In the Wake of the Wildfires, Mountain Lions Have Found Themselves in a Transformed World

Recent blazes have decimated the Santa Monica Mountains—and the habitat of L.A.’s big cats
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Somehow P-64 figured it out. Unlike his fellow mountain lions in the Santa Monica Mountains, the four-year-old cat—a young adult by mountain lion standards—learned how to safely get from one side of the 101 to the other.

Eighteen lions have died after being struck by vehicles on roadways in and around the Santa Monicas since 2002. But P-64 was a pioneer: Rather than dart across ten lanes of traffic at Liberty Canyon in Agoura Hills, he used a car-free route. P-64 discovered a culvert—a large pipe that allows creek flows to run beneath the freeway—and turned it into a subterranean bridge between the hills on either side of the 101.

Why he even tried it is a mystery. Smaller animals like raccoons, skunks, and possums frequently enter drain pipes. But mountain lions almost always avoid artificial structures, as well as most other human development.

The culvert spans 640 feet, not far from where wildlife advocates hope to build a $60 million landscaped overpass that would help mountain lions avoid the 100,000 vehicles that surge through here daily. Go inside and quite literally there’s no light at the end of the tunnel because of a slight jog in the middle. Not until the reinforced concrete pipe running from the freeway’s south side reaches two corrugated steel pipes leading to the north can you finally see all the way through.

Pitch-black, it’s an alien, intimidating underworld. Shine a light, and a tag above the steel pipes reads: “OI! OI! ILL BOYZ.” The crunch of footsteps on piles of valley oak leaves that have blown inside the roughly six-foot-wide openings echo with a startling metallic timbre. After storms, runoff pours through. But P-64 was undaunted. He used the culvert often enough that his territory came to include both sides of the freeway: from the Santa Monicas into the rolling Simi Hills and across the 118 into the Santa Susana Mountains, a vital connection to the lion populations of the San Gabriel Mountains.

In the brief nine months Santa Monica Mountains National Recreation Area (SMMNRA) biologists tracked his movements, P-64 traversed Southern California freeways more than 40 times. During the 17 years biologists have studied lions in the Santa Monicas and outfitted them with GPS radio collars, only four of the more than 70 cats monitored had ever successfully crossed the 101 even once.

P-64’s innovation earned him a nickname. He became known as the “Culvert Cat.” But for all of his cunning, he couldn’t survive November’s 96,949-acre Woolsey fire.

The severity of Southern California wildfires is typically measured in two ways: by acreage burned and the number of structures destroyed. By those standards, the Woolsey fire was the Santa Monicas’ most catastrophic blaze ever, destroying at least 1,600 structures and charring 250 percent more land than 1993’s 38,000-acre Green Meadow fire.

Those statistics tell only part of the story. Once the inferno was contained, 42 percent of the natural areas in the Santa Monicas and two-thirds of the wildlands in the Simi Hills burned.

“It was a massive ecological impact,” says Dr. Seth Riley, the SMMNRA wildlife ecologist who has headed the mountain lion study since its inception. (The research seeks to better understand “how mountain lions survive in an increasingly fragmented and urbanized landscape,” according to the National Park Service.)

When the Woolsey fire broke out near the Santa Susana Field Laboratory in the Simi Hills on November 8, park service biologists were actively tracking 13 mountain lions. Large animals like lions and mule deer, the cats’ favored prey, tend to fare better during blazes than smaller, less-mobile creatures that can’t cover enough ground to escape the flames. But the scale and intensity of the Woolsey fire was unprecedented.

A week or so after the fires began, there was good news: Based on GPS signals, 12 lions had survived. Many apparently were outside the fire zone, either in unburned areas east of Malibu Canyon or west of the heart of the conflagration. At this point P-64 was somewhere in the Simi Hills and the dead cat was P-74, a young male collared only two months earlier, who perished November 9 in the western range between Yerba Buena Road and Mulholland Highway. That was the day the fire blew up to 70,000 acres.

Especially in the immediate aftermath of a wildfire, the impact on wildlife is difficult to gauge. But once the blaze was out and the ground cooled, the surviving lions found themselves in a drastically transformed world. “In a lot of areas it was just a moonscape,” says Riley. “There was nothing left. We’re looking at a huge, unintentional ecological experiment. You have a population of large carnivores that’s already isolated by freeways and development. Then you burn close to half of their natural area.”

The ground was scorched black. The stands of chaparral and tangles of creekside vegetation in canyons that the lions use to move undetected through the mountain range were reduced to charred stumps and broken branches. The destruction of their habitat meant that the lions faced additional challenges to their survival, especially related to hunting.

woolsey fire aftermath
November’s Woolsey fire burned more than 80 percent of National Park Service land in the Santa Monica Mountains.

Ted Soqui

The fate of an alpha predator is inseparable from the fate of its primary prey. Temporarily at least, the mountain lions in the Santa Monicas will likely find fewer deer to eat. A 2015 study that examined how mountain lions respond to wildfire shows that during the 2003 Cedar fire in San Diego County, about one-quarter of radio-collared deer perished, according to T. Winston Vickers, a wildlife veterinarian at the UC Davis Wildlife Health Center and coauthor of the report. “It’s amazing that anything can es cape during these fast-moving fires,” he says.

And because mountain lions are ambush predators that conceal themselves before pouncing on deer rather than pursuing their prey over distance, the loss of the chaparral and canopy will further hinder their hunting success.

But in the short term, wildfires tend to be more disruptive than catastrophic for mountain lions. Vickers says the animals adjust to the new normal by finding different routes through their territories. Research shows that the San Diego County fires didn’t lead to more turf battles among the highly territorial cats, though the situation could be different in the Santa Monicas where Vickers says the territories are closer together.

According to the 2015 study, surviving deer can begin to prosper after a fire, especially if they have access to nearby unburned areas to hide. The deer benefit both from the lions’ loss of ambush cover and from the greater nutrition found in fresh growth emerging in charred areas. Thanks to decent rains in late fall, many burned areas in the Santa Monicas have started to green up with both non-native grasses and native shrubs, most of which resprout quickly after fires.

“We know that there can be an increase in prey numbers during the two- to seven- year postfire period, and so in that sense fire can be good for lions,” says Vickers. “But the real question is: What’s the big long-term effect?”

As adapted to periodic wildfire as the Santa Monicas are, the increase in fire frequency because of drier conditions and more human ignition sources threatens to permanently alter the mountain range’s vegetation mix. Chaparral, not a single species but a community of shrubby plants comprised primarily of chamise and ceanothus in the Santa Monicas, typically grows back to its prefire status, presuming there has been an interval of 15 to 20 years between blazes. Historically in the state, according to the California Chaparral Institute, large fires burned through stands of chaparral only every 30 to 150 years.

But in the Santa Monicas, larger and more frequent fires now threaten to convert chaparral into non-native grasslands, a landscape ill-suited to mountain lions. Consider this: Both the Woolsey fire and the simultaneous 4,531-acre Hill fire, which began near Camarillo, raged through terrain that had burned just five years earlier during 2013’s Springs fire. Based on park service research, portions of the Santa Monicas have burned ten times since 1925, an average of once every eight years.

Even before the Woolsey fire, mountain lions in the Santa Monicas faced a host of existential challenges. To borrow writer Carey McWilliams’ description of Southern California, the mountain range is truly an island on the land for the cats.

Hemmed in by the Pacific Ocean on the south and virtually separated by the 101 from neighboring Southern California ranges, the cats largely live in isolation. As much as Angelenos have celebrated P-22, the Instagram-ready lion photographed in front of the Hollywood Sign and who has survived for six years in Griffith Park, elsewhere in the range an epic of territorial battles, incest, and familicide plays out.

“We know that there can be an increase in prey numbers during the two- to seven- year postfire period, and so in that sense fire can be good for lions. But the real question is: What’s the big long-term effect?”

With territories that can span 200 square miles, generally all young males and usually half of juvenile females disperse from their birth areas, both to establish their own domains and especially to avoid confrontations with adult males, who will attack and kill perceived rivals—even their own cubs. In perhaps the most notorious incident, a male lion killed one of his sons and its mother when she tried to protect her offspring.

“Over the course of the study, the biggest source of mortality in our mountain lion population has been other mountain lions,” says Riley. “Fighting and killing each other, in particular males killing other males, mostly subadults. That’s something that occurs in other populations, especially unhunted ones. But we certainly think it’s exacerbated here by the fact that the animals can’t disperse because of freeways and development.”

Such isolation also reduces the genetic diversity of the local lion population. The arrival of a litter of kittens—absolutely adorable with their spotted coats and blue eyes—always inspires hope but often comes with a note of caution. Many of the litters are a product of inbreeding, be it fathers with daughters or brothers with sisters. One batch of kittens was positively Targaryenesque in its incestuous complexity: In 2018, P-53 gave birth to a litter likely sired by P-12. That made him the kittens’ father, grandfather, great grandfather, and great-great grandfather.

All of which makes P-64’s death even more significant. Long before he entered the culvert, P-64 had made the challenging passage across the 118. Captured and collared near what would later be the ignition point of the Woolsey fire, he was only the second lion from mountains beyond the Santa Monicas to find his way into the range. He brought an infusion of fresh DNA into the otherwise stagnant gene pool; P-64 is believed to be the father of four female kittens born in May 2018.

When the Woolsey fire broke out, P-64 was prowling the core of his range. He began moving away from the flames, south through the Simi Hills and right toward Oak Park, Riley says. Then the lion headed north again.

“We speculate that he got up to the edge of development and then he had to make a decision: Do I keep going into this development or do I turn around and go the other way? It’s right in the middle of the fire, so there were probably crazy amounts of firefighting activity. We can’t read his mind, but that’s what probably happened. And what we do know is that he turned around and went the other way for a long distance. For a couple miles. He’s aware that the ground is hot, but what can he do? It’s hot everywhere around him. His paws were probably already badly burned by that time.”

Biologists received the final transmissions from P-64’s collar November 28, a sign that he was no longer moving, and biologist Jeff Sikich found the cat dead December 3, malnourished and with burned paws that prevented him from hunting.

P-64 and the thin thread of the culvert provided a tenuous connection to a healthier future for the lions in the Santa Monicas. Until another cat finds a dependable way across the freeway or the wildlife overpass gets built, the Santa Monica lion population will remain cut off on its fragmented island.

“There are these individual lions that through their curiosity end up finding some odd passageway that no other animal has used,” says Vickers. “It’s a testament to their individuality. These sort of one-off animals who find their way where others haven’t can be really critical. By regularly going through, P-64 left scent markers that might lead others to use that culvert. I have to think that once one lion started using it, there had to be potential for others to follow. So that’s the big disappointment of his fate.”


RELATED: How Does California Clean Up After a Disaster Like the Woolsey Fire? 


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