JWM study: Fire, urbanization pose threats to California pumas

Wild fires have been big news in California in recent months, and now new research is revealing how these fires are affecting pumas (Puma concolor) in the area.

“A mix of fire and urbanization in southern California are the two biggest stressors for wildlife populations in the region,” said Megan Jennings, a postdoctoral researcher at San Diego State University and lead author of a recent study published in the Journal of Wildlife Management.

Jennings, a TWS member, and her colleagues reviewed a decade’s worth of GPS data on pumas in the mountains, valleys and foothills of San Diego County, the Santa Ana Mountains in Orange County, and in parts of San Bernardino. The data, which came from the University of California, Davis Wildlife Health Center, was collected by the Southern California Puma Project. The team took note of how much time it took for landscapes to recover from fire and how pumas were using the habitat. “One of the reasons we did this [study] was because managers talk about how animals respond to fire,” Jennings said. “It’s a difficult thing to study because we can’t do it experimentally.”

After analyzing the data, the researchers found that pumas used post-burn areas within the first few years after a fire. Jennings believes the fresh regrowth that occurs after a fire provides forage for deer — puma’s primary prey. However, she says pumas are opportunistic in this behavior and are not necessarily seeking out these areas. In fact, the data showed that pumas kill more prey in burned areas, she said.

The higher frequency of fires is likely due to more people living in the areas and the vegetation that’s present, Jennings said. While pumas might not have problems a few years post-fire, further down the line, shrub-dominated vegetation will shift to grass-dominated vegetation, which is not the cats’ preferred habitat, according to Jennings. “Over the long term, increasing fire frequency could be harmful to the population,” Jennings said. Further, pumas already face landscape connectivity issues that contribute to a lack of gene flow and inbreeding. “These are interacting disturbances.”

Fires in southern California are often caused by equipment or vehicles, Jennings said, as well as arson, which is more difficult to manage.

She suggests the public needs more education about the detrimental effects of fire. “A lot of [the problem] is people management more than wildlife management,” she said. Jennings added that previous research shows more frequent fires occur in areas with intermediate housing density, and education in these areas might be helpful.

“This is something wildlife managers should continue keeping an eye on,” Jennings said. “There have been more frequent fires in the past decade and a half. Moving forward, there’s potentially an issue.”