Pumas & the California Endangered Species Act

Pumas are a Candidate Species under the California Endangered Species Act

In April 2020, the California Fish and Game Commission advanced six populations of pumas in the Central Coast and Southern California to candidacy under the California Endangered Species Act (CESA). The 5-0 vote to protect pumas came in response to a petition by the Center for Biological Diversity and the Mountain Lion Foundation. The Commission is currently reviewing if these populations should be listed under CESA.

What does listing mean?
If pumas are listed under CESA, the State would be required to implement a puma recovery plan, which could include building wildlife crossings over existing freeways, re-evaluating the use of deadly rat poisons, and limiting development in areas deemed puma habitat.

Which pumas are in need of protection and why?
Researchers have parsed California’s pumas into nine genetically-distinct subpopulations. Pumas within subpopulations are more genetically related to each other than they are to other subpopulations due to restricted wildlife movement. Of those nine subpopulations, six are at risk of extinction due to roads and development, which have caused habitat fragmentation, low prey availability, deaths from vehicle collisions, genetic isolation, health defects from inbreeding, and increased conflicts with humans that lead to depredation kills.

Stretching from San Francisco down to San Diego, these subpopulations include: 

1. Central Coast North (CC-N): From San Francisco through the Santa Cruz Mountains and the East Bay. (Counties of Alameda, Contra Costa, San Mateo, Santa Clara, and Santa Cruz.) The Santa Cruz Mountains make up the core area of the CC-N. 
2. Central Coast Central (CC-C): From Monterey to Santa Barbara (Counties of Monterey, San Benito, San Luis Obispo, and Santa Barbara).
3. Central Coast South (CC-S): Limited to the Santa Monica Mountains, Simi Hills, and the Santa Susana Mountains in Ventura and Los Angeles Counties.
4. San Gabriel/San Bernardino Mountains (SGSB): Occurs within the Transverse Ranges located northwest of the City of Los Angeles within Los Angeles, Kern, and San Bernardino Counties 
5. Santa Ana Mountains (SAM): Includes 1,533km2 of undeveloped areas in Orange, Riverside, and San Diego Counties.
6. Eastern Peninsular Range (EPR): East of the Santa Ana Mountains and south of the San Bernardino Mountains, the range runs through San Diego, Riverside, and Imperial Counties and the California-Mexico border. 

Combined, these six subpopulations are considered an Evolutionarily Significant Unit (ESU), because they are isolated from robust puma populations in the rest of the state, and the recovery of one individual subpopulation rests on reestablishing connectivity between all of them. In other words, the only way these six puma populations will recover is if pumas can move freely between subpopulations to reproduce. These six subpopulations up for listing are called the Southern California/Central Coast ESU. 

Mountain lions in the North Coast and inland populations (Nevada, Eastern Sierra Nevada, Western Sierra Nevada) are not included in the proposal for CESA listing because their populations are large, have higher levels of genetic diversity, and are well connected.  

Effective Population Size: How many pumas do we need to avoid extinction?
To avert extinction, conservation managers practice the 50/500 rule: a population of 50 pumas is needed to prevent inbreeding in the short term, and a population of 500 pumas is needed to retain enough genetic diversity to persist into the future.

Five of these six subpopulations are well below 50 pumas!CC-N: 33-66 pumasCC-S: 5-10SAM: 31-62SGSB: 10-20EPR: 63-126CC-C: 113-226Researchers warn that puma populations in the Santa Ana and Santa Monica mountains could go extinct within 50 years if no measures are taken. Pumas in the Santa Cruz, San Gabriel, and San Bernardino mountains share a similar fate.

How can we protect pumas?
Key to puma survival is connecting habitat so that pumas can move between subpopulations and move to larger blocks of quality habitat. Additionally, reducing rodenticide and other environmental toxicant poisoning is also necessary to puma populations to persist.

Policy
Every day approximately 20 crashes with large animals occur on California highways; that’s a total of 7,000 vehicle crashes per year!

Though California already has more than 100 wildlife crossings, it's not nearly enough. Governor Newsom took note, and in 2021, his budget allocated $61 million for building wildlife crossings across the state.

A year later, Governor Newsom approved the Safe Roads and Wildlife Protection Act, which requires the California Department of Fish and Wildlife and California Department of Transportation to craft a strategy to identify areas with high rates of wildlife-vehicle collisions and build wildlife crossings where necessary. Funding for this act would allow for up to ten wildlife crossings to be built a year.

In 2020, Governor Newsom also signed legislation AB 1788, which prohibits the use of second-generation anticoagulant rodenticides known to poison wildlife, including mountain lions.