UNIVERSITY PARK, Pa. — When fire ants were first introduced to the southeastern United States from Brazil in the 1930s, fence lizards didn't know how to react to these new predators.

"They pretty much just sat there while the ants swarmed and killed them," said Tracy Langkilde, professor and head of the Department of Biology in the Eberly College of Science.

A few decades later, the lizards have learned their lesson.

"Now they respond by jumping around to shake the ants off and running away," she said.

Langkilde has been studying how the lizards have changed their behavior over time. She is particularly interested in how their responses to stress influence their offspring's responses to stress.

"The effects of stress can sometimes be passed on from generation to generation," she said.

The fire ant-lizard scenario is just one way that Langkilde has been investigating how animals deal with changes in their environments.

Now her unique contributions in this area are being rewarded. She is being named Distinguished Herpetologist by the Herpetologists' League, an international organization of people devoted to studying herpetology — the biology of amphibians and reptiles. She will be presented with the award at the league's annual conference to be held July 24-28 in Snowbird, Utah.

"The Distinguished Herpetologist recognition is bestowed upon an individual based on his or her contributions to advancing scientific and public understanding of herpetology through research, teaching and service," said Willem Roosenburg, president of the Herpetologists’ League and director of the Center for Ecology and Evolutionary Studies at Ohio University.

In addition to presenting a lecture during the plenary session of the following year's Herpetologists' League meeting, the Distinguished Herpetologist is encouraged to publish a manuscript as the lead article in the journal Herpetologica.

"Prior recipients of this award are extraordinarily accomplished researchers, many of whom have directly influenced my research," said Langkilde. "To be listed among them is an enormous honor."

Langkilde said she hopes her receipt of the award will inspire other women to enter and stay in the field.

"Herpetology has traditionally been a male-dominated field," she said. "Recently, a lot of women have been joining the field, but they aren't the ones you see giving plenary talks and receiving awards. These women are doing really interesting research; I hope they will begin to be recognized more often for this work."

Roosenburg said he is looking forward to presenting the award to Langkilde.

"Tracy has published on a wide range of both native amphibians and reptiles and how they evolve in response to invasive species that create environmental change and stress for these species," he said. "In this way, she meets the criteria for the Distinguished Herpetologist award, which is given annually to an individual whose research with amphibians and reptiles has resulted in a body of work that is both comprehensive and significant in contributing to understanding the biology of these taxa."

Beyond lizard and fire ant interactions, Langkilde also uses as a model frogs living in areas adjacent to roads, mining or other human-based activities characterized by noise levels that can affect the animals' abilities to communicate.

"These types of noises can influence frogs' abilities to find mates, for example," said Langkilde. "I'm interested in the consequences of these environmental changes. Will male frogs with higher-pitched voices now be better at attracting females? Do these males with the higher-pitched voices necessarily have other traits that make them better or worse partners for females? How will these new partnerships influence offspring? There is a lot to investigate."

Langkilde noted that her success as a biologist has only been possible with the help of others.

"I am indebted to everyone who provided mentorship and support to me as I navigated my career path, and to the students and postdocs who were instrumental in making my research program a success," she said. "One of the greatest privileges of my career is empowering young scientists to go out and make their dreams a reality. I hope my receipt of this award serves as an inspiration to the talented young scientists that are making their mark on the field. I look forward to seeing how they shape the future of the field of herpetology."

Langkilde received a bachelor's degree in biological sciences at James Cook University in 1999 and a doctoral degree in tropical biology at the University of Sydney in 2005. She was a postdoctoral fellow at Yale University from 2005 to 2007. She joined the faculty in the Department of Biology at Penn State in 2007, and in 2016 she became head of the department. She has published more than 100 papers in peer-reviewed journals and given numerous invited talks throughout the United States and world.