The Camera Trap

Spotting a Bay Area Mammal Lifer: the American Mink

December 18, 2018
american mink
An American mink visits a camera trap in Sonoma County. (Photo by Sheila McCarthy, iNaturalist Creative Commons)

The Bay Area has its mammalian icons: Tule elk and mountain lions, gray foxes, coyotes and raccoons. We’re lucky to have so many wild neighbors almost right at our doors (and sometimes in our trash cans). But there are some we see less often, elusive sightings that are a lifer for naturalists.

Such is the case with this curious, slinky American mink (Neovison vison), caught on a camera trap in Sonoma County. You wouldn’t be alone if you didn’t know that minks were local; they’re more common in the northern part of the state, with Sonoma being the southernmost tip of their range.

Though the mink is a relative of the more familiar ferret and closely resembles one, there’s one key difference — the American mink is semi-aquatic, preferring to live in wetland areas or close to another body of water where it can munch on crustaceans and amphibians. A combination of close, dense fur and oily guard-hairs gives minks a waterproof coating that helps them maintain their lifestyle.

american mink
An American mink visits a camera trap in Sonoma County. (Photo by Sheila McCarthy, iNaturalist Creative Commons)

American minks were hunted widely for their fur, which was used in coats or fur trimming for luxury items for centuries. Demand in the late 19th century led to the advent of commercial farming, which continues to this day in the United States in the Pacific Northwest and upper Midwest.

Minks like to be alone, mostly, with the exception of a short mating season. How much territory an individual mink inhabits tends to vary — a larger body of water might support several, while a smaller pond might support one. Although they’re rare in the Bay Area, they’re expanding worldwide and are classified as “least concern” by the International Union for the Conservation of Nature.

In 2009, minks made a splash in Martinez, where they took advantage of a beaver dam to reproduce and make a new home. It’s difficult to say how many companions our Sonoma County friend has; even spotting one mink can be an incredible accomplishment.

Photographer Sheila McCarthy was lucky enough to capture this one thanks to the wildlife cameras that she manages on behalf of Sonoma County Regional Parks. She says she appreciates that it’s a rare find enabled by the camera trap: “Aside from on our camera, I’ve only seen them in person there one time.”   

If there are mink out there, what else might we be missing? Look beyond our most common neighbors and spend some time, and you might see something truly magical.

About the Author

Elizabeth Rogers is a writer based on the Peninsula. She writes Bay Nature's monthly Camera Trap column.