Date of Graduation
Spring 2025
Degree
Master of Science in Biology
Department
Biology
Committee Chair
Day Ligon
Abstract
Alligator Snapping Turtles (Macrochelys temminckii) have declined throughout much of their range, likely due to high hunting pressure and the proliferation of dams in the 20th century throughout the United States. In the western portion of the species’ range in Oklahoma, past population surveys found that its distribution had dwindled and become patchy, with few rivers supporting viable populations. The first objective of my study was to reassess the distribution of Macrochelys temminckii in the state. Borrowing insights from past survey efforts, I implemented a protocol designed to optimize detection rates by using preferred bait, restricting survey efforts to months when water temperatures are typically moderate, and conducting a level of search effort that minimizes risk of failing to detect small populations. Over the course of the survey, I captured M. temminckii at 14 of 22 sites, resulting in 174 captures of 148 unique individual M. temminckii. At one site where the species initially appeared to occur in abundance, I conducted a series of four survey efforts and used capture mark-recapture methods to estimate the population size to be 137 (95% CI: 84.6–190) individuals and density and biomass estimates of 37.9 M. temminckii per river km and 421 kg/km, respectively. Results from across all of the locations I surveyed filled in gaps in the known distribution of M. temminckii by detecting additional populations, as well as populations that had previously been determined to be extirpated. Chapter two of my research focused on turtle-leech interactions, specifically studying the distribution of the Smooth Turtle Leech (Placobdella parasitica) and Tuberculated Turtle Leech (P. multilineata) across turtle species and geographically across systems. I found that P. parasitica was far more abundant than its congener and exhibited a higher occupancy rate, prevalence, and leech load on Chelydra serpentina and Macrochelys temminckii than on any other species. However, P. parasitica occurred on all 9 species of turtles detected during my study while P. multilineata was observed on just 6 species. Patterns of prevalence across species may be influenced by phylogeny, morphology, and/or niche preferences of turtle hosts; more research is needed to determine the relative impact of these different factors.
Keywords
Macrochelys temminckii, Alligator Snapping Turtle, distribution, Oklahoma, habitat suitability, Placobdella parasitica, Smooth Turtle Leech
Subject Categories
Biology | Zoology
Copyright
© Tessa Nicole Irvine
Recommended Citation
Irvine, Tessa Nicole, "Distribution of Alligator Snapping Turtles (Macrochelys Temminckii) in Oklahoma" (2025). MSU Graduate Theses/Dissertations. 4036.
https://bearworks.missouristate.edu/theses/4036