At birth, a Channel Island fox pup can fit in the palm of your hand. The pups quickly grow to be about the size of a house cat.

Chuck Graham

STANDARDS

CCSS: 4.OA.B.4; MP5, MP6, MP8

TEKS: 3.5E

Outfoxing Extinction

How scientists saved one of the world’s rarest foxes from dying out

Jim McMahon/Mapman

You’d never know it today, but one of the world’s smallest species of foxes almost became extinct about 15 years ago. Known as the Channel Islands fox, it lives only on six of the eight islands in California’s Channel Islands. Thousands of foxes used to roam these islands.

But by the late 1990s, fewer than 200 foxes remained in the wild. They were declared endangered in 2004.

The National Park Service, scientists, veterinarians, and volunteers worked together to bring them back from the brink of extinction. Today, nearly 6,000 foxes live across the islands.

One of the world's smallest species of foxes almost became extinct. This happened about 15 years ago. You'd never know it today. The species is the Channel Islands fox. It only lives on six of the eight islands in California's Channel Islands. Thousands of foxes used to roam these islands.

But by the late 1990s, fewer than 200 Channel Islands foxes were left in the wild. They were declared endangered in 2004. 

The National Park Service, scientists, veterinarians, and volunteers worked together. They wanted to bring the population back. Today, nearly 6,000 foxes live on the islands. 

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.

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

National Parks Service

Laura Shaskey is a wildlife biologist at Channel Islands National Park.

But by the late 1990s, “the ecosystem was really out of balance,” says Laura Shaskey. She is a wildlife biologist at Channel Islands National Park.

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 throughout the United States, including the Channel Islands, during the mid-1900s.

With the bigger bald eagles gone, golden eagles came to the islands. The golden eagles ate pigs and foxes for food. (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 released young foxes throughout the islands.

But by the late 1990s, "the ecosystem was really out of balance," says Laura Shaskey. She is a wildlife biologist. She works at Channel Islands National Park.

At the time, thousands of pigs lived on the islands. They were descended from pigs farmers brought there in the 1800s. Also, human pollution caused bald eagles to die. This happened during the mid-1900s throughout the United States. This includes the Channel Islands. 

When the bigger bald eagles left, golden eagles came to the islands. The golden eagles ate 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. They created a captive breeding program. The group bred foxes in captivity. Then it released young foxes throughout the islands.

Peter Sharpe/National Parks Service

Scientists brought bald eagles back to the Channel Islands to help the ecosystem.

Next, scientists brought 61 young bald eagles to live in the region. They also removed the pigs and golden eagles from the islands.

The program was a huge success. The recovery was the fastest ever recorded for any animal on the endangered species list.

Shaskey knows the program’s work isn’t over. She and her crew 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.

Next, scientists brought 61 young bald eagles to live in the region. They also removed the pigs and golden eagles from the islands.

The program was a huge success. The foxes' recovery was the fastest ever recorded for any animal on the endangered species list.

Shaskey knows the program's work isn't over. She and her crew monitor the fox populations. They track foxes with radio collars. They also use microchips. Plus they vaccinate them against diseases. "I am very humbled to [be part of] such an amazing recovery," Shaskey says.

By 2000, only 15 foxes remained on Santa Rosa Island, one of the Channel Islands. Fill in the T-chart to the right. How many factor pairs do you have?

By 2000, only 15 foxes remained on Santa Rosa Island, one of the Channel Islands. Fill in the T-chart to the right. How many factor pairs do you have?

Write an equation to represent each factor pair.

Write an equation to represent each factor pair.

By 1998, only 15 foxes were left on San Miguel Island. Then golden eagles preyed on 5 foxes, and 2 died from other causes. How many foxes were left? Create a list of factor pairs for that number.

By 1998, only 15 foxes were left on San Miguel Island. Then golden eagles preyed on 5 foxes, and 2 died from other causes. How many foxes were left? Create a list of factor pairs for that number.

In 2001, scientists began a captive breeding program on San Miguel with 21 foxes. What are the factor pairs for this number?

In 2001, scientists began a captive breeding program on San Miguel with 21 foxes. What are the factor pairs for this number?

Today, about 40 bald eagles live in the northern Channel Islands. A student says there are 3 factor pairs for 40. Is the student correct or incorrect? Explain.

Today, about 40 bald eagles live in the northern Channel Islands. A student says there are 3 factor pairs for 40. Is the student correct or incorrect? Explain.

Write equations for all the factor pairs from part A.

Write equations for all the factor pairs from part A.

On Santa Cruz Island, the wild fox population grew from 50 in 2002 to 3 times as many in 2006. List all the factor pairs for the number of foxes in 2006.

On Santa Cruz Island, the wild fox population grew from 50 in 2002 to 3 times as many in 2006. List all the factor pairs for the number of foxes in 2006.

Today, about 2,170 foxes live in the wild on Santa Cruz Island. Would you say the program was a success? Explain why using math terms or equations.

Today, about 2,170 foxes live in the wild on Santa Cruz Island. Would you say the program was a success? Explain why using math terms or equations.

vaccinate

To protect against a disease by giving a vaccine shot 

Populations

Groups of the same species that live in one place 

ecosystem

A community of living things. A forest is an ecosystem, with a community of plants, animals, and microscopic organisms

factor pairs

Two numbers that make a product when multiplied together

Example: 8 has two factor pairs: 1 and 8, and 2 and 4

equation

A number sentence that includes an equal sign; the value of the numbers on each sign of the equal sign are the same

Example: 5 + 4 = 9

endangered

A plant or an animal that is in danger of becoming extinct, usually because of human activity

extinct

No longer existing; having died out completely

captive breeding

A program in which animals reproduce in a zoo or human-run enclosure to help the species

roam

To wander around without a purpose or plan 

T-chart

A chart you fill in with friendly numbers to help you calculate elapsed time

Example: Anna began reading at 10:42 a.m. and finished at 11:12 a.m. Filling in a T-chart with increments of 10 minutes (a friendly number) helps us determine that she read for 30 minutes.

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