Research overview: puma-deer population dynamics in western North America

An overview of the central predator-prey relationship between cougars and mule deer, the staple prey across much of the western United States. Puma density tends to track deer abundance, and puma predation is a major source of deer mortality, raising enduring questions about whether cats limit, regulate or merely thin deer herds. This survey synthesizes long-term studies of kill rates, prey selection by deer age and condition, and how habitat, weather and alternative prey such as elk modulate the relationship. It examines the compensatory-versus-additive debate, source-sink dynamics, and how puma predation interacts with hunting and winter severity. The topic is central to ungulate management and to recurring controversies over predator control in deer-focused jurisdictions.