Mountain lion at wildlife camera, Bear Creek Redwoods Open Space Preserve. Photo by De Anza College

Because Rancho San Antonio Open Space Preserve is adjacent to a densely populated urban area it is Midpen’s most-visited preserve. It is also habitat for many wildlife species, including mountain lions. Occasionally, visitors report sightings and encounters with mountain lions, including a non-fatal attack in February 2020. This is currently the first and only preserve where we have implemented a wildlife photo index research project beginning in the fall of 2020. 


The objectives of the Wildlife Photo Index Research Project are to learn the following about mountain lions and other wildlife in Rancho San Antonio Preserve:

  • Population: Diversity and abundance
  • Geography: Distribution across the landscape
  • Influences: Factors affecting wildlife behavior

The results of Midpen’s Wildlife Photo Index Research Project, in conjunction with a separate mountain lion collaring study, will help guide Midpen’s science-based preserve management to best protect visitors and wildlife, and fulfill our balanced mission of preserving and restoring the natural environment and providing for ecologically sensitive public enjoyment.


We’ll be sharing wildlife images, insights and findings throughout the study. View some of the most recent wildlife photos in the gallery below and sign up to stay informed with resource management project updates.


The Wildlife Photo Index method was created by the Wildlife Conservation Society and the Zoological Society of London, and is an internationally recognized way to acquire statistically viable wildlife data over a large geographic area. Motion-activated still cameras are placed in a non-biased grid system and are solely for wildlife research.

This method is being used by other park and open space agencies in our region, allowing our collective data to provide a big-picture view of wildlife in regional open space, and inform our land management allowing people and wildlife to coexist in the Bay Area.


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Photo Gallery

  • Mountain lion in Rancho San Antonio Open Space Preserve on October 29, 2020 at 2:30 a.m.
  • A rare spotted skunk in in Rancho San Antonio Open Space Preserve on October 17, 2020 at 11:14 p.m. October
  • Owl hunting a rabbit in Rancho San Antonio Open Space Preserve on October 23, 2020 at 1:14 a.m. October
  • Young black-tailed deer buck and San Francisco Bay beyond, Rancho San Antonio Open Space Preserve on October 12, 2020 at 7 p.m.