Mountain Lion Study in San Diego County








The Institute participated in research examining the relationship between mountain lions (pumas), bighorn sheep, deer, domestic animals, and people in eastern San Diego County in southern California. The project was focused on activity in Cuyamaca Rancho State Park, Anza Borrega State Park, and surrounding areas. It was a collaborative effort among California State Parks, the Wildlife Health Center at the University of California, Davis, the California Department of Fish and Game, IWS, and others. The study is overseen by Dr. Walter M. Boyce, Co-Director of the Wildlife Health Center at U.C. Davis.

Mountain lion captured and collaredThe objectives of the study, initiated in 2001, include estimating puma population density, determining individual home ranges, assessing the animals’ health status, and identifying puma activity patterns in relation to people and prey. Dr. Winston Vickers, Staff Veterinarian for IWS (left in photo), assists in puma captures, conducts physical exams, and collects samples to assess the animals’ health and disease status. Dr. Vickers has also conducted a survey of residents living near the parks to gauge opinions about current mountain lion management strategies, and to determine the percentage of pet and livestock owners in the area who adequately protect their animals from mountain lion predation.

Although puma attacks on humans are very rare, the number of dangerous encounters has increased in recent years. Since 1890, there have been 15 documented attacks on humans in California; twelve of those attacks, resulting in three deaths, occurred during the last 18 years. Two of those attacks, one fatal and one non-fatal, occurred within Cuyamaca Rancho State Park itself. Public safety concerns for park visitors were among the factors precipitating the puma project.

Since fieldwork began in 2001, we have studied 20 pumas, including 16 captured and collared in or near the parks. In accordance with the study objectives, capture and tracking data have been continuously collected and analyzed. Study results relating to puma behavior patterns indicate that pumas and people generally have opposite activity periods. Although pumas are least active during daylight hours when park visitors are most active, overlapping activity periods do occur around dusk and dawn. Pumas using the parks also tend to avoid buildings and campgrounds but move closer to the extensive system of trails and fire roads as night falls. With rising numbers of annual visitors to area parks for recreation, park managers continue to be concerned about increased opportunities for dangerous human-puma encounters.

Project researchers will continue to study the puma population in and around both parks. Because Cuyamaca Rancho State Park was extensively burned in the October 2003 Cedar Fire, new data are expected to provide unique information regarding post-fire puma behavior. Project findings will be used by park personnel to educate people about appropriate behavior in puma habitat, and steps that pet and livestock owners in the area can take to protect their animals. Additionally, considering the changes in vegetative cover caused by the fire, park managers may find the study results beneficial in managing trail and campground use by visitors