There is a report in the LA Times that the mountain lions of Southern California are approaching what they describe as an “extinction vortex”. As I understand it, this means that when the population numbers have decreased to a certain level then there’s no chance that the mountain lion in that location can survive because of inbreeding depression.
As a consequence the state Fish and Game Commission are arguing that six isolated and genetically distinct mountain lion ‘clans’ from Santa Cruz to the US-Mexico border are a distinct subpopulation and threatened by extinction.
This clashes with housing development. Once again people are facing the age-old problem of population growth requiring housing development which puts the squeeze on wildlife habitat. This is a classic example. The Fish and Game Commission have been petitioned (by conservationists) to classify these mountain lions as threatened which is controversial.
“It will raise a lot of eyebrows amongst developers and others who will point out that, overall, mountain lions are doing okay, but the weight of scientific evidence suggest that in certain places they are in serious trouble. So, listing these lines as threatened is not an outlandish notion.”Justin Dellinger, senior environmental scientist with the Wildlife Investigations Laboratory at the California Department of Fish and Wildlife.
We’ve reached a critical point for mountain lions in Southern California. Individual lions face horrible deaths from car collisions or rat poison, while their populations become increasingly isolated and inbred in ever-shrinking islands of habitat hemmed by freeways and sprawl.”Tiffany Yap, a biologist at the Center for Biological Diversity and lead author of the petition
If the state Fish and Game Commission agree the petition it will have a dramatic effect upon residential and commercial development. It would be prohibited or limited in mountain lion habitat within a region covering about a third of the state. Developers have said that the petition is absurd. They argue that the mountain lion is thriving statewide. However, in southern California the mountain lion is declining in population numbers in the Santa Ana, San Gabriel, San Bernardino, Santa Monica, Santa Cruz and Tehachapi Mountains.
“Our goal is to increase survival rates and stabilize genetic diversity among mountain lion populations. That can only happen when they are not constantly getting hammered.”Lynn Cullens of the nonprofit Mountain Lion Foundation
In the Santa Monicas, the 101 Freeway is a major barrier to gene flow for a group of 10 mountain lions. Similarly, in the Santa Anas the 15 Freeway restricts movement of mountain lions. Then there’s traffic accidents. Motorists have hit and killed 17 mountain lions in the Santa Monica Mountains since 2002.
Comment: these arguments between developers and conservationists will crop up more often in years ahead. There is only one long-term outcome, the gradual extinction of the mountain in California due more residential and commercial development.