Almost two decades ago, the wolves were relocated to Yellowstone National Park in an effort to return them to where the animals had been hunted to extinction.
The change would result in hunting the nocturnal predators at a time when conservationists feel the animals are only beginning to gain a foothold and the federal agency is facing numerous lawsuits from those opposed to the wolf being removed from the endangered species list.
"I think it was successful in that it demonstrated that clearly it can be done," Paul Paquet, a senior scientist at the Raincoast Conservation Foundation and adjunct professor at the University of Victoria, says of the reintroduction effort.
"Whether it can be sustained is where the questions is."
The problem lies not in whether the wolves can adapt, says Paquet, but whether people who have lived without the top-tier predators for generations can do so. He believes the U.S. Fish and Wildlife Service should not lift the endangered designation.
"It is true that it can be very difficult to live with wolves if you're trying to make a living as a rancher or a farmer," Paquet says.
The last wolves were killed in Yellowstone in 1926. The massive park covers the northwest corner of Wyoming, and a small percentage of the park dips into Montana and Idaho.
In 1995, the first 14 grey wolves from Jasper National Park in the Rocky Mountains were reintroduced in Yellowstone National Park. Seventeen more were relocated there the following year.
As the wolf population increased, the repercussions — good and bad — were seen far and wide. Elk declined but beavers increased. Coyotes declined but their prey increased. Cattle predation spurred opposition.
As early as 2005, under pressure from ranchers and state officials, the federal agency turned over management of wolves in Montana and Idaho to the states. Eight other states followed.
In the spring of 2008, the U.S. Fish and Wildlife Service lifted the endangered status of the Northern Rocky Mountain population of grey wolves and the first legal wolf hunt went ahead in Montana the next year.
By the end of 2012, the agency estimated the wolf population was almost 1,700 adults and in June 2013 it proposed removing the grey wolf from the list of threatened and endangered species across the country.
"This population has exceeded its recovery goals for 11 consecutive years. Thus, this population has been delisted and is now being successfully and responsibly managed by the states," the agency says on its website, calling the reintroduction an "amazing success."
"The proposed rule is based on the best science available and incorporates new information about the wolf’s current and historical distribution in the contiguous United States and Mexico," the website says.
The long-term goal is to maintain an average of about 1,000 wolves.
Delisting is premature says Noah Greenwald of the Centre for Biological Diversity, which has taken the U.S. Fish and Wildlife Service to court over wolves before and will do so again if the agency proceeds.
"Several states have enacted aggressive hunting and trapping seasons," says Greenwald.
He said people have prejudicial views against wolves and are putting pressure on American politicians for the hunt.
Similar debates are taking place in Canada.
The Alberta Fish and Game Association has proposed bounties across the province because the animals are hunting popular big-game animals. In British Columbia — where the predator population is at a historic high while their prey populations like moose and caribou are at historic lows — the provincial government's draft plan for managing wolves doesn't offer a bounty but also doesn't rule out a cull in future.
The public comment period on the U.S. Fish and Wildlife proposal ended last month and a final decision is expected this year.
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