Low-Impact Human Presence in Nature Changes Wildlife Behavior

A new study of hiking trails in Glacier National Park serves as further evidence that the presence of humans in remote areas creates a “landscape of fear” for wildlife local to that region, thus affecting how the wildlife interact with the environment.

The study, published in Scientific Reports, was carried out by researchers from Washington State University and the National Park Service. The team studied the behavioral patterns of wildlife along hiking trails in Glacier National Park while the park was closed to prevent COVID-19 from spreading to the nearby Blackfeet Indian Reservation, then again after the park had reopened and people were hiking the trails again. Comparing the patterns, they found that when human hikers were present, 16 of 22 mammal species native to that area changed where and when they accessed certain areas. Some species even went as far as completely abandoning certain areas or only visiting them at night in an effort to avoid humans. These behavioral patterns were consistent with the patterns of prey in a landscape of fear, which is a “spatially explicit distribution of perceived predation risk.” In other words, a prey species feels a heightened sense of risk. Landscapes of fear emerge when apex predators move into a region.

The idea that humans may have been perceived as apex predators by the animals in Glacier National Park surprised researchers. “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,” said Daniel Thornton, WSU wildlife ecologist and senior author of the study.

While the study was clear that wildlife behavior was affected by human presence, the authors emphasize that more research is needed to determine if the animals’ rates of survival are negatively affected. “Maybe they [animals] 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,” commented Alissa Anderson, recent WSU master’s graduate and first author of the study.

Thornton said that park managers must maintain a balance between ecological conversation and public use. “It’s obviously important that people are able to get out here, but there might be a level of which that starts to be problematic,” he said. “Some additional research could help get a better understanding of that and help develop some guidelines and goals.”