DNA tests performed on a litter of mountain lion kittens recently born in the Santa Monica Mountains indicate the kittens are the result of inbreeding. Wildlife experts say the results tell a tale of limited mobility for big cats in the Santa Monica Mountains, and underscore the need for a wildlife corridor across the 101 Freeway to allow wildlife to safely pass back and forth between the Simi Hills and the isolated Santa Monica Mountains.
The three kittens—one male and two female—were born in the Malibu Springs area in November and ear-tagged by National Park Service biologists in early December. Preliminary tests performed by a specialized biology lab at UCLA identified the father as Puma-12 (P-12), who is also the father of the kittens’ mother.
“There are fewer than 10 mountain lions in the Santa Monica Mountains, which is not enough for a genetically diverse population,” Dr. Seth Riley, an urban wildlife expert at Santa Monica Mountains National Recreation Area (SMMNRA), a unit of the National Park Service (NPS) said. “They have the lowest genetic diversity of any mountain lion population in the state.”
While parks officials say the cubs appear to be healthy, repeated inbreeding over time can lead to physical problems such as heart issues and sterility. Riley and other experts said the only way to prevent future inbreeding is to create a wildlife corridor across the 101 Freeway.
“Unfortunately, this litter of kittens is the latest example of first-order inbreeding in which a father mates with his offspring,” Riley said. “Allowing safe passage from the Simi Hills into the Santa Monica Mountains is our best shot at addressing the lack of genetic diversity in the local population.”
The cost of building a tunnel under the freeway has been estimated at $10 million.
The 101 and 405 freeways as well as farming and development completely surrounding the Santa Monica Mountains are barriers to the movement of most four-footed wildlife, essentially confining them to an island.
P-12 is the only radio-collared mountain lion documented to have successfully crossed the 101 Freeway in the 13 years the big cats have been studied. He crossed from the Simi Hills over to the Santa Monica Mountains near the Liberty Canyon exit in Agoura Hills in 2009.
The Liberty Canyon exit has long been identified as the best location for establishing a wildlife crossing because of the natural habitat on both sides of the freeway and its connection to vast areas of open space.
In October, a mountain lion attempting to cross into the Santa Monica Mountains was struck and killed by a car in the same location.
“The fact that this young male chose to cross, unsuccessfully, at Liberty Canyon shows how critical this wildlife corridor is for maintaining genetic diversity in the Santa Monica Mountains,” said Riley. “If this most recent lion had successfully crossed and mated, he would have brought new genetic material to the population south of the freeway.”
The NPS has twice applied, unsuccessfully, to secure $10 million in federal transportation funding to build a tunnel under the freeway. Kate Kuykendall, public affairs officer for the Santa Monica Mountains National Recreation Area, said a third attempt will be submitted shortly. The project would likely involve collaboration between a number of public and private agencies, such as the national Department of Transportation, Caltrans and the National Wildlife Federation, she said.
The Los Angeles Times reported last week that the Santa Monica Mountains Conservancy (SMMC) is considering whether to provide $200,000 to the California Department of Transportation (Caltrans) to study wildlife crossing alternatives at Liberty Canyon. Dash Stolarz, director of public affairs, confirmed that the issue is expected to be on the agenda for SMMC’s board meeting February 27.
Joe Edmiston, SMMC’s executive director, favors a landscaped crossing over the freeway. Such crossings have been used successfully in Canada, Europe, and the U.S. Northwest, but the estimated cost of building an overpass as opposed to a tunnel, “is yet to be determined,” said Stolarz.
“I’m arguing pretty aggressively for an overpass,” Edmiston told the Times.