In the wake of the worldwide lockdowns initiated in 2020 due to the rapid spread of COVID-19, an unforeseen consequence emerged – a major shift in the behavior of wild animals globally.
The phenomenon was recorded through GPS trackers on 43 distinct species, spread across the world during lockdowns. This venture was the result of collaborative international research led by Aarhus University.
With the world at a standstill and streets abandoned, animals gained more freedom to roam. The extent of lockdowns varied from country to country.
Places like China witnessed an almost total confinement of their civilian population, whereas Spain introduced weeks-long curfews, only allowing residents to venture out for essential tasks like grocery shopping.
This resulted in a stark decrease in traffic and human presence in typically frequented areas like forests and parks.
Now, with access to a year’s worth of GPS data from various terrestrial mammals, scientists have been able to contrast animal behavior during this unique window with their typical patterns.
For instance, Denmark’s contribution to this global project focused on data from four stags from Oustrup Hede, situated just north of Herning.
According to Professor Peter Sunde of the Aarhus Department of Ecoscience, this tracking made it feasible to discern differences in the stags’ behavior before and after the lockdowns.
Professor Sunde described this unanticipated period as an unparalleled experiment, shedding light on how human activity influences wildlife behavior.
While it is no secret that most mammals live in close proximity to human settlements and are impacted by our daily activities, the newfound data underscores the extent of this impact.
Sunde said: “The results reveal that our presence hinders animals’ ability to move around. All mammals need to find resources to sustain themselves every day, but the data shows that the presence of cars and humans stresses the animals and limits their movements to small empty areas.”
“However, during the lockdowns, we saw that the animals roamed closer to roads and cities. This gave them a bigger area to move around in. However, this only applied to areas that were already heavily impacted by humans.”
“The lockdowns had the opposite effect on areas with low human activity. Probably because natural areas were visited by more people than usual.”
Although the primary trend seemed to be that animals ventured out more, they also displayed contradictory patterns of movement in some places.
“The figures show that animals generally reacted differently during different types of lockdown. Probably because the disturbance factor decreased in areas with hard lockdowns, while people in countries with soft lockdowns, such as Denmark, spent more time outdoors than before the lockdown,” explained Sunde.
When analyzing animal movement, the research team relied on a parameter known as the 95th percentile, which represents the five percent longest journeys based on GPS positions.
The general movement was found to be 12% lower in spring 2020 compared to the previous year, suggesting animals took fewer or shorter “long journeys.” However, when observed over a ten-day span, animals in hard lockdown zones traveled greater distances.
“Whereas the hour-to-hour movements of the animals are tactical responses to what’s happening in their immediate vicinity, their patterns of movement over a ten-day period reflect more strategic choices. The animals go where they assess there’s more food and less danger,” said Sunde.
“The study clearly shows that, on a ten-day basis, the animals travelled longer distances in areas where human activity had decreased. The absence of humans gave them a larger area to roam and better opportunities to optimize their own situation – and they took advantage of this. Conversely, their roaming area decreased in areas with soft lockdowns because humans flocked into natural areas.”
Now, as human activity surges, the implications of these findings become ever more significant. Sunde advocates for a more informed approach towards planning human activities in nature.
“We can use this new knowledge to become better at planning our activities in nature. We now know that our mere presence dampens the activity of many species. This can ultimately have an impact on where different mammal species can live and in what numbers,” said Sunde.
“We should bear this in mind when planning new constructions, roads or even small forest paths. Human activity puts a strain on many animals.”
“But that doesn’t mean we shouldn’t spend time in forests. However, the people who organize public access to nature need to know that this has consequences for wild animals. For many years, Danish policy has centred on getting people to use nature as much as possible.”
Around Denmark, many new shelters and mountain-bike tracks have been constructed in recent years, which places a greater strain on wild animals.
“We still know very little about how increased human activity in nature, such as overnight stays and cycling, impacts the prevalence and population of animals. But I can well imagine that increased recreational use of nature might lower the population densities of disturbance-sensitive species such as deer,” said Sunde.
The research is published in the journal Science.