Senior Honors Projects, 2020-current

Creative Commons License

Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.

Date of Graduation





Document Type


Degree Name

Bachelor of Science (BS)


Department of Biology


Grace Wyngaard

David McLeod

Patrice Ludwig


The Red-eared Slider, Trachemys scripta is an invasive species responsible for declines in turtle species across the world. Trachemys scripta is native to two parts of southern Virginia but the species has been introduced throughout the rest of the state, often related to the release of pet trade animals. This study aimed to identify the extent of Trachemys scripta’s establishment and impact on native species in Harrisonburg, Virginia. Turtles were trapped in a mark-recapture study during the springs and summers of 2018, 2019, and 2020 in four local ponds in Harrisonburg, Virginia. Cormack-Jolly-Seber population models were constructed using data collected in 2018 and 2019 for two species, Trachemys scripta and Chrysemys picta, which revealed slightly larger populations of Chrysemys picta than Trachemys scripta. Turtle populations in the local ponds were observed to increase after a large-scale die-off in 2018. Trachemys scripta appears to be established and capable of spread in Harrisonburg, with large, persistent population sizes, reproduction over multiple years, and documented movement between ponds. However, it is unclear how or if Trachemys scripta may negatively impact native species as its main potential competitor, Chrysemys picta also appeared to have healthy populations and was even more abundant that Trachemys scripta.



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