They started life as city boys. In Washington, Seth Riley (at right in the photo) grew up interested in snakes (not the political kind), and in Chicago, Jeff Sikich sometimes went fishing with his grandfather. How things change. Both are now hands-on wildlife specialists in the long-running mountain lion project at the National Park Service in the Santa Monica Mountains, where they monitor the region's biggest surviving carnivore — about 10 or 15 cats, as far as they know. In all, the project has tracked about 40 over 13 years. Sikich, who has also put tracking collars on jaguars in the Amazon and tigers in Sumatra, has collared 11 mountain lions here, among them stars like Griffith Park's P-22, and P-41, recently discovered prowling the Verdugo Mountains. Like the mountain lions, Riley and Sikich know the urban-wildland interface face to face.
What's the status of mountain lions in these parts?
Riley: There's good news and bad news. We have lots of high-quality habitat in Southern California. Our population in the Santa Monica Mountains is reproducing; survival rates for adults are pretty high; they have plenty of deer, which is their main prey. The bad news is none of the areas, specifically the Santa Monica Mountains, is big enough for a viable population.
Sikich: An adult male mountain lion can roam from 200 to 250 square miles. The mountains are roughly 275 miles, bordered by hard barriers — the ocean, the freeways, the Oxnard agricultural fields. We can fit maybe one or two adult males and a sprinkling of four to six females — females have a much smaller range.
Riley: The leading causes of death in our area are from adult male mountain lions killing younger ones. That's because the young animals can't disperse. Typically all male mountain lions and half of the females disperse to find their own range. Here they try [but] run into freeways and development — and into adult males — and get killed.
P-12, a young male in the Santa Monicas who actually survived [crossing the 101 Freeway], [has] bred extensively — he keeps fathering litters. In one of his most recent litters, all three [young cats] dispersed and two of them crossed the 101, which was surprising.
What's become of plans to build a wildlife overpass or underpass for the 101, to provide access to more habitat?
Riley: We have almost nothing in the way of good crossings on the 101. We're a long way from building anything. We're working hard on it, with Caltrans and state parks and many different groups.
Sikich: Every year it seems like we're closer and closer to getting something built.
What's the holdup?
Riley: Money. A tunnel would [cost] less but would not be as effective for many different species as an overpass. When the freeway was built, no one was thinking about trying to maintain connections for wildlife. When you're conserving mountain lions, that's probably helping to conserve a lot of other smaller things too. [An overpass] would be a huge statement about conservation and Southern California and the fact that this area cares about the environment and wildlife.
Make the case for why we need mountain lions.
Sikich: Our mandate is to protect and conserve all species. We don't know all the complicated ecological roles these animals play in our mountains, but we do know the mountain lion is our last remaining large carnivore.
What other large carnivores were here?
Sikich: Grizzly bears and wolves. The mountain lion is preying on deer, so if you remove lions from that equation, we don't know what would happen. It's an experiment we don't want to conduct. Besides these complicated ecological roles, to many people's minds mountain lions play a spiritual role. All large carnivores bring out a sense of wildness in people. If we didn't have these large carnivores in our mountains, it would be a sad day.
The last Californian killed by a mountain lion was evidently repairing his bike when he was attacked on a wilderness trail in Orange County in 2004, but people still fear that.
Riley: It's incredibly rare. Unfortunately we don't know why it happens in the situations it does. We've studied 41 mountain lions over 13 years [in the Santa Monica Mountains region] and never had any evidence of aggressive behavior toward people — and that's in a fragmented area with millions of visitors every year. These mountain lions are seeing us, and they're running the other way.
The news media and social media went crazy when P-22, the Griffith Park mountain lion, was found under a house.
Sikich: P-22 has multiple Facebook accounts, Twitter accounts, even a Tinder account!
Riley: Some of the tweets are very funny, like "Don't call me P-22, my name is Raoul." The coverage helps people become aware and concerned about mountain lions and wildlife generally.
Your mandate — rather like the "Star Trek" prime directive — is to study and not to interfere. In 1999 you were out tracking a female, P-4, and her kittens, and realized she was being attacked by her mate.
Sikich: We had an adult female, an adult male and their offspring. We were interested to see what happened. We followed these animals. All of a sudden they had this confrontation. Two of the kittens ran by me; there were vocalizations for about three hours. These adult males definitely overpower the females. If he wanted to go in and kill her right away [he could have]. Maybe he was attempting to breed. We just don't know what he was doing.
And then you got the "mortality signal" from her collar.
Riley: Two days later we hiked in. We saw P-1 just hanging out. We waited for him to leave and Jeff and I went and picked her up. It was relatively unusual: Males will kill other males; there are hardly any cases we know of where adult males have killed females they've mated with. That seems like a bad strategy.
Could this be stress behavior from confined habitat?
Riley: It's hard to be sure, but we do think some of these [unusual] behaviors are more common here. We've seen multiple instances of males mating with their daughters. We think it's made more likely by the fact nobody can disperse.
Sikich: This species used to be coast to coast, from the bottom of South America almost to the Arctic. In North America they were basically eliminated everywhere east of the Mississippi except Florida. Florida panthers got down to fewer than 30 animals. They actually had inbreeding [problems] — holes in the heart, major reproductive issues. There was a lot of concern about, are we messing up this work, [but] they brought in eight females from Texas, five of whom reproduced, so now the population is maybe close to 200 and all the genetic issues basically disappeared.
California's state population isn't at risk, but the local ones are isolated, like the new guy in the Verdugos, P-41.
Sikich: He's an adult, maybe 8 years old. In the wild, 12 years is an old mountain lion. The Verdugos are a small patch of habitat surrounded by development and freeways, roughly 19 square miles. We're really interested about whether he's crossing the 210 and getting into the San Gabriels.
Riley: Griffith Park is even smaller, like eight square miles. It's amazing that [P-22] has been there for three years. As far as we've seen, that's the smallest home range anyone's recorded for a male adult. There's plenty of prey, but he's been there for three years now and there's no breeding opportunities for him.
I read that the first condor chick born in the wild in Big Sur in a century was being treated for lead poisoning, from eating the carcasses of wildlife that had been shot. What about poisons in the food chain from household rat poisons and the like?
Sikich: Two of our study animals, P-3 and P-4, died of anti-coagulant toxicity. We believe they killed and ate a coyote that had killed or eaten a ground squirrel [that had eaten] poison put out by a homeowner or golf course or apartment complex. Most of the mountain lions we've tested have definitely been exposed to these poisons. That definitely is an issue.
So many species get to the edge of extinction. Do you ever feel that you're fighting a rear-guard action?
Sikich: I'm hopeful mountain lions can be here in the future. The habitat is good for that; there's momentum about a wildlife crossing.
What should we call them? Mountain lions? Cougars? Pumas?
Sikich: Any. The mountain lion holds the Guinness record for the animal with the most names!
This interview has been condensed and edited. firstname.lastname@example.org