Mysterious American Cat: The Mountain Lions of Los Angeles

It is useful to start at the end, which is also the beginning: at the far side of an imaginary bridge, picturing a mountain lion slinking over the rise to the east, hugging the shadows and contours of the easy-rolling ridge, then arriving at the 101 freeway’s eight lanes. Mountain lions have died here before, crossing from one sliver of wilderness to another—from the inland, semi-coastal ranges in the Angeles and Los Padres National Forests, across the Simi and San Fernando Valleys, to the Santa Monica Mountains, which run along the Pacific Ocean before elbowing eastward, inland again into the middle of Los Angeles. If the mountain lions don’t die crossing over, those moving westward into the Santa Monicas enter the home range of a famous and stressed-out cat family with a particularly famous son, whose likeness has been printed on magazine covers and T-shirts. The lions here are celebrated and beset upon by all sides—they’re cramped, which is why they are also so ill at ease. It was these cats, the famous group, we were trying to imagine finding a way eastward, over the freeway, escaping L.A.

The crossing point where the bridge might be is named, too perfectly, Liberty Canyon. It is not much of a canyon, more of a dry, narrow valley, or a choke point between a few large hills. We—biologists, ecologists, animal-corridor experts, a few scientists employed by the California Department of Transportation, and I—were here imagining mountain lions and the bridge that they might cross mostly because the bridge will be expensive—many tens of millions of dollars, certainly. It will also be the first of its kind: an overpass in the second largest urban area in America, constructed primarily for critters. Hikers, too, perhaps. Not building the bridge would eventually mean that the isolated population of famous lions roaming the hills of Malibu and Hollywood would collapse after so much inbreeding. This was what we were on the hill to weigh: the worth of an apex predator living alongside another apex predator, the apex of all apex predators, which is, of course, us.

Americans have been good at killing mountain lions for a long time, and still are. The minimum estimate is that 65,665 have been shot or poisoned or trapped or snared by bounty hunters, sport hunters, hunters paid by the federal government, state governments, and city governments from 1907 to 1978 throughout twelve states in the West. Mountain lions are still hunted for sport in Wyoming and South Dakota. But even left alone, mountain lions will live fast and hard and die in spectacular ways, often fighting one of their own, or drowning in irrigation canals, or suffering a fatal kick to the ribs from an elk or particularly brave mule deer, or breaking its back during a failed leap. In one instance, an old cat researchers had named Snaggletooth ran into a manzanita bush and a five-inch stop pierced its throat, after which it bled out in the sand. But Snaggletooth was getting old for a cat, pushing seven.

Today the US Department of Agriculture’s Wildlife Services (previously called the more ominous and accurate Animal Damage Control Department) kills some 200 mountain lions each year at a cost of about $30 million.

The effect is at least questionable and almost certainly adverse. Kill a lion, and another one will move into its territory, this one younger, bolder, dumber, and more likely to take down livestock or approach humans. Mountain lions communicate through code: scrapes or scratches on tree bark, or piles of pine needles, leaves, and dirt gathered under a tree or along a ridge line, and sometimes peed or shit upon. Males leave far more of these scrapes or piles than females, who, like house cats, tend to bury their stool fastidiously. Males take up more room, too. The cats use the scratches and bodily fluids to locate and, mostly, avoid their own kind. Being cats, they...