https://www.theatlantic.com/science/archive/2020/07/pandemic-roadkill/613852/

Acknowledging the virus’s silver linings can feel ghoulish. But mounting evidence suggests that we’re in the midst of an unprecedented roadkill reprieve.BEN GOLDFARBJULY 6, 2020

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Spring is a bloody season on American roads. Yearling black bears blunder over the asphalt in search of their own territories. In the West, herds of deer, elk, and pronghorn scamper across highways as they migrate from winter pastures to summer redoubts. A smaller-scale but no less epic journey transpires in the Northeast, where wood frogs, spotted salamanders, and eastern newts emerge from their winter hideaways and trek to ephemeral breeding pools on damp March nights, braving an unforgiving gantlet of cars along the way.

Among all creatures, it’s these amphibians—tiny, sluggish, determined—that are most vulnerable to roadkill. This year, though, their journey was considerably safer.

Greg LeClair, a graduate student at the University of Maine, leads The Big Night, a citizen science initiative in Maine through which volunteers tally up migrating frogs and salamanders and escort them across roads. This spring, he assumed that coronavirus concerns would shut down the project; instead, he rallied more participants than ever. “I think people were just home and had nothing else to do,” he told me. All of those volunteers found an amphibious bonanza. In previous years, LeClair said, the project’s participants counted just two live animals for every squashed one. This spring, they found about four survivors per victim. “The ratio of living animals to dead doubled,” LeClair marveled.https://f8b438117f75da65027ebf7524395299.safeframe.googlesyndication.com/safeframe/1-0-37/html/container.html

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Maine’s amphibians are just one of the collateral beneficiaries of the novel coronavirus, which has ground civilization to a halt. Travel bans have confined many of us to our couches; post-apocalyptic photos of empty freeways have circulated on social media. With Homo sapiens sidelined, wildlife has tiptoed forth. Lions basked on a road in Kruger National Park, normally crowded with tourists. Wild boars rooted in Barcelona’s medians. Roadkill surveyors in places as far apart as Santa Barbara and South Africa told me they’ve seen fewer carcasses this year than ever before. In Costa Rica, where Daniela Araya Gamboa has conducted years of roadkill studies aimed at reducing the harm of cars, highways have become less perilous for ocelots, cryptic wildcats bejeweled with black spots. In the more than three months since the pandemic began, Araya recently told me, her project had logged only one slain ocelot. “We have an average of two ocelot roadkills each month during normal times,” she added.

The human cost of COVID-19 has, of course, been so incomprehensibly tragic that acknowledging the virus’s silver linings—the cleaner air, the forestalled carbon emissions—can feel ghoulish. But there’s no denying that the abrupt diminishment of human travel, a phenomenon scientists recently dubbed the “Anthropause,” has generated profound conservation benefits. Mounting evidence suggests that we’re in the midst of an unprecedented roadkill reprieve, a stay of execution for untold millions of wild creatures. “This is the biggest conservation action that we’ve taken, possibly ever, certainly since the national parks were formed,” Fraser Shilling, co-director of the Road Ecology Center at UC Davis, told me. “There’s not a single other action that has saved that many animals.”

Roadkill’s decline is so significant precisely because its impacts are ordinarily so catastrophic. One recent study calculated that cars crush about 200 million birds and 30 million mammals in Europe every year; in the United States, the toll has been estimated, albeit imprecisely, at more than 1 million each day. In Brazil, researchers wrote in 2014, roadkill has surpassed hunting to become “the leading cause of direct, human-caused mortality among terrestrial vertebrates.”

Given the scope of the carnage, even a temporary respite can save an astonishing amount of wildlife. That’s what Shilling and his colleagues documented in a recent report that analyzed collision statistics and carcass-cleanup figures from the handful of states that systematically collect roadkill data. In California, they found, roadkill fell by 21 percent in the four weeks after the state issued its stay-at-home order in March. In Idaho, the reduction was 38 percent; in Maine, it was 44 percent. A year of reduced travel, Shilling estimated, would save perhaps 27,000 large animals in those three states alone.

And although state records focus on the hefty mammals that endanger drivers—deer, elk, moose, bears, and the like—they’re mum on smaller critters, such as snakes, frogs, and birds, all of which have likely thrived during COVID-19. “We’re measuring the large animals, but I suspect it’s true for all animals, including insects,” Shilling said. (In Texas, millions of monarch butterflies succumb to grilles and windshields during their migrations to Mexico.) Add up all those less conspicuous casualties and extrapolate globally, and it’s hardly a stretch to say that hundreds of millions, perhaps billions, of wild animals will ultimately be spared because of the pandemic.

Nor is it just hyper-abundant animals, such as squirrels and raccoons, that are finding succor during the Anthropause. In California, the poster species for highways’ harms is the mountain lion, several populations of which may soon be protected under the state’s Endangered Species Act. Shilling found that mountain lion roadkill plummeted 58 percent after the shutdown. “When you’re talking about such small populations, you get even one cat taken out by roadkill, and that can spell doom,” Beth Pratt, the California director of the National Wildlife Federation, told me. The Anthropause isn’t merely protecting individual lives, it turns out—in some places, it may be safeguarding the persistence of entire species.

Although all available evidence suggests that net roadkill rates have dropped, it’s conceivable that, on some roads, deaths have actually ticked upward. For many species, cars—loud, terrifying, alien—deter animals from crossing altogether, leading one early road ecologist to describe traffic as a “moving fence.” In Oregon, researchers found that mule-deer collisions peaked at around 8,000 cars per day; beyond that threshold, the ungulates appeared to abandon their migration routes entirely rather than attempt to cross. As traffic has declined during COVID-19, then, animals may feel more comfortable venturing onto certain highways, at their peril—leading ultimately to localized roadkill hot spots. And even if it wasn’t more abundant this spring, roadkill might, in some states, simply be more visible, as agencies tasked with cleaning up carcasses divert resources to the coronavirus response.

How long will the benefits of the roadkill reprieve linger? In early March, Shilling and his colleagues found, Americans drove 103 billion total miles; by mid-April, shutdowns had reduced our collective travel to 29 billion miles, an astonishing 71 percent cut. As travel bans have eased, though, traffic has crept up again, to about half its pre-pandemic levels in California and Maine. Although cities like Milan, London, and New York have seized the opportunity to install new bike lanes and de-emphasize cars, many urban areas have registered more gridlock, as commuters spurn public transit for the socially distant cocoons of their personal vehicles.https://f8b438117f75da65027ebf7524395299.safeframe.googlesyndication.com/safeframe/1-0-37/html/container.html

“COVID is going to have a very short-term effect,” Sandra Jacobson, a retired U.S. Forest Service biologist specializing in transportation, told me. “At some point the world, but especially our country, is going to have to realize that we cannot simply continue to add more and more vehicles indefinitely.”

Shilling is less convinced of the Anthropause’s transience. After all, some of the trends that COVID-19 has spawned—the rise of remote work, for instance—may dampen our enthusiasm for getting behind the wheel. “Coming out of the pandemic, we will hopefully learn lessons,” he said. “One of them might be that we can get a lot of benefits out of not driving.”

Either way, the spring’s gains won’t be immediately undone. In Maine, LeClair told me, more amphibians safely reaching their mating ponds should mean more translucent, gelatinous clumps of successfully laid eggs—and, with luck, more migrants in 2021. “If we’re seeing more next year, we can get an idea that this pandemic might have actually boosted some populations,” he said. The benefits of the great roadkill reprieve, in other words, may outlast the pandemic itself.

We want to hear what you think about this article. Submit a letter to the editor or write to letters@theatlantic.com.BEN GOLDFARB is an environmental journalist based in Spokane, Washington. He is a 2019 Alicia Patterson Foundation fellow and the author of Eager: The Surprising, Secret Life of Beavers and Why They Matter.