(CN) — U.S. national parks are known for observing nature as it is — wildlife and all. Strolling through hiking trails can feel like a glimpse of nature untouched by humans. However, new research from the University of Washington shows that wildlife in national parks drastically change their behaviors when people are around.
Published Thursday in People and Nature, researchers explain their findings after setting up motion-sensor cameras in Glacier Bay National Park, an intentional location for the study. Nestled on the southeast coast of Alaska, it is one of the least trafficked, with about 40,000 visitors annually. In contrast, Yosemite National Park welcomed 3.29 million visitors in 2021.
“This park is extremely remote. You can't drive to it; the only way to get there is to fly in or go in with a boat," said Laura Plugh, associate professor at the University of Washington School of Environmental and Forest Sciences, in an interview. "Most people who see this park do so just from the deck of a cruise ship — if you take a cruise ship up to Alaska, it will go into the park and tour around, and people can see the beautiful glaciers calving into the water, fjords and wildlife. The people on the cruise ships don't ever actually set foot in the park.”
Plugh and her team selected five pairs of sites — each pair had a motion-detecting camera in a heavy human-traffic area and one where humans weren’t allowed. The cameras ran day and night for two years, giving an inside look at the behaviors of black bears, brown bears, moose and wolves.
“One of the notable patterns was that the detections dropped off for every species once you went from zero people at a site to more than zero,” Plugh said. “I was actually not anticipating finding any effects of people on the wildlife in this park because I thought there are way too few people to have an impact. So, I was really surprised when we actually did see an effect.”
Wolves had the strongest response to human presence, seeming to completely leave an area if there were more than 20 hikers. At sites the wolves were partial to, they shifted to more nocturnal behaviors. Moose also left heavy-use areas but utilized some human sites presumably for protection from wolves.
The research funded by the National Park Service is being used to inform park managers about crafting fewer and more highly trafficked areas instead of extensive trail systems. Researchers felt that the wildlife had a strong response due to the low traffic in Alaska, so Plugh also set up camera traps in the Cascades Mountains in Washington and found the same results.
“There is certainly a trade-off of having experiences in wilderness areas that can be incredibly healthy for people's mental and physical health, and having that connection to nature can really motivate people to try to protect wild places," Plugh said.
"I think it's not a real black and white issue — this affects animals, so it's bad nobody should recreate anymore. There are a lot of positive outcomes from people recreating nature, so the challenge is sort of figuring out how we do that while still allowing there to be enough places for animals to be minimally disturbed," she said.
Read the Top 8
Sign up for the Top 8, a roundup of the day's top stories delivered directly to your inbox Monday through Friday.