Canis lupus, better known as the gray wolf, will no longer be protected under the Endangered Species Act in three states. The 13 years of protection have been effective at allowing the wolf population in the Northern Rockies of the United States, the US Department of the Interior has said.

"The wolf population is doing great. The ESA [Endangered Species Act] worked. We've got a lot of wolves in a lot of places," Ed Bangs, wolf recovery coordinator for the US Fish and Wildlife Service, said to BBC.

However, there are also some who think the decision was taken too quickly. The loss of federal protection allows hunters in Idaho, Montana and Wyoming to target the 1,500 wolves. Environmental groups said they are prepared to sue the government to put the animals back under protection.

"The enduring hostility to wolves still exists," said Earthjustice attorney Doug Honnold, who is preparing the lawsuit against the US Department of the Interior's Fish and Wildlife Service, to AP. "We're going to have hundreds of wolves killed under state management. It's a sad day for our wolves."

"With hundreds of trained professional managers, educators, wardens and biologists, state wildlife agencies have strong working relationships with local landowners and the ability to manage wolves for the long-term," said Lyle Laverty, Assistant Secretary for Fish and Wildlife and Parks to the Rocky Mountain News.

The gray wolf or timber wolf, Canis lupus, is the largest wild member of the Canidae family, weighing in at around 70–150 pounds. Overall across the world, the wolf is classified as being of least concern for extinction, as categorized by the International Union for the Conservation of Nature and Natural Resources (IUCN).