Roadkills: The Fast Lane to Extinction

It’s not a new story. The paper came out in late 2025, published quietly in Academia Biology, and then vanished into the academic void. No glossy press release, no environmental outcry, no viral tweet with a crushed capybara and a crying emoji.

But Mammals on the Move: Patterns, Drivers, and Solutions for Roadkill in Southeastern Brazil should have been national news. It laid bare a truth most Brazilians already sense when driving the endless ribbons of highway that slice through the country: the asphalt is an ecosystem of death.

Over a four-year study along the SP-300 highway in São Paulo state, researchers counted 5,364 animals killed—from giant anteaters to armadillos and capybaras, Brazil’s semi-official mascot of chill. In total, 64 percent died instantly, another 35 percent disappeared wounded, and barely one percent made it to rehab. Scale that up nationwide, and you get the kind of number that only appears in disaster fiction: 475 million wild animals run over every year in Brazil.

The Silent Massacre

The study’s maps look like forensic scans: red blotches where nature bleeds out. Hotspots cluster near rivers and soy fields, where fragmented forest meets highway. The culprits aren’t poachers or fires, but headlights.

The most common victims? Capybaras—social, water-loving, and tragically curious. They wander out at night to warm themselves on the asphalt. Behind them, the nine-banded armadillo trundles in the dark, blind and slow. Then come foxes, anteaters, and the occasional maned wolf—Brazil’s lanky, ginger-haired ghost of the savanna—crushed by trucks carrying meat or grain.

Roadkill has become so routine that even conservationists call it “collateral damage.” The country measures development in lanes paved, not species saved.

Asphalt Colonialism

Brazil’s 1.7 million-kilometre road network was sold as a symbol of progress—a way to connect the interior, move goods, and modernize. But in ecological terms, it’s a 20th-century war machine still operating in the 21st. Every highway divides an ecosystem, traps wildlife in genetic islands, and pushes species like the giant anteater closer to extinction.

The researchers proposed a list of fixes—wildlife corridors, fences, slower speed zones—but implementation remains microscopic. Some concession companies install “eco-passages,” short concrete tunnels no animal dares to enter. Others put up a sign with a cartoon capybara and call it a day.

Meanwhile, roadkill keeps rising. The economic cost of animal collisions topped €2 billion in 2021, but money talks louder than mourning.

The Animals No One Sees

Ask a trucker on the SP-300 and he’ll shrug: “We hit something every week. Mostly capybara. Sometimes dogs. Never stop.” On TikTok, kids film flattened anteaters for shock views. In roadside ditches, vultures circle the buffet.

Wildlife deaths are invisible by design. There’s no daily count, no memorial, no collective grief—just a quiet, endless attrition. Each corpse vanishes under heat and tires until the next one appears.

The Brazilian road system isn’t just moving cars. It’s erasing entire species in real time.

Can We Fix the Asphalt?

The solutions exist—but they demand imagination, not just engineering.

Environmentalists argue that wildlife corridors and underpasses can work if they’re properly placed. Fence off danger zones, guide animals toward crossings, and restore native vegetation near rivers so species have a reason to use them. It’s not rocket science; it’s empathy turned into infrastructure.

The authors of the 2025 study even suggested heat maps as planning tools: overlaying animal mortality data on road networks to redesign traffic flow, limit speed, or redirect highways away from ecological corridors.

But the problem isn’t only technical—it’s political and cultural. Brazil’s road system is run like a business: concessionaires profit from tolls, not from animal survival. Environmental mitigation is an afterthought buried in PDFs. To make it real would require pressure from regulators, municipalities, and—more importantly—drivers who refuse to accept this level of death as normal.

What would a humane road look like? Maybe it’s a road that slows down. One that doesn’t slice through every riverbank. One that admits it’s part of nature, not above it.

Until then, Brazil’s highways remain fast-moving memorials to the species that built no highways, burned no fuel, and yet pay the price for both.

Study: Mammals on the Move: Patterns, Drivers, and Solutions for Roadkill in Southeastern Brazil
Authors: Gabriela C. F. Ramos, Matheus J. Araújo, Márcia Marinho (UNESP)
Published: October 2025, Academia Biology