Mountain Lions and People Are Learning How to Live Together : Environment: The huge carnivores are repopulating former habitats in the West, startling humans who have moved into the areas.

As the elusive mountain lion--the once-hunted ghost of North America--makes an amazing comeback in the Western United States, the problem of peaceful coexistence with people becomes critical.

Maurice G. Hornocker, who has studied the big cats since 1963, dispels two myths long used to justify eradicating the animals: that mountain lions will overrun the countryside and are a danger to big-game herds.

“These animals are very territorial and limit their own numbers,” Hornocker, the founder and director of the Hornocker Wildlife Research Institute in Moscow, Ida., said. “The size of a mountain lion’s territory is determined by the food supply. Only so many cats can live in a given area.

“Lions kill deer and elk routinely, but most of their prey are very young or very old, not of breeding age.”

Hornocker believes that humans can still make room for lions, but that they must understand the big carnivores even better to develop appropriate management programs.

Mountain lions, also called cougars, pumas, panthers, painters and catamounts, were hunted by European settlers in North America who saw them as competitors for deer and other game and as a threat to their livestock. Bounties were paid for lion skins.

Indiscriminate killing of wildlife, along with massive habitat destruction, wiped out lions in the East outside Florida. And they were almost eradicated from the West.

Today they have been pushed into remote regions. Still, no other New World mammal has a range that matches the cougar’s, from the Canadian Yukon deep into South America.

Every state with lions except Texas regulates the killing of the animals. Consequently, lions are repopulating former habitats in the West, sometimes startling humans who have moved into those areas. The cat remains maddeningly elusive.

Unlike lions and tigers, the mountain lion can’t roar, but it can purr. Its silence, punctuated only occasionally by a howl that can sound like a woman’s scream, adds to the cougar’s mystique.

And unlike most other carnivores, cougars are specialized killing machines. Their teeth, claws, speed and elusiveness are designed to bring down fresh meat. They prefer to kill their own food, rarely eating carrion.

In places such as the foothills of the Rocky Mountains outside Boulder, Colo., people have moved into the lion’s historic home. Certain individual lions show little fear of humans, and while most Boulder residents appreciate the presence of such a beautiful and mysterious animal, they are also concerned about the safety of their children and pets.

Occasionally lions--usually young and inexperienced--attack humans. California biologist Paul Beier has examined records of unprovoked attacks in the United States and Canada between 1890 and 1990. Of the 53 documented attacks, nine were fatal.

By comparison, Beier said, about 40 people die from bee stings in the United States each year, and about 80 from lightning strikes.

Thirty of the 53 lion attacks on humans occurred in British Columbia. Twenty took place on Vancouver Island, where mountain lions have been hunted intensely.

“Perhaps,” Hornocker said, “the hunting pressure has genetically selected the most aggressive as survivors.”

Mountain lions have created anxious moments recently in the United States, approaching people in Texas at Big Bend National Park, in northwestern Montana and in California.

And there have been tragedies: A 5-year-old boy was killed in Montana in 1989, and an 18-year-old jogger in Colorado was killed in 1991. Earlier this year, a 9-year-old boy was mauled in a California state park near Santa Barbara.

Wildlife officials in the West promote lion safety guidelines, much as they do with bears. Visitors to lion habitats should carry a big stick and make noise as they hike to let the animal know they are approaching.

Lions are intimidated by height, so if a cougar is sighted in the area, parents should hoist children onto their shoulders.

If attacked, a person should neither run nor play dead. Hornocker advises: “Stand firm, fight back and yell--most people who have resisted an attack have successfully fought off the lion.”

Despite their increasing and sometimes frightening presence, mountain lions have been winning greater protection.

In 1990 in California, where perhaps as many as 5,000 lions range up and down the coastal mountains as well as the Sierra Nevada and southeastern deserts, voters handed lions a historic victory.

A state law passed that year bans sport hunting of lions. A young woman from the Mountain Lion Foundation told Hornocker, “We don’t believe it is ethically or morally correct to kill such splendid animals just for trophies.”