Researchers: Local Mountain Lions Face Genetic Threat

Morgan Hill-area mountain lions are being described by local researchers as a fragmented and vulnerable population, not a region with too many cats. A May 21 report in the Morgan Hill Times said scientists tracking lions in the Santa Cruz Mountains disputed claims in local letters that the animals are “dangerously overpopulated.” Chris Wilmers of the UC Santa Cruz Puma Project and wildlife researcher Rick Hopkins said the central problem is isolation — especially the difficulty of moving between the Santa Cruz Mountains and other habitat blocks through Coyote Valley. The California Fish and Game Commission in February listed mountain lion populations in parts of the central coast and southern California as threatened under state law, citing habitat loss, fragmentation and isolation. ### Why are researchers pushing back on the idea of “too many” mountain lions? Phil Salgado, a Morgan Hill resident, has published multiple letters since December arguing that local lions are under “intense territorial pressure,” according to the Morgan Hill Times. Researchers quoted in that report said his calculations rely on a false assumption that mountain lion home ranges do not overlap. Rick Hopkins, who studied mountain lions in the Diablo Range for nearly a decade, told the paper that assumption is wrong and said he documented as many as 10 adult lions per 100 square miles in the least human-influenced parts of his study area. (morganhilltimes.com) Chris Wilmers, a professor in UC Santa Cruz’s Environmental Studies Department and director of the Santa Cruz Puma Project, told the paper that densities in the Santa Cruz Mountains run on the low end of two to three animals per 100 square kilometers, or roughly five to six lions per 100 square miles. The Santa Cruz Puma Project says it tracks mountain lions with telemetry collars and movement data to study habitat use and movement corridors in and between the Santa Cruz Mountains. (morganhilltimes.com) ### What do scientists say is the actual threat in this region? The California Fish and Game Commission said on Feb. 12 that mountain lion populations in parts of the central coast and southern California warranted threatened status under the California Endangered Species Act. The commission cited habitat loss, habitat fragmentation and isolation of small populations caused by expanding human infrastructure. (morganhilltimes.com) Coyote Valley has become central to that discussion because it is the most direct landscape connection between the Santa Cruz Mountains and inland ranges. A 2016 UC Santa Cruz Puma Project document prepared for the Santa Clara Valley Habitat Agency said researchers did not document any mountain lions entering Coyote Valley or crossing the Highway 101 corridor during the monitoring period. The document said the lack of vegetative cover and dominance of development, agricultural land and open grassland likely contributed to that absence, while noting the inference was based on a small sample of dispersing animals. (wildlife.ca.gov) ### Why does Coyote Valley matter so much? The Santa Cruz Puma Project says its work is intended in part to guide “important movement corridors” for lions within and between the Santa Cruz Mountains. The Santa Clara Valley Habitat Agency lists Coyote Valley wildlife connectivity work among regional corridor projects presented to its wildlife corridor technical working group. (scv-habitatagency.org) Peninsula Open Space Trust and the Santa Clara Valley Open Space Authority have also described Coyote Valley as a wildlife crossing focus area. A 2024 POST update said the Open Space Authority, POST and the city of San José were working on the Coyote Valley Conservation Areas Master Plan and that protected lands on the valley floor totaled more than 1,500 acres at that point. (santacruzpumas.org) ### What happens when a mountain lion kills livestock or pets? California law still allows action in depredation cases, even as the regional population now has threatened status. The California Department of Fish and Wildlife says property owners should report actual or potential mountain lion depredation and that a depredation permit may be issued for confirmed cases through a stepwise process that prioritizes effective nonlethal actions. (openspacetrust.org) The department also says livestock or pet owners can request a depredation permit when an animal has been injured or killed by a mountain lion. The Morgan Hill debate has unfolded partly because sightings and ranchland conflicts are highly visible. Researchers quoted in the May 21 report said those incidents do not by themselves show a population boom and argued that fragmented habitat and limited dispersal remain the more important conservation facts. ### What comes next in this story? (wildlife.ca.gov) The Santa Clara Valley Habitat Agency’s corridor working group continues to post wildlife connectivity materials, including Coyote Valley presentations, on its public website. The Santa Cruz Puma Project also continues to publish tracking and research updates through its project site. Those two efforts — corridor construction and long-term monitoring — are likely to remain the main public markers of whether Santa Cruz Mountains lions can move more safely through the region. (morganhilltimes.com) (scv-habitatagency.org)