Humans create a "landscape of fear" for wildlife

A new study led by the Washington State University (WSU) and the U.S. National Park Service has found that, even without hunting activities, humans seem to have a strong negative influence on the movement of wildlife in the Glacier National Park. The experts examined activity on hiking trails during and after a Covid-19 closure of the park. According to the results, humans often create a “landscape of fear” like other apex predators, significantly changing how animals use an area simply with their presence.

The scientists discovered that when human hikers were present, 16 out of 22 mammal species – including both predators and prey – changed when and where they accessed certain areas of the park. While some completely abandoned places they previously used, others used them less frequently and some shifting to more nocturnal activities in order to avoid humans.

“When the park was open to the public, and there were a lot of hikers and recreators using the area, we saw a bunch of changes in how animals were using that same area,” said study senior author Daniel Thornton, a wildlife ecologist at WSU. “The surprising thing is that there’s no other real human disturbance out there because Glacier is such a highly protected national park, so these responses really are being driven by human presence and human noise.”

Initially, the researchers also expected to find an effect called “human shielding,” when human presence causes some large predators to avoid a certain area, providing opportunities for smaller predators or even some prey species to use that area more frequently. However, the analysis revealed such an effect on a single species, the red fox, which was more present on and near hiking trails since its competitors, coyotes, generally avoided such areas when humans were using them.

Species such as black bears, white-tailed deer, and elk showed a significant decline in the use of trails when the park was open, while others like the mule deer, the snowshoe hare, the grizzly bear, and the coyote decreased their daytime activities. Yet, a few species, including cougars, seemed largely indifferent to human presence.

Although these findings suggest that low-impact recreation is quite concerning, future research is needed to assess whether it has negative effects on wildlife survival. “This study does not say that hiking is necessarily bad for wildlife, but it does have some impacts on spatiotemporal ecology, or how wildlife uses a landscape and when,” said study lead author Alissa Anderson, a resent WSU master’s graduate. “Maybe they are not on the trails as much, but they’re using different places, and how much does that actually impact species’ ability to survive and thrive in a place, or not? There are a lot of questions about how this actually plays into population survival.”

“It’s obviously important that people are able to get out there, but there might be a level of which that starts to be problematic. Some additional research could help get a better understanding of that and help develop some guidelines and goals,” Thornton concluded.

The study is published in the journal Nature Scientific Reports.

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By Andrei Ionescu, Earth.com Staff Writer

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