This is Part 2 of an illustrated series on road ecology. Part 1 covers how roads affect wildlife and the environment.
What is a wildlife crossing?
We learned in part 1 how roads fragment habitats, prevent animals from moving, and put them in danger of collision.
Wildlife crossings are structures built over or under roads to help animals cross safely and to reconnect habitats. They often work in tandem with fences. Fences keep wildlife off roads and guide them toward safe crossings.
Here are a few types of wildlife crossings.
Overpasses
This is an overpass in Banff National Park in Canada. This crossing allows animals like grizzly bears and elk to pass over a large four-lane highway.
Christmas Island is a small island off the west coast of Australia famous for its red crabs. After the first wet-season rains, millions of red crabs migrate from the forests to the ocean. Officials close some roads to prevent cars crunching crabs. Other roads have special fences and bridges to help migrating crabs cross safely.
Canopy bridges
Canopy bridges span gaps in forest canopies so tree-dwelling animals can cross roads.
In Costa Rica, a conservation group is building rope bridges high in the trees to help slow-moving sloths cross roads safely … and at their own pace. Other animals, like monkeys and possums use these bridges too.
Underpasses
Wildlife underpasses help animals move under roadways.
The Trans-Canada Highway in Banff National Park has both overpasses and underpasses. Pumas, also known as cougars or mountain lions, seem to prefer going under highways rather than over them.
In the U.S., Australia, and other countries, people are building tunnels under roads to let turtles move from one waterway to another. Small underpasses also help other small creatures like toads and echidnas.
Crossings are not a perfect fix. Not all animals use them. Sometimes animals that we don’t want crossing roads do, such as feral cats. Building crossings can be expensive or inconvenient.
Things you can do
Here are other ways we can help animals stay safe around roads:
Be a helper: In New Jersey, U.S. kids act as crossing guards for salamanders each year in spring.
Pay attention to signs and warnings: Warning signs alert drivers to nearby animals. We can reduce speed limits in certain places or when animals are known to cross.
Look out for temporary road closures: We can close roads at night, during migrations, or other seasonal animal movements.
Drive less, walk more.
Read part 1: How roads affect wildlife and the environment
Educator tip: Challenge students to design their own creative wildlife crossing! Should it go over or under the road? What animals would use it, and what features would make it safe for both animals and humans?
By Megan Strauss
