Gray wolf populations in a six-state region of the northern Rocky Mountains are proving resilient to aggressive management practices.

The overall number remained just under 1,700 at the close of 2013, according to figures released by various state and federal agencies.

Despite warnings from wildlife advocates concerned more liberal hunting and trapping regulations would crash wolf numbers, the count is down just six percent since the animal lost federal protection in 2011, the Washington Post reports. Idaho saw the most significant drop in 2013 after broadening hunting and trapping regulations and hiring government agents in helicopters to eradicate entire packs. But it’s still home to at least 659 wolves.

“Wolves are very tenacious, they’re very prolific,” said Mike Jimenez, federal wolf recovery coordinator for the Rockies and a biologist with the U.S. Fish and Wildlife Service. “The population is very secure, but it doesn’t remove the controversy.”

When it comes to conflicts, wolves killed at least 143 cattle and 476 sheep in 2013 — 51 fewer cattle and six fewer sheep than the year before. Wyatt Prescott, vice president of the Idaho Cattle Association, said he hopes hunters and trappers keep the numbers from going back up.

“We’re not trying to annihilate wolves, but we would continue to advocate for a sheer reduction,” in their numbers, Prescott said.