Last August, driven by the instinct to establish his own territory and find a mate, P-32, one of only a handful of male mountain lions left in the Santa Monica Mountains, navigated three freeways before being struck and killed by a vehicle, the 13th lion to die on a highway in the area since 2002.

There’s only around a dozen lions left in the Santa Monica Mountains, the range running from the Pacific Ocean through Los Angeles, America’s second-largest metropolis. The area cats are trying to escape because they’re trapped on an island of habitat, fenced in by freeways, hostage to urban development and isolated from the rest of their population. The last documented fresh blood entered the area in 2009, when a single male successfully crossed the U.S. 101. That male mated once, and introduced much-needed fresh genes.

An adult male’s home range can extend over 500 square kilometers. The Santa Monicas encompass about 700 square kilometers. There’s simply not enough land for each of the several males left to establish new territory and find mates and therefore not enough fresh genetic material to keep this population stable.

To further complicate matters, inbreeding, lions killing one another over territory and for mates and rodenticide from eating animals infected by poison are also destroying their population. Sure, there are neighboring mountains with viable lion populations—the Santa Susana Range to the north, which borders Los Padres National Forest and Angeles National Forest to the east—but they might as well be on the moon, because lions can’t cross the freeway and simply can’t get in.

NPS field biologist Jeff Sikich setting up remote cameras at a deer kill site. Credit: Adam Popescu

Hiding in plain sight

The kill was only a around 100 meters from the road, but you wouldn’t know it from driving by. The scene was shrouded by a patch of bay trees and thick chaparral, up a steep incline that weaved into a drainage, muddy from just a few centimeters of rain the night before, the first in months. There wasn’t much left of the victim—a young mule deer. Just the head, hooves, entrails, an exposed rib cage and a patch of gray fur that its killer licked off with a bristled, sandpaper-textured tongue. With the incident captured on camera, the culprit’s identity was indisputable. “A female mountain lion with a cub,” says Jeff Sikich, a National Park Service (NPS) field biologist who’s spent the last 13 years studying lions in the Santa Monicas.

Sikich, renowned for humane capture techniques, and a career that’s included jaguar, leopard and tiger tracking, used the cats’ GPS radio collar signature to pinpoint their position, and remote cameras to capture the feeding. Popping the camera’s memory card into his laptop, he rifled through images from the night before: a kitten with leopardlike spots, centimeters from the camera. And its mother, displaying muscled front shoulders and powerful limbs adapted for running down big game. Her sculpted and proportioned body counterbalanced by a long tail. All motion, grace, speed and strength.

Just because we don’t see lions doesn’t mean they don’t walk in our midst—or that they don’t see us. Large, close-set eyes give them such sharp depth perception that these ghost cats can gauge the exact distance of any prey, even of humans.

Once these lions roamed our very backyards, the hills we jog, the city itself. Now the Santa Monica lions, the only apex predator operating within a megacity, live on borrowed time. “They’re looking for a way out,” Sikich says. “Especially young males. Out of all the young males we’ve followed in the Santa Monicas, and I think there’s been 16, none have lived to the age of two. All have been killed either by being hit on a freeway or running into the adult male in the Santa Monicas.”

Being trapped in a small area is also the source of anomalous behavior, with fathers mating with daughters and granddaughters, and repeatedly killing of relatives with dominant males slaying sons and brothers. Normally, males kill cubs to bring their mothers back into estrus. But it’s rare for them to kill their own offspring. Here, this incestuous tragedy is common.

Sikich estimates the carrying capacity for the region south of the U.S. 101, where his lions are trapped, is “one or two adult males, roughly four to six adult females and kittens, 10 to 15 tops,” numbers that “genetically cannot sustain a population in the future without connectivity to areas in the north, across the freeway.” Sikich doesn’t mince words when he says this group will die if something doesn’t change.

Jeff Sikich retrieving images from the deer kill site. Credit: Adam Popescu

Connecting urban wildlife

Genetic diversity among the Santa Monica cats is the lowest of any lion population in North America, except for the Florida panther. The precedence is troubling. In Florida decades of inbreeding led to reproductive failure. Lions from Texas were introduced to buoy that population, which has since stabilized. But biologists here have likened translocation to a Band-Aid. Yes, there’s enough game to support local lions, and despite being on our doorstep, ample habitat to keep them here; Sikich says there’s no evidence that they’re even turning pets into easy meals. The issue is that they’re stuck. With no new DNA, the clock’s ticking into the ultimate signs of inbreeding: sterility. “Without increasing connectivity and building wildlife crossings, mountain lions are definitely going to be lost here,” says wildlife ecologist Seth Riley with the National Park Service at Santa Monica Mountains National Recreation Area, who has led the NPS mountain lion study since it began in 2002. Riley’s talking about the proposed crossing at Liberty Canyon, a safe passage in an undeveloped stretch of 101, near Agoura Hills. The plan is to build a bridge between natural habitats on both sides of the freeway. It’s been done in Montana and Canada, but never on this scale—never over 10 lanes of pavement.

Liberty Canyon is ideal because it’s the most direct path between the surrounding mountains, and GPS data has shown lions frequent the area. This bridge will benefit other species, as well: bobcats, deer, reptiles, all have shown genetic differentiation between populations separated by freeways. The vision is in place. The issue is cost. “It is expensive,” Riley admitted as cars whizzed by on one of the world’s busiest thoroughfares—175,000 vehicles a day. “Estimates are $30 million to get across 101, and then $50 million, which would be the best thing, to cross 101 and a road right nearby. Certainly a lot, although in the context of what it costs to do transportation projects, it’s actually not that much.”

Earlier this year, the project received $1 million in state funding. And the plan’s building support. CalTrans, the transportation bureau responsible for all state roadwork, and a coalition of local politicians and 501(c)(3) nonprofits have teamed to search for financial backing. But the biggest advocate could be a 46-year-old fundraiser with a 15-centimeter puma tattooed on her left bicep. Although NPS can’t lobby for funds directly—they establish the need with research—she can.

Beth Pratt-Bergstrom is the National Wildlife Federation’s California director, and the founder of Save LA Cougars. To hear her tell it, she’s “not your average tree hugger. I have an MBA, I’m all about capitalism and the value of things. For too long we haven’t incorporated the cost of maintaining healthy ecosystems and wildlife, and this is a pretty cheap solution.”

Although it’s hard to equate such sums with frugality, Pratt-Bergstrom has a tested plan: a combination of private philanthropy, plus state and federal dollars already earmarked for conservation. Which means it won’t be a ballot issue for taxpayers. This mix of public and private has worked in the Great Lakes and the Everglades, where more than $100 million was raised, and recently in Silicon Valley, where tech tycoon Larry Ellison donated $50 million for a wildlife sanctuary. “Fifty million should be scaring me off, but it’s really a capital campaign rather than a wildlife campaign,” she continues. “This is a chance for Los Angeles, an area that has long been beat up as the environmental bad guy, to redeem itself and set an example for the world.”

Sikich showing remote cam video from the night before. Credit: Adam Popescu

So far, not much has been raised, about $1.3 million. That amount is due to another cat’s celebrity, P-22, the lion, who in 2012, braved two freeways and the Hollywood hills, before settling in Griffith Park an 20-square-kilometer islet east of downtown where he’s now the lone prisoner.

Pratt-Bergstrom says with fundraising only starting in September, she has yet to press her foot on the gas. Still, the wheels seem greased.

CalTrans is making improvements to the proposed site, installing and modifying fencing to direct wildlife away from the freeway, and the Mountains Recreation and Conservation Authority, a local land management agency, is vegetating the existing undercrossing. A $200,000 CalTrans environmental design study has been funded, and it’s expected the project could break ground in 2019.

California State Sen. Fran Pavley, whose Agoura Hills home is just minutes from the proposed crossing, has helped organize focus groups and project support, describing it both as an opportunity for the public and our responsibility. “Now, we need local, regional and national financial backing,” says Pavley.

“There’s no bad guy here,” Pratt-Bergstrom says. “CalTrans wants to do this, the land is fine, this is really a matter of raising the funds. When we talk about the value for this crossing and whether the price tag is worth it, most of us in California, we’ve voted on conservation in ballot measures, we want mountain lions in the landscape. Without this happening, mountain lions will disappear.”

How long can the Santa Monica lions wait before the effects of isolation are reversed? If the construction begins, will it be completed in time? Because if one or both of the local males die, it’s curtains for the Santa Monica lions.