In Rare Feat, Mountain Lion P-61 Crosses 405 Freeway

One of the mountain lions living amid Los Angeles’ urban sprawl was able to cross the 405 Freeway last month, wildlife biologists said Thursday.

The cat known as P-61 was able to complete the feat in the Sepulveda Pass that connects Brentwood and the San Fernando Valley on July 19, traveling sometime between 2 and 4 a.m. when the interstate is less busy, according to a news release from the Santa Monica Mountains National Recreation Area.

It’s rare for the big cats to successfully traverse the well-trafficked freeways that segment their territory.

P-61, a male believed to be about 4 years old, is the first cat outfitted with a GPS-collar who has crossed the 405 Freeway. Biologists began collaring cats 17 years ago to study how they survive in the urban environment.

Another cougar, P-18, was hit by a car and killed while crossing the 405 in 2011, and another lion not part of the study was fatally struck there in 2009, officials said.

In 2017, kittens P-51 and P-52, were killed by cars in separate incidents while crossing the 118 Freeway — just a month after their mother, P-39, had suffered the same fate.

At least 18 mountain lions have been fatally struck by vehicles in the area studied by national park staff since 2002.

The most famous freeway-crossing cat is perhaps Griffith Park resident P-22, though little is known about his journey east since he wasn’t collared at the time. DNA tests indicate he was born in the Santa Monica Mountains before traversing both the 405 and 101 freeways about seven years ago, according to researchers.

The freeways effectively fence the cougars in to isolated habitats, causing seriously low genetic diversity and threatening their long-term survival.

Biologists say they’ve observed numerous mountain lions going right up to the freeway’s edge without crossing.

Plans are in the works to construct wildlife crossing bridges that would allow big cats to move freely across both the 101 and 405, but it’s unclear when that would actually come to fruition.

Another lion is believed to live in the same relatively small area between the 405 and 101 freeways as P-61. Officials have been spotting the uncollared male occasionally on surveillance cameras for the past five years.

“It will be interesting to see if P-61 stays in the area, whether he decides to challenge the uncollared lion, or if he heads back to the other side of the freeway,” Jeff Sikich, one of the biologists in the study, said in a statement. “Although it’s a relatively small area of habitat, it’s certainly larger than the Griffith Park area and does have a patchwork of natural areas.”

P-61 joined the research project in October 2017. When he was last captured, he weighed 119 pounds.

The most recent cat to join the study is P-75, a female found at a trailer park in the Pacific Palisades in late June. She’s the 75th mountain lion to be a part of the study, but only the 10th currently alive and active.

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