Animal bridges, also known as wildlife crossings, help animals navigate human infrastructure — and they're beautiful to look at.
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When human infrastructure spreads into nature, problems usually follow. Transportation corridors like highways, train tracks, and canals can cut off wildlife from their natural habitat, forcing animals to make dangerous — and frequently fatal — journeys through busy thoroughfares. But wildlife crossings, also known as animal bridges, have aimed to helped.
It may seem like a strange idea: can wild animals really be compelled to cross a bridge or navigate a tunnel? However, since the idea first emerged in the 1950s, animal bridges have proven to be a huge success.
Not only have they protected countless animal lives, but these wildlife crossings have also helped prevent vehicle-animal collisions, which can cause billions of dollars worth of damage every year.
The Evolution Of Animal Bridges
As cars became more common around the world, so did vehicle-animal collisions. Vehicle collisions are estimated to kill more than one million animals ever day, and National Geographic reports that they can cost up to $8 billion a year in medical costs and vehicle repairs.
In the 1950s, France came up with an idea to help save animals — and humans — from these collisions. The country began building "game bridges" or passages à faune sauvage to help animals cross busy roadways. Soon, the idea began to spread across Europe.
In the Netherlands, wildlife crossings have expanded rapidly. The country now has more than 600 crossings which protect animals like badges, boars, and deer. The country is even home to the Natuurbrug Zanderij Crailoo, the world's longest animal bridge. This crossing is half a mile long and transects a rail line, a river, a business park, and sports complex.
M.Minderhoud/Wikimedia CommonsA segment of the Natuurbrug Zanderij Crailoo in the Netherlands.
"[Wildlife] crossings are extremely effective," Ben Goldfarb, the author of Crossings: How Road Ecology Is Shaping the Future of Our Planet, told Smithsonian Magazine in 2024. "Typically, they reduce vehicle collisions by 90 percent or so, in part because, typically, you've got a crossing and then you've got roadside fences that funnel the animals to the crossings and allow them to safely cross the highway. So there's lots of research showing that animals definitely use these things."
So what do animal bridges generally look like? And what kind of animals use them?
Wildlife Crossings Around The World
Though widely known as "animal bridges," wildlife crossings can be both bridges and tunnels. Canada's Banff National Park, for example, has dozens of wildlife crossings which include both bridges and underpasses.
"The basic technology isn't all that different [from pedestrian bridges or tunnels] but you want to make them look like habitat," Goldfarb explained. "You want an animal to feel comfortable crossing this novel, weird structure. So typically, the overpasses especially will have shrubs and even whole trees and dirt."
In Canada, the wildlife crossings were a "wild" success. Between 1996 and 2016, park officials documented more than 150,000 animals using the new infrastructure, including bears, cougars, and moose. Across the world on Australia's Christmas Island, a bridge built specifically for migrating red crabs in 2012 has also saved scores of them from being crushed by cars.
ChrisBrayPhotography/Wikimedia CommonsThe red crabs of Australia's Christmas Island have benefited from the construction of animal bridges, which help them to migrate safely.
Indeed, animal bridges have saved animals both big and small.
"It used to be that engineers and biologists were very focused on the big animals, the deer and the elk," Goldfarb noted. "And now we're also thinking, 'Well, wait a second, what does a meadow vole or a snake or a lizard need to feel comfortable on these crossings?' You tend to see lots of rock piles and log jams and other little micro-habitat features that might induce an animal to run across."
The Incredible Impact Of Animal Wildlife Crossings
Today, the success of animal bridges continues. Arizona, for example, has built roughly 20 wildlife bridges since 2000, and has seen a 90 percent drop in wildlife-related highway accidents in one part of the state known for migrating elk. But not only have animal bridges saved countless animals, they've also been extremely beneficial for humans.
USFWS/Southeast/Wikimedia CommonsA Florida panther using a wildlife crossing.
"In many cases, [animal bridges] actually pay for themselves," Goldfarb said. "Sometimes the transportation department will propose a new $5 million wildlife overpass, and everybody shakes their head about the idea of spending $5 million on helping elk cross a highway. But actually, by preventing all of these really dangerous, expensive crashes with animals and vehicles, these crossings are actually recouping their own construction costs. And that's a big part of the reason that so many transportation departments around the country are really embracing them."
Indeed, many communities are continuing to embrace the idea of wildlife crossings. In Southern California, the Wallis Annenberg Wildlife Crossing is being constructed over the 101 freeway west of Los Angeles. More than 200 feet long, the bridge — once completed — will be the longest wildlife crossing in the world. According to Atmos, it will help bobcats, coyotes, deer, snakes, and other animals navigate dangerous roads. Most importantly, it's intended to help mountain lions on either side of the freeway to meet and mate, thus refreshing their gene pool.
Though the idea may seem strange, wildlife crossings have truly been an astounding success. Not only have these bridges saved countless animal lives and revitalized their populations, but they're also beneficial for humans. Animal bridges make the road safer for both wildlife and human drivers.
And many of them — designed to blend in with the environment and entice animals to cross — are absolutely stunning to behold. In the gallery above, enjoy a look at some of the most incredible animal bridges from around the world.
After this look at some animal bridges that blend man and nature, find out about how animals in Chernobyl's Red Forest are surviving — and flourishing. Then, discover the stories of some of Earth's most unbelievable prehistoric animals.
