According to a study released on Tuesday, mountain lions in the Santa Monica Mountains may go extinct in the future.
Santa Monica mountain lions heading towards extinction
Researchers from the National Park Service, UCLA, UC Davis and Utah State University believe that there is a 99.7 percent chance that the mountain lions will be extinct within 50 years unless more lions are introduced to the gene pool. They say that if the situation doesn’t change, the decline of the mountain lions would be rapid.
Decreasing genetic variability would reportedly become evident in as few as 15 years. This could reach a point of no return in around 35 years.
Around 15 mountain lions are still living in the Santa Monica Mountains, and conservation efforts aimed at saving them have been subject to numerous studies. However this latest study is the first to predict how much time the population might survive, according NPS wildlife ecologist, associate adjunct professor at UCLA and senior author of the study Seth Riley.
Isolation caused by traffic-choked highway
This particular population is isolated from other mountain lions by the 101 Freeway, which stops lions from the Simi Hills, Santa Susana Mountains and Los Padres National Forest from reaching them. This causes limited breeding opportunities. It is not unusual for two males in the group to mate with their own offspring. This leads to dangerously low levels of genetic diversity, which increases the likelihood of poor health and extinction.
“We have worked for years with our partners to increase connectivity across the 101 (Freeway) for all animals, but this study really drives home how serious the threat is for mountain lions, the species most at risk of being lost,” Riley said.
Researchers compared the mountain lions to a group of panthers in Florida. Mountain lions and panthers are the same species. The Florida panthers nearly went extinct due to low biodiversity.
The panther population developed holes in their hearts, and male panthers became sterile. Riley says that the population became generally weaker and more susceptible to disease.
After eight new panthers were brought in from Texas the population rose from 25 to 200. A similar solution could be used in Los Angeles, but scientists believe that more immediate action could be taken.
Conservation efforts could save lions
One possibility is to build a wildlife overpass over the 101 Freeway. This would be used by the lions as well as bobcats and other animals.
The project has been christened the Liberty Canyon Wildlife Crossing and would cost around $50 million. It is subject to a National Wildlife Federation fundraising effort called “Save LA Cougars.”
“So we can look to what happened to Florida panthers as a cautionary tale,” said lead author John Benson, a wildlife ecologist at UCLA.
Another group of cougars in the Santa Ana Mountains in Orange County also have among the lowest genetic diversity ever recorded. This population may be subject to a study from scientists.
However all is not lost for the Santa Monica mountain lions. If one new lion could be introduced every 2.5 years, the likelihood of extinction falls dramatically.
According to Riley the reproductive and survival rates are “pretty good” despite the isolation of the population. This is due to the high-quality habitat provided by the Santa Monica Mountains National Recreation Area. On the other hand the outlook worsens the more time passes and genetic isolation gets worse.
Some mountain lions have crossed the 101 Freeway, but plenty of them die on the crossing.
“It is amazing we still have mountain lions in Los Angeles,” Riley remarked.