Tracy Langkilde

Professor of Biology; Dean of the Eberly College of Science

Tracy Langkilde

Research Summary

The interface of ecology and evolution to understand how an organism's traits are matched to its environment and responds to novel selective pressures imposed by global environmental change, and the consequences of this adaptation.

Huck Affiliations


Publication Tags

Lizards Glucocorticoids Corticosterone Temperature Sceloporus Undulatus Lizard Reptiles Color Fire Ants Animals Plastics Ant Ants Pregnancy Population Exposure Predation Breeding Triiodothyronine Immunity Physiological Stress Predators Predator Environmental Factors Hemagglutination

Most Recent Papers

Ecoimmune reallocation in a native lizard in response to the presence of invasive, venomous fire ants in their shared environment

Catherine Tylan, Maria Horvat-Gordon, Paul A. Bartell, Tracy Langkilde, 2020, Journal of Experimental Zoology Part A: Ecological and Integrative Physiology on p. 792-804

The influence of hunting pressure and ecological factors on fecal glucocorticoid metabolites in wild elk

David C. Ensminger, Catharine Pritchard, Tracy Langkilde, Tess Gingery, Jeremiah E. Banfield, W. David Walter, 2020, Wildlife Biology

Effects of temperature on plasma corticosterone in a native lizard

Andrea Racic, Catherine Tylan, Tracy Langkilde, 2020, Scientific Reports

Trade-off between Thermal Quality and Predation Risk at Timber Rattlesnake Gestation Sites

Mark W. Herr, Julian D. Avery, Tracy Langkilde, Christopher A.F. Howey, 2020, Journal of Herpetology on p. 196-205

Obtaining plasma to measure baseline corticosterone concentrations in reptiles

Catherine Tylan, Kiara Camacho, Susannah French, Sean P. Graham, Mark W. Herr, Jermayne Jones, Gail L. McCormick, Melissa A. O'Brien, Jennifer B. Tennessen, Christopher J. Thawley, Alison Webb, Tracy Langkilde, 2020, General and Comparative Endocrinology

Glucocorticoid and triiodothyronine concentrations do not correlate with behavior in vicuñas (Vicugna vicugna)

Catharine E. Pritchard, Rupert Palme, Tracy Langkilde, 2020, General and Comparative Endocrinology

Plastic sexual ornaments: Assessing temperature effects on color metrics in a color-changing reptile

B. A. Assis, Benjamin Jarrett, Gabe Koscky, Tracy Lee Langkilde, Julian Avery, 2020, PLoS One

Glucocorticoids do not influence a secondary sexual trait or its behavioral expression in eastern fence lizards

K. J. MacLeod, G. L. McCormick, T. Langkilde, 2019, Scientific Reports

History of predator exposure affects cell-mediated immunity in female eastern fence lizards, Sceloporus undulatus (Squamata: Phrynosomatidae)

Kristen Sprayberry, Catherine Tylan, Dustin A.S. Owen, Kirsty J. MacLeod, Michael John Sheriff, Tracy Langkilde, 2019, Biological Journal of the Linnean Society on p. 944-951

Contrasting Responses of Lizards to Divergent Ecological Stressors across Biological Levels of Organization

Rory S. Telemeco, Dasia Y. Simpson, Catherine Tylan, Tracy Langkilde, Tonia S. Schwartz, 2019, Integrative and Comparative Biology on p. 292-305

Most-Cited Papers

Traffic noise causes physiological stress and impairs breeding migration behaviour in frogs

Jennifer B. Tennessen, Susan E. Parks, Tracy Langkilde, 2014, Conservation Physiology

The role of behaviour in the establishment of novel traits

Marlene Zuk, Elizabeth Bastiaans, Tracy Lee Langkilde, Elizabeth Swanger, 2014, Animal Behaviour on p. 333-344

Invader danger

Whitney P. Trompeter, Tracy Lee Langkilde, 2011, Hormones and Behavior on p. 152-158

The impacts of invaders

Sean P. Graham, Nicole A. Freidenfelds, Gail L. McCormick, Tracy Lee Langkilde, 2012, General and Comparative Endocrinology on p. 400-408

Hot boys are blue

Tracy Lee Langkilde, Katherine E. Boronow, 2012, Journal of Herpetology on p. 461-465

Evading invaders

N. A. Freidenfelds, T. R. Robbins, Tracy Lee Langkilde, 2012, Behavioral Ecology on p. 659-664

How do duration, frequency, and intensity of exogenous CORT elevation affect immune outcomes of stress?

Gail L. McCormick, Katriona Shea, Tracy Langkilde, 2015, General and Comparative Endocrinology on p. 81-87

Does environmental enrichment really matter? A case study using the eastern fence lizard, Sceloporus undulatus

Renee L. Rosier, Tracy Langkilde, 2011, Applied Animal Behaviour Science on p. 71-76

Female lizards discriminate between potential reproductive partners using multiple male traits when territory cues are absent

Lindsey Swierk, Matthew Ridgway, Tracy Langkilde, 2012, Behavioral Ecology and Sociobiology on p. 1033-1043

Latitudinal and seasonal variation in reproductive effort of the eastern fence lizard (Sceloporus undulatus)

Weiguo Du, Travis R. Robbins, Daniel A. Warner, Tracy Langkilde, Richard Shine, 2014, Integrative Zoology on p. 360-371

News Articles Featuring Tracy Langkilde

Tracy Langkilde Named New Penn State Eberly College of Science Dean

Tracy Langkilde will become the dean of Penn State’s Eberly College of Science, effective October 1. She will replace Douglas Cavener, who stepped down in June to continue teaching and researching full-time.

Sunnier but riskier

Conservation efforts that open up the canopy of overgrown habitat for threatened timber rattlesnakes — whose venom is used in anticoagulants and other medical treatments — are beneficial to snakes but could come at a cost, according to a new study by researchers at Penn State and the University of Scranton.

Biology professor, department head recognized for study of amphibians, reptiles

Professor of Biology Tracy Langkilde has been named Distinguished Herpetologist for her contributions to the field by the Herpetologists' League, an international organization of people devoted to studying the biology of amphibians and reptiles.

Research shows frogs can adapt to traffic noise

Frogs don’t like living near noisy highways any better than people do, but new research suggests that frogs, like hardened city-dwellers, can learn to adapt to the constant din of rumbling trucks, rolling tires and honking horns.

Penn State Researchers Discover Lizards Probably Handle Sex And Stress Better Than People

A new study by Penn State researchers shows that stress doesn’t affect the sexiest features of male eastern fence lizards, definitively proving that lizards have their shit together way more than humans do.

Research: Features that make lizards appealing to potential mates are resilient to stress

Physical traits and behaviors that make a lizard sexy — features used to attract potential mates and fend off competitors — may be important enough that they do not change in the face of stress. A new study by researchers at Penn State reveals that the blue and black badges on the throats and abdomens of male fence lizards — and signaling behaviors used to show them off — are not affected by low levels of stress-associated hormones, unlike many other traits.

Ecology Alum Jennifer Tennessen Brings Acoustics to Killer Whale Conservation

Dr. Jennifer Tennessen applies the lessons of her interdisciplinary research at the Huck to her professional work with killer whales in the Pacific Northwest.

Stressed Ancestors May Improve Immune Response in Future Generations

City Frogs Are the Sexiest Frogs

Two new studies show how certain animals can adapt to the din of human activity in surprising ways.

Lizards quickly adapt to threat from invasive fire ants

Some lizards in the eastern U.S. have adapted to invasive fire ants — which can bite, sting and kill lizards — reversing geographical trends in behavioral and physical traits used to avoid predators.