Oregon State Researcher Documents Rare Wolverine in California

Reports of wolverine sightings occur occasionally in California, but none of those sightings have been confirmed.

A rare wolverine has been documented in the Tahoe National Forest by a researcher from Oregon State University working with colleagues at the U.S. Forest Service’s Pacific Southwest Research Station – the first confirmed sighting of the animal in nearly three-quarters of a century. Photo courtesy: Katie Moriarty - Oregon State University

(TRUCKEE, Calif.) - A rare wolverine has been documented in the Tahoe National Forest by a researcher from Oregon State University working with colleagues at the U.S. Forest Service’s Pacific Southwest Research Station – the first confirmed sighting of the animal in nearly three-quarters of a century.

Katie Moriarty, a graduate student in OSU’s Department of Fisheries and Wildlife, has been conducting research in the forest on the effects of landscape change on American martens. The project, funded primarily by the Pacific Southwest Research Station, uses a large array of cameras that remotely capture images of martens and other animals through the use of motion sensors or heat detectors.

However, one of the cameras captured an image from behind of a larger animal with telltale black and brown markings that experts say is a wolverine.

William J. Zielinski, a research ecologist with the Pacific Southwest Research Station, sent the image to Jeff Copeland, a noted wolverine expert with the Rocky Mountain Research Station. Copeland said he “couldn’t convert it into anything else” other than a wolverine.

“It looks like the real deal,” Copeland added.

Zielinski said reports of wolverine sightings occur occasionally in California, but none of those sightings have been confirmed. The last documented occurrence of a wolverine in the state dates back to the 1920s, he said.

The North American wolverine is the largest member of the weasel family and adults can weigh as much as 40 pounds. With its bushy tail and broad head, it resembles a small bear and has a similar diet – insects, berries, small animals, birds and carrion.

Wolverines are more common in the north-central United States, including Minnesota, Michigan and North Dakota, and also can be found in Idaho, Utah, Colorado and Wyoming.

Moriarty, who is pursuing a master’s degree in wildlife science at Oregon State, said the sighting on camera of a wolverine was “hugely unexpected.”

“This may be an important scientific ‘stumble,’” she said. “Wolverines are, at the least, extremely rare and some people consider then to have been extirpated in California. I had hoped to get marten detections with the cameras, and I have captured a couple, but getting a wolverine was quite a surprise.

“This season, I’ve obtained images of black bear, bobcat, many coyotes, spotted skunk, Stellar’s jay, common ravens, mice, and long- and short-tailed weasels,” Moriarty added. “It’s a fantastic wildlife assemblage.”

Moriarty has been working in the Tahoe National Forest under the tutelage of Zielinski, a wildlife ecologist, and Eric Forsman, a wildlife ecologist at OSU and the U.S. Geological Survey. Both are members of Moriarty’s graduate committee.

Zielinski, who is an expert at detecting rare mammals including wolverines, lynx, marten and fishers, said the U.S. Forest Service will begin seeking more evidence of wolverines in the region. In addition to the camera array, researchers will try to collect hair and scat samples and compare them to an existing DNA database that may tell them from where the wolverine originated.