Out of sight

Look: Animals in national parks dramatically shift their behavior with humans around

They’re onto us.

Every year, around 300 million people visit U.S. national parks.

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The 423 parks in the National Park System offer visitors a chance to see landscapes and animals in their natural state — or as close to it as most of us are likely to see.

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But what if just visiting a National Park changes how the animals there behave?

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That’s the conclusion of a new study led by University of Washington researchers and published in the journal People and Nature.

Mira Sytsma

For the study, researchers placed 40 motion-activated cameras across Glacier Bay National Park, located on Alaska’s southeast coast.

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With only 40,000 visitors per year, Glacier Bay let researchers study animals less accustomed to humans than those somewhere like the Great Smoky Mountains National Park, which gets nearly 15 million yearly visitors.

Glacier Bay is a great park to explore what the lower limits are where humans start to affect wildlife behavior.”

Senior author Laura Pugh

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Researchers tracked how often moose, wolves, black bears, and brown bears appeared on the cameras. With no humans around, brown bears and moose appeared up to eight times per week, black bears up to six times, and wolves up to four times.

Mira Sytsma

Mira Sytsma

If any humans were seen on camera in a given week, there were a maximum of five brown bear sightings, four black bear sightings, and two moose and wolf sightings.

All four animals disappeared from the least-visited areas for weeks with at least 40 visitors.

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In some areas, moose actually showed up more when people were nearby.

Mira Sytsma

The study’s authors say they may be using humans as shields since wolves leave an area almost as soon as humans arrive.

The researchers acknowledge animals at more popular parks may be less shy of humans than those at Glacier Bay. For smaller parks, though, an increase in visitors could drastically change animal behavior.

Mira Sytsma

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The researchers conclude that parks could use this data to mitigate impact. If humans change animal behavior, it may be better to concentrate visitors in one area and let native animals roam free elsewhere.