TRUCKEE, Calif. — Scientists following up on a rare wolverine sighting in the Sierra Nevada set up cameras and captured video of the animal scurrying in the snow, scaling a tree and chewing on bait.
They believe the wolverine is the same one that eight years ago became the first documented in the area since the 1920s.
Chris Stermer, a wildlife biologist with the California Department of Fish and Wildlife, set up the remote cameras in the Tahoe National Forest after officials at a field station sent him photos in January of unusual tracks in the snow near Truckee.
“They were definitely wolverine tracks,” Stermer told the Sierra Sun newspaper (http://bit.ly/2apR99p).
Wolverines, a member of the weasel family that look like a small bear with big claws, once were found throughout the Rocky Mountains and as far west as the Sierra. An estimated 250 to 300 wolverines survive in remote areas of Montana, Wyoming, Idaho, Oregon and Washington state, according to wildlife officials.
Prior to the 2008 sighting, scientists were convinced fur trapping during the early 1900s had wiped out the species in California. Now, a warming planet is threatening to shrink the deep mountain snows that wolverines need to den, scientists say.
The male carnivore near Lake Tahoe apparently migrated from the Sawtooth Range in Idaho, Stermer said.
Since then, the animal that scientists nicknamed Buddy has been detected more than 20 times over nearly 300 square miles, but it had not been sighted since November 2014, Stermer said.
Video from the remote cameras soon provided additional evidence. One clip recorded the night of Feb. 19 offers a glimpse of the wolverine before it scurries away. A second daytime clip captured Feb. 27 shows it climb a tree before chomping and tugging at a baited sock.
“When you see them on video, a wolverine is a pretty exciting species to have in California,” Stermer said. “With the population we have in California, thinking that we can have a wild wolverine amongst us is pretty amazing. It really begins to restore our larger carnivores back in California.”
Stermer is awaiting test results on DNA samples taken from saliva collected from the tree bait to confirm its identity.
“I’m pretty certain — 95 percent — that it’s the same animal,” he said.
If the DNA samples match, Buddy is estimated to be at least 9 years old, Stermer said. The life expectancy of a wild wolverine ranges from 6 to 10 years, he said.
Talk of reintroducing wolverines in California has been put on hold while the U.S. Fish and Wildlife Service considers its response to a federal court order in Montana that overturned its decision denying protection of the animal under the Endangered Species Act, Stermer said.
U.S. District Judge Dana Christensen ordered wildlife officials to act as quickly as possible to protect the species as it becomes vulnerable to a warming planet.