First Comprehensive Study Of Mountain Lions In California Brings Back Worrying Population Results

mountain lion looks over Los Angeles at night

iStockphoto / Jason Klassi


California has long been home to one of the most robust mountain lion populations in the United States even as historic numbers have waned over the decades. For years, estimates put the population of California mountain lions between 4,000 and 6,000, a statistics I’ve cited in countless articles here at BroBible over the years.

Scientists at the California Mountain Lion Project have just completed ” the first comprehensive estimate of mountain lions in California,” as reported by the LA Times, and what they found is the actual number of cougars living in California is close to half than previously thought.

Instead of the 4,000-6,000 previous estimate, this comprehensive field study determined there are between 3,200 and 4,500 mountain lions in California. The study was done primarily using GPS collar tracking and scat samples to then map out population densities using genetic information from the scat samples and existing GPS collar information. They used trail cameras, field observations, and countless other tools at their disposal.

According to the LA Times, the study found the most robust cougar populations in CA are in the “coastal forests of Humboldt and Mendocino counties of Northwest California.” Conversely, the lowest population numbers are found in “high desert east of the Sierra Nevada range in Inyo County.”

Justin Dellinger is a large-carnivore biologist. He is also heads up the California Mountain Lion Project. He spoke with the LA Times and shed some light on where the previous ‘4,000 to 6,000’ population estimate came from.

Dellinger said “that old figure was just a back-of-the-envelope calculation without much data to support it. The new, more accurate information we collected will be used to conserve and manage mountain lions more appropriately.”

Their findings, according to the Times, will be peer reviewed before being published in a scientific journal later this year. This massive research project cost roughly $2.45 million and spanned 7 years.

The end goal here is to better inform development and construction projects. Knowing where cougar population numbers are most/least robust can aid policy makers in making new development decisions.

Interestingly, the 7-year study came back with two population estimates: 3,200 and 4,511. So to say there’s a ‘range’ might be a bit misleading as the two population estimates were specific. But it now falls in the hands of policy makers (and peer reviewers) on which population estimate to trust more.