The first image on the camera card shows a flash of fuzz amid the forest. In the next, the doe walks more clearly into view. With each photo, a story unfolds. The mule deer faces away, munching something on the ground. Then she cocks her head as if she can hear the shutter of the hidden camera. The deer comes closer, and closer, until each individual soft hair of her belly comes into focus.
These are just a handful of the dozens of pictures on this memory card captured over three months on a camera stealthily staked off trail in a part of the Blithedale Summit Preserve where coast live oaks grow along a northern spur of Mount Tam. The preserve is managed by Marin County Parks but, in an example of how One Tam partners are working across boundaries, a trio of Golden Gate National Parks Conservancy staffers led by Lisette Arellano, the organization’s community science program manager, are out checking the preserve’s wildlife cameras. Trudging off trail, the small team seems sure-footed. They’ve dealt with trickier conditions to get to the cameras: clambering through coyote brush, rubbing up against poison oak, even being attacked by wasps. “It’s not like we picked spots because they were easy to get to,” Arellano jokes.
Every quarter, different teams from the Parks Conservancy, Marin County Parks, National Park Service, and Marin Municipal Water District take turns servicing the 128 cameras, which have become vital tools for tracking mammals, large and small, across One Tam lands. Each motion-sensitive camera, staked at a precise point on a grid, snaps a picture when an animal passes by. The photos contribute to One Tam’s Wildlife Picture Index (WPI), a method for arraying wildlife cameras to collect data that was developed by the Wildlife Conservation Society and the Zoological Society of London. Quantifying the presence or absence of species in a landscape is part of a statistical measure of its ecological health.
WPI data collection began here in 2014, alongside the birth of One Tam, and helped illustrate the need for a network. The WPI methodology requires camera traps to be set within about a half mile of each other to get an adequate occupancy measurement, so the project had to cross agency property boundaries. All the One Tam partners contributed funding and staff and helped identify prime camera-trap locations on their lands, and all groups have a stake in the project’s success. Lack of data, particularly regarding potential impacts on fauna, often poses a challenge to stewardship and wildlife-management plans. Getting more data about where wildlife lives, and in what numbers, could be critical for shaping and securing approval of future stewardship plans.
One Tam volunteers sort through the 2 million photos the cameras collect mountain-wide each year, a feat that staff could never do alone. One Tam regularly trains community members to identify and log the species shown in the photos, then hosts picture-identification parties. “You don’t often see an animal, you see a blur,” volunteer Marianna Riser says. “So you pick out the pieces you can identify and put them together. It’s kind of like a puzzle.”
With everyone in one room examining photos, it’s a social experience: someone yelping in excitement at a good find, another person calling fellow cataloguers over to come help identify a creature.
“I’ve done quite a bit of hiking, and you rarely see animals because they hear you coming from so far away,” Riser adds. The WPI is a chance to see the mountain and its wildlife in a whole new way.