Are Alaskan trappers to blame for declining Denali Park wolf population?

Craig Medred | Dec 27, 2012

There’s one thing in the world of Denali National Park wolves about which everyone seems to agree: The much-loved, sometimes-loathed carnivores that roam the 7,370 square miles of park wilderness have seen better days. A fall census found only 57 of the animals in nine packs, the lowest count since 1986, although the number of packs had increased since last year.

The data was almost immediately used to attack trappers in the Healy area of the Alaska Interior. The survey results, wolf activist Rick Steiner told the Associated Press, "confirm fears expressed earlier this year by wildlife conservation advocates and biologists regarding the continued take of park wolves when they cross the park's northeastern boundary onto state lands."

Denali is the most visible, if not the most popular, park in the 49th state. Consequently, the story quickly attracted national and international attention and Steiner, a former marine biologist for the University of Alaska, followed up by again petitioning Alaska Commissioner of Fish and Game Cora Campbell to close trapping along the northeast boundary of the park. He was joined by the Alaska Wildlife Alliance, the state's main animal protection group.

The state Board of Game, a hunter-dominated group that sets seasons and bag limits for hunting and trapping, promptly vetoed that idea, as it had several times before. The board argued there was no evidence of a serious decline in the wolf population in the Denali area and contended its job was to find balance in the value of dead wolves, which provide lucrative fur, and live ones, which attract wildlife watchers to the park.

'More valuable alive than dead' 

The latter were dismayed when the human-habituated -- and thus more visible -- Grant Creek pack broke up this spring. They blamed trapping. “To me, and I know probably 400,000 other people who visit Denali, these wolves are way more valuable alive than dead. I don’t know what they get for a wolf pelt, but it’s not much,” Valerie Connor, conservation director for the Alaska Center for the Environment, told the Los Angeles Times.

She and others are convinced the Grant Creek pack split up because a pair of its females were trapped, but it is hard to make a definitive case for this belief. Scientists who've worked with wolves in Denali for decades say packs are in a constant state of flux. As world-renowned wolf researcher L. David Mech noted in the book "The Wolves of Denali,'' the most powerful, wild carnivores live tumultuous lives. Wolves are constantly leaving packs to look for better hunting or breeding opportunities, and wolves are constantly killing each other.

Wolves killing wolves 

"The primary mortality cause of 57 wolves aged 9 months or older in Denali Park and Preserve during our (nearly decade long) study was death from other wolves, and that cause claimed about five times the rate of wolf deaths as any other known natural cause such as accidents or disease,'' wrote Mech. He also observed that "our estimated rate of human-caused wolf mortality in Denali is the lowest of any large wolf population that has been studied anywhere except Isle Royale, the national park land in Lake Superior, which is closed and uninhabited for eight months of the year.

"Conversely, our rate of wolf mortality inflicted by fellow wolves was one of the highest reported, at least partly because human-caused mortality was so low. The natural state of a wolf population seems to include high natural-caused turnover.'' The "natural state'' of Denali wolves has become an issue these days because of that small, fall count. The number itself doesn't seem to trouble scientists much.

"As you know from Layne (Adams') work and others, wolves and packs are incredibly dynamic,'' Grant Hilderbrand, the regional wildlife biologist for the National Park Service said in an email in which he suggested that the low wolf count is itself suspect.

"One factor that may influence the spring and fall numbers you are looking at is that we have had some less-than-ideal tracking conditions this fall,'' he said. "We have a couple of territories where we haven't been able to locate wolves.  They may be there, and we are missing them. Or they may not be...."

Rare summer die-off? 

The spring and fall census numbers for Denali are interesting in that they reflect something never before witnessed in the park: a major, over-summer die off, if the numbers can be believed. This sort of thing is almost unheard of, but census numbers dropped from 70 in March of the year to 57 in October. The decrease of 13 wolves amounts to nearly a 20 percent decline in the Denali wolf population.

Only twice since 1979 has the population declined over the summer. And in the two cases on record, once in 1986 and again in 1997, the change amounted to but three or four wolves. The norm is for the population to grow significantly. It jumped, by way of illustration, from 93 in March 2007 to 147 that fall. That is an extreme example, but the population seldom goes the other direction.
"It is odd,'' said biologist Vic Van Ballenberghe. “But considering that some of them didn't raise pups apparently, probably there (were) some summer losses.''

Van Ballenberghe studies moose in Denali. He is a long-time advocate for wolf protection in Alaska and a former member of the Board of Game. He said he got the report on reproductive failures earlier this year from Denali biologist Tom Meier. Meier, a co-author with Adams and others on the "Wolves of Denali,'' had been in charge of monitoring wolves in the park.

He died suddenly and unexpectedly in August. Adams, a biologist for the U.S. Geological Survey currently studying musk oxen in Alaska, said Meier's death could have complicated efforts to get an accurate survey.

Counting wolves challenging 

Finding and counting wolves in packs that contain radio-collared animals is pretty straightforward, but finding packs lacking collared animals -- let alone wolves that have taken off on their own -- sounds a lot easier than it is in practice. It turns out to be a lot like hunting in that it helps to know not only what you're looking for but the best places to look. And, Van Ballenberghe said, counting packs with radio-collared animals can present some problems, too.

"You need to be sure you observe that pack more than one or two times because they do split up,'' he said. Packs tend to be more cohesive in that fall than in the spring, but there is no guarantee of catching the animals together at any time.

"If it was a standard wolf census over a big area,'' he added. "Then it's easier to miss animals in some cases.''

But even if the count missed a pack or two, as Hilderbrand suggests, putting the actual number of wolves closer to 70 than to 60, there remain questions about what is going on with the most charismatic carnivore in what is undeniably the state's most popular national park for wildlife viewing.

Even at 70 wolves, Van Ballenberghe noted, "That's half of what was there not too many years ago. That's a pretty a pretty significant decline, and there hasn't been a significant decline in any of the three species in recent years.''

Wolf numbers peaked at 147 in October 2007. They have generally been falling ever since. Hilderbrand admits no one knows why, but points to some possible contributing factors.

Wolf numbers related to hares? 

"(Snowshoe) hares are definitely down dramatically,'' Hilderbrand said, "and our lamb-ewe ratio (among Dall sheep) is also quite low at 11 to 100, the lowest since 1993."

Wolves can't live on hares in Denali. They aren't a primary prey. But in times of abundance, they can become a significant alternate food source and help support population numbers.

The same can be said of salmon. In a pioneering study, Adams found salmon a key component of the diet of wolves in the northwest corner of the park. The salmon, chums and silvers, come up the Kuskokwim River. Kusko salmon runs have been struggling in recent years. Could that have contributed to wolf declines? Possibly, Adams said, but nobody is studying that at the moment.
Sheep ewes, meanwhile, are the easiest targets for the wolves that hunt sheep.

Today, the Park Service is dead-set against any kind of wolf control in Alaska parks. But from 1930 to 1934, it conducted wolf control in Denali to protect sheep. The practice was stopped in 1935 but resumed in 1936 under the guise of gathering wolf carcasses for "food habit studies.'' That continued until 1938.

By then, the Park Service was caught in much the same place as the Alaska Board of Game is these days. The Camp Fire Club of America, a powerful group at the time and one that helped create the park, wanted wolves exterminated. Some of the country's top scientists, meanwhile, wanted all parks left alone as sanctuaries for predators in a nation where predators were under attack on all fronts.
The Park Service decided to try to extract itself from the middle of the controversy by commissioning a scientific study. It called in scientist Adolph Murie, whose studies in the park eventually conceded that wolves killed a lot of sheep but argued that the wolves and sheep existed in a state of "balance.'' It was the first shot at the "balance of nature'' theory that would eventually gain many adherents, but the theory didn't stick at the time.

"Murie was sent back to the park in August 1945 for a month and found that the sheep population had declined from about 2,700 in 1941 to about 500,” according to the book "The Wolves of Denali." “He recommended killing 10 to 15 wolves in sheep range and continuing wolf control until sheep increased.''

Wolf control in the park resumed and continued until 1952. The balance-of-nature theory, meanwhile, continued to gain ground and hit its zenith in 1970 when Mech in published an article in Reader's Digest, then the most popular publication in the country, titled "In Defense of the Wolf.'' It argued that wolves and their prey existed in a state of equilibrium beneficial to both. Years later, having watching big swings in predatory and prey in natural ecosystem, Mech would reject that theory, recognizing that in nature the balance is more like a teeter-totter.

There has, however, been some interesting research done since the 1970s, including some by the late Gordon Haber, a controversial fan of wolves and Denali biologist who died in a plane crash while observing the animals. Haber posited the idea of a multiple-equilibrium theory, wherein predators and their prey could exist in fairly static numbers for long periods of time. Imagine a fat guy on one end of the teeter-totter and small child on the other. There are some scientists who ponder whether the Denali ecoystem might fixed in what Haber would have called a "lower equilibrium'' -- even if few are willing to talk about it publically.

'Vigorous and viable' 

As Mech and the others observed in the book, "Wolves are not unusually abundant in Denali, but the population is both vigorous and viable.''

The same could be said of the main wolf prey in the park -- moose, Dall sheep and caribou. Adams spent a long time studying the Denali caribou herd, which once numbered over 20,000 animals. It dropped to 10,000 a couple decades before Alaska statehood, but stayed stable at that level for almost 20 years.

Then it began another decline, and the herd was down to about 1,000 animals in the 1970s. A slow rebound began late in that decade, and the herd eventually grew to more than 3,100. Adams, who was studying the caribou for part of that period, hung around Denali thinking he might get to witness a rebound. It never happened.

The herd peaked at 3,700 in 1990 and then began a decline. It now numbers 1,760, according to the park service. It appears to have plateaued in a range of 1,500 to 3,000 and become stuck there. Adams now wonders what it will take for the population to again blossom.

Moose are in a similar situation. Populations are generally low -- less than half a moose per square mile -- and stable with one key exception. Moose numbers spike up in the northeast corner of the park near the boundary with state lands where wolf trapping takes place.

The bigger moose population there may be luring wolves within range of trappers. It could also be that the bigger population of moose there is allowing moose to spread out into the rest of the park and provide food for more wolves.

Undoubtedly, interest groups in and out of the 49th state will go on fighting over whether to save the wolves or kill the wolves in a struggle that seems as unresolvable as reaching peace in the Mideast. One side thinks it unfair that an area the size of Denali is closed to the hunting and trapping of wolves. The other thinks it outrageous that viewable wolves -- the animals that don't naturally shy away from people -- might run the risk of getting caught in a trap if they leave the park.

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