Abstract

Bog Turtles (Glyptemys muhlenbergii) are some of the most imperiled turtles in North America, and because of threats posed by habitat loss and collection for the pet trade, the species currently is listed as threatened under the U.S. Endangered Species Act. Numerous studies have investigated home ranges and movements of this species, and reported home-range sizes have varied widely. Typically, these studies were conducted at different sites and used different home-range estimators, and these factors may influence home ranges. Few studies have assessed the impact of estimator choice on home-range size for Bog Turtles or how habitat changes have affected their movements. Our study investigated home-range sizes of female Bog Turtles at two sites in Maryland, using multiple home-range estimators. Female turtles were tracked using radiotelemetry between April and August in 2013 and 2014. Home-range sizes differed significantly between study sites but did not differ significantly between years. Choice of estimator had a significant effect on home-range size; 50% kernel and 95% minimum convex polygons were similar, but 95% kernels were significantly larger than 50% kernels or 95% polygons. A study conducted at one of our two study sites over 15 years ago reported smaller home-range sizes than were found in our study, perhaps indicating that habitat has deteriorated at that site.