One of the wolves released in Colorado in December killed a calf this week — the first verified livestock killing by one of the wolves that was part of the state’s voter-mandated reintroduction effort.

A rancher discovered the carcass on Tuesday in Grand County, and Colorado Parks and Wildlife officials on Wednesday confirmed the calf was killed by a wolf.

Wildlife officials initially refused to disclose whether the responsible wolf was one of the 10 released in the state in December or was one of the two wolves remaining from a pack created by animals that migrated from Wyoming in 2020.

In response to questions from The Denver Post, Colorado Parks and Wildlife spokesman Travis Duncan wrote in a Wednesday afternoon email that he could not disclose which group the wolf or wolves belonged to in order to “protect the wolves that CPW reintroduces, along with landowner information and interests.”

He reversed course Wednesday evening after receiving further questions and confirmed that the wolf or wolves involved in the killing had been from among those released in December. Duncan would not say how many wolves were involved in the kill.

The risk of wolves preying on livestock fueled strong opposition by ranchers to the reintroduction, which found most of its support from urban voters.

The calf carcass had teeth marks on its hindquarters and neck and hemorrhaging under its hide, all of which are consistent with a wolf attack, CPW Area Wildlife Manager Jeromy Huntington said in the release.

Investigators also found wolf tracks nearby.

Wildlife officials believe there are 12 wolves in Colorado: the 10 introduced in December and two from a pack that established itself in Jackson County after migrating from Wyoming. The wolves released in December were set loose in Grand County and neighboring Summit County.

All of the wolves have GPS collars that record the animals’ locations every four hours, though one collar stopped functioning in the last month.

The owner of the calf will be eligible for fair-market compensation through the state’s reimbursement program for kills and injuries to livestock caused by wolves. The calf’s owner was not identified.

Colorado Parks and Wildlife staff will continue to work with ranchers in the area and encourage the use of non-lethal deterrents, according to the news release.

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