By Martin Griffith, AP

A wolverine appears to be thriving in the northern Sierra Nevada seven years after being confirmed as the first one in California since 1922, researchers said.

More than two dozen documented sightings of the solitary predator have occurred since it was first observed in March 2008 about 15 miles northwest of Truckee, said Chris Stermer, a biologist with the California Department of Fish and Wildlife. The same wolverine is believed to have been last detected in November by a motion-sensing camera in the Tahoe National Forest near Fordyce Lake, which is 15 miles southwest of where it was originally seen.

The male appears healthy with dense fur and ample weight, Stermer said, and has staked out a 300-square-mile swath of the Sierra between Interstate 80 and Highway 49 as its territory.

“I think it’s exciting,” he said. “It gives us some hope of bringing back some apex predators like that. It would be exciting to have wolverines back in the Sierra.”

Though its DNA has been linked to wolverines in Idaho’s Sawtooth Range, biologists are still unsure whether it wandered down to California or was released into the Sierra by someone. Positive identification of the wolverine spotted Nov. 3 near Fordyce Lake is pending genetic testing by the U.S. Forest Service’s Rocky Mountain Research Station in Fort Collins, Colorado. Some of its fur was obtained for the test.

“Based on our history it’s most likely going to be the same individual, but our hope is it’s not,” Stermer said. “Our hope is we have a pair here so they can mate … We’re hoping that one animal turns into a population.”

The odds are good over time that some wolverines will venture south to California from Idaho and the Cascades, he added. Once found throughout the Sierra and Rocky Mountains, wolverines were wiped out across most of the U.S. by the 1930s due to unregulated trapping and poisoning campaigns, said Bob Inman, a wolverine researcher with the Wildlife Conservation Society.

In the decades since, they largely have recovered in parts of the West, where 250 to 300 of the animals live, but not in other parts of their historical range. In the Lower 48, they live primarily in Montana, Idaho, Wyoming and Washington. Larger populations persist in Alaska and Canada.

California has the habitat to support higher wolverine numbers, Stermer said, and his agency has discussed the possibility of reintroducing them to the state.

“They avoid residential areas and livestock. There’s not a lot of controversy with having wolverines around,” he said. “How many pairs can the habitat support? That’s the question.”

The rarely seen members of the weasel family have a reputation for ferocity and strength out of proportion to their size. Adults are about as big as medium-size dogs.