Four gray wolves were killed in the Sierra Valley following what California wildlife authorities described as an unprecedented level of livestock attacks.

According to the California Department of Fish and Wildlife, in an online Facebook post, the action was carried out in coordination with the U.S. Fish and Wildlife Service after months of non-lethal management efforts failed to prevent further losses.

Officials said the decision was based on the best available science and understanding of wolf behavior.

Between March 28 and Sept. 10, the Beyem Seyo pack was responsible for 70 livestock deaths. Statewide, there were 110 confirmed or probable wolf-related livestock losses during that time, meaning the pack accounted for about 63 percent of the total.

From Sept. 10 to Oct. 14, 17 additional confirmed or probable livestock losses were documented.

The California Department of Fish and Wildlife said it continues to work with livestock operators and federal partners to investigate depredation events and manage wolf activity across the region.

More information about the state’s wolf management efforts is available at wildlife.ca.gov.