Canadian wolves transferred to the United States in a repopulation experiment 13 years ago now have U.S. lawyers howling.
The four-footed Canuck immigrants have done so well that they have become the focus of two different lawsuits. One is trying to keep them an endangered species and protect them from hunters; the other aims to remove their protection and declare open season on them.
"Sometimes it seems like all we do is sue each other," said Ed Bangs, a U.S. Fish and Wildlife official in Missoula, Mont., who heads the wolf repopulation project.
In 1995 and 1996, two groups of grey wolves totalling 66 individuals were trapped in Alberta and British Columbia and taken south of the border to repopulate areas of Idaho, Montana and Wyoming, where they had been eradicated by ranchers and hunters.
The wolves have thrived.
Mr. Bangs said the official count is now 1,645. This spring's litters have probably brought that tally to about 2,000.
"We really appreciate the wolves [Canadians]sent and they have done great," he said.
In fact, they've done so well that in February, 2008, Fish and Wildlife announced to great fanfare that the wolves would no longer be considered an endangered species.
But that decision was overturned in court last summer. Fish and Wildlife tried again - with the change that wolves in Wyoming would still be considered endangered.
This week, a coalition of environmental groups filed another lawsuit to have the wolves in all three states declared endangered again.
"Delisting will allow the states to knock the number [of wolves]back down," said Andrew Wetzler of the Natural Resources Defence Council.
"If I were a Canadian biologist, I would be disappointed that we are effectively snatching defeat from the jaws of victory."
The state of Wyoming, which wants a near-unrestricted wolf hunt, has filed its own lawsuit against Fish and Wildlife in an attempt to have the wolves delisted.
"When we introduced wolves, both sides sued us," Mr. Bangs said. "And now both sides are suing us again."
Mr. Wetzler said the most recent science suggests the region needs at least 2,000 wolves to sustain a healthy, genetically sound population. On average, only two out of every 16 wolves breed.
Delisting the wolves would be a disaster, he said. During the period in 2008 when wolves were no longer on the endangered list, about 100 were killed by government officials.
He said state officials are obliged to maintain only 300 wolves, a number dating back to the 1980s that is supposed to guarantee a sustainable population.
"That number is patently inadequate," said Mr. Wetzler. "It's bad science."
Mr. Bangs doesn't deny that some progeny of the original Canadian wolves will die if the delisting stands - probably up to 150 wolves in Idaho alone.
But he points out that last year was a record for livestock losses and payments due to wolf predation. Officials had to kill 265 problem wolves.
"There's a lot of wolves out there and they're causing a lot of damage," said Mr. Bangs, who favours a managed annual hunt to control populations.
He maintains that adequate protection is in place for the wolves and points out that state officials must still report to the federal agency for five years after the delisting.
Something about wolves pushes people's buttons, said Mr. Bangs.
"They're great animals and if people would just appreciate them for animals and not give them these supernatural powers, everybody would be better off - including the wolves.
"People are just very emotional about wolves."