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Hello, Babies!

These cute black-footed ferret kits are helping scientists save this entire species

March 2025
By Susan Cosier and Kathryn Free

Suzi Eszterhas/Minden Pictures

Since the 1980s, scientists have been breeding black-footed ferrets in captivity to bring the species back from the brink of extinction.

Two tiny black-footed ferret kits sit in a green plastic box. A caregiver reaches in, scoops one fuzzy baby into each hand. Then she places them one at a time on a metal scale for a checkup.

The kits, named Sibert and Red Cloud, are two of the newest black-footed ferrets born in captivity at the Smithsonian Conservation Biology Institute (SCBI) in Front Royal, Virginia. They are part of a decades-long conservation project to help save their species from extinction.

Two tiny black-footed ferret babies sit in a green plastic box. A caregiver reaches in and picks up one fuzzy kit with each hand. Then she places them one at a time on a metal scale. It’s part of a checkup to make sure the babies are healthy.


The kits are named Sibert and Red Cloud. They are two of the newest black-footed ferrets born in captivity. They were born at the Smithsonian Conservation Biology Institute (SCBI) in Front Royal, Virginia. The kits are part of a decades-long conservation project. The project wants to save their species from extinction.

Revive & Restore

Silbert (left); Red Cloud (right)

Black-footed ferrets are one of the most threatened mammal species in North America. But there’s something extra special about Sibert and Red Cloud. Their mother was a clone—an individual with the exact same DNA as a ferret that lived decades ago. Their birth last summer is a historic first.

“Until now, no clone of an endangered species had successfully reproduced,” says biologist Ben Novak. Novak is the lead scientist at Revive & Restore, an organization that uses technology like cloning to aid wildlife conservation. The group works closely with the U.S. Fish and Wildlife Service on black-footed ferret breeding and research. The birth of Sibert and Red Cloud is a crucial step in bringing back this adorable species, which almost disappeared.

Black-footed ferrets are one of the most threatened mammal species in North America. But Sibert and Red Cloud are extra special. Their mother was a clone! She has the exact same DNA as a ferret that lived decades ago. Their birth last summer made history.


“Until now, no clone of an endangered species had successfully reproduced,” says biologist Ben Novak. Novak is the lead scientist at Revive & Restore. The organization uses technology like cloning to help animals. The group works with the U.S. Fish and Wildlife Service to help black-footed ferrets. They study how the animals live and try to raise new kits. The birth of Sibert and Red Cloud is a big step in bringing back the cute species.

First Cloned Endangered Species
Watch a video about the cloning of black-footed ferrets.

Jim McMahon/Mapman

On The Brink

More than a century ago, millions of black-footed ferrets lived across the Great Plains of North America. They chattered and scurried across the landscape. Their primary food source was prairie dogs, a burrowing grassland animal.

In the 1800s, farmers began moving to the Great Plains and killing prairie dogs, which they saw as pests. Without enough prairie dogs to eat, black-footed ferret numbers dwindled. And in the early 1900s, rodents that had arrived in the U.S. on trading ships introduced a deadly disease called sylvatic plague. Both ferrets and prairie dogs died in huge numbers. By 1979, black-footed ferrets were thought to be extinct.

But in 1981, one surviving population was discovered in Meetseetse, Wyoming. Conservationists captured 24 wild ferrets and brought them into captivity. They bred the ferrets at places like SCBI and the National Black-Footed Ferret Conservation Center in Colorado. By 1991, they began releasing ferrets into their native habitat.

Millions of black-footed ferrets lived across the Great Plains of North America more than a hundred years ago. They chattered and scurried across the land. They mainly ate prairie dogs. Prairie dogs are burrowing grassland animals.


Farmers began moving to the Great Plains and killing prairie dogs in the late 1800s. The farmers thought the prairie dogs were pests. Black-footed ferrets didn’t have enough prairie dogs to eat. That caused the number of black-footed ferrets to drop. A disease called sylvatic plague arrived in the early 1900s. It was brought to the U.S. by rodents on trading ships. The disease caused a huge number of both ferrets and prairie dogs to die. Black-footed ferrets were thought to be extinct by 1979.


But one surviving population was discovered in 1981. Conservationists captured 24 wild ferrets in Meetseetse, Wyoming. The conservationists brought the ferrets into captivity. They bred the ferrets at places like SCBI and the National Black-Footed Ferret Conservation Center in Colorado. They began releasing ferrets back into their native habitat by 1991.

 iStockPhoto/Getty Images

All black-footed ferrets alive today came from only 7 individuals.

Cells On Ice

Over the next few decades, biologists bred more than 11,500 black-footed ferrets in captivity. They released up to 220 per year into the wild in the western U.S., Canada, and Mexico. But there was a problem: All ferrets born since 1981 were descendants from just 7 of the original 24, so every captive-bred ferret was closely related. Their offspring were more susceptible to illnesses. That made it hard for the wild population to grow. “Genetic diversity is linked to the health and survival of a population,” explains Novak. “A population needs variation to deal with changes that come its way.”

Biologists have raised more than 11,500 black-footed ferrets in captivity since then. They released up to 220 per year. The ferrets were released into the wild in the western U.S., Canada, and Mexico. But there was a problem. All ferrets born since 1981 were descendants from just 7 of the original 24. That meant every ferret was closely related. Their babies could get sick more easily. That made it hard for the wild population to grow. “Genetic diversity is linked to the health and survival of a population,” explains Novak. “A population needs variation to deal with changes that come its way.”

More than 11,000 black-footed ferrets have been bred in captivity.

USFWS National Black footed Ferret Conservation Center

This is Noreen. She's one of the first three identical ferret clones born!

Scientists needed a way to improve the health of the black-footed ferret population. Thankfully, conservationists had looked ahead when they brought the first ferrets into captivity. A ferret named Willa didn’t reproduce before she died in 1988. But biologists had collected some of her skin cells and froze them. This  preserved Willa's DNA.

Researchers compared Willa’s DNA with that of living ferrets. They found that Willa’s genetic material was significantly different—meaning it could boost the population’s genetic diversity. In 2020, scientists used biotechnology to insert Willa’s DNA into the egg cell of a domestic ferret. A month later, Elizabeth Ann—Willa’s identical clone—was born. Two more Willa clones, Antonia and Noreen, were born in 2023.

But there was still a big question: Would the clones be able to reproduce? No clone of an endangered species had ever given birth to healthy young before. Elizabeth Ann was healthy, but she could not have babies.

Scientists needed a way to improve the health of black-footed ferrets. Thankfully, conservationists had looked ahead. A ferret named Willa didn’t have kits before she died in 1988. But biologists had collected and frozen some of her skin cells. This meant the biologists had Willa’s DNA.


Researchers compared Willa’s DNA with the DNA from living ferrets. They found that Willa’s genetic material was very different. That meant it could boost the population’s genetic diversity. Scientists used biotechnology to insert Willa’s DNA into the egg cell of a ferret in 2020. A month later, Elizabeth Ann was born. She was Willa’s identical clone! Two more Willa clones, Antonia and Noreen, were born in 2023.


But scientists still had a big question. Would the clones be able to reproduce? No clone of an endangered species had ever given birth to healthy young before. Elizabeth Ann could not have babies. 

Jeff Vanuga/NPL/Minden Pictures

This captive-bred ferret was released in Arizona.

Finally, this past fall, Antonia gave birth to Sibert and Red Cloud. The kits’ father was another ferret bred in captivity at SCBI. For scientists like Novak, the birth is cause for celebration. It dramatically improves the odds that the wild population—currently around 350 ferrets—will survive and continue to grow bigger.

“It changes the history books,” says Novak. “Never before has someone been able to reach into the past and bring back diversity that was lost.”

This past fall, Antonia gave birth to Sibert and Red Cloud. It was a first! The kits’ father was another ferret bred in captivity at SCBI. The birth is cause for celebration for scientists like Novak. It makes it much more likely that the wild population of around 350 ferrets will survive and continue to grow bigger. “It changes the history books,” says Novak. “Never before has someone been able to reach into the past and bring back diversity that was lost.”

Suzi Eszterhas/NPL/Minden Pictures

Newborn kits weigh less than 10 grams!

SOLVING ONE-STEP EQUATIONS

A one-step equation requires only one step to solve for the variable. You can use the inverse operation to “undo” the operation to isolate the variable and solve for the unknown.

EXAMPLE

In 2020, there were roughly 315 black-footed ferrets living in the wild. That’s 130 more than x, the size of the wild population in 2010. Write and solve an equation to find x.

STEP 1

Identify your known and unknown information to write the word problem as an equation.

315 = x + 130

STEP 2

Isolate the variable by undoing the addition on both sides.

315 = x + 130
–130       –130
185 = x

So there were a total of 185 wild ferrets in 2010.

SOLVING ONE-STEP EQUATIONS

A one-step equation requires only one step to solve for the variable. You can use the inverse operation to “undo” the operation to isolate the variable and solve for the unknown.

EXAMPLE

In 2020, there were roughly 315 black-footed ferrets living in the wild. That’s 130 more than x, the size of the wild population in 2010. Write and solve an equation to find x.

STEP 1

Identify your known and unknown information to write the word problem as an equation.

315 = x + 130

STEP 2

Isolate the variable by undoing the addition on both sides.

315 = x + 130
–130       –130
185 = x

So there were a total of 185 wild ferrets in 2010.

Use this information to write and solve one-step equations about black-footed ferrets and the reintroduction program. Record your work and answers on our answer sheet.

Use this information to write and solve one-step equations about black-footed ferrets and the reintroduction program. Record your work and answers on our answer sheet.

Black-footed ferrets live up to 9 years in captivity. That’s 3 times y, their maximum lifespan in the wild. Write and solve an equation to find y.

Black-footed ferrets live up to 9 years in captivity. That’s 3 times y, their maximum lifespan in the wild. Write and solve an equation to find y.

Captive-bred ferrets have been released at 29 reintroduction sites. That’s 193 less than a, the amount of habitat in acres that each reintroduced ferret needs. Write and solve an equation to find a.

Captive-bred ferrets have been released at 29 reintroduction sites. That’s 193 less than a, the amount of habitat in acres that each reintroduced ferret needs. Write and solve an equation to find a.

Before Europeans arrived in North America, there were about 502,000 square miles of prairie habitat. That’s 100 times greater than h, the amount of undisturbed prairie habitat today. Write and solve an equation to find h.

Before Europeans arrived in North America, there were about 502,000 square miles of prairie habitat. That’s 100 times greater than h, the amount of undisturbed prairie habitat today. Write and solve an equation to find h.

At least 150 black-footed ferrets are released into the wild every year. That’s 1/20 of s, the minimum population conservationists hope to achieve. Write and solve an equation to find s.

At least 150 black-footed ferrets are released into the wild every year. That’s 1/20 of s, the minimum population conservationists hope to achieve. Write and solve an equation to find s.

There are currently about 280 black-footed ferrets living in captivity. That's 30 more than n, the number of prairie dogs an average family of black-footed ferrets in the wild will eat in a single year. Write and solve an equation to find n.

There are currently about 280 black-footed ferrets living in captivity. That's 30 more than n, the number of prairie dogs an average family of black-footed ferrets in the wild will eat in a single year. Write and solve an equation to find n.

A. It takes about 90 days for a kit to grow large enough to hunt a prairie dog. That’s 55 more than d, the age in days when a kit first opens its eyes. Write and solve an equation to find d.

A. It takes about 90 days for a kit to grow large enough to hunt a prairie dog. That’s 55 more than d, the age in days when a kit first opens its eyes. Write and solve an equation to find d.

B. The age in days when a kit first opens its eyes, d, is 1/2 of u, the total number of days kits stay underground after they’re born. Write and solve an equation to find u.

B. The age in days when a kit first opens its eyes, d, is 1/2 of u, the total number of days kits stay underground after they’re born. Write and solve an equation to find u.

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