A pack of wolves returned after a three-year hiatus to kill three dozen sheep on a farm north of Park Falls on Monday.

Paul and Judy Canik woke Monday morning to find 31 of their Katahdin lambs and five adult females had been killed by wolves sometime between midnight and 6 a.m.

“Evidently we were sleeping too sound and didn’t hear the dogs,” Paul said. “They usually bark loud enough to alert us whenever the wolves are around.”

The couple has several Spanish Mastiff guard dogs on the farm to help ward off predators, but since wolves killed two of the expensive purebreds a few years ago, the couple keep the dogs penned at night.

This is the second time the Caniks have suffered a large loss of sheep from their farm. In 2016, wolves, potentially of the same pack, killed 17 of their bighorn sheep, valued at $1,200 each. After that depredation, the USDA Wildlife Service installed two miles of fladry — a string of colored flags that move in the wind — accompanied by electric fencing around the perimeter of the pasture. That fencing had not been installed yet this year when the attack happened Monday.

The pack in the area of the Caniks’ farm is known as the Flood Creek Pack and was counted at eight individuals this winter, according to USDA Supervisory Wildlife Biologist Dave Ruid.

Ruid said sheep and poultry are particularly vulnerable to wolves, especially in April and May when their natural forms of prey are at limited availability. In mid to late May when white-tailed deer begin fawning, there is generally a decline in livestock depredations.

As in the 2016 killing, Monday’s is considered a surplus killing, in which wolves kill more than they can eat, or perhaps don’t eat what they kill at all. The reason for this is somewhat unknown, but it is much easier for a wolf to kill a sheep confined to a pen than natural prey, which may trigger their instincts as a predator, according to Ruid.

Twenty-four of the lambs were carried off-site, while the rest were found scattered around the pasture, and all five of the dead or dying ewes were found uneaten.

“The one pregnant ewe carrying triplets, she survived by standing in the middle of the pond,” Paul said. The Caniks recovered just two injured ewes and two lambs.

“Those wolves have got pups right now and of course they’ve gotta get food to them,” Paul said. “Of course this is real easy for them. And they’re also training last year’s young how to kill.”

Brad Koele, Woodruff-based wildlife biologist for the Wisconsin Department of Natural Resources, said in this particular case, it is suspected that livestock hunting is a learned behavior for these wolves — a cycle which is difficult to break.

Koele said that if wolves were not currently listed as an endangered species, the DNR would likely take lethal action in order to curb the problem at Caniks’ farm, trapping and removing wolves that come onto the property.

“There are lots of wolves and wolf packs out there that aren’t causing any issues to livestock,” said Koele. “Packs that do kill livestock often teach their young, and we see them preying on farm animals again and again.”

According to Ruid, Wisconsin averages between 25 and 35 farms throughout the state that experience issues with livestock depredation on an annual basis. Although it is significant to the individual farmer, wolf-caused livestock depredations are not a significant problem in the state, according to Ruid.

The most recent wolf population numbers for Wisconsin show a statewide count for 2017-18 at 905 to 944 animals, according to the Wisconsin Department of Natural Resources.

Due to the endangered species listing, there are no provisions for lethal removal of gray wolves in the state. Live translocation is also not an option since there are no vacant areas in the state, Ruid said.

Through the USDA and Wisconsin DNR, farmers with confirmed wolf depredations can claim reimbursement from the state, which generally takes 1 1/2 to 2 months to receive.

For now, the Caniks plan to put a radio on a hill in the middle of the pasture to scare wolves away.

Any livestock producers in northern Wisconsin who suspect they are experiencing wolf-related issues should call the USDA-Wildlife Services at 800-228-1368.