WHILE WE’VE ALL been locked inside, creatures have been reclaiming the empty streets. Earlier this month, animal control officers captured a mountain lion in downtown San Francisco. In Italy and Spain, the wild boar have moved in. OG fliers like geese are staking claim to airports. Urban rats are boldly foraging during the day and sleeping in cars—well, at least under the hood, where they gnaw on wiring, thinking they’re edible roots.
This is an unprecedented time in modern history—and a unique opportunity for science. A group of researchers last week termed it the “anthropause” in the journal Nature Ecology & Evolution, a name they coined “to refer specifically to a considerable global slowing of modern human activities, notably travel.”
“There is an amazing research opportunity, which has come about through really tragic circumstances,” says lead author Christian Rutz, an evolutionary ecologist at the University of St. Andrews and Harvard University. “And we acknowledge that in the article. But it’s one which we as a scientific community really can’t afford to miss. It’s an opportunity to find more about how humans and wildlife interact on this planet.”
Historically, this has been difficult to study. Researchers might have been able to compare how species behave in a protected area versus a neighboring unprotected area, or an urban versus a rural environment. “The problem with all of these approaches is that they usually refer to just a handful of sites,” says Rutz. “And what happened here in the anthropause is that we have this global slowing of human activity, which gives us these really valuable replicates, where we can look at the effects of human activity across geographic regions, across ecosystems, and importantly, also across species.”
Take the fishers—carnivorous mammals in the weasel family—living in North America. “They were supposed to be out in the woods far away from people, and somehow they entered cities again,” says ecologist Martin Wikelski of the Max Planck Institute of Animal Behavior and University of Konstanz, coauthor on the anthropause paper. “This is a change in culture—it’s not a genetic change.”
That is, this isn’t a case of a species gradually acclimating to city life. That can come about because individual fishers plucky enough to risk the danger of moving into an urban area might prove to be more “fit”—for example, maybe they would find new sources of food that give them more energy to pursue a mate. If this behavior helps them produce more offspring, the genetics that code for urban pluckiness would get passed along too. So generation after generation, a species would adapt to city life. It’s the same principle behind the domestication of dogs: One theory goes that wolves visited human encampments for scraps, over time growing tame enough to play fetch with humans instead of biting our faces off.
But with the fishers, the behavioral change in the anthropause happened waaaaay too fast to be genetic. Instead, it could be a change driven by choices made by individuals or groups of animals. “You see that personalities differ,” says Wikelski. “There may be now a selection for certain personalities to enter cities, and that may be propagated through their culture.”
“The global experiment on the transmission and retention of information in animal societies is just unbelievably beautiful,” Wikelski adds.
Scientists can watch such rapid, dramatic behavioral shifts thanks to increasingly sophisticated monitoring equipment. Tracking collars of course map an animal’s movement, but some now come equipped with inertial measurement units, or IMUs, the same sensors that let you shift your phone around to control a game. This allows researchers to determine if a wild animal has suddenly accelerated, indicating that it might have been startled. An even more sophisticated monitoring device might detect the animal’s heart rate or listen with a microphone to its interactions with its peers.
“It’s the Fitbit for animals,” says Wikelski. “Are they sick? Are they fine? Are they interacting? How quickly are they moving? Are they getting up at the right time, at the same time as before? Are they active differently during the night, during the day?”
During the anthropause, researchers can marry this data that tracks animal behavior with data that tracks human behavior, particularly traffic, to show whether a species might be exploiting our absence or going about its business as usual in the wild. As the anthropause continues and eventually wanes, scientists will be able to watch how a species adapts, answering questions that would have been impossible to tackle if not for the pandemic.
Researchers have been trying to solve one of these riddles for decades: Are animals afraid of our built environment—roads, buildings, and other infrastructure—or are they afraid of us? “We suddenly didn’t have humans in many areas,” says ecologist Matthias-Claudio Loretto of the Max Planck Institute of Animal Behavior and University of Konstanz, coauthor on the anthropause paper. So, he says, if animals will visit these places during the pandemic shutdown, “they’re obviously just normally afraid of humans.”
On the other hand, if a particular species didn’t penetrate a populated area even with humans gone these past few months, that might be an indication that it’s the built environment keeping them away. But conservation biologists can look at the species that did traipse through an area and note the paths they took.
The riddle gets more nuanced in urban places where the restrictions on movement haven’t been particularly strict. Maybe a city has allowed residents to go for walks, so animals are still avoiding public parks, but are instead turning up in places that are entirely shut down to people. Some cities may have restricted driving, while others didn’t—researchers can look at both traffic and animal data to see how species in different areas adapted.
The anthropause is bringing scientists a unique opportunity to study how animals move through built environments; this knowledge could inform new modifications to urban areas to provide safe passage for animals. For example, maybe if we learn that a development or freeway has sliced a species’ habitat and population in two, we could reunite them to encourage genetic diversity—isolated populations, after all, tend to inbreed. “It’s not good enough that managers tell animals where to go,” says Wikelski. “Animals should tell us where they need to go, where they want to go. It’s the animal-defined corridor that we need.”
But not every animal species has benefited from the freedom of having fewer humans around. The generalists among them, like coyotes, rats, and wild boar, may comfortably move about city streets, taking any food they can. But there’s nothing for a mountain lion in downtown San Francisco—its prey, like deer, remain in the hilly regions to the south of the city.
The Covid-19 lockdown could even be catastrophic for some endangered species. In Africa, iconic species like the rhino rely on protected areas and armed guards, all funded by tourism money that’s evaporated and may not fully return for two years. “That becomes a real issue in terms of guards being there—both being allowed to be there with social distancing, but also in terms of them getting paid to do the work,” says James Fitzsimons, the Nature Conservancy’s director of conservation in Australia, who wasn’t involved in the new anthropause article. “So many of the wildlife parks in Africa rely on that tourism dollar to subsidize, or indeed sustain them.”
Some islands, too, require constant upkeep to protect native species, campaigns that have now halted. On Gough Island in the South Atlantic, for instance, invasive mice have been eating seabird chicks alive, killing over 2 million birds a year. An eradication effort is now on pause, with untold consequences for those native avians.
And when it comes to wildlife data, the pandemic giveth and the pandemic taketh away. Australia is emerging from an apocalyptic wildfire season, which saw the virtual obliteration of some of the continent’s ecosystems. “A lot of species have been impacted hard, and threatened spaces have lost the majority of their habitat,” says Fitzsimons. “One of the key responses was, of course, to be monitoring the recovery of those species, going out and surveying where populations are. A lot of that has been severely hindered by Covid-19, the social distancing and the restrictions on travel that have gone with that.”
Humans meddling with habitats during the pandemic is also imperiling some species. Emboldened by suddenly lax enforcement, loggers have been plundering forests: Between late March and early May, Tunisian officials recorded 10 times the number of forest violations compared with the same period last year. Conservationists are concerned that matters will only get worse, as nations slash their environmental budgets in the coming years to recover from the economic toll of the pandemic.
Still, the anthropause has afforded scientists an unprecedented opportunity to study animal behavior. And they’re getting a little help from their friends: We the citizen scientists. This spring, the annual City Nature Challenge, organized by the California Academy of Sciences and the Natural History Museum of Los Angeles County, asked urbanites to document biodiversity in their backyards and neighborhoods by taking photos and uploading them to the iNaturalist app. Over 40,000 citizen scientists tallied 815,000 wildlife observations. (Researchers from the Los Angeles museum also recently announced that during the lockdown they’d discovered nine new insect species collected via backyard traps, thanks to another citizen science project called BioSCAN).
The idea is to get people to connect with nature, especially in the long days of sheltering in place. “But that next step is using these data for science and for conservation, and for planning and management,” says Rebecca Johnson, codirector of citizen science at the Cal Academy. “All of the data are open and freely available for anyone to use.” By monitoring wildlife with iNaturalist, you too could provide scientists with unprecedented insight during the anthropause.
“It really was kind of an emotional thing,” Johnson says, “because you knew that people were all doing this together, even while we were apart.”
wired.com, 29 June 2020