For a lot of animals, the early months of the pandemic were a break from people. With human movements stilled, birds sang louder. Whales could relax in quieter oceans. Fish swam in clearer canals, while lions lounged on empty golf greens. 

Not all species benefited from this “ anthropause”: Poaching and deforestation also took off during lockdowns. But in the U.S., shelter-in-place orders likely saved millions of animal lives, in “what could be among the largest conservation actions ever taken in the U.S. since the formation of the National Park System.” 

That’s according to a recent study published in Biological Conservation, which found the number of deer, moose, coyotes, cougars and other large wild animals killed per day on state highways in California, Idaho, Maine and Washington fell 34% between mid-March and mid-April 2020, as driving fell 71%. Mountain lions in California saw a 58% drop in highway mortality. These declines in mortality were unprecedented, and they quickly reversed as vehicle traffic picked up in the spring and summer months. 

While the study only accounts for large mammals whose vehicle-collision deaths get reported by state agencies, past research has estimated that 1 million vertebrates are killed every day on U.S. roads and highways. That means potentially tens of millions of birds, reptiles, amphibians and mammals avoided death during that first month of lockdown, according to Fraser Shilling, co-director of the Road Ecology Center at the University of California, Davis and the paper’s lead author. To him, that underscores the direct connection between human policies and the fates of animals.

“If we want to protect wildlife for the next generation, we have to reduce traffic or give them a safe way across the road,” he said. 

That sentiment, or at least the second part of it, has recently gained traction in Congress. Both of the five-year surface transportation bills proposed by the Senate and the House dedicate $350 million and $400 million, respectively, for the creation of wildlife passages across roads that fragmentize habitats and block migration routes. 

According to Susan Holmes, federal policy director of the Wildlands Network, an environmental conservation group, this is the first time that such legislation has contained funding for these kinds of projects. They enjoy notably bipartisan support, partly attributable to the fact that many species threatened by highways and automobiles, such as mule deer, elk, and pronghorn, are popular among hunters. Republican Senator John Barrasso, who co-sponsored the Senate bill, hails from Wyoming. “That’s home to some of the most important big game migration corridors in the country,” said Steve Kline, chief policy officer of the Theodore Roosevelt Conservation Partnership, a hunting and fishing advocacy group.

Large, charismatic species such as panthers and bighorn sheep are also broadly popular among people, as well as highly dangerous to ram into with a car. “Everyone knows someone who has hit wildlife on the road, if not themselves,” Holmes said. West Virginia, home to Republican Senator Shelley Moore Capito, who chairs the transportation and infrastructure subcommittee, leads the U.S. in wildlife collisions, which killed 185 people in 2019 and injure tens of thousands annually. Wildlife collisions are costly in other ways, too: A deer strike can bring $6,000 or more in vehicle damages. 

Wildlife crossings have been shown to be hugely effective: Collisions involving wildlife dropped 88% after a set of overpasses and underpasses was built for elk and moose along Highway 9 in Colorado, and 90% after an underpass for mule deer opened beneath Highway 97 in Oregon, according to ARC Solutions, an organization that promotes animal crossings. North America has only a few compared to Europe, where the first overland bridges appeared in the 1950s; the Netherlands boasts more than 450, including one of the world’s longest, while Germany has dozens.  

Recent proposals include the $87 million Liberty Canyon crossing over U.S. 101 in Los Angeles, which would reconnect critical habitat for mountain lions on the brink of extinction in the Santa Monica mountains. Years in the making, the public-private project is expected to break ground by the end of the year. While it relies mostly on private and philanthropic funds, the crossing was earmarked by Democratic Congressman Ted Lieu for an additional $5 million in the House surface transportation bill.

“For those of us who’ve been pushing these ideas for a long time, it’s exciting to see them enjoy this widespread acceptance,” said Beth Pratt, California regional executive director for the National Wildlife Federation, which is leading the project alongside state and regional agencies. “Who doesn’t want to stop poor animals from getting stomped by cars?”

But building bridges for bobcats and underpasses for ungulates is in many ways a Band-Aid solution, pursued only after humans figure out that an existing road is a magnet for animal death. If wildlife needs were built into transportation planning processes and budgets from the get-go, crossings would be cheaper and easier to design, said Pratt. “Try retrofitting one of these over a 10-lane freeway in one of the most densely populated parts of the country,” she said. A more proactive approach to this type of infrastructure is the vision behind the Wildlife Corridors Conservation Act, which was introduced in the House in 2019 with bipartisan support.

Animal crossings are also still few and far between, and recent proposals to fund more of them don’t match the magnitude of need, Shilling said. California alone has hundreds of collision hotspots. As his new paper indicates, less driving period would save animal lives. Instead VMT is surging back to pre-pandemic levels in the U.S. — and in some states,  beyond it — as carbon emissions reach historic highs. Highway mortalities for California’s mountain lions are creeping upwards. 

“Roads are one of the top three contributors to wildlife declines,” Shilling said, pointing to climate change and poaching as the other two. “To think about stopping wildlife from going extinct, we aren’t currently trying to do much about it.”