Lion Killed on Freeway was Part of Research Study

A young mountain lion from the Santa Monica Mountains was struck and killed while attempting to cross the I-405 Freeway early Tuesday morning. A National Park Service official said although the death was tragic, the attention it has generated will help to make the mountain lion a less-mysterious creature to the general public.

NPS biologists identified the dead mountain lion as P-18. He is one of the 21 mountains lions that have been captured, collared and tracked by the NPS since 2002.

A vehicle struck the mountain lion on the southbound 405, just south of the Getty Center on-ramp between 4 a.m. and 7:30 a.m. The driver did not report the collision. P-18 was found at 7:30 a.m. when traffic started backing up because he blocked a portion of the lane, said Christie Brigham, chief of planning, science and resource management for the NPS' Santa Monica Mountains National Recreation Area. 

NPS biologists began studying P-18 and his two siblings when they were about one-month-old in April 2010. When the radio-collared mother left the den to go hunting, the researchers collared the three kittens. One kitten died at age three months and the two survivors stayed with their mother for nearly a year before going their separate ways. 

P-18 was most recently recaptured and studied at the east end of Malibu Creek State Park on Aug. 1. He weighed about 100 pounds and was found to have successfully killed at least one adult deer (the main prey of mountain lions), according to the NPS.

After separating from their mothers, males may take up to a year searching for their own "home range," or territory, dispersing away from their parents. 

"Male lions will force other males out of their own territory," said Woody Smeck, the NPS' superintendent for the Santa Monica Mountains National Recreation Area. "P-18's father (P-12) may have been flushing his own son out to the east, [forcing him to make the 405 crossing attempt]."

The Santa Monica Mountain range is somewhat of a closed environment, like an island—hemmed in by the Pacific Ocean and the 101 and 405 freeways. The NPS' radio collar studies have shown that male mountain lions establish large territories. The first mountain lion tracked in the program, P-1, roamed nearly the entire range of the Santa Monica Mountains—from Camarillo to Topanga State Park to the 101. The researchers have also learned that mountain lions almost never attempt to cross the 101 or 405 freeways.

"They go up to the 101 and the 405, and then turn around," Brigham said.

No mountain lions have ever been documented east of the 405; and only one has been observed crossing the 101 (a camera in 2009 caught him using the underpass at the Liberty Canyon exit to cross from the Simi Hills into the Santa Monica Mountains). So only two or three male mountain lion territories appear to exist at any given time in this area. The young males have a difficult time finding new territories, according to the NPS. The "island effect" also limits the genetic diversity of the species, which sometimes results in inbreeding.

NPS biologists have captured and collared 17 mountain lions in the Santa Monica Mountains since 2002. Another four were collared in the Simi Hills and Santa Susanna Mountains. The biologists use an alpha-numeric system to identify all captured animals; using the letter "P" for puma (the genus name) to designate the mountain lions. In addition to the 21 mountain lions that have been named, at least one adult male appears to have eluded capture.

Smeck said there is a silver lining in P-18's tragic demise.

"This particular incident has generated a lot of attention and interest," he said. "The stories that are out there are pulling the veil of mystery away from these animals. I think they co-exist quite well with people. Their population has been stable over the 10 years we've studied them, and the fact they still exist at all is an incredible success story for Southern California."

Smeck said the publicity could help toward achieving the NPS' goal of connecting isolated areas of parklands with interlinked green corridors to allow wildlife safe movement from one area to another. This would enable them to disperse into new territories and avoid inbreeding. 

"The key is making sure we can create viable crossings [for wildlife]," Smeck said. "They’re already using a few underpasses; and on the 118, they're using an equestrian tunnel. We know they work."

Brigham said the NPS is working closely with Caltrans to establish wildlife-crossable freeways. They have begun the process by applying for a federal grant that is currently under review to construct a wildlife crossing tunnel near the Liberty Canyon exit off the 101. A response to the application is expected by February.