Adult males use their hindfeet to scrape duff into a small pile to declare their territory. Females generally occupy ranges from 20 to 60 square miles. Females breed first at two or three years of age, then every 18 to 20 months thereafter. Young may be born at any time of the year. Gestation period is 88 to 97 days.
Litters range from one to six, generally two or three.
Damage is often random and unpredictable, but when it occurs, large numbers of livestock can be killed in short periods of time, a behavior known as surplus killing. Rabies, feline leukemia and Lyme disease have been documented in California mountain lions. Younger mountain lions, dispersing from fully occupied mountain lion habitat, may also end up in these areas, trying to establish their own territories. In the rural areas of California, mountain lion range commonly overlaps livestock grazing land. To prevent predation of domestic livestock or pets by mountain lions, exclusion, using heavy woven wire fencing at least ten feet high is required.