Laura Bliss is CityLab’s West Coast bureau chief. She also writes MapLab, a biweekly newsletter about maps (subscribe here). Her work has appeared in The New York Times, The Atlantic, Sierra, GOOD, Los Angeles, and elsewhere, including in the book The Future of Transportation.
Their best hope: a proposed freeway wildlife crossing.
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.
That might be happy news for the hikers who are occasionally menaced by the big cats, but sad for a lot of other reasons. Urban biodiversity seems to be a good thing, and the popularity of L.A.’s hometown mountain lions has helped raise awareness among Angelenos about other kinds of wildlife. Luckily, there is a glimmer of hope for the charismatic felines: A wildlife crossing over Highway 101, a major urban barrier for many species in the Santa Monica Mountains, would allow animals to enter in and out of the mountain lion’s current isolated range. A proposal for such a crossing is currently in the works by CalTrans, and private fundraising efforts so far have raised about $1 million. The researchers of the new paper say that such a bridge could be the SoCal cougars’ best chance of survival.
"If we were able to get one new mountain lion every two years or, even every four years, it would considerably lower extinction probability," John Benson, the lead author and a post-doctoral researcher at UCLA, told KPCC.
What’s an urban wildlife lover to do? Head on over to Save LA Cougars to pitch into the crossing project. And while you’re at it, don’t use rat poison, and support the preservation of natural spaces within cities. It’s good for all animals, humans included.