The Last Days of L.A.'s Mountain Lions?

The mountain lions of Los Angeles have made a big splash over the past few years, especially since the National Park Service discovered one charismatic male, dubbed P-22, living not far from the Hollywood Sign in the Santa Monica Mountains. But their days may be numbered. According to new research published Tuesday in the Proceedings of the Royal Society B, the urban cat population faces a strong likelihood of extinction within half a century.

Using demographic, genetic, and environmental factors, researchers from the NPS, UCLA, UC Davis and Utah State University estimated survival odds for the tiny population of mountain lions who live penned in by freeways and urban development in greater Los Angeles. (The researchers believe that there are roughly 15 in the Santa Monica Mountains at any given time.) Although the animals are already inbreeding, so far they’ve managed to keep up fairly healthy rates of population growth. But their genetic diversity is likely to sharply decline in coming decades, and that could start to drag on their ability to survive and reproduce, a phenomenon known as “inbreeding depression.” If it occurs among the Santa Monica Mountains population, the cats have a 99.7 chance of vanishing within 50 years, the researchers found.