California mountain lions are adapting to human schedules: Study

Mountain lions in the greater Los Angeles region are consciously shifting their activity to avoid interacting with human residents, a new study has found.

Big cats living in areas with higher levels of human recreation may be more nocturnal than those inhabiting more remote areas, where felines tend to be active at dawn and dusk, according to the study, published on Friday in Biological Conservation.

Although mountain lions prefer to avoid people, the natural areas inhabited by the cats and other wildlife are also heavily trafficked by human recreationists, the study authors noted.

“People are increasingly enjoying recreating in nature, which is fantastic,” lead author Ellie Bolas, a Ph.D. candidate at the University of California, Davis, said in a statement.

“This flexibility we see in mountain lion activity is what allows us to share these natural areas together,” Bolas continued. “Mountain lions are doing the work so that coexistence can happen.”

To determine whether and how lions were adapting to human activity, the researchers monitored the movements of 22 big cats that were living in the Santa Monica Mountains and the surrounding area, between 2011 and 2018.

They conducted these analyses on data they acquired from GPS and accelerometer collars that other biologists had fitted on the lions as part of a separate long-term study. At the same time, the authors also tracked and quantified human recreation in the region, using a GPS database that people opted to make public.

The researchers found that Griffith Park — a large municipal park in northern Los Angeles — hosted the highest levels of recreational activity, while the Santa Susan Mountains and Los Padres National Forest had the least human traffic.

The least nocturnal mountain lion was a female in the central and western Santa Monica Mountains. Females in general, the researchers observed, were more active near sunrise and during daylight hours, in comparison to males. The authors hypothesized that this difference might be attributable to a female instinct to avoid the males, who could endanger them and their kittens.

The most nocturnal lions were two males living in small, isolated areas that had many trails, high levels of human recreation and were adjacent to high-density development and freeways. Both of those cats inhabited two of the tiniest home ranges on record for adult males.

The urban experiences of these two cats and others showed how mountain lions tend to avoid people rather than becoming too habituated to them, the researchers concluded.

“These results are really important in that they show how humans may be affecting wildlife in less obvious ways than killing them with vehicles,” co-author Seth Riley, branch chief for wildlife at Santa Monica Mountains National Recreation Area, said in a statement.

On the other hand, Riley emphasized “the amazing fact that a population of a large felid predator persists in one of the largest urban areas in the world.”

“That would not be possible if mountain lions weren’t able to adjust to human activity in ways like this,” he said.

While it has become clear that these big cats are adjusting to humans, the study authors highlighted a need for humans to return the favor. People should both make themselves aware that dawn and dusk can be prime time for mountain lion activity and take extra precautions when driving at night, as these felines may be out on the prowl, the scientists noted.

“Even something as innocuous as recreation can add to these other stressors we’re bringing into their lives,” Bolas said. “But we can feel a sense of optimism that they are flexible in the timing of their activity. Coexistence is happening, and it’s in large part because of what mountain lions are doing.”

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