Spatial Ecology and Predator-Prey Interactions of Mountain Lions in California's San Francisco North Bay

Understanding spatial ecology and predator-prey interactions are central to wildlife ecology and conservation. We tracked mountain lions with GPS telemetry to evaluate space use, predator-prey interactions, and resource selection in California’s San Francisco North Bay, USA. In Chapter 1, we evaluated the influence of human disturbance on home range size, prey composition, and kill rates on black-tailed deer (Odocoileus hemionus columbianus) across an urban-rural gradient. Both males and females increased home range size with increasing development at low to moderate levels of development, but female home range size stabilized across greater proportions of development while male home range size decreased, possibly due to constrained movement. Deer kill rates, prey composition, and time spent at kills did not vary relative to human infrastructure or natural landscape features relevant to predation (e.g., cover, productivity). The rate at which mountain lions killed deer in the North Bay was generally comparable to estimates reported across North America. In Chapter 2, we investigated scale-dependent responses by mountain lions to their primary limiting factors along a gradient of human disturbance. Mountain lions exhibited flexible strategies by selecting home ranges in both more and less developed areas. Within home ranges, responses to human infrastructure were highly variable as a function of both distance from tree cover and the amount of human infrastructure present. In Chapter 3, we evaluated resource selection by mountain lions at locations where they consumed black-tailed deer, their primary prey. Mountain lions strongly selected tree and shrub cover at feeding sites. However, their selection of primary productivity increased as a function of cover, indicating that mountain lions exhibited the strongest selection of areas with vegetative features where prey were likely both abundant and vulnerable. Our work highlights the significant overlap between mountain lions and people in the North Bay as mountain lions killed and consumed their primary prey surprisingly close to buildings (mean = 373 m). Mountain lions are highly adaptable and respond flexibly to human disturbance as some aspects of their behavior varied strongly relative to human disturbance (e.g., space use, resource selection), whereas other aspects appeared to be more consistent (e.g., predation). Advisor: John F. Benson