Effects of urbanization on the population structure of freshwater turtles across the United States

David R. Bowne, Elizabethtown College
Bradley J. Cosentino, Hobart and William Smith Colleges
Laurel J. Anderson, Ohio Wesleyan University
Christopher P. Bloch, Bridgewater State University
Sandra Cooke, High Point University
Patrick W. Crumrine, Rowan University
Jason Dallas, Rider University
Alexandra Doran, Elizabethtown College
Jerald J. Dosch, Macalester College
Daniel L. Druckenbrod, Rider University
Richard D. Durtsche, Northern Kentucky University
Danielle Garneau, State University of New York at Plattsburgh
Kristen S. Genet, Anoka-Ramsey Community College
Todd S. Fredericksen, Ferrum College
Peter A. Kish, Moravian Academy
Mary Beth Kolozsvary, Siena College
Frank T. Kuserk, Moravian College
Erin S. Lindquist, Meredith College
Carol Mankiewicz, Beloit College
James G. March, Washington & Jefferson College
Timothy J. Muir, Augustana College, Rock Island
K. Greg Murray, Hope College
Madeline N. Santulli, Siena College
Frank J. Sicignano, Siena College
Peter D. Smallwood, University of Richmond
Rebecca A. Urban, Lebanon Valley College
Kathy Winnett-Murray, Hope College
Craig R. Zimmermann, Rogers State University


Landscape-scale alterations that accompany urbanization may negatively affect the population structure of wildlife species such as freshwater turtles. Changes to nesting sites and higher mortality rates due to vehicular collisions and increased predator populations may particularly affect immature turtles and mature female turtles. We hypothesized that the proportions of adult female and immature turtles in a population will negatively correlate with landscape urbanization. As a collaborative effort of the Ecological Research as Education Network (EREN), we sampled freshwater turtle populations in 11 states across the central and eastern United States. Contrary to expectations, we found a significant positive relationship between proportions of mature female painted turtles (Chrysemys picta) and urbanization. We did not detect a relationship between urbanization and proportions of immature turtles. Urbanization may alter the thermal environment of nesting sites such that more females are produced as urbanization increases. Our approach of creating a collaborative network of scientists and students at undergraduate institutions proved valuable in terms of testing our hypothesis over a large spatial scale while also allowing students to gain hands-on experience in conservation science.