CHEYENNE — For the past decade and a half in Wyoming, there have been few issues as polarizing and emotional as wolves.
Since their reintroduction in the mid-1990s, hunters and ranchers say wolves are severely depleting elk populations in northwestern Wyoming, devastating sport hunting and depriving them of their livelihood. Conservationists and some outfitters, though, hotly dispute that.
But amid all the heated words and strong feelings on both sides, the exact effect wolves have on elk in Wyoming is still unclear.
Numbers game
This much is clear: Overall, the populations of both wolves and elk are growing in Wyoming.
As of 2009, there were at least 44 wolf packs in the state, composed of a minimum of 320 wolves, according to the U.S. Fish and Wildlife Service. That’s a statewide increase of 6 percent over the previous year.
At least 224 of those wolves lived outside Yellowstone National Park, covering an area from Big Piney to Cody.
The wolves’ primary food source is elk. During the winter, when wolves are most active, each wolf kills about 1.8 elk per month. Usually, they seek the most vulnerable members of a herd: the old, young and sick.
The overall statewide elk population, meanwhile, remains fairly high.
According to the Wyoming Game and Fish Department, in 2008 only one elk herd unit, the Wiggins Fork herd in the DuBois-Crowheart area, had an estimated population below the department’s population objectives.
Difficult to count
However, the Northern Yellowstone elk herd, Yellowstone National Park’s largest and most famous elk herd, is only about 40 percent of its size before wolves were reintroduced to the park, said Doug Smith, Yellowstone’s wolf biologist. Most of the seven other herds in the park are difficult to count, Smith said, as they migrate in and out of Yellowstone’s boundaries.
While Wyoming’s elk population as a whole is steady, there’s a worrisome trend: More and more elk calves are dying before reaching adulthood.
Elk herds need a ratio of about 25 calves for every 100 females — or cows — to sustain a high enough population to allow for hunting.
But since wolf reintroduction, many herds’ calf-to-cow ratios have dipped well below that level. In 1987, the entire Clark’s Fork elk herd unit, which lives between Cody and Yellowstone, had 40 calves for every 100 cows, a Game and Fish survey found. In 2008, that number had dropped to 23 calves per 100 cows.
Of course, within the herd, numbers can vary dramatically on the local level. A new Game and Fish survey of different groups within the Clark’s Fork elk herd this year, for example, found calf-to-cow ratios ranging from 12 per 100 to 57 per 100.
But the declines in elk calves reaching maturity have many hunters and outfitters worried — and crying “wolf.”
‘All shades of gray’
But how much of a role do wolves play in affecting these population trends?
A 2007 study by the Wyoming Game and Fish Department found that of eight elk herds in wolf-occupied areas, four suffered “significant declines” in juvenile survival rates of between 24 and 36 percent. In the other four herds, wolves didn’t appear to be causing any significant decline.
“The only herds with recruitment rates that will not support hunting or possibly even stable populations, are the herds with significant wolf predation in addition to other factors,” the study concluded.
However, those findings are now being called into question.
A study of Yellowstone elk between 2003-2005 found that grizzly and black bears — not wolves — are by far the No. 1 threat to elk calves. Bears, the study found, are responsible for about 60 percent of elk calf predator deaths in Yellowstone while wolves kill between 14 to 17 percent and coyotes kill up to 11 percent.
Game and Fish wildlife biologist Doug McWhirter said those findings jibe with his research into two elk herds near Cody.
But McWhirter cautioned against generalizing about the causes of elk death, as they vary by place and time.
“Everybody likes a short, sweet assessment of things,” he said, “but that isn’t always the case — and it’s definitely not the case with this.”
Smith echoed that warning in talking about what caused the massive population crash within the Northern Yellowstone elk herd.
A drought in the late 1990s and early 2000s likely made elk more susceptible to predators, Smith said. And as Yellowstone’s elk population exploded after massive forest fires in 1998 created prime elk habitat, the terrain might have just not been able to support that many elk, he said.
Adding to the mystery, the local wolf population in the herd’s area has plummeted from 94 in 2007 to 32 this year, Smith said.
One of the reasons the debate about wolves’ effect on elk has become so intense, Smith said, is because it’s such a complex issue.
“People love black-and-white answers — they love it,” Smith said. “And I think this wolf debate is all shades of gray.”
Area 67
But to many hunters and outfitters who traverse the mountains and valleys of northwest Wyoming, there isn’t much ambiguity about what they’re seeing.
“I’m out almost every day all winter, and wherever you go you find dead elk that the wolves have killed,” said Fritz Meyer, who runs Wind River Mountain Outfitters in Dubois.
Before wolves were reintroduced, Meyer would lead 40 to 50 antlerless-elk hunts a year. But now he does about three to four per year, as the state has slashed the number of elk hunting permits in his local hunting area, Area 67, from 1,550 to 150 over the past 15 years.
And when he does go out, Meyer said, the elk, facing constant wolf harassment, are nervous and spook more easily.
Research may show that bears are the primary killers of elk calves, Meyer said, but that doesn’t mean wolves aren’t making a huge impact as well.
“It’s not the straw that broke the camel’s back, it’s the lead pipe,” he said.
Dubois game warden Cole Thompson said there are more elk in Area 67 than at any point in the past 20 years, though he doesn’t know why.
Part of it, he said, could be that more and more hunters are worried about eradicating the local elk population entirely.
“The feelings people have (are), ‘Oh my god, the wolves are killing everything and they destroying everything,’ ” Thompson said. “And so people are afraid, the general public is afraid to kill any elk.”
Investigation continues
The debate over wolves’ effect on elk in Wyoming is part of a larger fight between the state of Wyoming and the federal government. While Idaho and Montana now manage their wolf populations themselves, in Wyoming wolves are still under federal protection because the U.S. Fish and Wildlife Service has rejected the state’s proposed wolf management plan. A federal judge is now considering whether to overrule the feds’ rejection of the plan.
In the meantime, the issue will continue to draw headlines — most recently, about a rally hunters and outfitters held in Jackson on Saturday to draw attention to wolves’ role in declining elk numbers.
And as the debate continues, biologists and researchers are working to get a more complete picture of the complex relationship between wolves and elk.
“The problem is, it’s hard to tell a very complicated story,” Smith said. “There’s no question that getting to the bottom of this is difficult. But I think we need to take the time to do it.”
Contact Jeremy Pelzer at jeremy.pelzer@trib.com or 307-632-1244.
No comments:
Post a Comment