The male mountain lion known as P-61 has successfully crossed the 405 freeway, an extremely rare passage for Santa Monica Mountains cougars hemmed in by freeways and the ocean, the National Park Service announced Thursday.

The GPS-collared lion, thought to be about 4-years-old, crossed the massive freeway in the Sepulveda Pass area in the predawn hours of July 19, the park service said.

It’s the first time in the 17 years the lions there have been tracked that a collared lion has successfully made the treacherous journey.

Los Angeles’ most famous cat, P-22, crossed both the 405 and 101 freeways to make his home in Griffith Park more than seven years ago, but he was not collared at the time and little is known about his travels to get there. Researchers say there is an uncollared male in the area between the 405 and 101 where P-61 now is, but little is known about him.

At least two cougars have been hit by cars and killed trying to cross the 405, one in 2009 and another in 2011.

“Although P-61 successfully crossed the 405, his feat is a reminder of how challenging Southern California’s road network is for mountain lions and other wildlife, as well,” said Jeff Sikich, biologist for Santa Monica Mountains National Recreation Area. “Others haven’t been so lucky.”

Give it up to male mountain lion P-61! 💪🏽😃👊🏽🔥

This four-year-old cat somehow managed to cross the 405 Freeway in the Sepulveda Pass area on the morning of July 19 between 2 and 4 a.m., according to National Park Service biologists. That's a rare and amazing feat! (1 of 4) pic.twitter.com/aSsS2LESge — Santa Monica Mtns (@SantaMonicaMtns) August 8, 2019

Males are more territorial than females, often killing rivals, particularly younger males. They also require more turf than females. That raises questions of what will happen now with two males in the area between the 405 and 101 freeways. The uncollared lion there has been captured by surveillance camera footage dating back 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,” said Sikich. “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.”

Man-made crossings planned

Lions in both the Santa Monica and Santa Ana mountains are at risk of extinction because of inbreeding and the lack of genetic diversity, with biologists and others proposing man-made freeway crossings to help bring fresh genes into the areas. P-61’s crossing does not change that situation because he crossed out of the area that needs new genes and there are no known females were he is now.

GPS monitoring has found that the lions in both ranges approach the freeways with some regularity — likely indicating a desire to seek out new territory — but rarely cross.

The Santa Monica mountain lions west of the 405 live in a habitat island of about 230 square miles bordered by freeways and the Pacific Ocean. There are an estimated seven adult lions there — five females and two males — along with eight kittens and subadults, according to a study released earlier this year.

The small population makes the lions slightly more at risk of extinction than those in the larger Santa Ana Mountain range, which straddles the Orange, Riverside and San Diego county lines. That habitat island is nearly 600 square miles with an estimated 16 adult lions — 11 females and five males — plus 13 kittens and subadults.

Winston Vickers, a veterinarian at UC Davis who studies the Santa Ana mountain lions and contributed to the report, said records regarding cats killed on Interstate 15 are incomplete but that from 2013 to 2018 there were four confirmed deaths.

“Most lions we’ve tracked have just approached (Interstate 15) and not even tried it,” Vickers told the Southern California News Groups earlier this year. “They just turned back.”

A $60-million wildlife bridge over 10 lanes of Freeway 101 at Liberty Canyon in Los Angeles has been designed, but it’s far from ready for groundbreaking. Fundraising for the Santa Monica Mountains project, begun in 2015, has been steady but slow, with $8.4 million raised, according to #SAVELACOUGARS, the coalition raising the money.

To help the lions in the Santa Ana Mountains, students and faculty at Cal Poly Pomona have developed alternative plans for a crossing of Interstate 15 in Temecula. The Nature Conservancy spent $1.7 million to buy 73 acres next to the freeway for use as part of a crossing, but there is no fundraising yet for construction.

Successful passage

The most famous of the region’s mountain lions — which are also called cougars, pumas and panthers — are the few who’ve successfully crossed freeways. At the top of the list is the male known as P-22, born in the Santa Monica Mountains in 2009.

In the case of P-22, he crossed both the 405 and 101 freeways to make his home in Griffith Park — where he’s the only cougar and isn’t breeding. Nonetheless, the Hollywood bachelor has been featured in national publications and has his own Twitter, Facebook and Instagram pages.

More significant biologically are P-12 and P-45, in the Santa Monica Mountains, and three cougars in the Santa Ana Mountains. Those are the five cats who in the past 15 years have successfully crossed freeways to bring fresh genes into those ranges.

P-12 crossed the 101 freeway from the north at Liberty Canyon in 2009 and has fathered at least eight litters. That initially helped diversify the gene pool, but now his genes have become part of the limited diversity and he’s begun mating with his own offspring, twice with a daughter and twice with a granddaughter.

P-45 crossed in the same area and was first identified in the Santa Monica Mountains in 2015. It’s unclear whether he’s alive or has offspring.In the Santa Ana Mountains, M86 made it across Interstate 15 from the east, around 2011. He was found dead in 2015 and is believed to have sired 11 kittens, including a litter with one of his daughters.

M119 made the trip across Interstate 15 and was first identified west of the freeway in 2013. There hasn’t been a confirmed sighting of him since 2016. It’s not known if he is alive or has offspring.

M151 is believed to have also made the trip over the Interstate 15. He was killed by permit in 2016 after attacking domestic animals south of the Ortega highway. It’s not known if he has offspring.

Click here to see a National Park Service video of P-61.