Home range, seasonal movement patterns, and overwintering ecology in two Spotted Turtle (Clemmys guttata) populations in northwest Indiana

Abstract

Land-use change has resulted in natural habitats becoming fragmented and disjunct. Wetland ecosystems
in the United States are one example that has impacted wetland-adapted species. One species, the Spotted Turtle
(Clemmys guttata), lives and relies on freshwater wetland habitats. Unfortunately, relatively little is known about the
spatial and habitat requirements for C. guttata, especially in fragmented habitats. Using ground-based radio-telemetry
and thermal ecology, we calculated seasonal home ranges and examined overwintering ecology for 30 adult turtles
from April 2022 to January 2023 at two sites in northern Indiana. We then calculated annual and seasonal (seasonal
movement areas, SMA) home ranges using 100% Minimum Convex Polygons (MCP) and annual 95%, 90%, and
50% kernel density estimates (KDs). Our results show MCPs were not significantly different between sexes or sites
but differed significantly across seasons (highest in spring). Annual KDs (95%, 90%, and 50%) did not differ between
sites. Daily mean air temperatures prior to overwintering were 12.01 °C and no turtle was recorded to have a carapacial
temperature below 0.5 °C. Results of this study show that even in these highly fragmented areas Spotted Turtles can
operate similar to other populations in more natural habitats. These data can be used to help develop management
plans for Spotted Turtle populations in disjunct and/or urban areas.