College of Arts and Sciences Newsroom

By Dave Larsen

University of Dayton biologist Maggie Hantak will study how salamanders with different color variations respond to climate change under a $498,267 grant from the National Science Foundation.

Hantak’s research focuses on two “color morphs” of the Eastern red-backed salamander, one of the most common amphibians in the northeastern U.S.

Color morphs refer to animals of the same species that vary in color but also differ in additional traits such as diet and habitat preference. One salamander “morph” that Hantak is studying has a red stripe and is associated with cooler and wetter areas; the other is unstriped and completely black, and prefers warmer and drier conditions. 

Her goal is to examine whether the two morphs differ in traits that are influenced by temperature — including thermal physiology, body size and behavior — under different climate conditions. The research will provide information on how multiple color variants may support species resilience in the face of rapid environmental change.

“These color morphs seem to vary in their temperature preferences — their thermal biology is what we call it,” said Hantak, assistant professor in the UD Department of Biology. “When you have a single species that has a wider geographical range or broader thermal tolerance, that might allow the species to persist during extreme weather and climate change. It buffers the species in a way.”

The three-year grant runs through July 2027 and includes funding for a doctoral student to assist in Hantak’s research, much of which will be done at the Smithsonian Institution in Washington, D.C. She also plans to bring at least two undergraduate students on each trip to work in the Smithsonian’s collection.

Hantak said the Smithsonian has the world’s largest collection of salamanders, with more than 70,000 specimens of the single species she is studying. Those specimens are preserved in ethanol, which causes their colors to fade. However, the stripe outline remains visible, allowing researchers to determine which specimens are striped or unstriped.

Hantak and her students will measure the length of specimens across decades to learn how their traits may have changed over time and determine whether climate change is impacting one or the other morph’s body size more significantly.

To expedite the process, they will lay out batches of salamanders, photograph them with a scale bar and then measure the specimens on UD’s campus from the photographs.

She also will collect live salamanders in the field at sites including at least one Dayton-area Five Rivers MetroPark, as well as locations in northern Ohio, where the Cleveland native did her doctoral research.

In addition, Hantak and her students will look at salamander behavior in terms of temperature preference as well as “thermal avoidance,” which examines how the salamanders respond to increasing temperatures in the laboratory setting.

Cara Brensike, a sophomore environmental biology major and sustainability minor from West Chester, Ohio, has worked in Hantak’s lab since her first semester at UD. This summer, she studied behavioral differences in temperature preference between the two salamander color morphs through the College of Arts and Sciences Dean’s Summer Fellowship program, which allows undergraduate students to conduct summer research in any academic discipline under the guidance of a faculty mentor with funding from the Dean’s Fund for Excellence.

“I constructed an arena out of plexiglass and created a temperature gradient along the bottom of it using a heating pad and ice pack placed at opposite sides of the arena,” Brensike said. “Each salamander’s temperature was measured and recorded every two minutes for a 20-minute period with a temperature gun. This helped give an indication of whether the striped or unstriped salamanders were more tolerant to warming temperatures.”

Brensike said working in the lab has given her confidence in her academic abilities, as well as experience for future research positions and possibly graduate school.

Her work also helps advance Hantak’s research into the adaptive differences between morphs amid changing climatic conditions.

“We are hoping to learn if the unstriped salamander is more fossorial, or spends more time underground, than the striped salamander, which is an important way in which they could avoid the increasingly hot temperatures at the surface,” Hantak said. “Understanding these morph differences could reveal critical adaptations that enable this species to survive by more effectively avoiding harmful temperature extremes.”