gastrointestinal nematodes, which can cause GI problems and influence overall well-being.
“Just like you might need to de-worm your dog, these mice get similar types of infections in the forest,” Kolz said.
Collecting Fecal Samples
Throughout the summer term in July, Field Mammalogy students like Gabi Leon set traps, held mice and collected fecal samples to send to a lab for analysis.
“I’ve worked with plants before but nothing like this. We’re working directly with moving beings and observing their behavior and collecting data,” Leon said. “It’s a different experience, and it’s something I don’t think I could get on campus in Ann Arbor or anywhere else.”
“We are taking a holistic approach to investigate parasite impacts on the well-being of these wild animals using a variety of methods. We’re using mouse fecal samples to characterize their microbiomes, or the community of organisms in their guts,” Koltz said. “Using those same fecal samples, we’ll also look at changes in their diets, or what they’ve been eating recently, and at stress levels. Next year, we’ll document how infection affects mouse exploratory behavior and anxiety as well.”
Trap, Examine and Set Free
Leon, a junior who majors in ecology and evolutionary biology at the University of Michigan, enjoyed the field work of placing live traps at night throughout the forest with bait and a temperature tracker — to identify the exact time a mouse entered the trap “rather than putting out expensive cameras,” she said — and returning the next morning to see what they caught.
The students learned how to safely get each mouse out of a trap and hold them by the scruff of the neck. They worked in teams to record the mouse’s sex, weight, foot size, ear size, reproductive condition and more.
“We got a chipmunk once, which was exciting,” Leon said.
She said the best part of the experience is knowing that she contributed in a hands-on way to research with partners from prestigious universities and helped those scientists in their mission to answer important questions about how disease shapes ecosystems.
“It’s super cool that we get to have collaborations among schools. And that’s the beautiful thing about science. It’s never just one person. Never just one thing,” Leon said. “It’s people working together. And that’s a lot of what the Bio Station is. I mean you’re living with these people, you’re eating meals with these people, but then you’re also going out in the field, you’re making hypotheses, you’re measuring mice. It’s a team effort. Really nothing happens here alone. I feel it’s really appropriate that the University of Michigan students are working with other schools and other labs in order to further scientific study.”
Inspiring Careers
The research opportunities available for undergraduate and graduate students at UMBS play an important role in inspiring careers through mentorship and hands-on work with scientists from around the world.
Annie Cress served as a teaching assistant for the Insights From Trees course this summer at UMBS. The graduate student researcher previously took courses at the field station as a U-M undergraduate student.
Cress also helped Koltz with the mouse parasite project in the Burn Plots.
In fact, a few weeks after leaving UMBS for the season in August, Cress started her Ph.D. program with Koltz at the University of Texas at Austin.
"Since attending classes at UMBS after my freshman year, I’ve been fascinated by how community dynamics shape ecosystem ecology,” Cress said. “Exploring knowledge gaps and the intricate interactions within northern ecosystems inspired my senior honors thesis at U-M and ultimately led me to pursue my Ph.D. at the University of Texas at Austin in Dr. Koltz's and Dr. Amy Wolf's labs.”
Cress plans to return to the Douglas Lake campus next summer to continue the disease ecology research.
“I’m thrilled to return to UMBS, not only to advance this project but to collaborate with the incredible scientists, students and staff,” Cress said.
Watch the video or scroll down to view a gallery of photos.
Founded in 1909, the U-M Biological Station is one of the nation’s largest and longest continuously operating field research stations.
Laboratories, classrooms and cabins are tucked into more than 11,000 acres along Douglas Lake to support long-term science research and education.
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