Science & Technology

Under Pressure: USU Ecologist Studies Animal Interactions in Changing Environments

By Mary-Ann Muffoletto |

Video by Taylor Emerson, Digital Journalist, University Marketing & Communications

Scorching summer heat in the world’s Northern Hemisphere is straining power grids, fraying nerves, fueling wildfires and sending people to the hospital. Many humans can find at least temporary respite, but their activities are having a huge impact on more vulnerable species – namely, lizards.

Utah State University physiological ecologist Susannah French is studying the effects of human-induced changes on varied lizards, including iguanas of the world’s tropics and, closer to home, the American Southwest’s side-blotched lizard.

French fosters collaborations with colleagues from diverse disciplines across USU, in addition to creating meaningful learning opportunities for students. In recognition of her outstanding efforts, the Department of Biology and USU Ecology Center professor was named the university’s 2022 Faculty Researcher of the Year.

“We’re examining whether environmental changes, including those caused by human disturbances, result in modifications to the lizards’ stress responsiveness, reproductive success and immune function,” said French, who was awarded a prestigious National Science Foundation Faculty Early Career Development Program (CAREER) grant in 2014.

She said the ways in which reptiles, including lizards, regulate and maintain key life-history processes– especially in a changing environment– are not well understood.

“We use an integrative approach to examine how these organisms cope with costly, competing demands,” French said. “Through our work in the field and in the lab, we integrate endocrine, immune, behavioral and energetic techniques to investigate physiological interactions and determine the role energy plays in regulating these interactions.

The ecologist’s work takes her across varied continents and ecosystems. French studied iguanas in the remote, sparsely populated Galápagos Islands – a place she said is an "incredibly pristine site of diverse species that inspired Charles Darwin’s theory of evolution in the 19th century and reminds me of why I got into science."

French also studied lizards in popular tourist areas in the Bahamas, where human visitors are loving rock iguanas to death with sugary treats. She also makes frequent trips to southern Utah’s iconic red rock sites to examine how lizards are coping with increased temperatures, human development of desert oases and the spread of non-native, invasive plans, including cheatgrass.

Because lizards are abundant in many parts of the world, French says people tend to underestimate the impact of anthropogenic disturbances on the small creatures.

“Lizards play an important role in the Earth’s ecosystems and play critical roles as both predator and prey species,” she says. “By studying reptiles, we learn a lot about the environmental health of our world and how species adapt to environmental changes.”

As a child, the Illinois native dreamed of becoming a veterinarian because she loved animals, the outdoors and anything to do with science.

Undergraduate research experiences at the University of Illinois encouraged French to pursue graduate study and she completed a doctoral degree from Arizona State University in 2006. Named USU’s Undergraduate Research Mentor of the Year in 2017 and the College of Science’s Graduate Research Mentor of the Year in 2018, French strives to provide similar research opportunities.

“I work with amazing students and colleagues,” she said. “It’s very rewarding to see young scientists getting excited about research, forging their own paths and moving on to great opportunities and diverse careers.”

USU physiological ecologist Susannah French (left) works with two students in the lab. French was awarded the 2022 Faculty Researcher of the Year award.


Mary-Ann Muffoletto
Public Relations Specialist
College of Science


Susannah French
Associate Professor and Associate Department Head
Department of Biology and USU Ecology Center


Environment 267stories Climate 152stories Animals 92stories

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