STANDARDS

NGSS: Core Idea: LS4.D

CCSS: Reading Informational Text: 5

TEKS: Science: 3.2D, 3.9A, 4.2D, 5.2D, 5.9C, 6.2E; ELA: 3.9D, 4.9D, 5.9D, 6.8D


Monkey Crossing

How building a bridge could help save golden lion tamarins in Brazil

JUAN CARLOS MUÑOZ/MEDIA BAKERY 

TINY CREATURES: Tamarins are among the smallest primates. Adults weigh less than 2 pounds!

A tiny monkey jumps from tree to tree in a rainforest in Brazil. It’s chasing a tasty bug to eat. Suddenly, the trees dead-end at a highway. The bug escapes, and the monkey has nowhere to go.

This adorable primate is a golden lion tamarin. It lives in the Atlantic Forest along Brazil’s eastern coast (see Disappearing Forest). That area has been ravaged by deforestation. Over centuries, people have cut down most of the forest to make space for cities and farmland. What’s left are isolated pockets of trees.

A tiny monkey jumps from tree to tree. It lives in a rainforest in Brazil. It’s chasing a tasty bug to eat. Suddenly, the trees dead-end at a highway. The bug escapes. The monkey has nowhere to go.

This cute primate is a golden lion tamarin. It lives in the Atlantic Forest. The forest is found along Brazil’s eastern coast (see Disappearing Forest). But little of the forest remains. People have cut much of it down. They wanted to make space for cities and farms. Only small pockets of forest are left.

SCOTT WARREN/AURORA PHOTOS

Small isolated patches of forest can trap animals that need to move freely.

Living in these fragmented areas puts the tamarins in danger. If the animals can’t move around to find food and mates, they can’t survive.

Luckily, scientists are working on a solution. They’re helping to build a bridge over a major highway dividing the forest. Tamarins will be able to use the bridge to travel between two sections of forest on either side. That should give tamarins the room they need to thrive.

“It’s about keeping nature connected,” says ecologist Clinton Jenkins. He’s the vice president of SavingSpecies, a conservation group involved in the project. “Nobody likes to be trapped in a little space.”

Living in these patchy areas puts tamarins in danger. The animals can’t move around to find food and mates. That makes it hard for them to survive.

Luckily, scientists are working to solve the problem. They’re helping to build a bridge. It will cross a major highway. The bridge will link two sections of forest. They’re on either side of the road. Tamarins will be able to use the bridge to travel. That should give them the room they need.

“It’s about keeping nature connected,” says Clinton Jenkins. He’s an ecologist at SavingSpecies. The group is helping with the project. “Nobody likes to be trapped in a little space,” says Jenkins. 

Losing Ground

EDWIN BUTTER/SHUTTERSTOCK.COM

Golden lion tamarins were once common in parts of the Atlantic Forest. But for decades, people hunted them for food and because they thought the animals carried diseases. By the 1970s, fewer than 200 of the tamarins remained in the wild. So scientists began breeding them in zoos and releasing them into their natural habitat.  

Today, about 2,000 golden lion tamarins live in Brazil. But they’re still endangered. Part of the problem is that a major highway called BR-101 cuts right through parts of the forest where the animals live. “It’s impossible for the tamarins to cross the highway,” says Erin Willigan, the executive director of SavingSpecies. “They’re imprisoned on either side.”

Many golden lion tamarins once lived in the Atlantic Forest. But people hunted them for food for decades. They also thought the animals carried diseases. Fewer than 200 of the tamarins remained by the 1970s. So scientists began raising them in zoos. Then they released them into their natural habitat. 

Today, about 2,000 golden lion tamarins live in Brazil. But they’re still in danger of dying out. Part of the problem is the highway. It’s called BR-101. It cuts through the forest where the animals live. “It’s impossible for the tamarins to cross the highway,” says Erin Willigan. She runs SavingSpecies. “They’re imprisoned on either side.”

Bridge Builders

Scientists are teaming up to help the tamarins. They designed a bridge that will connect two sections of the tamarins’ habitat. The bridge will be covered with soil, grass, and trees to make it look like the natural forest (see A Bridge for Tamarins).

In the past few months, the scientists have been planting trees on each side of BR-101. When those trees mature, they will bring the edges of the forest right up to the sides of the bridge. Tamarins will be able to use the bridge to safely travel between two forested areas. “We’re going to bring families of tamarins closer to each other,” says Stuart Pimm, the president of SavingSpecies.

Scientists are teaming up to help the tamarins. They designed the new bridge. It will connect two parts of the tamarins’ habitat. Soil, grass, and trees will cover the bridge. That will make it look like the forest (see A Bridge for Tamarins).

The scientists have recently been planting trees. They placed them on each side of BR-101. The trees will grow larger over time. They’ll bring the forest edges to the sides of the bridge. Tamarins can cross the bridge. They’ll be able to move between the two forested areas. “We’re going to bring families of tamarins closer to each other,” says Stuart Pimm. He’s the president of SavingSpecies.

Connecting different tamarin populations will be good for the whole species. When animals mate, they pass along genes to their offspring. Populations of animals that have a diverse mix of genes are better able to fight off diseases.

The bridge in Brazil is mainly for the tamarins. But scientists expect other animals, such as wildcats, to use it too. Different species in an ecosystem depend on each other to survive. So protecting individual animals should  help preserve the biodiversity of the whole Atlantic Forest.   

Connecting tamarin groups will be good for the whole species. Animals pass along genes to their children when they mate. Some groups have a greater mix of genes. They’re better able to fight off diseases.

The bridge in Brazil is mainly for tamarins. But scientists think other animals will use it too. Saving one species, like tamarins, can help others. It could protect the biodiversity of the whole Atlantic Forest. Many creatures live in this ecosystem. They depend on each other to survive.

JONATHAN HORDLE/REX/SHUTTERSTOCK (GOLDEN LION TAMARIN); LUCIANO CANDISANI/MINDEN PICTURES (ZOOKEEPER)

  • Golden lion tamarins are social—even with people. That makes them popular in zoos.
  • A zookeeper releases a golden lion tamarin into the wild.

Room to Roam

Paths that connect animal habitat, called wildlife corridors, have been built all over the world (see Making Connections). Some are bridges that traverse highways. Others are tunnels under roads. These paths help animals move around while avoiding cars.

Scientists hope that wildlife corridors will also help animals cope with climate change. As temperatures rise, animals will need to move to cooler places to survive. “If you’re imprisoned in an area, it’s going to be really hard to move,” Pimm says.  

Workers began constructing the bridge for the tamarins in November 2018. It’s just the first corridor that SavingSpecies wants built in the Atlantic Forest. The group hopes to connect other patches of trees where animals live. “With a large enough forest, golden lion tamarins have a good chance at survival,” Willigan says.

Paths linking animal habitats are called wildlife corridors. They’ve been built all over the world (see Making Connections). Some are bridges that span highways. Others are tunnels under roads. These paths help animals move around. They also help them avoid cars.

Scientists hope wildlife corridors help in another way. Climate change is causing temperatures to rise. Animals will need to move to cooler places to survive. “If you’re imprisoned in an area, it’s going to be really hard to move,” Pimm says. 

Work began on the tamarins’ bridge in November 2018. It’s the first corridor built by SavingSpecies. But the group wants to create more in the Atlantic Forest. That will connect other patches of trees where animals live. “With a large enough forest, golden lion tamarins have a good chance at survival,” Willigan says.

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