Earlier this month, researchers in the Santa Monica Mountains discovered telltale signs of impending extinction among three male mountain lions, according to a statement released by the National Park Service on Sept. 9.
Biologists discovered three males with kinked tails (where the ends of the tails are shaped like the letter “L”). In addition, one of those mountain lions—a subadult male estimated to be one-and-a-half years old who was captured, collared, given a check-up and tagged as P-81 by biologists on March 4—exhibited cryptorchidism, which means he had an undescended testicle. The other two may have cryptorchidism, but scientists cannot be sure because the other two were only captured on remote cameras. Scientists theorize that the mountain lions could be related and could even be siblings.
Mountain lions in Florida were found to have some of these same genetic features, which experts said were “linked with inbreeding depression,” according to a 2016 paper co-authored by biologists from Florida and UCLA. “Inbreeding depression,” according to the statement, “is a phenomenon that occurs when a lack of genetic diversity beings to negatively affect survival or reproduction.” In Florida, male mountain lions who had either one or both testicles remain undescended were sterile and likely unable to reproduce. Eighty to 90 percent of that mountain lion population—called Florida panthers—had kinked tails and whorls in their fur. Some even had holes in their hearts that reduced the efficiency of their circulatory systems.
In the research paper, “modeling predicted a 99.7 percent chance of extinction within 50 years, with a median time to extinction of just 15 years” for a mountain lion population similar to the one in Florida—now being compared to the local population in the Santa Monica Mountains.
The mountain lions of the Santa Monica Mountains area suffer both from inbreeding, which is when animals mate with close relatives, as well as “genetic drift,” “which describes the loss of genetic diversity over time when there is a small population of animals,” according to the statement.
In that Florida case study, scientists were able to save the population by importing eight female mountain lions from Texas to breed with the remaining males. There are now hundreds of mountain lions where there were once only dozens.
Seth Riley, a biologist for the National Park Service and a professor at UCLA, said that for the Santa Monica Mountains mountain lions, it would make more sense to increase habitat connectivity instead of importing new mountain lions because there is a healthy population of mountain lions in Los Padres National Forest to the north. This connection, however, would require a wildlife overpass which would move animals over more traffic than anywhere else in the world. Several local organizations are raising money for the project, which is in its final design phase and is slated to begin construction in late 2021.
Scientists have been studying the Santa Monica Mountains population for 18 years, and only earlier this month dubbed this summer “the summer of kittens” due to the multiple litters of mountain lions discovered this year.
On Sept. 15, a Malibu resident reported to The Malibu Times they spotted a female mountain lion walking up the hillside cul de sac of the gated community on Rey De Copas Lane. The resident said they believed the mountain lion to be in heat due to her calls.