A North American river otter has been photographed in a closed area of Cloverdale Ranch Open Space Preserve, just south of Pescadero. The Midpeninsula Regional Open Space District says it is the first documented return of the species to the Pacific side of the Peninsula since the 1800s.
The animal was captured by a wildlife camera set up by Ken Hickman, an independent researcher who works with Midpen. KQED reported the otter has been seen twice, in July and September, moving through the coastal prairie and waterways of the 6,700-acre preserve, which Midpen acquired in 2023.
"Checking wildlife cameras can be like Christmas, but river otters haven't been known to occur on the San Mateo Coast since the 1800s," Hickman said in Midpen's announcement.
Where did it come from?
Nobody knows yet. River otters once ranged from Alaska to Santa Barbara County, but the 19th-century fur trade and later pollution wiped them out across much of that range. They have come back north of the Golden Gate and show up in Bay wetlands. The nearest other documented sighting is about 20 miles away, near Lexington Reservoir in the Santa Cruz Mountains, Midpen wildlife ecologist Matt Sharp Chaney told KQED. He said it is also possible the otter swam down the coast from Marin County's population.
Why biologists are excited
"River otters can serve as vital bioindicators," Sharp Chaney said in the district's release. Otters need clean water and plenty of food, so their presence suggests the watershed is healthy. The ranch is working grazing land that also supports coho salmon, steelhead trout and the San Francisco garter snake. Before Midpen took over, the San Mateo County Resource Conservation District and Peninsula Open Space Trust completed pond and floodplain restoration projects there.
Sharp Chaney asked anyone on the coast who has seen an otter or signs of one to report it to the River Otter Ecology Project's Otter Spotter community science platform, KQED reported.