Twelve days after a puma killed one person and hurt another in Southern California, researchers at the University of California, Davis, today released the most intensive scientific assessment to date of the complex relationships between pumas and people on the expanding urban fringe.
The report details the lives of 20 pumas straddling two worlds -- one a popular state park rich with natural prey but shared with a half-million hikers, bikers, campers and horse riders, and the other woodsy communities where cats, dogs, chickens, pigs, goats and alpacas are easy pickings but eating one can get a puma killed.
From those details, the researchers make recommendations to help pumas and humans co-exist -- recommendations that should be useful as dangerous encounters increase throughout the American West.
"Mountain lions inspire a range of emotions including fear, awe, anger and wonder," said the leader of the study, Walter Boyce, director of the UC Davis Wildlife Health Center. "This study is designed to provide objective information so that people can make decisions and take actions based on facts rather than emotions."
The report summarizes the first three years of the Southern California Puma Project, a long-term research study conducted by UC Davis for California State Parks in and around Cuyamaca Rancho State Park in San Diego County. The park is located 75 miles south of the site of the two Jan. 8 puma attacks in Orange County.
The report was written by a team of UC Davis researchers led by Boyce, a wildlife veterinarian and researcher. The UC Davis team worked in close collaboration with rangers, game wardens and biologists from State Parks and the California Department of Fish and Game. They tracked 20 pumas (Puma concolor, also known as mountain lions or cougars) for three to 27 months from March 2001 through December 2003.
By putting satellite radio collars on the cats and then regularly recording their locations, the researchers were able to examine the pumas' beds, dens, kill sites and food caches, creating both intimate individual portraits and general overviews of the local puma population.
By analyzing human use of the park's facilities (two large campgrounds, two equestrian campgrounds, two primitive camps, a school camp and 100 miles of trails), the researchers were able to compare human and puma activity patterns.
They found that Cuyamaca pumas were generally inactive by day in oak woodlands. The pumas traveled and hunted from 1.5 hours before dusk to 1.5 hours after dawn and frequently visited communities outside the park where people kept hobby animals in open pens. They lived largely on wild deer or bighorn sheep (in nearby Anza Borrego Desert State Park) but also killed pets, small livestock and hobby animals.
Although there were lots of pumas and people in the park, the pumas largely avoided contact with the people.
Eleven of the 20 pumas died during the study. Four were shot for threatening or killing domestic animals; four died of unknown causes, likely disease; and one each was killed by another puma, hit by a car on an interstate highway, and starved after being burned in the Cedar Fire.
The study also gives some glimpses into individual cats' existence. One big male, M01, was the first lion the researchers collared -- after it stole a dead deer from the project's pickup truck. He was the only puma that never crossed a major paved road and one of three pumas that died for unknown reasons in June 2003. An old female, F13, had a severe 1- to 2-week-old jaw injury when collared in October 2002 and ranged more widely than most of the study pumas -- possibly because she could catch only small prey -- and she was killed by another puma as she scavenged a dead deer.
Female F07 was a steady provider who, with her two male cubs, killed 10 of the study's radio-collared bighorn sheep, 17 uncollared bighorn sheep and two radio-collared deer, and killed or scavenged a domestic cat. Young male M09 sired two cubs with female puma F08, had 43 percent of his home range outside of the park on private property, and was shot dead one night as he left the yard of a property owner who had chickens running loose.
"Ultimately it's up to the people who live, work and play in mountain lion habitat to decide if they want to share the environment with an animal that can kill them," Boyce said. "Attacks are rare, but there is no guarantee of safety. Studies like ours show that there are many things each of us can do to avoid conflicts between mountain lions and people and domestic animals. Information and education are key to balancing the needs of wildlife and people."
The researchers made these recommendations for the operations of Cuyamaca Rancho State Park:
- Educational programs about puma behavior and human safety in puma habitat should be continued and expanded. Because the biological integrity of pumas in the state park is affected by what happens outside as well as inside park boundaries, State Parks and Fish and Game officials should take responsibility for educating private property owners in how to keep their domestic animals safe.
- When they plan locations of new trails and campgrounds, park officials should consider pumas' needs for plant cover when hunting, traveling and sleeping. Particularly in the Cuyamaca park, which was almost completely burned in the recent Cedar Fire, there are few places of refuge for wild animals, and people who visit those unburned areas now may be at increased risk of encountering pumas.
- The food caches pumas normally make after a kill, where they scrape dirt and plant litter over the dead animal and return periodically to eat, should not be removed when found near human activity because the loss of the food simply forces the puma to hunt and kill another animal. Instead, the dead animal should be dragged to a safer location 100 to 300 yards away, or the area can be temporarily closed to people.
- In light of the dramatic habitat changes wrought in Cuyamaca Rancho State Park by the Cedar Fire, as well as the need to improve our understanding of puma-human interactions, it is important for the Southern California Puma Project to continue. The report concludes, "The information gleaned will be useful ... for all of the people who live and recreate in puma country."
The authors of the report are Walter Boyce, UC Davis field biologists Linda Sweanor and Jim Bauer, and former UC Davis field biologist Ken Logan, now a carnivore researcher at the Colorado Division of Wildlife.
The UC Davis Wildlife Health Center is a program of the campus' School of Veterinary Medicine.