Sad news for fans of mountain lions in the Santa Monicas and nearby mountain ranges: Three baby mountain lions were killed in two separate incidents in the last half of January. And biologists are saying the unfortunate deaths underscore the need for more and safer ways for wildlife to cross Southern California highways.
On January 20 a young kitten was struck by a car on Kanan Dume Road in Malibu, dying of its injuries. Just eleven days later, on January 31, two pumas thought to be about ten months old died while apparently trying to cross Highway 126 west of Santa Clarita. That section of Highway 126 runs through an area considered critical for connecting puma populations in the Santa Monica Mountains with cats roaming mountains elsewhere in Southern California.
All in all, since the National Park Service began tracking the region's mountain lions 12 years ago, 13 lions have died from injuries caused by traffic in and near the Santa Monica Mountains. That's more than one a year, and it's distressingly close to the total number of adult pumas now thought to inhabit the Santa Monica Mountains -- about 15.
The threat of roadkill harms more than just the unfortunate pumas that get hit by cars. As a result of the Santa Monicas being almost completely surrounded by either urban development, farms, or coastline, it's difficult for lions to migrate into or out of the range. That almost inevitably leads to inbreeding, which threatens the long-term viability of the population. And due to their relatively cramped living quarters, Santa Monica Mountains pumas often come into conflict with one another. Male lions kill other males in order to reduce competition, and having fewer males then leads to an even higher likelihood of inbreeding.
"Roads are a challenge not only because mountain lions keep getting hit and killed by cars, but also because major roads such as freeways lead to reduced genetic diversity and also higher rates of lion-on-lion conflict," said Dr. Seth Riley, an urban wildlife expert at Santa Monica Mountains National Recreation Area (NRA). "If we want to keep mountain lions in the Santa Monica Mountains, we need a better system of wildlife crossings."
One crossing being eyed for improvement, near the Liberty Canyon exit along the 101 Freeway in Agoura Hills, was the scene of an earlier fatality when an adult male puma was struck and killed in October. That puma was apparently trying to make it from the Upper Las Virgenes Canyon Open Space Preserve into the Santa Monicas: the Liberty Canyon area is the one remaining bit of undeveloped corridor between the coastal mountains and the wildlands to the north of the San Fernando Valley.
National Park Service staff from Santa Monica Mountains NRA along with Caltrans, the Resource Conservation District of the Santa Monica Mountains, and the Santa Monica Mountains Conservancy are working to promote a study of possible ways to make it easier for pumas, and other wildlife, to make it across the 101 at Liberty Canyon. Options on the table include an overpass and a tunnel. The biggest stumbling block: the project's cost, estimated at $10 million.