Mountain Lion Predation on Mule and Black-tailed Deer: A Perspective on The Complex Impacts of An Iconic Predator

Predation is a fundamental process that shapes ecological communities. The impact of mountain lion (Puma concolor) predation on their prey, however, is a debated topic among wildlife managers and their primary constituents, hunters and conservationists in North America. Here we present a perspective and highlight recent literature on the direct and indirect (i.e., non-consumptive) effects of mountain lion predation on 2 of its primary prey species in western North America, mule and black-tailed deer (Odocoileus hemionus). We assert that direct effects of mountain lion predation outweigh indirect effects. The population level impact of mountain lion predation on deer, however, is often context dependent and is influenced by complex species interactions including with other carnivores (e.g., kleptoparasitism) and prey (apparent competition). We also contend that understanding the impacts of additive and compensatory predation on the population dynamics of deer are ultimately required to ascertain population level effects of mountain lion predation. Finally, we highlight several key areas for future research.