Cougar comeback in Riverside County?

Seven male cougars have crossed Interstate 15 near Temecula over the last 15 years, and one has sired 11 kittens, leaving wildlife biologists heartened because it shows that a single male can enhance genetic
diversity among inbred cougar populations, it was reported today.

But the fact only one managed to reproduce shows how tough it is to diversify the gene pool in the small, isolated populations of mountain lions remaining in the Santa Ana Mountains, according to a study published Tuesday in the online journal Royal Society Open Science and cited today by the Los Angeles Times.

The research team led by Winston Vickers, a veterinarian at the UC Davis Wildlife Health Center, is proposing a “puma conservation network” along a 2-mile stretch of the freeway, comprised of wildlife corridors, bridges and improvements in underpasses currently occupied by homeless camps.

An estimated 20 mountain lions currently prowl the Santa Ana range. Vickers said there are a number of ecological reasons to protect the big cats.

“Removing the top predator could have serious cascading effects all the way down the food chain to birds and plants,” he said, according to The Times. “Mountain lions help control populations of deer, coyotes, raccoons and other species. … “Increasing numbers of deer could potentially lead to more
collisions with vehicles.”

Mountain lions are not endangered in California but are classified as a “specially protected species.” The statewide population of about 6,000 is relatively stable.

One of the largest mountain lion populations in Southern California is confined within 275 square miles in and around the Santa Monica Mountains National Recreation Area, which is bordered by the Pacific Ocean, major freeways, housing and commercial developments and agricultural fields.

Studies suggest that terrain — bisected by Interstates 405 and 101 — may have reached its carrying capacity with two or three adult male lions, four to six females and some kittens. Inbreeding is a serious problem among these big cats, which have extremely low genetic diversity.

“Enabling lions to cross the freeways safely could help these struggling populations stave off extinction,” Vickers said, according to The Times.

On Wednesday night, a mountain lion was struck and killed while attempting to cross I-15 near the Temecula Creek bridge, Vickers said.