The cougar, Puma concolor, is a large, solitary apex predator with the most extensive range of any terrestrial mammal in the Western Hemisphere. Also known as a mountain lion or puma, this impressive feline is found from the Canadian Yukon down to the southern Andes Mountains. Understanding what sustains this large carnivore requires looking beyond its primary menu to occasional, opportunistic meals, such as small rodents.
The Primary Diet of the Cougar
Cougars are classified as obligate carnivores, meaning meat is an absolute necessity for survival. Their diet is heavily specialized toward large, hoofed mammals, known as ungulates. In North America, approximately 68% of a cougar’s diet consists of these large animals, with deer—including mule deer and white-tailed deer—being the most frequently hunted prey.
The preference for large prey like elk, moose, or bighorn sheep is driven by the need for high caloric density to sustain the cougar’s large body mass. A single large kill provides enough meat for multiple feedings, offering a highly efficient energy exchange. This dietary pattern can shift regionally, such as in Central and South America where smaller prey become more common. A large male cougar in North America typically kills a deer or elk every nine to twelve days to meet its metabolic demands.
When Cougars Consume Small Mammals
Cougars are generalist and opportunistic predators, meaning they will consume smaller prey, including mice, although they specialize in large prey. The consumption of small mammals is rare and serves only as a supplementary food source. Other smaller animals like rabbits, raccoons, porcupines, and beavers are taken more frequently than mice, but these still make up a small portion of the overall diet.
The circumstances under which a cougar consumes a mouse are typically driven by necessity or simple opportunity. During periods of food scarcity, cougars will turn to smaller, less calorically rewarding animals when primary ungulate prey is unavailable. Juvenile cougars may also opportunistically consume small rodents while learning and practicing their predatory skills.
The low caloric return of a mouse means it is consumed as an incidental snack rather than a targeted hunt. The energy gained from a single small rodent is negligible compared to the 8 to 10 pounds of meat an adult cougar typically eats daily. Therefore, the presence of mice in a cougar’s diet reflects the cat’s adaptability, not a routine hunting practice.
Hunting Techniques and Energy Requirements
The cougar’s hunting strategy is optimized for taking down large prey, which explains their dietary preferences. They are ambush predators that rely on stealth and surprise, stalking through dense cover before delivering a powerful, short-distance leap. This technique is designed to incapacitate a large animal quickly, often using a suffocating bite to the neck.
Chasing and catching a quick, small mouse is a poor energetic investment compared to securing a deer that provides food for a week or more. The cougar’s metabolism and hunting style dictate a preference for maximizing energy efficiency through large kills.
A successful kill is often dragged to a secluded area and then covered, or “cached,” with debris like leaves and soil. This caching behavior protects the carcass from scavengers and allows the cougar to return and feed on the kill for several days. Securing and conserving a large meal further reduces the need to expend energy on frequent hunts for small, low-return prey.