Mountain lion. Photo: California Department of Fish and Game.

But after a bit of research, I learned that tranquilization is never an option in situations like this—it takes up to 30 minutes for the tranquilizer to take effect, during which time the situation could turn much worse. Wardens with the California Department of Fish and Game don’t even carry tranquilizers; Berkeley Police sure don’t carry tranquilizers, either. And, Fish and Game does not relocate wild animals that display this kind of bold behavior, because they’re still too much of a threat. These policies make sense—and so does a mountain lion walking in streets of Berkeley, when you really think about it.

Over 50% of California is mountain lion habitat. Mountain lions can be found wherever there are deer, their main prey item. As we humans have built houses and highways, we’ve broken up the mountain lions’ habitat into fragmented patches. To move between patches of habitat, mountain lions have to cross our streets and highways. Mountain lions are territorial, and their territories tend not to overlap; these animals need a lot of space.

My friend Chris Wilmers, a professor at UC Santa Cruz, studies mountain lion movement and behavior. He catches mountain lions and fits them with GPS-accelerometer collars, which record their every movement. He’s learning how the lions move through the landscape. You can learn more about his research, and the Bay Area Puma Project, in QUEST’s Tracking Urban Lions. Chris’s research will show us which areas the mountain lions are using, and how we can connect these habitat fragments, so mountain lions can move safely from patch to patch.

Last week, the plight of urban lions came close to home—or rather, close to work. I work at the Lawrence Hall of Science, in the hills above the UC Berkeley campus. I found out, via email, that three mountain lions, probably a mother and two juveniles, have been seen several times near the Lawrence Berkeley Lab, just down the slope from where I work. And, two dead deer and one dead goat found near the Lab’s buildings strongly suggest that the lions aren’t just taking an evening stroll.

Clearly, we coexist with mountain lions. Our habitat is their habitat. But there are things we can do to prevent encounters; fill your garden with plants that deer find distasteful, so mountain lions won’t be tempted to stalk their prey in your backyard. (See A Gardener’s Guide to Preventing Deer Damage.) Don’t leave food outside for pets. Don’t leave pets outside, or run or bike alone, at dawn, dusk, or nighttime, when mountain lions hunt. And, if you do encounter a mountain lion, stand tall, make noise, and fight back. Find more info here.

Until Chris figures out where we should build wildlife corridors, I’ll be sure not to walk alone from my office to my car during darkling hours; one more reason not to work late!

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Credit: Felidae Foundation.

It's amazing that such large animals can live so near to urban areas and remain unseen – particularly since these animals inspire such fear and alarm whenever there is a reported sighting.

In a UC Davis study in Southern California, researchers found that humans and cougars live in close proximity to each other and often cover the same territory. And in Pacific Grove, near Monterey, cougars have been seen by police officers late at night on city streets.

In one unique incident in the Big Sur area, south of Monterey, a woman thought her dog was chewing something under her bed late one night. She shooed the animal out, smacked it on the rear end, and made it leave her bedroom – only to see a full-grown cougar stare back at her from her doorway.

These incidents are extremely rare. According to the California Department of Fish and Game, there have only been 14 mountain lion attacks in the past century. Most people don't see mountain lions. And in fact, wildlife officials say, almost all of the reported sightings of cougars are actually something else – dogs, bobcats, even deer. There was a report last year of a jogger in the Palo Alto hills being knocked over by a cougar, but that report was likely fabricated.  Humans might have a chance to spot a mountain lion only around dawn and dusk, officials say, and usually in remote areas at those times.

After California banned mountain lion hunting in 1990, the population doubled and possibly even tripled, according to state wildlife experts. But now, they say, those numbers have leveled off. Mountain lions are often killed by wildlife agencies when the big cats stray into urban areas. And many cougars die when they're hit by cars.

But the population remains relatively constant, at an estimated 4,000 to 6,000 animals in California. And that's because of their ability to remain almost invisible to humans.

Mountain lion hunters and researchers say that sometimes, even when a lion has been treed, even when the dogs are barking and other people are pointing to where the animal is, it can be hard to spot.

That's why they’re called the stealth predator. Now, researchers in the mountains above Silicon Valley are using new technology to learn more about these elusive animals.

Listen to the Tracking Urban Lions story online.

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