Modeling habitat connectivity and movement of Blanding’s turtles (Emydoidea blandingii) across a fragmented landscape in Rouge National Urban Park, Ontario, Canada

Abstract

Rouge National Urban Park is a highly fragmented park in Canada’s most populous city, Toronto, Ontario. Habitat fragmentation has been found to hinder conservation efforts due to the associated increased risks of species mortality when travelling between habitat patches. The park contains a population of endangered Blanding’s turtles (Emydoidea blandingii) augmented through a head-starting program that supplements wild populations by releasing captive raised young. Blanding’s turtle habitat size requirements are often underestimated, and little is known regarding the habitat selection of Blanding’s turtles in Rouge Park. This thesis examines the movement paths and habitat selection of Blanding’s turtles within the urban park. Blanding’s turtle habitat within the park was mapped using PlanetScope 3m Visible-Near Infrared remote sensing imagery. Habitat connectivity was modelled by completing a graph network and a least cost pathway (LCP) assessment. These assessments resulted in an evaluation of landscape connectivity and areas of facilitated turtle movement, as well as an LCP resistance map which identified discrete barriers to movement. Rouge Park contains 32 locations of road intersections along 16 paths of turtle movement, with a maximum of 4 road intersections per path. Although Rouge Park provides a less fragmented landscape than the surrounding area, there is only a moderate level of habitat connectivity within the park as a whole. It is anticipated that this model of turtle movement will help to target management and policy decisions, as well as habitat restoration efforts within Rouge National Urban Park and the surrounding area.