Cougars in Crisis

A hungry cougar prowls the hills outside Los Angeles, California. The big cat spots a deer—its favorite prey—on a nearby ridge. But there’s a deadly obstacle in its way: a 10-lane highway filled with speeding cars. Should the cougar risk its life and cross the road?

This is a problem for many animals living near Highway 101. The road runs along California’s Santa Monica Mountains. To the north is a vast area of wilderness. Animals living south of the highway, including about a dozen cougars, are stuck in a much smaller area.

A hungry cougar prowls the hills outside Los Angeles, California. The big cat spots a deer on a nearby ridge. That’s the cougar’s favorite prey! But danger lies between the cougar and dinner. A 10-lane highway is filled with cars. Will the cougar risk its life and cross the road?

This is a problem for many animals near Highway 101. The road runs along California’s Santa Monica Mountains. A large area of wilderness lies north of the road. But animals also live south of the highway. They include about a dozen cougars. And they’re stuck in a much smaller area. 

“The freeway acts like a fence,” says Miguel Ordeñana. He’s a biologist at the Natural History Museum of Los Angeles. If the area’s cougars don’t have the freedom to roam, experts say, they could die out within 50 years.

That’s why the National Wildlife Federation is building a bridge over Highway 101 called the Wallis Annenberg Wildlife Crossing. It aims to help cougars, deer, foxes, and other creatures move between the two areas.

“The freeway acts like a fence,” says Miguel Ordeñana. He’s a biologist at the Natural History Museum of Los Angeles. Experts say these cougars need freedom to roam. Without it, they could die out within 50 years.  

So the National Wildlife Federation is building a bridge over Highway 101. It’s called the Wallis Annenberg Wildlife Crossing. It will help animals move between the two areas. Cougars, deer, foxes, and other creatures will use it.

Conservationists have built thousands of wildlife crossings. To decide where to build them, researchers study where animals are most often hit by vehicles. They also use the Global Positioning System, or GPS, to track where animals travel.

The design of a crossing depends on its location and the animals using it. Animals are more likely to use paths that resemble their habitats. Bridges are usually covered with local soils and plants. Tunnels under roads are often made to mimic streams.

The Wallis Annenberg Wildlife Crossing will be covered with local trees and flowers. It will also have walls to quiet the noise from highway traffic. Builders expect to finish the bridge in 2025. Then scientists will use cameras to study how animals use it. “The people of Los Angeles are not giving up on their wildlife,” says Ordeñana.

Conservationists have built thousands of wildlife crossings. Researchers must decide where to build them. So they find out where vehicles hit animals most often. They also track animals’ paths with the Global Positioning System, or GPS.

How is a crossing designed? That depends on its location and the animals using it. Paths are made to look like animals’ habitats. Then animals are more likely to use them. Bridges are usually covered with local soils and plants. Tunnels are built under roads. They are made to look like streams.

Local trees and flowers will cover the Wallis Annenberg Wildlife Crossing. It will also have walls. That will quiet the noise from highway traffic. Builders expect to finish the bridge in 2025. Then scientists will set up cameras. They’ll study how animals use the crossing. “The people of Los Angeles are not giving up on their wildlife,” says Ordeñana.