Elk populations are falling—but don't just blame the wolves, say Idaho Department of Fish and Game officials.
A recent study of the causes of female elk mortality shows that elk populations are at or below goals in 19 of Idaho's 29 elk management zones, including the Sawtooth and Smoky mountain regions in central Idaho.
The report that there are fewer elk in the region doesn't come as news to Fish and Game or to local hunters.
"Most of this has been fairly clear for at least a while," said Ed Mitchell, public affairs officer for the department. "The results were no real surprise."
But falling numbers doesn't always mean increased predator impact. Regan Berkley, wildlife biologist for the department's Magic Valley Region, said the reasons for the elk decline are varied and far from simple.
"We've definitely seen elk population declines in the Sawtooth zone," Berkley said. "As to all of the causes for the decline, I don't think we have them pinned down yet."
According to the study, elk populations are affected by four major factors: habitat, weather, predators and human hunters.
For example, the elk population in the Lolo zone—in north-central Idaho—has had an estimated 20 percent of its female elk population killed by wolves, but Fish and Game attributes some of the population drop to deteriorating habitats.
Craig White, a staff biologist with Fish and Game, says the habitat in the Lolo region is in a period of transition, still recovering from a huge fire around the turn of the century. Forest canopy is just beginning to return to the region, choking out the shrubs and meadows elk graze on.
Still, White said, the elk decline is not easy blame on one factor.
"It's not really one thing or another, it's a cumulative impact," he said.
As elk population declines were being reported anecdotally by hunters, the news that predators impact elk populations does not surprise anyone in the know. "We all know that wolves eat moose, deer and elk. That's what they do," said White. "The question is what impact that has on populations."
Berkley described the effects of wolves on elk as "mixed," especially in the Southern Mountains wolf management zone, which encompasses much of the Wood River Valley and central Idaho east to the Montana border.
"In portions of the Magic Valley Region, wolves may be [a threat]," she said. "But in others, they may not be. It really varies."
According to the Fish and Game study, wolves are a significant cause of elk death in three zones, including the Sawtooth and Smoky Mountain zones just north and west of the Wood River Valley.
Over the course of the three-year study, which spanned 2005 to 2008, wolves in the Smoky Mountain region killed 5 percent of the female elk in the area, while cougars killed 4 percent and hunters took 3 percent.
In contrast, the neighboring Pioneer region slightly to the east saw only 1 percent of its elk population killed by wolves.
What kind of impact the hunting of wolves will have on these figures remains to be seen, as Idaho's first hunting season on the predators didn't happen until 2009.
Garrick Dutcher, program manager for the wolf conservation group Living with Wolves, argues that while wolves are causing some elk populations to drop, it's all to the benefit of the larger ecosystem.
"The dynamics of prey and predator find their own balance," he said. "No predator has ever eliminated their prey. ... There is no sport-killing in nature."
Wolves and elk evolved together, said Suzanne Stone, spokeswoman for the conservation group Defenders of Wildlife.
"Wolves and elk co-evolved and have shared the land for thousands of years," she said. "There is every indication that elk populations will remain strong despite the return of wolves to the region."
To an extent, Berkley said she agrees with the notion that prey-predator relationships find a level.
"There's an element of truth to that," she said. "Evidence suggests that predators and prey do set a balance, but when you look at the change on habitats that people have exerted ... that changes things."
Dutcher argues that the prey-predator balance between elk and wolves is being affected by human hunters—and that Fish and Game isn't motivated to limit that impact.
"It's not to say that Fish and Game is anti-wolf, but the wolves are threatening their revenue stream," Dutcher said.
Elk tags sell for $30.75 for Idaho residents, while wolf tags sell for $11.50.
While elk hunters bring more revenue to the department than wolves, both because of tag prices and because elk far outnumber wolves, Mitchell denied that elk-population objectives are financially motivated.
"It's not about how many elk tags we can sell," Mitchell said. "Elk tag sales are important ... but so are a lot of other things."
The department has already limited tag sales on cow elk in an attempt to stabilize populations in the Sawtooth elk region west of Stanley, and non-tribal hunters can only kill antlered elk in the Lolo region.
Tag sales are based on a number of factors, said Berkley.
"We look at the whole picture every year," she said, adding that more active wolves in a region doesn't necessarily mean fewer tags will be issued.
Wolves are a part of the decision-making process, she said, but not the only part.
Despite the study's showing that elk are declining in certain areas, some wolf advocates see the study as a step toward acceptance of the predators' role, because it clearly defines other threats to elk populations.
"It's a nice moment for wolves," Dutcher said of the study. "People are getting the idea that, OK, these animals have a niche."
Katherine Wutz: firstname.lastname@example.org