Why did the wildlife cross the road?

Why did the wildlife cross the road?

To expand into new territories and look for mates or food. It isn’t hard to imagine why animals need to move around, but when you work in conservation, the more interesting question is: how?

There’s a road that runs through the jungles of Puerto Viejo de Talamanca in Costa Rica. Until a few years ago, it had never been properly paved. When the work crews first came through to turn it into a paved road, with smooth pavement and yellow lines, those of us who live here knew it would have an impact on the local wildlife, but we had no idea how much. The New Road, as it’s now called, meant more cars coming through faster than ever, and, to further expedite the traffic, large trees on either side of the road were cut down.


Sloth road
Sloths on the ground look more like a baby trying to crawl. / Photo: Suzi Eszterhas


Habitat fragmentation has a huge impact on the species that live there. Just like us, they need to get from point A to point B, but unlike us, white-faced capuchins don’t have driver’s licenses (probably a good thing), turtles don’t know how to use crosswalks (probably a bad thing), and snakes don’t look like obstacles until it’s too late (definitely a bad thing).

The problem of habitat fragmentation and wildlife road mortality is not unique to Costa Rica, but is a worldwide issue. In Canada over 6,000 animals per year are recorded as roadkill. These deaths are tragic to the animals involved as well as the species they represent and the biodiversity they support.

Solutions from Canada

In Canada, The Nature Conservancy of Canada (NCC) is a leader in protecting natural areas and biodiversity across the country, but the lessons learned and proven strategies for integrating natural spaces with human development are applicable everywhere.


Turtle using the passage / Credits: Long Point Causeway


NCC has supported innovative projects such as the T5 Eco Passing over a major highway in Ontario, an ambitious grassy bridge that connects large restoration areas on either side of the highway, and the Long Point Causeway Improvement Project, a community-based revitalization of the causeway linking Long Point Peninsula and Lake Erie. The conservation community has come back with a very simple answer to the question:

How does wildlife cross the road?

Back in Costa Rica, the new road through Puerto Viejo has an average elevation of about 10 centimeters above sea level and frequently runs through the Maritime Zone, which is fewer than 50 meters from the coastline, making the “under” solution problematic. Water tables are so high most of the year that even shallow holes quickly flood.

Solutions from Costa Rica

Armed with durable lengths of green rope, a few courageous tree climbers, and a three-meter-long slingshot (yes, really), The Sloth Conservation Foundation’s (SloCo’s) and its Sloth Crossing Project team have installed over 130 bridges connecting giant jungle trees across high-traffic areas along Costa Rica’s Caribbean coast.


A single rope Sloth Crossing wildlife bridge
A single rope Sloth Crossing wildlife bridge


Sloths, monkeys, kinkajou, possums, tree frogs, and dozens of other animals are very happy to move from tree to tree without ever setting foot on the ground — or near the road. These simple bridges look like a tightrope of thick, green cable, and are installed 15 or more meters above the road. Large trucks can pass safely underneath, and the nimble canopy dwellers can climb along overhead.

The next stage

SloCo will soon be launching Phase 2 of the Sloth Crossing Project, which is to install cameras along the ropes to monitor how many and what kinds of wildlife the sloths share bridges with.


camera trap crossing


People and wildlife both need to get where they are going as safely as possible. The good news is that these requirements are not mutually exclusive! Reducing traffic collisions is in everybody’s best interest, and one thing proven by conservationists around the world is that where there’s a will, there’s a way. All it takes is an open mind and a little bit of imagination.

-Ames Reedder

In collaboration with NCC

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