Creek crawlers and lab scholars

Cassie Ellenberger’s interest in amphibians runs deep. The Kennesaw State University biology student has a series of frogs tattooed on her right arm, and she keeps several as pets at home.

Therefore, it should come as no surprise that she recently found herself knee-deep in a stream near Powder Springs, Georgia, collecting amphibians as part of associate professor Todd Pierson’s research into the effects of urbanization on the reproductive habits of the two-lined salamander. Wearing a frog T-shirt, blue jeans, and a tall pair of rubber boots, Ellenberger swept her hand underneath roots along the banks, pulling a salamander or two with each pass of her hand.

Ellenberger and two of her classmates joined Pierson in the stream that day, aiming to collect samples from about 100 salamanders. They’ll extract DNA from the samples and analyze them to determine how encroaching neighborhoods and roads have affected their reproductive habits. Ellenberger said she recognizes the importance of both aspects but, being the amphibian lover that she is, the field work feeds her soul.

“There is nothing like being able to just go outside and catch as many salamanders as you can,” she said. “A lot of the sites are beautiful, too. You see a lot of other wildlife, and that's super fascinating as well.”

In 2024, Pierson received a three-year, $380,238 grant from the National Science Foundation through a program called Building Research Capacity in Biology (BRC-BIO). The program broadens research participation by undergraduates at Carnegie-designated R2 institutions like KSU, and other smaller institutions as well. Pierson’s current research derives from this grant, and he said it’s a year-round commitment, from the students in the field recently to a team research class he’ll teach this fall that will involve the classroom, the lab, and the field.

“Our lab, like many other labs at Kennesaw State, heavily integrates undergrads into research,” he said. “In a one-on-one mentorship format, our capacity as research faculty is limited because our time is limited. A lot of faculty get very creative about integrating research and the classroom together, and that's one thing we're doing in this grant.” 

A self-described “muddy-boots ecologist,” Pierson grew up in Indiana and earned his bachelor’s degree in ecology at the University of Georgia before earning his doctorate at the University of Tennessee. After his post-doctoral experiences, he joined the KSU faculty in the Department of Ecological, Evolutionary and Organismal Biology in 2020. 

All these moves were intentional, as the Southern Appalachian region is rich and diverse with salamanders; Pierson says the amphibians give an indication of the health of the environment – as well as the effects of urbanization on the ecosystem. Kennesaw State’s location in the Atlanta metropolitan area allows Pierson and his research group to find plenty of salamanders and thus get a measure of those indicators.

“Some wildlife thrive in human-altered environments, including these salamanders that we study,” he explained. “We’re doing all this research in parks in Cobb County and Fulton County, places that you might drive by and not know they exist. To me it’s a cool way to bring these big ideas in evolutionary biology to our local parks.”

Pierson’s enthusiasm for salamanders drew recent KSU graduate Fer Montes de Oca Sierra to the Pierson lab in 2023, when he took a class from Pierson, who noticed Montes de Oca’s shirt that depicted an axolotl, a breed of salamander found in Mexico. He also waded into the creek to search for salamanders on a recent summer day, filling a plastic canister with specimens, collecting DNA samples and then releasing the amphibians back into the creek before heading back to campus.

“Dr. Pierson is super-interested in salamanders, and he transmits that interest to students,” Montes de Oca said. “I’ve learned so much in his lab about doing research and how important these animals are, and I’ll take those things with me.”

Ellenberger said she’d like to stay with the Pierson group and continue with the salamander research, though she acknowledges the University’s excellence in all kinds of research. 

“KSU has so many opportunities and so much fascinating research going on,” Ellenberger said. “Mosquitoes, robots, snakes – there’s something for everyone.”