Kitten siblings P-46 and P-47 are seen at their den in the western Santa Monica Mountains in this photo provided by the National Park Service.Д«ut how can inbreeding lead to extinction? And if over time if youвЂ™re only mating with close relatives, youвЂ™ll rapidly lose genetic diversity in a population like that. So what that leads to is inbreeding, which is mating between close relatives. The major problem with being isolated, for mountain lions in the Santa Monica Mountains, is they donвЂ™t have opportunities to reproduce with any other mountain lions except those that live there too. The second concern is inbreeding, which is again related to isolation.

But in a small population, that could quickly lead to a greater probability of extinction. In a normal population thatвЂ™s larger and more connected to surrounding areas, they can withstand that. How well are they surviving and reproducing? In a small population like the Santa Monicas, one of the big concerns is you can have animals surviving and reproducing, and just by random chance, you have a bad year of survival or letвЂ™s say a couple bad years of survival. Why are you worried they might now become locally extinct? Mountain lions have lived in this area since before Europeans arrived. And so our interest was really: how likely is the population to go extinct over a given time frame? And the time frame we chose was 50 years. We know weвЂ™re dealing with a really small population thatвЂ™s isolated from the surrounding areas, and most importantly, isolated from other mountain lions by large freeways, development and agriculture. What question were you trying to answer with your study? Two nearly grown mountain lion kittens and their mother were recently spotted at the western end of the Santa Monica Mountains by remote camera. To understand more about the plight of the Santa Monica mountain lions, KPCC spoke with the studyвЂ™s lead author John Benson, a post-doctoral researcher at UCLAвЂ™s La Kretz Center for California Conservation. It needs to reach $10 million by early 2017 to keep Caltrans on track with planning efforts. So far, the group has raised $1.2 million. The project will be privately financed, and the National Wildlife Federation is spearheading the fundraising effort. The proposed location at Liberty Canyon in Calabasas would link cougars in the Santa Monicas to populations in the Simi Hills and Santa Susana Mountains. The likelihood of the Santa Monica Mountain lions becoming locally extinct due to inbreeding is nearly 100 percent, according to the study вЂ“ that is, unless Caltrans completes a $60 million wildlife crossing over the 101 freeway thatвЂ™s currently in the final design phase. As a result, they have the lowest genetic diversity of any group of mountain lions in the Western United States (another group in Orange County is in a similarly precarious situation). The freeways act like a genetic prison, keeping new mountain lions out of the area and forcing the Santa Monica mountain lions to mate with their close relatives. There are only about 15 of them living in the area bounded by the ocean, farmland to the west and the 101 and 405 freeways. Scientists have known for some time that mountain lions in the Santa Monica Mountains are a small, isolated population - but they didn't know how likely the animals were to become locally extinct due to factors like inbreeding and small population size.

ThatвЂ™s the conclusion of a paper published Tuesday in Proceedings of the Royal Society Bby scientists with UCLA, the National Park Service, and other institutions. If nothing changes, mountain lions could disappear from the Santa Monica Mountains within 50 years.

Los angeles mountain lion