The range of the Gray wolf used to extend across almost the entire northern hemisphere, today they inhabit less than 5 percent of their original territory. Ingo Wagner/AFP

On Tuesday, Wisconsin began allowing the hunting and killing of wolves that had, until 2011, been protected by the Endangered Species Act. But scientists say the change is premature and could lead to the devastation of the gray wolf population in the state.

The state's kill-limit was set at 251 wolves by the Department of Natural Resources (DNR) — meaning about one-third of Wisconsin's wolf population could be killed legally. The hunt will last until February or until the limit has been reached.

According to the DNR's website, no one had reported killing a wolf as of late Tuesday morning.

The gray wolf was removed from the endangered species list in 2011 following a decades-long federal government campaign to repopulate the animals after they were nearly wiped out in the early 20th century. Legal hunting seasons began in some states the next year, prompting an outcry from scientists who said the wolves' population was not yet at a viable level.

"These are arbitrary and capricious decisions that violate their own policies about what it means to recover a species," Amaroq Weiss, West Coast wolf organizer for the Center for Biological Diversity, told Al Jazeera.

Scientists are worried the wolf population in the state is still too fragile to survive hunts, and warn the wolves' disappearance will have significant impacts all the way down the food chain.

The gray wolf, which once flourished across the entire Northern Hemisphere, evolved over millions of years to play a crucial role in regulating its ecosystem.

Wolves tend to eat older, injured or less healthy animals, according to Weiss, which makes the wolves' species of prey healthier. Also, when prey like deer and elk are hunted by wolves, it keeps them on the move and prevents overgrazing.

Plants and their roots, in turn, provide stability to riverbeds so they don't erode, and the flora also provides roosting places for migrating birds. Vegetation supplies beavers with materials for dams, which then create the deep pools that young fish need to survive.

"It's a beautiful, complex tapestry ... that shows the level of interaction that must happen between apex predators and their environment for the full health of the system," Weiss said.

"Yellowstone is a good example because of its tremendous photographic record dating from the 1800s, when wolves were still in the park, until today. Since wolves were removed in 1926, in the photos you see elk just standing around because there are no predators. And you see the elk's effect on vegetation by overgrazing because they are able to stay in the same area instead of constantly moving."

Those who say the wolf population needs to be kept at a lower level say the hunt is a way to manage wolves that ravage farmer's livestock.

In Wisconsin, the goal is to eventually reduce the wolf population to 350, but experts say that number may be too low for the species to remain viable.

"Scientists used to talk about recovering species to the minimum viable levels; then they began to understand the complex ecological relationships and said instead we need the populations back at the level where they are functioning in the role they evolved to fill," Weiss said.

To maintain ecological stability, most scientists say 5,000 to 7,000 wolves are necessary in the Great Lakes region alone. But ranchers and hunters — and the political officials they support — disagree.