An individual-based modelling approach to estimate landscape connectivity : a case study with bighorn sheep (Ovis canadensis) and tiger salamanders (Ambystoma mavortium) in the Okanagan Valley, British Columbia

Preserving connectivity, or the ability of a landscape to support species movement, is among the most commonly recommended strategies to reduce the negative effects of climate change and human land use development on species. Connectivity analyses have traditionally used a corridor-based approach and rely heavily on least cost path modeling and circuit theory to delineate corridors. Individual-based models are gaining popularity as a more ecologically realistic method of estimating landscape connectivity; however, this remains a relatively unexplored approach. The overarching aim of this thesis was to assess the utility of an individual-based modeling approach as a tool for identifying species-specific functional connectivity across a landscape and to apply this approach to identify a network of wildlife corridors in the Okanagan Valley for two selected species of interest: the bighorn sheep (Ovis canadensis) and tiger salamanders (Ambystoma mavortium). A series of computer models that simulate sheep and tiger salamanders traversing a landscape by following simple movement rules were developed. Simulations were then run to determine baseline connectivity between subpopulations of both species and the impact of various land management and environmental change scenarios on connectivity. The results of this work show how species might use the Okanagan landscape to colonize suitable yet unoccupied habitats, move in response to climate change, and breed with subpopulations that are spatially isolated. More generally, the use of an IBM in this study highlights the power of this method to identify how species might make broad use of a landscape for movement and migration. It identifies connectivity to areas that are suitable yet not currently occupied, emphasizing the importance of designing conservation plans that encompass more than just current species ranges. The individual-based approach also provided a more realistic representation of how animals perceive and move in their habitats than traditional approaches to identify corridors such as least cost path analysis. Application of this approach elsewhere can provide effective quantitative support for decision makers seeking to incorporate wildlife conservation and connectivity into land use planning.Arts and Sciences, Irving K. Barber School of (Okanagan)Biology, Department of (Okanagan)Graduat