Using CMR to Investigate the Population Ecology of Painted Turtles in a Suburban Lake
Board Location: #69
Discipline: Ecology Environmental and Earth Sciences
Subcategory: Ecology
Session: 3
Omnia Mamyo - University of Illinois at Chicago
Co-Author(s): Dr. Leigh Anne Harden, Benedictine University, Lisle, Illinois
Anthropogenic changes to the environment put turtle species at
risk. Freshwater turtles are considered bioindicators, in which
their population status reflects the health of their environment.
In the continental US, painted turtles (Chrysemys picta) are the
most ubiquitous and well-studied freshwater turtle species,
making their populations particularly effective for us to monitor.
We used capture-mark-recapture methodology in summer
months from 2018 to 2024 to assess the population ecology of
painted turtles inhabiting a suburban lake in northeastern IL. We
deployed 14 sardine-baited hoop-net traps in Lake St. Benedict
(Benedictine University, Lisle, IL) every other week for four trap
nights. Upon capture, turtles were measured, given a unique ID
code and immediately released at capture location. Since 2018,
we have captured 169 unique individual painted turtles (94M,
37F, 35J), which is ~112 turtles per hectare. Using a Cormack-
Jolly-Seber model open population, the recapture probability
was 0.36 ± 0.05 (36%), the population abundance across all
years was 303.2 ± 30.4 turtles, and mean survival probability
was 0.72 ± 0.15. Across years, trap locations 1, 5, 12, 13 were
frequented most, with interannual variation. Overall, except for
2019, yearly survival and abundance were relatively stable, with
increased juvenile captures in 2024, indicating successful
recruitment of young turtles.
Funder Acknowledgement(s): LSAMP Program
Faculty Advisor: Dr. Leigh Anne Harden, lharden@ben.edu
Role: I contributed to this project by actively participating in the capture-mark-recapture fieldwork for painted turtles at Lake St. Benedict. This involved deploying hoop-net traps, measuring and marking turtles, recording data such as morphometrics, sex, and health, and releasing them at the capture site. I also assisted with analyzing the data using a Cormack-Jolly-Seber model to estimate population dynamics like capture rates, survival probabilities, and abundance.