Teaching Through Turtles
Painted Turtles (Chrysemys picta) are a freshwater turtle found throughout North America. Identified by yellow or red markings on their head, legs, and tail; their skin and shells are typically colored a dark green.
The road cuts deep through the Sandhills, carving out a path between pastures. During the first week of August, the grass has started to dry, turning from a bright green to a dull golden glow. The heat bakes the rows of standing corn, and cicadas sing in the shade of cottonwoods that line the county road. Black Angus cattle work their way through the pastures to water tanks, tails in constant motion to beat back the swarm of flies descending on each herd. Despite a few farmhouses on the route, it is easy to find solitude in these hills. The Nebraska Sandhills are a unique ecoregion in the Great Plains consisting of over 19,600 square miles of grass-covered sand dunes. The largest intact temperate grassland remaining in the world, it stretches across central and western Nebraska. With extensive areas of pastureland and an abundance of spring-fed ponds, it is ideal for large-scale cattle ranches, earning itself the nickname “God’s own cow country.”
As we parallel the barbed-wire fences of nearby farms, I stare through the cracked windshield of the research station’s pickup, in its bed, turtle traps piled exceedingly high. Held down by a few ropes and a lot of good faith, these wire contraptions sway as we cross the railroad tracks and strike potholes en route to our destination.
Students help unload traps from the back of “Morus”, a pick-up used at Cedar Point Biological Station (CPBS). Located in the Sandhills near Ogallala, Nebraska, CPBS offers hands-on learning across multiple fields of biology.
A few miles from Lake McConaughy, near UNL’s Cedar Point Biological Station, the dusty roads and dry pastures lead to a spring-fed pond, one that Larkin Powell has been visiting for more than 20 years. Within this pond, there’s a population of painted turtles that has been monitored for the past two decades. Larkin, a population ecologist and the director of the School of Natural Resources at the University of Nebraska–Lincoln (UNL), started this project during a field techniques course to provide students with hands-on experience. Larkin has been a professor at the University since 2001 and has been prioritizing experiential learning for students throughout those 25 years. As a professor, he has led trips for students to Puerto Rico, Namibia, the Boundary Waters, as well as other excursions throughout the state of Nebraska. Despite his new influx of responsibilities as Director of the School of Natural Resources, Larkin continues to take time for these trips, specifically an annual excursion to the turtle pond on the edge of the Sandhills.
When the project started over 20 years ago, the School of Natural Resources required all students to take a field techniques course at Cedar Point near Ogallala, Nebraska, during their fall break. Students learned the basics of radio telemetry, mark recapture studies and other common practices of wildlife biologists. This is how Larkin first came to find the pond, just a few miles from Cedar Point’s campus, and home to a large population of painted turtles. Since then, the required course has been moved back to the University’s East Campus in Lincoln, but each summer, Larkin takes a few students west to continue this data set and gain hands-on experience in the field.
“When it started, it was just a fun class activity—collecting data in a way students would enjoy. We could capture enough animals, and as time went by, it evolved” Larkin said. “Fundamentally, the project examines the general population biology of this isolated turtle pond—whether its population is growing or shrinking.”
This project has given insights into the lifespan, habits, and growth of these animals. Over the two decades of data collection, trends in growth have directly correlated with climate patterns. Reduced growth was observed in years of drought as turtles adapted to changing environmental factors. Despite a changing environment, the population of turtles has stayed stable. Through the years, hundreds of students have worked at the pond. They have gained skills, but were also prompted to ask questions about the world around them. As a result, observations about migration within this population have been highlighted. Turtles will often disappear from the pond for years at a time, only to return with the expected rates of growth, proving that the turtles traverse across the landscape to different water sources. These bodies of water are separated by miles of dry land, an extremely impressive feat for these small, slow-moving creatures, and prompts the question “how can a creature like this navigate the landscape so effectively?”
The pond itself is quite unique, isolated, and spring-fed, and holds a stable population of 100-150 painted turtles. The pond runs between two hillsides and dams near a county road, maintaining around 6 feet of depth even during severe drought. Its banks are easily accessible, allowing for large floating traps to be placed a few feet off the shore each summer.
Students ensure that a trap is floating correctly after placing it in the pond. The black mesh submerges underwater to allow turtles to crawl up in an attempt to sun. These turtles will often continue into the middle of the trap, where they fall in and are held for a short time until the traps are checked.
Maddie Thompson, a student at the University of Nebraska–Lincoln (UNL) removes painted turtles from the trap and places them in a bucket. These turtles will be transported a short distance and measured for the study.
I was first introduced to the project in the summer of 2024. As an undergraduate student at UNL, I pursued a variety of experiential learning opportunities and was lucky to be invited along on that year’s turtle tagging. Two of my good friends and I spent the first week of August learning about mark-recapture studies from Larkin while catching over a hundred turtles.
The mornings started early, arriving at the pond before the summer heat took hold. We would check each of the floating traps we had placed earlier that week, pulling the turtles that had been caught overnight. The grass around the pond was often wet with dew and pulled at the white five-gallon buckets used to transport the turtles. On good days, a chorus of claws scratched at the walls of the buckets as a multitude of turtles attempted to explore this strange new mode of transportation. Soon they were carried to our makeshift research station: the county road less than a hundred yards away. Parked in the shade, the tailgate of Larkin’s truck had been accessorized with calipers, scales, and an array of papers to record measurements. We worked in teams of two, one person handling the turtle while the other took multiple measurements of the shell. These measurements of the carapace (top of the turtle) plastron (bottom of the turtle) and each bridge (pieces connecting both plastron and carapace) allowed us to understand the growth of the turtles under the current environmental conditions. Those data points were then relayed to another person who recorded new measurements, checked old data, and identified each individual by their unique tag number and shell pattern. It was chaotic, but prompted creativity and teamwork to process over 50 turtles each day.
Maddie Thompson holds a turtle as another student uses calipers to measure plastron width.
A turtle is placed briefly in a bag to have its weight measured. Each turtle is handled with extreme care by qualified students under expert supervision.
Larkin gave us guidance, experience, and a great education. His instructions not only covered how to properly take data, but also how to apply the knowledge we have gained in college to our future careers. While measuring weight, we discussed the proper way to write research papers and while aging individuals, Larkin gave us advice on processing large sets of data. His lessons were littered with humor and real-life examples, letting us know he too, had been in our shoes. During these long days, it struck me that on top of great research experience, we were learning to be better students, future employees, and human beings.
Larking Powell (left) holds a turtle for first-time students to observe. Initial observations can provide a lot of information about the turtle. Claw and tail length indicate the sex of the turtle, while size is also a great indicator of age.
Larkin Powell records data as students take measurements of captured turtles. These data sets extend over 25 years and turtles are often recaptured.
The heat would start to catch up to us as the morning continued–sweat beading on my brow as I grabbed from a bucket of what seemed like an endless source of shelled creatures. Sometimes muddy from their time in the water, a quick cleaning revealed the ornate decor of each organism, spectacular reds and yellows covered their face and shell. I never took too much notice of these creatures before my time at the turtle pond, but I left with a deeper appreciation for such beautiful animals.
Joe Kouba, a fisheries and wildlife student at UNL, shows off the plastron coloration unique to the western subspecies of painted turtles (Chrysemys picta bellii).
While our mornings were spent trapping and tagging turtles, evenings were spent fishing at Lake Ogallala or visiting the Keith County Fair, where we learned more about agriculture or outdoor recreation. Larkin told us stories about his life experiences and helped us to make memories of our own, showing support as we continued to learn. Our time working with Larkin was more than labor, it was extremely apparent how dedicated he was to granting new experiences to his students. He slowed down often, answering questions and allowing for discussion as we experienced new things, like small-town rodeos or my friends’ first time fishing.
Larkin sits surrounded by students at the Keith County Fair.
“Each year he goes above and beyond to teach us about more than conservation and tries his hardest to give us new experiences.” Maddie Thompson, a fisheries and wildlife student said. “The nights we spent at the Keith County fair watching the combine derby or fishing at lake Ogallala are memories that will last forever.”
Storm clouds roll over the Keith County Fair’s lawn mower race. One night of the “turtle trip” is dedicated to experiencing the culture of the Sandhills. Larkin and the students leave CPBS for an evening of food and fun at the local county fair.
His patience granted us time to grow, while his willingness to adventure and improvise left us with lasting impressions and great stories. In many ways, it seemed he was just as excited and engaged as we were.
“That’s a big reason why I became an ecologist—to be outside and learn through doing. In middle school, I was part of a science club doing field observations. In high school, I worked at a 4-H camp on the nature staff. I’ve always been drawn to outdoor learning and teaching. We have nearly 300 undergraduates in the School of Natural Resources. It’s tough to provide individual experiences for every student, so if I can engage 3-5 each summer, that’s a contribution toward that goal.”
After working with the turtles and these datasets, students have published two manuscripts observing the impact of drought on the species. Though not every group has used this long-term data for a publication, Larkin still knows there’s value in this work.
“It’s had an impact. One of the first students, Lindsay, was in a summer research program and is now the principal at the Zoo School [Science Focus Program] in Lincoln. Another became a doctor, another a priest. Several have gone to grad school, especially those involved in data analysis. The experience gives them a resume boost and helps guide their future.”
I have gained valuable experience, created lasting connections, and met some of my best friends tagging turtles. During this time with Larkin, I have received advice on how to structure scientific research, navigate funding, and expand my network outside of the university. It is a project I’ve looked forward to throughout the years, and my fellow students can say the same.
“Tagging turtles with Larkin the past two summers I have learned more than I ever could in a classroom” Maddie explained. “It’s obvious how much he cares for his work, but especially his students. He goes out of his way each day to ensure we learn necessary skills while also having a lot of fun”
And it’s not just the students who enjoy their time in the field, Larkin says the work is extremely rewarding for him as well.
“Being with students in the field keeps me energized. Every year brings something new, even after 21 years. Their excitement helps keep me excited. When I eventually step away from the university, I’ll need to find something to replace the energy students bring to my life.”
Larkin and students embark into the field to retrieve turtles from the traps.
Larkin’s energy for this kind of work is contagious. I have travelled to Namibia with Larkin and his wife, Kelly, spent the past two summers tagging turtles, and studied under Larkin during undergrad at the UNL. Each of these experiences were unique and engaging. They have allowed me to grow and learn in ways I haven’t experienced in a classroom environment. It’s because of educators like Larkin–his hardworking nature, willingness to create connections, and constant investment in the next generation–that the future of conservation continues. The School of Natural Resources at UNL has a motto, “Where it’s our job to help you find a way to make the world a better place,” and I can say Larkin Powell is doing just that.
