Narrow bridges

These 50 Meter High Rope Bridges Are Helping Costa Rican Sloths Survive Deforestation

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Zoologist Rebecca Cliffe knows that some people see sloths as “boring, lazy animals,” but she thinks there’s something special about their slowness.

“I always describe it a bit like trying to swim in a lake of Nutella,” said the pundit and sloth enthusiast. The flowis Matt Galloway. “Everything is in slow motion, and they’re just very peaceful, adorable creatures that don’t need much to survive.”

Rebecca Cliffe is a zoologist and founder of the Sloth Conservation Foundation. For 13 years, she worked to protect sloths and their habitats in Costa Rica. (Suzi Eszterhas)

What they need are trees, in dense proximity to each other. Sloths spend most of their lives in trees above ground, away from hazards such as cars and power lines.

They also use leaves for shade and sustenance, and vines and branches for travel.

“Sloths can’t run and they can’t jump, so they really need trees to physically connect and ride each other,” Cliffe said.

For years, this was not a problem for most sloth populations. But as land development has cleared patches of rainforest in places like Costa Rica, sloths are forced to move across the ground more often, leaving them vulnerable to attack and even death.

“I first came [to Costa Rica] 13 years ago it was a whole different place,” Cliffe said. “It was wild and the roads were single lane and the trees were connecting on the road – and over the last 10 years the development got completely out of control.”

That’s why Cliffe and his nonprofit, The Sloth Conservation Foundation, are focused on saving not just sloths, but their habitats as well. They work with communities that develop land to help keep sloths and their needs in mind.

“I think what’s important is that people do [economic development] in the right way and we do it with wildlife in mind,” she said.

Lazy Special Bridges

One way Cliffe and his crew achieve this is by building special bridges that sloths can travel on.

“These are basically wildlife bridges that help sloths move from tree to tree in urban areas and [avoid] …have to get down to the ground,” she said.

Cliffe said these bridges are remarkably simple: each bridge is made of a single string of rope, tied between different trees at alternating heights.

These ropes can go up to 50 meters in the air – and some of them even go through buildings and houses.

“I have a tree climbing team, and…they go up and set them up. They just tie them around the branches,” she said.

Cliffe says some of the bridges she and her team have built for sloths in Costa Rica are up to 50 meters high. (The Sloth Conservation Foundation)

Although ropes aren’t natural for sloths, Cliffe said they’re used to climbing thin structures like vines. After some initial hesitation, “as soon as they realize this structure is safe, they climb on it,” she said.

“If it’s there, they’ll use it once they trust it.”

Cliffe said nearly 30 other species of animals have also used the bridges so far, including monkeys and lizards.

“My favorite was a tree frog,” she said. “A little frog jumped along the rope, from one tree to another.”

Sloths aren’t the only animals using the rope bridges built by Cliffe and his team. Nearly 30 other species of animals, including monkeys, lizards and frogs, have also used the bridges. (The Sloth Conservation Foundation)

A win-win for coexistence

Cliffe is aware that human expansion into wild places will not stop. But, she said, the key to moving forward is to develop in ways that allow wildlife and people to coexist peacefully.

This will require some flexibility from humans, but she said work is being done to keep animals like sloths in mind, including by governments.

Last year, the government of Costa Rica announced that two-toed and three-toed sloths would become the country’s national symbols.

Cliffe said the announcement gives sloths certain legal protections, including ensuring the conservation of sloths in Costa Rica and implementing aerial wildlife crossings on state highways.

It also benefits the country’s tourism industry, according to Cliffe. She said Costa Rica’s tourism industry generates billions of dollars every year, and that’s partly thanks to lazy people.

“[Tourists] want to see sloths, and they google it and Costa Rica is the place to see sloths, so everyone comes here to see them,” she said.

A sloth uses one of the rope bridges built by Cliffe and his crew. (The Sloth Conservation Foundation)

Cliffe said the work being done to protect sloths and their habitats is a win-win situation for everyone involved, from local communities in Costa Rica expanding their land to sloths using bridges to cross treetops.

“It brings wildlife onto their property, so they can live in the wild… [and] sloths win. Everyone is happy,” she said.


Written by Mouhamad Rachini. Produced by Ariane Robinson.