HABITAT USE AND MOVEMENTS OF BLANDING’S TURTLES (EMYDOIDEA BLANDINGII) AND WOOD TURTLES (GLYPTEMYS INSCULPTA) IN A SHARED LANDSCAPE
Blanding’s Turtles (Emydoidea blandingii) and Wood Turtles (Glyptemys insculpta) face population declines range wide, largely because of degradation and loss of habitat in the landscapes they occupy. Studies of spatial ecology inform land managers of both the resource needs of animal populations and provide insight on site specific conservation priorities. I examined movements and habitat use of overlapping populations of Blanding’s Turtles and Wood Turtles at a site in northern Michigan. I used radio telemetry to locate turtles of each species over the course of two active seasons. I examined full active season and bi-weekly movement patterns and compared activity between the species and sexes of each using one-way analysis of covariance (ANCOVA) and repeated measures analysis of variance (RM ANOVA), respectively. Using multiple commonly used spatial metrics, including range length, 100% minimum convex polygons (MCP), 95% MCP, 50% MCP, and 95% kernel density estimation (KDE), I estimated seasonal activity ranges of turtles and examined site fidelity, making comparisons of species and sexes using two?way multivariate analysis of variance (MANOVA). Finally, I used Euclidean Distance Analysis to examine habitat use at Johnson’s 2nd and 3rd orders of selection, making comparisons at different levels using MANOVA. Movement analyses suggest that Blanding’s Turtles and Wood Turtles at this site travel similar distances over the active season and during different seasonal periods, though females of both species make slightly larger movements during the spring nesting season and male Wood Turtles move more than females in late summer. Activity ranges were individually variable, but comparable among species and sexes. Wood Turtles do appear to exhibit site fidelity at this site, occupying similarly sized and overlapping activity ranges year to year. Habitat selection was evident at the 2nd order for Wood Turtles, indicating favorable use of creek, mid?canopy, and high-canopy upland habitat types and avoidance of river habitat. Blanding’s Turtles also showed selection of habitat at the second order, with scrub-shrub and cut or burned areas ranking highest among available habitat types. Neither Wood Turtles nor Blanding’s Turtles showed evidence of habitat selection at the 3rd order, which may indicate an abundance of high?quality habitat available to these species at this site. Maintenance of corridors between high-use habitat areas, and mitigation of threats especially during times of greater movement may be advantageous to the conservation of Blanding’s Turtles and Wood Turtles at this site.
- Master of Science
- Biological Sciences
- Fort Wayne