Dissertation Defence: Cougar (Puma Concolor) Demography and Foraging Ecology in the Southern Interior of British Columbia, Canada

Siobhan Darlington, supervised by Drs. Adam Ford and Karen Hodges, will defend their dissertation titled “Cougar (Puma Concolor) Demography and Foraging Ecology in the Southern Interior of British Columbia, Canada” in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Biology.

An abstract for Siobhan Darlington’s dissertation is included below.

Examinations are open to all members of the campus community as well as the general public. Registration is not required for in-person exams.

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Abstract

Large carnivores face complex challenges in human-modified landscapes, where mortality risk, resource availability, and habitat structure interact to shape population dynamics and predation patterns. In this dissertation, I examined how environmental and anthropogenic factors influence cougar (Puma concolor) demography, survival, and predation strategies in the southern interior of British Columbia, Canada. Using GPS-collared individuals, kill site investigations, remote cameras, and spatial modelling, I integrated demographic, dietary, and spatial ecology approaches to understand how cougars navigate trade-offs between ecological opportunity and risk.

In Chapter 2, I analyzed population demography and cause-specific mortality of 56 GPS-collared adults and 59 ear-tagged kittens. Human activities were the main source of adult mortality, while predation dominated kitten deaths. Survival varied by sex, season, and landscape features, with higher risk near roads and agricultural areas. Kittens were most vulnerable in early denning stages, particularly when maternal care was reduced or dens were distant from recent cutblocks and roads.

In Chapter 3, I examined prey selection and dietary overlap among 38 cougars using 875 kill sites and prey availability data from 146 remote cameras. Males killed larger prey than females, and prey use varied seasonally. Diet similarity was highest at intermediate spatial overlap, indicating that territorial neighbours partition resources to balance competition and prey availability.

In Chapter 4, I assessed habitat drivers of predation across 886 kill sites. Kill sites were concentrated in core home ranges and influenced by terrain and disturbance features. Deer kills were associated with rugged terrain in snow months and with cutblocks and burns 10–20 years post-disturbance in snow-free months, enhancing both prey catchability and abundance. Multi-species clustering was limited, but these habitats increased hunting success for multiple ungulate species.

These chapters illustrate how mortality risk, prey dynamics, and landscape features interact to shape cougar ecology in human-dominated ecosystems. This work advances understanding of carnivore–prey dynamics and provides guidance for mitigating human–wildlife conflict and conserving wide-ranging predators in heterogeneous landscapes.