When the spreading coronavirus pandemic prompted lockdowns in the early months of 2020, people stayed home and traffic volume quickly plummeted.

As a result, many animals started traveling longer distances, and were willing to venture closer to roadways, according to a new study in the journal Science.

Researchers looked at the movements of over 2,000 animals from 43 mammalian species that were being tracked with GPS devices around the world. This included everything from pumas in California to elephants in South Africa to reindeer in Norway.

It turns out that, on average, the animals traveled 73% farther during the initial COVID lockdowns than they did during the same time period a year earlier. The animals also crept 36% closer to roadways.

The findings offer new insight into the ways that everyday human behavior can directly impact the lives of wild animal populations.

From pandemic lockdowns, an experimental opportunity

Marlee Tucker, a researcher with Radboud University, says that she and her colleagues knew from previous research that animals living in places with a high human presence tended to move around less.

"We weren't really able to tease apart why that was," says Tucker, who says that roads and other human structures might act as physical barriers, for example, or human activities might affect the availability of food resources.

When the lockdowns started, she says, "we thought, 'Oh, this is quite a sort of unique opportunity that we can actually disentangle or separate the effects of human mobility.' "

While they saw some variability between species and individuals, their study shows that many mammals can quickly adapt to sudden changes in the amount of traffic on roads.

"This was quite sort of exciting to see," says Tucker, "because it shows that animals still have the capacity to change their behavior in response to us changing our behavior."

Clues for managing wildlife

The work caught the attention of Colleen Cassady St. Clair, a professor of biological sciences at the University of Alberta, who was not involved in the study but wrote a commentary accompanying its results.

"It's not usually possible to separate the effects of the road infrastructure from the effects of traffic. So in a sense, this was a huge global experiment, on a scale that's never been done before," says St. Clair.

Understanding how animals respond to road traffic can be important for the management of wildlife and protected areas, she says. In Canada's Banff National Park, for example, temporary road closures were recently shown to improve the quality of habitat available to wildlife.

"Changes in road traffic," says St. Clair, "can profoundly affect other species and their use of landscapes."

Copyright 2023 NPR. To see more, visit https://www.npr.org.