Valley View News
- Dec 19, 2022
- 2 min read

Wildlife Crossing: A Mountain Lion's Last Hope

By Rocky Walker

AGOURA HILLS, CA - The Wallis Annenberg Wildlife Crossing is the first wildlife crossing of its kind-spanning over ten freeway lanes. With a target completion date of 2025, Los Angeles hopes it'll keep the local mountain lion population alive.

Photo Credit: Rocky Walker, the crossing site

Los Angeles plans to protect the local ecosystem with a wildlife crossing over the 101 freeway in Agoura Hills- connecting the Santa Monica Mountains to the Simi Hills. Officials said urbanization has a toll on wildlife.

The main goal of the Wallis Annenberg Wildlife Crossing is to repair the low genetic diversity of the wildlife in the area. It's caused by habitat fragmentation, affecting particularly the Santa Monica mountain lion.

Death from rat poisons is one cause of the death of wildlife in the city. One study found 28 out of the 29 mountain lions studied tested positive for one or more rodent poisons, with seven dying from rodenticide poisoning as of November 2021.

The National Park Service started a study in 2002 of Santa Monica mountain lions, finding cases of inbreeding and lower genetic diversity.

The lions have the lowest genetic diversity rate found in the West. It compares to the Florida panther's population in the 90s-- dwindling its way to extinction.

The decline in genetic diversity brought birth defects, such as kink tails and undescended testicles. Studies show some of the lions have on average a 93 percent abnormal sperm rate. With fertility now being affected, a crossing proves urgent.

“That entire ecosystem has been cut off by that freeway," said Beth Pratt, California Regional Executive Director of the National Wildlife Federation and leader of Save LA Cougars."The other side is the pacific ocean. Any mountain lions there, they're literally breeding themselves out of existence.”

This crossing is decades in the making, leading back to a 1987 study that identified the location as one of the three key choke points in the area for safe animal passage.

The study was incorporated in a 1990s report by Santa Monica Mountains Conservancy titled “Critical Wildlife Corridor/Habitat Linkage Areas Between the Santa Susana Mountains, the Simi Hills, and the Santa Monica Mountains.”

Santa Monica Mountains Conservancy since then acquired the land that's now for the Wallis Annenberg Wildlife Crossing.

“It'll recreate and reestablish an actual land linkage between the mountain ranges,” said Rorie Skei, the Santa Monica Mountains Conservancy Chief Deputy Director.

Other species of flora and fauna-from coyotes and cottontails to harvester ants and native sage plants can use the crossing. Officials said it's a step to allow both urbanization and natural habitats to co-exist.

Rocky Walker video report