Photo by Tony Hisgett [CC-BY-2.0], via Wikimedia Commons
Photo by Tony Hisgett [CC-BY-2.0], via Wikimedia Commons

A study of Southern California mountain lions, many of which are hemmed in by freeways and human development, are inbred because of a lack of newcomers, according to a study published Wednesday.

The study by UC Davis, in partnership with The Nature Conservancy, included the largest genetic sampling of mountain lions in the area.     School of Veterinary Medicine researchers at UC Davis collected and analyzed DNA samples from 354 mountain lions statewide, including 97 from Southern California, and the pumas in the Santa Ana Mountains had less genetic diversity than those from nearly every other region.

Big cats that live in the Santa Anas show dramatic genetic isolation and have less in common with mountain lions in the Santa Monica Mountains than relatives in the Sierra Nevada, underscoring the increasing seclusion of pumas in Southern California.

The Santa Ana mountains are surrounded by a population of about 20 million people. A  habitat link to the southeast connects pumas to the peninsular range of the Santa Anas, but the mountain lions would have to cross 10-lane Interstate 15.

Male mountain lions sometimes kill their male offspring if they are perceived as  competitors for food or mates. They also sometimes mate with their female offspring if no other females are around.

The study, published in the journal PLOS ONE, highlights the need to give the cats — their home ranges can be as big as 380 square miles or a small as 10 square miles — a way to get around and find mates.

The study also showed that the Santa Ana pumas recently went through a “population bottleneck,” when the population’s size sharply decreased to a fraction of its original size.

“The genetic samples give us a clear indication that there was a genetic bottleneck in the last 80 or so years,” said lead author Holly Ernest, a former professor with the Karen C. Drayer Wildlife Health Center and the Veterinary Genetics Laboratory at UC Davis. “That tells us it’s not just natural factors causing this loss of genetic diversity. It’s us — people — impacting these environments.”

Pumas in the Santa Monica Mountains are similarly threatened by inbreeding and lions killing other lions, according to a study co-authored by Ernest published in September’s issue of Current Biology.

Just one lion was known to bring new blood into the Santa Monica Mountains by crossing the Ventura (101) Freeway during the study period.

City News Service

Leave a comment

Your email address will not be published.