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.