Tourists are far more likely to see wolves in Denali National Park and Preserve when there is a protective no-hunting buffer established in key wolf habitat outside the park, according to a new study.

The study, published in the journal PLOS ONE, found that when the 122-square-mile buffer was in place from 2000 to 2010, the likelihood of seeing a wolf in the park was more than twice that of the years when the buffer was absent.

Debate has long raged over the impacts of hunting and trapping near the park borders. The Alaska Board of Game in 2000 established the protective buffer on state-managed land along the park's eastern and northern edges, banning wolf hunting and trapping there. But the board eliminated the buffer in 2010 and placed a six-year moratorium on any potential resurrection. One of the board members who opposed that decision in 2010, Ted Spraker, predicted that trappers would be blamed if tourists were unable to view wolves in the park.

The new study provides the first objective evidence that a buffer barring wolf hunting and trapping outside the park boosts wolf viewing inside it, the authors said.

"Whether the outcome will sway decision-makers is unknown, but it provides additional information that we hope will be used when considering management options," said lead author Bridget Borg, a Denali National Park biologist who was working on her doctorate at UAF's Institute of Arctic Biology when she completed the study.

Since 2010, the state Board of Game has rejected proposals to bring back the no-hunting-or-trapping buffer zone through emergency action. Conservation groups like the Alaska Wildlife Alliance have been seeking to reestablish the buffer; trappers have opposed those efforts. This year, the Board of Game imposed some new restrictions that will shorten the wolf-hunting season in the area north of the park starting in 2017.

The Alaska Department of Fish and Game is also evaluating the idea of a conservation easement outside the park that would be established in cooperation with the National Park Service, a department official said. Both agencies "consider this approach a potential long term solution," though compromises to accomplish it remain elusive, Bruce Dale, director of the department's Division of Wildlife Conservation, said in a March 31 letter to Rick Steiner, one of the Alaska environmentalists who has been advocating for an easement.

The newly published study used observations made during bus trips into the park from 1997 to 2013.

The study echoed similar findings from Yellowstone National Park, where wolves were reintroduced in 1995. Yellowstone visitors' likelihood of seeing wolves was 45 percent higher in years when there was no hunting of animals from packs associated with that park's road, the study found.

Implications go beyond Denali and Yellowstone, the study said.

The opportunity to see large predators in their natural habitat is important to ecotourism worldwide, Borg said. But large carnivores range over wide areas and seldom stay confined within the boundaries of preserves, so many regions face cross-boundary management challenges similar to those at Denali and Yellowstone, she said.

"Consider the case of the hunting death of Cecil the lion and the subsequent questions about the impacts to viewing opportunities for people who travel specifically to see lions in that region," she said in her email, referring to the well-known lion from Zimbabwe's Hwange National Park that was killed last year by an American hunter.