Date Approved

5-16-2022

Graduate Degree Type

Thesis

Degree Name

Biology (M.S.)

Degree Program

Biology

First Advisor

Dr. Jennifer A Moore

Second Advisor

Dr. Paul Keenlance

Third Advisor

Dr. Joe Jacquot

Academic Year

2021/2022

Abstract

Turtles are arguably the most threatened group of vertebrates on the planet. Anthropogenic influences such as habitat loss and fragmentation, road mortality, subsidized predators, climate change, and illegal collection have contributed to their global decline. Understanding which isolated populations of turtles are viable despite these synergistic threats is crucial for making conservation and management decisions. In Michigan, the spotted turtle (Clemmys guttata) is a threatened species subjected to many negative anthropogenic influences that accelerate its rapid population decline. In order to properly sustain their populations, the goal of my research was to investigate relevant factors that help us understand the influences on this population’s viability, including their spatial ecology and habitat selection. We trapped and marked turtles within vernal pool and fen habitats in southwest Michigan. VHF radio telemetry and mark-recapture techniques were used to track turtles (n =22) across two active seasons (Spring-Fall 2020; Spring-Fall 2021). This allowed us to delineate home ranges, assess habitat selection, and detect influences on their daily movement patterns. Male turtles exhibited larger wAKDEc home ranges (3.71 ha SE ± 0.52 ha) than females (2.31 ha SE ± 0.38 ha) across the two field seasons. Home ranges were much smaller than those of turtles from other populations in similar northern latitudes. Smaller home ranges were attributed to easily accessible resources or confinement within the landscape. Precipitation, minimum, and average temperatures significantly influence the turtles’ daily movement rates. Habitat selection was evident at both 2nd and 3rd order spatial scales, with emergent wetland as one of the most selected habitats and dry-mesic forest as the most avoided. We recommend that management agencies conduct analyses of this species' habitat selection and spatial ecology at multiple scales. These results can be applied to managing populations in similar latitudes that occur in similar habitats.

Download

Share

COinS