Wildlife biologists are searching the craggy wilderness and rolling pastures of Northern California for seven missing gray wolves that thrilled environmentalists and frightened ranchers after becoming the first wolf pack to make the state home in nearly a century.

The family, known as the Shasta Pack, disappeared from southeastern Siskiyou County over the past year, mystifying state biologists who said it is unusual for the canine pack hunters, also known as timber wolves, to abandon established territory.

None of the gray wolves — who despite their name sport distinctive black coats — have been seen since May 2016 when researchers confirmed the presence of a lone juvenile in the rural region, which is a mix of public and private property.

“We’re reasonably confident that last year they did not use the same area as a pack as they did the year before, and we don’t know why,” said Pete Figura, a senior environmental scientist for the California Department of Fish and Wildlife. “Why they were not detected anywhere else this past summer we don’t have a clear explanation for.”

Figura said there are a number of possible explanations — including migration to a new region with more prey — but research has shown that most wolf packs cling to and protect their breeding grounds, especially during the summer. He acknowledged, though, that this behavior has generally occurred in areas with multiple packs, which is not the case in mostly wolf-free California.

The state has genetic samples of each member of the Shasta Pack, so members can be identified by testing fur or scat, Figura said.

Black wolves were spotted in the late spring and summer of 2016 in southern Oregon, Figura said, but no evidence was found that would help biologists determine their identity. Fresh wolf tracks were also spotted in late January about 10 miles from the pack’s Siskiyou County stomping grounds.

“We detected some tracks and collected some scat and are awaiting DNA analysis,” he said. “It could have been a member of the Shasta Pack or a completely different animal. We don’t know at this time.”

Then again, it is no secret that the muscular predators were not exactly received with open arms in Siskiyou County, where some ranchers have threatened to employ the “three S’s” — shoot, shovel and shut up — if any of the sharp-toothed meat-eaters got near their livestock.

Back to Gallery Missing in California: 2 adults, 5 pups, sharp teeth,... 2 1 of 2 Photo: John Stephenson, USFWS 2 of 2 Photo: Oregon Department of Fish and Wildlife 2014



The Shasta Pack is believed to have killed and eaten a calf in November 2015, the first reported case of livestock predation by wolves since their return to California, further raising tensions. That was also the last time the entire pack was known to be together.

Figura said he has no evidence to suggest the wolves were killed in retaliation. Unfortunately, none of the animals was wearing a radio collar, so movements can only be followed by relying on sightings and trail cameras, following tracks or collecting scat.

The presence of Canis lupus in California comes decades after the last known native California wolf was trapped and killed in Lassen County in 1924. The first wolf to enter the state since then was OR-7, a radio-collared animal from Oregon that dispersed from the Imnaha Pack and crossed the border in late 2011.

OR-7 created a sensation when he traveled 2,500 miles through seven counties. Then, in 2013, OR-7 returned to southwestern Oregon, where he found a mate. Now almost 8, he has had litters of pups for three consecutive years and is the leader of the Rogue Pack. They are among 110 wolves in 15 packs in Oregon, many of which are dispersing into the southwestern part of the state, near the border.

Wolves were listed as endangered in California in 2014 just as the federal government was removing protections in the Northern Rockies and Western Great Lakes. Oregon delisted their wolves in 2015. California regulators, anticipating the further dismantling of federal laws, have since developed a comprehensive wolf conservation plan emphasizing the use of nonlethal methods of control.

Besides the Shasta Pack, two wolves were confirmed in Lassen County last summer. The male was identified as the son of OR-7, but so far there is no evidence of any pups.

“As the first confirmed wild wolf family in California in nearly a century, the significance of (the Shasta) pack cannot be emphasized strongly enough,” said Amaroq Weiss, the West Coast wolf organizer for the Center for Biological Diversity. “The fact of no sightings of this wolf family — despite being an all-black pack and thus highly notable when spotted — is extremely troubling.”

Weiss fears the animals will suffer the same fate as an Oregon wolf that was killed by poison laid out for coyotes Feb. 26 in northeastern Oregon. The spring-activated trap, called an M-44, killed the wolf known as OR-48 with cyanide powder after it was set by trappers with the U.S. Department of Agriculture’s Wildlife Services, prompting an investigation.

Poisoned traps like the M-44 are illegal in California, but Weiss said it is legal for licensed hunters to kill coyotes — or for property owners to shoot or trap them when they prey on or threaten livestock.

“The point is it is really, really common for people who encounter wolves to think they are coyotes and shoot them,” Weiss said.

Weiss said accidental killing and poaching of wolves are disturbingly common in Wisconsin and throughout the Northern Rockies. In Washington state, she said, one of the first wolf families confirmed there in decades was almost entirely wiped out by poachers.

“It is my great fear this may have happened to the Shasta Pack, and my deep hope that this is not the case,” she said.

Figura said the Shasta Pack may yet turn up.

“We’re looking for them,” he said. “Part of our job and our hope is to keep track of California’s wolves, and we are certainly trying to do that.”

Peter Fimrite is a San Francisco Chronicle staff writer. Email: pfimrite@sfchronicle.com Twitter: @pfimrite

History of wolves

in the west

Up to 2 million gray wolves once lived in North America, including a healthy population in California.

Europeans, fed by big, bad wolf myths, began killing them when they arrived on the continent. By 1900, the creatures synonymous with the wild frontier had been driven to near-extinction in the lower 48 states.

The last known native California wolf was trapped and killed in Lassen County in 1924.

In the mid-1990s, 66 Canadian wolves were released in Yellowstone National Park and central Idaho in an attempt to bring the apex predator back.

Wolves have since spread across the Rocky Mountains, into Idaho, Washington, Oregon and California.

Roughly 5,500 wolves now live in the United States.