Mountain Lion

The mountain lion (Puma concolor) is southern California’s top carnivore. As both an umbrella and a keystone species, it is an important indicator of ecosystem health. The Nature Reserve of Orange County’s habitats and location make these lands a valuable, and possibly critical, resource for the ecology and conservation of the mountain lion in the Santa Ana Mountains as a whole.

This species faces several threats in southern California, including habitat loss and fragmentation from urban and agricultural development. Genetic studies indicate that mountain lions in the Santa Ana Mountains are significantly isolated from other southern California populations by development and Interstate 15. Inbreeding has increased in the Santa Anas’ mountain lion population over time, and continued lack of immigration creates the concern that it could be worsening. The mountain lion is also vulnerable to being hit by vehicles as they cross roads, as well as the effects of climate change, wildfires, and disease/toxin exposure.

Five metrics were used to assess mountain lion health, including minimum number and density estimates, distribution, breeding, and genetic diversity. These were only evaluated for the Central Study Area because no mountain lions live in the Coastal Study Area. Minimum number, density, and distribution were found to be good, with no change in trends and a high level of confidence in those assessments. Breeding—based on the numbers of females and kittens—is in a condition of caution with a declining trend and a moderate level of confidence in this assessment. Lastly, genetic diversity is of significant concern and is declining, with a high level of confidence.