Demography, Movement Patterns, and Habitat Selection of Blanding's Turtles at Canadian Nuclear Laboratories in Chalk River, Ontario

Abstract

The development and implementation of effective species and population-specific management strategies requires population-specific information. To demonstrate the relative extirpation risk associated with various road mortality scenarios for a population of Blanding’s turtles at Canadian Nuclear Laboratories in Chalk River, Ontario, a Population Viability Analysis was conducted. Road mortality of two adult females every ten years resulted in population extirpation within 200 years relative to a stable population not experiencing road mortality. To accommodate informed decision-making for the management of this species at risk, the movement patterns and habitat selection of this Blanding’s turtle population were described. There was no significant difference between males and females in distance moved between relocations in either the spring or the summer, but turtles moved greater distances in the spring than in the summer. Annual and seasonal home range size did not differ between the sexes or between spring and summer periods. A compositional analysis indicated Blanding’s turtles preferred marsh habitats over bog, swamp, lake, and upland. Matched-paired logistic regression was used to determine selection of microhabitat features, such as type of vegetation, in the spring and summer. Turtles preferred sites with warmer air temperatures, shallower water, a higher availability of open water, and greater coverage of emergent and floating vegetation types in the spring period. In the summer period, turtles preferred sites characterized by cooler, deeper water, a higher availability of open water, and greater coverage of emergent and floating vegetation types. This population of Blanding’s turtles appears to be relatively small and the continued threat of road mortality indicates a delicate situation for its persistence. Considering seasonally preferred habitats will best inform management decisions for seasonal work restrictions and future development plans.