FAIRBANKS — A study published Thursday looks into the often-debated issue of why visitors have been seeing fewer wolves in Denali National Park.
The study had a mixed bag of results that will be unlikely to satisfy people on either side of the issue. It found a strong correlation between wolf-viewing success and the presence of the now-defunct wolf protection buffer zone outside the park boundary. However, the study did not find a statistically significant relationship between declining wolf-viewing numbers and the numbers of wolves killed by hunters and trappers.
In general, the study concluded that hunting and trapping opportunities come at a cost to nonconsumptive wildlife viewers, even when the wolf harvest is relatively small.
“These findings show that harvest of wolves adjacent to protected areas can reduce sightings within those areas despite minimal impacts on the size of protected wolf populations,” the authors wrote at the conclusion of their abstract.
The article was published in the online journal PLOS ONE, an open-access scientific journal of the San Francisco-based Public Library of Science. The article is available online at bit.ly/1r3ZJ0p. The paper studied the area around Yellowstone National Park and around Denali National Park and Preserve.
The lead author was Bridget Borg, a Denali National Park wildlife biologist and University of Alaska Fairbanks doctoral student. Funding came from the National Park Service, the U.S. Geological Survey, the National Park Science Foundation and several individuals.
Why study wolf views?
Wolf viewing rates are an economic indicator in a tourism economy where many visitors say the prospects of seeing a large predator like a wolf is the reason they come to Alaska.
In recent years, fewer wolves have frequented the Denali Park Road area that is most visitors’ window into the 6 million acre park. In 2015, the Park Service reported park employees saw wolves on 5 percent of westbound bus trips between Savage River and the Eielson Visitor Center, down from 45 percent in 2010.
Supporters of hunters and trappers in the area argue their average harvest of five wolves a year isn’t a major factor in the declining wolf-viewing numbers. They argue snow depth is a bigger driver of wolf population in the park because it determines how successful wolves will be in winter hunting.
Unlike in the Lower 48, Alaska wolves have never been endangered. Alaska’s state government has liberalized wolf hunting regulations and funded wolf hunting by helicopters in recent years as part of its predator control program to increase important moose and caribou populations. Alaska’s wolf hunting regulations often put the state at odds with the federal government and environmental groups.
The authors of this week’s paper describe their work as “the first quantitative evidence that harvest of wildlife adjacent to protected areas can reduce wildlife sighting opportunities.”
The study's findings
For Denali National Park, the authors used data on wolf populations, wolf harvests and wolf sightings along Denali Park Road between 1997 and 2013.
In a finding celebrated by wolf protection advocates, the study concluded that wolf viewing was more than twice as common on years when there was a protective buffer zone than on non-buffer years. The Alaska Board of Game created a buffer to the northeast of the park in 2000 but repealed it in 2010. On average, the probability of seeing a wolf in the years when there was no buffer zone was 10 percent but rose to 22 percent on years when a buffer zone existed. The Yellowstone part of the study also found a correlation between wolf sightings and the years when no wolf hunting was allowed.
The study provided some backing to hunters, trappers and their supporters in that it didn’t find a statistically significant link between wolf-viewing success rates and the number of wolves killed by hunters and trappers.
The authors suggested a mechanism that might explain why more people see wolves when there’s a buffer zone. The paper didn’t directly address the theory but stated it might be because the wolves become more wary and avoid the Park Road when they’ve noticed hunting and trapping in the area.
The study also didn’t find a link between the harvest of breeding wolves and wolf-viewing success. Advocates for the buffer zone have long argued there is a link, that hunters and trappers disproportionately hurt wildlife viewing opportunities when they kill wolves that are important members of wolf packs.
The study didn’t address variables such as prey population numbers and snow depth. The authors acknowledged that changes in wolf populations and sighting success rates may be related to these nonhuman factors, but they argued that moose and caribou numbers have been relatively consistent between 1997 and 2013 and that there has been no significant trends in snow depth in that period.
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