How Wild Animals Really Reacted to Our COVID Lockdowns

When humans retreated largely into the indoors during the COVID-19 pandemic, nature breathed a little easier. But how exactly did global wildlife respond to the sudden disappearance of humanity? Viral stories about animals reclaiming urban spaces or the "nature heals" concept abound, but the scenario is more complex than people might think. In reality, animals around the world responded in different ways depending on factors including their place in the food web, their local environment, and the level of human development in their habitats.

A global study headed by University of British Columbia conservation biologist Cole Burton took advantage of pandemic conditions to look into how shifts in human activity affect wildlife. The team coordinated hundreds of researchers carrying out the analysis of 5,400 camera traps across 102 sites in 21 countries. Their effort has produced one of the most extensive camera trap studies ever, reflecting 852 years' worth of footage, or 311,208 days of observation. The study findings, published in the journal Nature Ecology & Evolution, provided an unprecedented view of how animals coped with lockdowns and how they responded as people came out of their homes and started hitting the roads again.

Changes in Wildlife Due to Lockdowns

Researchers in the British Columbia Golden Ears Provincial Park, whose trails and campsites were left vacant, have seen a striking increase in mountain lion sightings. With fewer people, these big cats seemed to feel more comfortable in expanding their territories. What was surprising, however, was that the same cameras recorded fewer deer sightings. But when the lockdown was lifted and people began to return, the mountain lions seemed to fade away, while deer sightings returned once more.

Meanwhile, however, on the more distant Pacific Rim National Park Reserve black-tailed deer populations went into decline when human visitors returned. The mixed results hint at a very interesting ecological dynamic: the response of each species was dependent not only on whether or not humans were absent or present in the immediate environment but also on, for instance, the area typically being more "wild" or having been more developed and so accustomed to human presence/activity before the pandemic.

Such findings speak to an "incredible amount of variation" in how animals react to humans, Burton says. Such variations are why conservation plans must consider what species need and what they are doing. "Learning what animals are doing—and whether we are disturbing them, even when we don't see them—is important," he explains, "both personally and professionally." Such a study inspired Burton to see if global data might reveal larger-scale trends.

Key Patterns in Wildlife Response

Analyzing their data in detail, Burton and his team observed that there were key patterns about the way that animals responded to the shifting human presence through the duration of the pandemic:

Species' place in the food chain has an effect on how responses were brought about.

Animals' responses to human presence were strongly related to their trophic level, or position within the food chain. Active carnivores, for example mountain lions, avoided people more everywhere. Thus, for example, wolverines in Banff National Park had reduced activity levels once tourist restrictions were removed. These patterns are in line with other studies suggesting that most of the carnivores tend to avoid humans and human-modified landscapes, as the costs associated with interacting with humans outweighed the potential benefits to these species.

Amount of Human Development Was an Important Predictor

In addition to the distinction between carnivores and non-carnivores, another important predictor of animal behavior was the level of human development in a given landscape. In more developed landscapes, many herbivorous and omnivorous species, such as deer and several bear species, appeared to adapt to the human presence. For example, deer were reportedly more active in Golden Ears as people returned; this trend, Burton hypothesizes may be owing to the "human shield" effect where herbivores feel safer from predators in areas of greater human activity. As carnivores are less likely to enter such human altered habitats, the deer and other herbivores remain freer to range.

Omnivores like black and brown bears exhibited an additional form of adaptation. In the developed regions, where human activities are more frequent, these bears became noon quadrupeds with resources like garbage or scraps and escaped from direct interactions. This adaptation is practical for bears since they are attracted by human-related sources of food, being the species of omnivores. However, anything larger than these animals, such as bears, will by their nature present a greater risk in contact with humans; hence, adaptation to a more nocturnal cycle freed them to move safely through human spaces.

Mixed Reactions to Human Presence Spark New Questions

Some of the findings were more indirect. For instance, in some developed areas, herbivores such as deer became more active when human presence resumed once again, a fact that might suggest that these animals had, through yet another process, become slightly inured to the human presence. Burton attributes this "human shield" effect as the cause for this shift: because the carnivores shun people generally, herbivores may thrive in regions of high human population, where the risk of encountering a predator is low.

The reactions of the omnivores were highly interesting. First of all, bears seemed to be rather tolerant of the degree of human activity, benefiting from accidentally created sources of food-like garbage-but also changed their timing to become more active at night. "They can tolerate humans up to a point," Burton explains, pointing out how human presence can be both source of food and possible risk for big omnivores like bears.

According to Cardiff University ecologist Sarah Raymond, the lead researcher did very well to scope and deep dive in the study that will reveal the breadth of responses from different species on human activity. She goes further to say, "We are so entrenched in the Anthropocene ecosystem that we overlook the effects we are having on the environment," she says.

Practical Applications for Coexistence

According to Burton, the study should guide efforts in finding a balance between human activities and wildlife conservation. For example, curtailing human presence within natural spaces during nighttime may allow more leverage in accessing resources by nocturnal animals without fear of disturbance. That could include readjusting visitor guidelines within particular parks and open spaces in suburbia, taking into consideration the animals' natural schedules.

This research demonstrates we are not a temporary visitor to the wildlife habitat; we continue to alter it, says Burton. For the benefit of wildlife, he suggests, "we need to start thinking about making available to animals an opportunity to access resources when we're gone." That way, we reduce unintended stress to the animal and allow it to express more of its wild behaviors in our shared space.

Beyond the "Nature Is Healing" Myth

Survey results bring to mind the fact that while the "nature is healing" which swept many around the world during the early pandemic days captured so much of the imagination, it wasn't to be taken as a factual account of the situation. "We can't just roll back the clock and keep people out of certain areas indefinitely," Burton says. "The challenge is finding ways to coexist sustainably," he writes. "This paper demonstrates that animals do and can adapt to human presence—but at a cost, and with complexity.

Ultimately, Burton hopes research in this area eventually allows us to make smarter decisions that allow for both human enjoyment of natural spaces and the preservation of biodiversity.