Author ORCID Identifier
Date of Award
Doctor of Philosophy (PhD)
Jacob L Kerby
The Missouri River is a dynamic ecosystem that has been affected by anthropogenic modification and activity. The implementation of mainstem dams, reservoir formation, pollution, and non-native species invasions have greatly impacted this habitat and its constituents, particularly the false map turtle (Graptemys pseudogeographica). False map turtles are listed as a state threatened species in South Dakota and a focused large-scale assessment of their distribution and health has not been conducted since the 1960s. To address the gap in knowledge of how anthropogenic modifications to the Missouri River have impacted false map turtle distributions and health, the effect of a common info-disrupting contaminant, imidacloprid, on turtle chemical cue detection and foraging behaviors was determined. Ultimately, imidacloprid did not appear to have a significant effect on turtle foraging and chemical cue detection, although it was associated with turtle hyperactivity. Subsequently, effects on false map turtle dietary preferences in the presence of the invasive zebra mussel (Dreissena polymorpha) were compared between turtles that presumably had experience with zebra mussels and turtles presumably naïve to the invader. Turtles consumed similar quantities of mussels in similar amounts of time. Additionally, turtles preferred smaller mussels, but overall appeared to greatly prefer a native prey item rather than the invasive mussels. Following this conclusion, the transfer and bioaccumulation of the common naturally occurring metalloid, selenium, from the water column to zebra mussels to false map turtles was assessed. Zebra mussels accumulated selenium from the water column and consuming a zebra mussel only diet led to increased blood selenium concentrations in turtles over time. Finally, through field surveys throughout South Dakota and species distribution modeling, the current false map turtle distribution was determined. There were three distinct tracts of suitable habitat for this species that were identified due to their retention of riverine characteristics in the dammed reservoir dominated Missouri River. Collectively, this work spans many disciplines including ecotoxicology, behavioral ecology, invasion biology, landscape ecology, and maximum entropy modeling and highlights the importance of a wholistic interdisciplinary approach to intricate ecological issues such as species conservation.
Ecotoxicology, False Map Turtle, Herpetology, Invasive Species, Landscape Biology, Selenium
Number of Pages
University of South Dakota
Kase, Anna C., "The Effects of Anthropogenic Modification To the Landscape on Turtle Distribution and Health in South Dakota" (2023). Dissertations and Theses. 156.
Available for download on Tuesday, December 26, 2023