How Wild Animals Actually Responded to Our COVID Lockdowns

When the COVID pandemic hit British Columbia in spring 2020, Golden Ears Provincial Park closed its doors to visitors. No longer could hikers explore its hemlock forests or canoe in its lakes, but at least some of the park’s wildlife seemed to appreciate the situation.

During the closure, a camera trap network run by University of British Columbia researchers recorded a significant uptick in mountain lions. In a common, often half-joking cliché of the time, it seemed to many people that nature was “healing.”

“It’s a romantic idea,” says Cole Burton, a conservation biologist and wildlife ecologist at the University of British Columbia and co-author of the study. But, he adds, it’s ultimately flawed. The reality is likely much more complicated: While humans were indoors, he notes, the cameras spotted fewer deer. When lockdowns ended and visitors returned, mountain lion recordings dipped again, and deer recordings picked up. But at the Canadian province’s more remote Pacific Rim National Park Reserve, a network of camera traps found that black-tailed deer abundance declined when people streamed back in.

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Such are the contradictory-seeming results Burton and his colleagues found themselves sorting through as they used the pandemic’s unique circumstances to try teasing apart some complexities of wildlife responses to humans. Localized results such as the ones above are vital in order to “help us learn more about what the animals are doing and whether we are disturbing them, even when we don’t see them,” he says, “and that is important to me both personally and professionally.” In trying to make sense of such contrasting findings, Burton wondered what patterns might emerge from gathering relevant data from all around the world.

He put out an invitation to collaborate and eventually teamed up with hundreds of researchers worldwide, amassing data from 102 survey sites in 21 countries. This included observations from 5,400 camera traps covering a total of 311,208 days—or 852 years—before and during the pandemic. To deal with such a large volume of data, the scientists focused their analysis on mammals and how they reacted when human pressure increased again as pandemic restrictions eased. They also directly measured human activity with the camera traps.

In a study published March 18 in Nature Ecology & Evolution, Burton and colleagues analyzed these data and found what Burton calls “an incredible amount of variation in what people and animals were doing.”

In general, two broad patterns stood out. First, animals’ responses depended in large part on their position on the food chain, also known as their trophic level (such as carnivore, omnivore or herbivore). And second, the degree to which a location has been modified by people played a big role.

Carnivores, the scientists found, were less active when people were around, regardless of location (though large predators such as mountain lions were mostly absent from more developed areas). Among the most sensitive species were wolverines, which became much less active in Alberta’s Banff National Park, for example, when people returned after the COVID lockdowns.

Unexpectedly, however, as human activity increased in more developed areas, mammals such as deer were generally more active. “We’re scratching our heads,” trying to explain this, Burton says. One possible factor would be that humans may act as “shields” against carnivores because the latter might be more skittish and retiring when humans are around—something herbivores such as mule deer seemed to have learned. It also probably has to do with acclimatization; Burton says that increased deer activity in Golden Ears, for example, may be partly caused by the “human shield” phenomenon, whereas in the more remote Pacific Rim park, the herbivores may have been more sensitive and averse to human presence to start with.

This pattern held true for omnivores such as brown and black bears, too—to an extent. These species sometimes became more abundant when human activity increased in various locations that are more developed. But the bears also became more nocturnal. “They can tolerate humans up to a point,” Burton says. This may be because a bigger human presence can mean more resources (more garbage or food scraps, for example), but interactions with people are riskier for a large omnivore than they are for a deer or rabbit.

Sarah Raymond, an ecologist at Cardiff University in Wales who wasn’t involved with the new study, says she particularly appreciated how this project—one of the largest camera trap studies ever—highlights “the breadth of responses from different groups of species to human activity, both those groups that are most vulnerable, such as carnivores, and those situations where populations appear to actually be attracted to anthropogenic resources or better adapted to living alongside humans.”

We need studies like this, she says, because “we’re so entrenched in the Anthropocene ecosystem that we overlook the effects that we’re having on the environment.”

Burton hopes the study results will help humans and animals better co-exist in the world. For example, one potential application of these findings could be to dissuade human nighttime activities in parks and suburban open spaces because many animals, including foxes and bobcats, become more nocturnal in modified landscapes with significant levels of obvious human presence. “In areas where we’re sharing space, we need to think about giving [animals] the opportunity to use resources when we’re not around,” Burton says. “As we push into that nighttime space, we might be affecting those animals.”

Ultimately, the study also underscores how some of the “nature is healing” anecdotes that came out during the early days of the pandemic were intriguing—but misleading. “We can’t just roll back the clock and keep people out of many areas,” Burton says. “We have to be practical about how to find that co-existence balance going forward.”