Removal as a Control Method for Trachemys scripta elegans and the Response of Chrysemys picta bellii
First Advisor
Dr. Catherine de Rivera
Date of Award
Spring 6-16-2024
Document Type
Thesis
Degree Name
Bachelor of Science (B.S.) in Environmental Science and University Honors
Department
Environmental Science and Management
Language
English
Subjects
Invasive species management, Red-eared slider turtle, Trachemys scripta elegans, Western painted turtle, Chrysemys scripta elegans, Biological invasions
Abstract
The red-eared slider is considered one of the most ubiquitous freshwater turtles globally. Several key ecological advantages and life history traits of this species jointly impact growth rates and survivorship of native freshwater turtles where sympatry occurs. Evaluation of current management actions for red-eared slider turtles is limited, resulting in a paucity of information to guide management for the species and conservation of declining native freshwater turtles. We used previously collected mark-recapture and removal sampling data from sites with sympatric populations of red-eared slider and western painted turtles. We examined the effects of control (trapping and removal) of red-eared sliders on (1) red-eared slider abundance (2) western painted turtle abundance and body condition (3) community composition. The estimated population size of western painted turtles decreased over time, though with wide confidence intervals, in Peninsula Drainage Canal and increased substantially in Smith and Bybee. However, in Smith and Bybee the estimated population size of red-eared sliders increased, despite continuous removal of the species. We did not detect a difference in the average body condition for western painted turtles as more red-eared sliders were removed. We also showed moderate evidence that management actions can change community composition by removing red-eared sliders, increasing the proportion of western painted turtles relative to red-eared sliders within the community. The questions we set out to answer are imperative to the management of these species and our study highlights the need to make improvements to mark-recapture study design and more systematic sampling to enable rigorous conclusions.
Recommended Citation
Swanson, Jacob Daniel, "Removal as a Control Method for Trachemys scripta elegans and the Response of Chrysemys picta bellii" (2024). University Honors Theses. Paper 1528.