In Lion Country

What is making cougars in Southern California seem so bold?

By Sylvia Wright

[Please note that paragraph seven contains an inaccuracy. Iris Kenna was not the first person killed by a cougar in California in 80 years. Her death on Dec. 10, 1994, was preceded by that of UC Davis alumna Barbara Barsalou Schoener '75, who was killed nearly eight months earlier.]

When they left the dead deer in the pickup bed on the night of March 5, UC Davis researchers Ken Logan and Linda Sweanor weren't too concerned about leaving the carcass unsecured in cougar country. The 90-pound doe, after all, was four feet off the ground, surrounded by the 16-inch-high truck bed and stiff with death and cold. So they merely joked that one of them should put on night-vision goggles and stand guard. Then they went to bed.

Partners in research and marriage, Logan and Sweanor had spent their careers studying cougars. They were the principal investigators on the most extensive cougar study ever done, in New Mexico's San Andres Mountains in 1985–95. Sweanor's thesis for her 1990 master's degree at the University of Idaho was on cougar social organization; Logan's doctoral dissertation there was on cougar ecology. So, last January, when they settled into rugged Cuyamaca Rancho State Park above San Diego to lead a new UC Davis research project, they had studied cougars more intensively than anyone in the world.

Even so, the Cuyamaca cougars would show them something new.

Biologists began thinking of Cuyamaca's cougars as a breed apart in the late 1980s, when a growing number of visitors reported encounters with cats that were unusually bold. "Typically, lions stay away from people," said Cuyamaca park superintendent Jim Burke. "In 25 years in other California state parks, I had only seen one. But when I got to Cuyamaca, it was pretty common that people were seeing mountain lions. It's a whole different world."

Cuyamaca's woods and meadows are a deer paradise, and deer are the primary prey of cougars (also known as mountain lions, catamounts and pumas). Cuyamaca is also a human paradise; just 40 minutes from metropolitan San Diego, it has 120 miles of trails for hiking, biking and horseback riding and 416,000 visitors annually.

By the 1990s, it seemed like deer, lions and people were often traveling the same trails. Park records show that from 1993 to 2000, visitors reported seeing mountain lions 201 times. Sixteen times, the lion behaved in a way that rangers and game wardens deemed threatening to human safety. Nine times, that behavior led officials to kill the lions. In September 1993 and January 1994, officials took the extraordinary action of closing the entire park to visitors while a potentially dangerous cougar was tracked down. That meant emptying out campgrounds, clearing hikers off the trails and turning away new park visitors.

Then, on Dec. 10, 1994, the worst occurred—a cougar killed school counselor Iris Kenna as she hiked alone near Cuyamaca Peak. It was the first time a cougar had killed a person in California in 80 years. Game warden Lt. Bob Turner of the California Department of Fish and Game watched the site where Kenna's body was found; when a lion arrived there later the same day, Turner shot it. Tests showed it was the animal that had killed Kenna.

In January 1996, a mountain lion charged a woman on horseback in the park. When Fish and Game wardens arrived at that scene a few hours later to investigate, a mountain lion came toward them. Again, Turner had to kill the animal. In 1998, Turner shot four lions in two days after they threatened campers and their dogs at the park's Los Vaqueros horse camp.

In the meantime, just a few miles to the east, researchers from the UC Davis School of Veterinary Medicine were conducting what seemed to be an unrelated study. There, in Anza-Borrego Desert State Park, an endangered population of fewer than 400 bighorn sheep was shrinking fast. Beginning in 1992, wildlife veterinarian and ecologist Walter Boyce, director of the UC Davis Wildlife Health Center, led the effort to find out why. Using novel investigative techniques, including DNA fingerprinting, Boyce and his graduate students discovered that disease was one key factor, but more important was predation: Of the 61 radio-collared sheep that died during the study, cougars killed 42.

"That was entirely unexpected," said Boyce. "We had assumed, based on all the available evidence, that infectious disease was to blame. But as soon as we began following the radio-collared animals, it became obvious that mountain lions were the major cause of death."

Relying heavily on the results of their research, one of Boyce's doctoral students, Esther Rubin, led the writing of the federal recovery plan for the sheep, which by that time numbered about 300. The plan was candid about the cougar issue. It said that if high levels of predation continued, it might be necessary to kill lions to help the bighorn survive. "But the ultimate goal of conservation efforts should be to establish a healthy ecosystem in which lion removal is not necessary," Boyce said. "If we were going to have both bighorn sheep and mountain lions in the Peninsular Ranges, we needed a much better understanding of lion ecology and predator-prey relationships."

Cuyamaca rangers were saying much the same thing about people and mountain lions in their park. "We just didn't have any information," Burke recalls. "We didn't even know how many lions were out there. We talked about it—wouldn't it be great to find out more about the lions and humans, to provide a safe place for both of them?"

For Boyce, when the cougar killed Iris Kenna in Cuyamaca, the two situations merged into one. "That really heightened my awareness that this wasn't a single-species issue or a single-location issue," Boyce said. "The public-safety component of cougar biology was the opposite side of the coin to the endangered-species component, bighorn sheep."

Now Boyce began to envision a new, larger study that would look at the situation long-term on a regional scale. He named it the Southern California Ecosystem Health Project and began the painstaking work of building political and financial support. His key allies were experts like Mark Jorgensen, a resource ecologist for California State Parks, who grew up in the Anza-Borrego Desert and returned from college to work for its preservation; husband and wife team Steve and Alison Torres, the biologists for the California Department of Fish and Game responsible for the management of sheep, mountain lions and deer in the entire state; and Esther Rubin, who had finished her Ph.D. program and was a conservation fellow studying bighorn sheep for the Zoological Society of San Diego.

The ecosystem study that Boyce and his colleagues envisioned was unprecedented. They wanted to concurrently examine the relationships of lions, humans, sheep—and deer, which seemed to be the factor that drew lions into close proximity with both sheep and people. Scientifically, there had never been a study that concurrently examined the relationships of three wildlife species and humans, with a goal of management recommendations for the welfare of all. Geographically, the study area would encompass more than 500 square miles in contiguous lands including Cuyamaca Rancho State Park, Anza-Borrego Desert State Park, Cleveland National Forest and other federal and state lands. Financially, the study would cost at least $1 million for the first three years.

Logistically, the researchers would need to put radio collars on as many deer, sheep and lions as they could catch. UC Davis would employ, besides Boyce, four biologists to work full time on the collaring, tracking and data-analysis elements of the project. Fish and Game would supply extensive support for the collaring and tracking, including helicopter time, hardware and expertise. State Parks would open its files on cougar encounters in the parks, help the UC Davis team survey human activities in the park and give the team wide latitude in capturing and tracking wildlife within park boundaries.

Lastly, there were the political aspects. For a creature that most Californians will never see, the mountain lion is remarkably charismatic. In 1990, Californians approved Proposition 117, banning cougar hunting. In 1996, even after cougar numbers had begun to rise, and the cats had killed Kenna in Cuyamaca and Barbara Schoener near Sacramento, voters again endorsed cougar protection. Yet hunting interests continued to lobby for lion management, while sheep advocates were nervously watching the lions eating away at the Peninsular Ranges bighorn population. In that political climate, Boyce feared the plan to study the lions might be seen as a threat to their protected status. As he worked to build support for the new study, Boyce stressed the importance of objective research: UC Davis intended, he said, "to get good science done, and make it available to wildlife managers and the public so it could be implemented into wise policy decisions to ensure public safety and the best stewardship of natural resources."

By mid-2000, the project was coming together. Boyce had amassed $1 million in cash and in-kind commitments—enough to carry the project for three of the 10 years he felt necessary. An anonymous Southern California conservationist donated $225,000; Mark Jorgensen committed $270,000 from State Parks; Fish and Game's Deer Herd Management Plan Implementation Project gave $220,000 and its Bighorn Sheep Management Plan committed $160,000 of funds it received from U.S. Fish and Wildlife Service; and the Zoological Society of San Diego agreed to cover the costs of Esther Rubin's research. "We were pooling our resources to address questions we're all interested in," said Steve Torres, chief of Fish and Game's Bighorn Sheep and Mountain Lion Conservation program.

With a plan and financing in hand, Boyce now had to find his lead cougar biologists, and he knew the two he wanted: Ken Logan and Linda Sweanor. But Logan and Sweanor were living in Moscow, Idaho, while Logan finished his Ph.D. dissertation on the 10-year San Andres cougar study. Boyce wasn't sure whether, having worked so long in the San Andres wilderness, the pair could be persuaded to come to urbanized San Diego County.

"The San Andres Mountains are one of the last remaining areas where cougar behavior is minimally influenced by people," Boyce explained. "For Ken and Linda, Cuyamaca was exactly the opposite: an area where cougars and people can't avoid each other." In the end, that was what won them over. "They know that cougar preservation has to involve people."

Sweanor, Logan and their 6-year-old son, Ori, moved into a cabin in Cuyamaca Rancho State Park in January. Field biologists Jim Bauer and Casey Lydon signed on as scientific aides, jointly employed by UC Davis and California Department of Fish and Game. Everyoneworking on the project attended a Fish and Game wildlife-capture refresher course. Then, on Jan. 23, Fish and Game biologist Randy Botta was trapping wild turkeys about 400 yards from the cabin when he found lion tracks. To Logan and Sweanor, the size of the pad prints suggested the cat was a male, and a big one. Backtracking, Sweanor found another set of tracks, smaller; it looked like the big male had a female friend in the neighborhood. The research team was elated, particularly Sweanor and Logan. "The biggest thrill was finally being back out in the field again, after being in front of a computer for two years, writing up the San Andres findings," Sweanor said. "It was just nice to be in lion country again."

After finding the tracks nearby, Sweanor and Logan realized that a lion might walk by and see Ori in his bedroom. Next day, Logan walked behind the cabin and saw lion tracks in the snow, five feet from the house. They closed Ori's bedroom curtains.

In the last week of February, six inches of snow fell at the cabin. Logan and Sweanor spent Feb. 23 and 24 working down the mountain with Botta, Boyce and other biologists, radio-collaring deer for the study. On the morning of Feb. 25, Sweanor stepped onto the cabin porch and discovered a cougar had walked under her floorboards in the night. A trail of big paw prints in the snow led directly up to the cabin, disappeared and emerged on the opposite side.

Logan tracked the big male for a mile to the park boundary. Then, confident it would be traveling by the cabin again soon, Logan returned home. He and Sweanor would try to catch and radio-collar this Cuyamaca regular. They would need bait; they asked the park rangers to get them a roadkill deer.

Mountain lions are carnivores and will eat a wide range of animals. Their favorite food is deer, and they are supremely adapted for killing such large prey. Weighing 70 to 160 pounds and stretching 5 to 7 feet long from nose to tail tip, they are equal in size to most deer. Their short muzzles, long legs and powerful shoulders are heavily muscled for bringing down struggling animals.

Cuyamaca chief ranger Laura Itogawa called Sweanor and Logan late on March 5 with the location of a roadkill doe. "Better get it fast, before someone takes it home for dinner," Itogawa said. Around 10 p.m., Logan wrestled the carcass into the research project's Toyota Tacoma pickup; back at the cabin, he left the dead deer in the pickup bed, tailgate up. He and Sweanor made their jokes about guarding the carcass, then slept.

"The next morning, Ken went out to the truck at about 7," Sweanor recalled. "He came back in and said, 'Well, the carcass is gone.' My first thought was that, like Laura had said, someone had taken the deer for venison. And we went out there, and there was no deer—just two deer hair stuck on the side of the truck."

A cougar apparently had caught wind of the carcass, daringly jumped into the truck to investigate, and hauled the deer out of the truck bed and out of sight. It had carried the carcass so high off the ground that Logan and Sweanor had trouble picking up a drag trail on their hands and knees. When they finally did pick one up, it led them the length of two football fields to a cache in dense chaparral.

"It made us both laugh," Sweanor said. "It was amazing to see that at 10 o'clock one night that carcass was in the back of the truck and by 7 the next morning it was gone, and to have a lion actually find it and take it away so cleanly. We'd never worked with cats that had been in close proximity to humans. But here, there are so many people around, and cats so close to human habitation—it's different. We're definitely going to be learning some new things."

Around the cache site, the biologists set their snares. Two nights later, they made the first lion capture of the new project: a healthy, 4-year-old, 140-pound male. He was tranquilized, fitted with a radio collar, designated Male 1 and released. A day and a half later, Sweanor located his radio signal 5.5 miles northwest of the capture site, near Temescal Creek, in good deer habitat.

On March 28, the team collared a second male. M2 was 2 to 3 years old and weighed 109 pounds. As summer progressed, Logan and scientific aide Bauer settled into a routine of searching for lion signs and settingand checking snares. Sweanor began amassing data on previous human-lion interactions in the park, and she and scientific aide Lydon monitored the collared deer and lions. Bighorn specialist Rubin continued to analyze bighorn sheep data with Boyce and made plans with Fish and Game and State Parks to put radio collars on more sheep in the fall.

On July 14, Logan and Sweanor's daybreak snare-check revealed cougar M3 in a snare in lower Stonewall Creek. He was a youngster, only about 8 to 10 months old and weighing 58 pounds. His mother was nearby. The team had been tracking and trying to catch these individuals for several weeks. M3 was fitted with a radio collar that would expand to accommodate his growth and released. In the next few days, he and his mother were seen at a deer kill two miles south of where he was captured.

By the time the summer visitor season ended in Cuyamaca Rancho State Park, Sweanor was starting to build a picture of the lions' movements. In typical cougar fashion, they covered a lot of ground. M1 tended to ramble throughout the park and to the west, covering a range of at least 140 square miles—three times the size of the park. M2's range covered about 76 square miles, including large areas south and east of the park. M3 and his mother were moving in and out of the park, staying put for a few days each time they killed a deer.

Sometimes, as Sweanor climbs Cuyamaca ridges to scan for M1's radio signal, she thinks back to that night in March when he stole away the deer carcass. "I know that mountain lions are strong. They have very powerful forelegs and claws, and incredibly strong, short jaws with tremendous musculature—much stronger than a wolf. A single lion can pull down a bull elk six times its weight," she mused.

"Still, that cat pulling the deer out of the truck—I would have liked to have seen it myself."

Sylvia Wright writes about the environmental sciences for the UC Davis News Service.