Aerial view of a wildlife crossing near Zakrzów, Poland

Built for paws, not people. Wildlife crossing near Zakrzów, Poland

Roads solved one problem but quietly created another. People could travel faster than ever, while wildlife now faced highways cutting across routes they had followed for generations. The result was more collisions, fragmented habitats, and isolated wildlife populations. That challenge led to building wildlife crossings called ecoducts: bridges or tunnels designed to reconnect habitats and give animals a safe way across busy roads. Some of the earliest modern examples appeared in France during the 1950s, and the idea soon spread across Europe. Countries such as the Netherlands helped refine ecoduct design by building wide green bridges covered in soil and native vegetation, from grasses and shrubs to trees.

Today, countries around the world use these crossings. In the United States, overpasses and underpasses help species such as elk, pronghorn, black bears, and Florida panthers cross busy highways safely. Sometimes the smartest bridge is the one you barely notice—because wildlife sees it as part of the forest, not the highway.