Outfoxing Extinction

To understand why the fox populations got so low, it helps to know about their ecosystem. The Channel Islands are one of the most biologically diverse places in North America. More than 150 species live there—and nowhere else on the planet.

But by the late 1990s, “the ecosystem was really out of balance,” says Laura Shaskey. She’s a wildlife biologist with the National Park Service. At the time, thousands of pigs lived on the islands. They were descended from pigs farmers brought in the 1800s. Also, human pollution caused bald eagles to die across the U.S.—including the Channel Islands—in the 1950s. With the bald eagles gone and plenty of pigs as prey, golden eagles came to the islands. They ate both the pigs and foxes. (The bald eagles had preferred fish.) “Over 90 percent of the fox population disappeared,” says Shaskey.

Scientists took action. In 1999, they worked with veterinarians to create a captive breeding program. The group bred foxes in captivity and then released young foxes on each island. Next, scientists brought 61 young bald eagles to live in the region. They also removed the pigs and golden eagles from the islands. The entire program was a huge success. The recovery was the fastest ever recorded for any animal on the endangered species list.

But the program’s work isn’t over. Shaskey and her crew still monitor the fox populations. They track foxes with radio collars and microchips. They also vaccinate them against diseases. “I am very humbled to be part of such an amazing recovery,” Shaskey says.             

Why did so many foxes disappear? To understand that, it helps to know about where they live. The Channel Islands have some of the most diverse wildlife in North America. More than 150 species live there and nowhere else on the planet.

But by the late 1990s, “the ecosystem was really out of balance,” says Laura Shaskey. She’s a wildlife biologist with the National Park Service. For one thing, thousands of pigs lived on the islands. Farmers had brought the first ones in the 1800s. Native bald eagles had also died off in the 1950s. Human pollution caused this to happen across the U.S.

With the bald eagles gone, there was more room for other large birds. Golden eagles started to move to the islands. There were plenty of pigs for them to prey on. And unlike bald eagles, which mostly ate fish, golden eagles ate foxes too. “Over 90 percent of the fox population disappeared,” says Shaskey.

Scientists and veterinarians quickly took action. In 1999, they started breeding foxes in captivity. Then they released young foxes on each island. This helped the population grow.

Next, scientists brought 61 young bald eagles to the area. They removed the pigs and golden eagles. The entire program was a huge success. It was the fastest-ever recovery for an animal on the endangered species list!

But the work isn’t over. Shaskey and her crew still monitor the foxes. They track foxes with radio collars and microchips. They vaccinate them against diseases. “I am very humbled to be part of such an amazing recovery,” Shaskey says.