Endangered Black-Footed Ferrets Are Making a Comeback—But There’s Still a Long Way to Go

Declared extinct in 1980, conservation efforts allowed the black-footed ferret a comeback after a previously undiscovered colony of 130 individuals was found on a ranch in Meeteetse, Wyoming, just one year later.

Using only seven breeding ferrets from the newly uncovered Wyoming colony, conservation scientists were able to reestablish their numbers in captivity before reintroducing them back into the wild.

Today, black-footed ferrets have been upgraded to the endangered species list with an estimated 206 black-footed ferrets alive in the wild and several hundred more in captivity.   

Threats 

In many ways, helping black-footed ferrets comes down to protecting another species: the prairie dog. North American ferrets are almost completely dependent on prairie dog colonies for everything from food and shelter to raising their young.

Since prairie dogs are considered an agricultural pest in most regions, they are routinely deliberately exterminated and have experienced widespread declines as a result.

Ferrets are also threatened by habitat conversion to farmland or human settlement and disease like sylvatic plague—both of which prairie dogs are also susceptible to.

Invasive Diseases

Sylvatic plague is a bacterial disease transmitted by fleas that afflicts many wild rodents, including both black-footed ferrets and prairie dogs.

Black-footed ferrets use prairie dog burrows as dens to raise their young and escape larger predators or harsh weather. Prairie dogs also make up over 90% of the black-foot ferret’s diet.

Not only does this disease have the ability to wipe out entire colonies of wild rodents after they’re introduced, the populations that do survive typically experience a reemergence 5–15 years after previous plague outbreaks.

Development

Conversion of prairie grasslands to agricultural uses, housing, or other development projects can very easily destroy black-footed ferret and prairie dog habitat, sometimes unintentionally.

Since North American prairie dogs have a bad reputation for competing with cattle for forage material and damaging grazing lands or croplands, farmers often take measures to shoot or poison them as well.    

Low Genetic Diversity

Low genetic diversity is particularly problematic among black-footed ferrets due to the fact that most of the world’s remaining individuals came from the original colony found in Wyoming. Gene diversity of the current captive population is estimated to be about 86% of the original gene diversity that was present in the population’s founders.

Fragmenting habitat runs the risk of lowering the genetic diversity within ferret subpopulations as well, both in the wild and in captivity (which can cause issues like immune system dysfunction and reduced reproductive success). 

What We Can Do

Black-footed ferrets are the only ferret species native to North America, but that’s not the only reason why state and federal agencies, conservation organizations, Indigenous groups, and private landowners are working tirelessly to protect them.

As "flagship species," black-footed ferrets contribute to the health of the continent’s grassland ecosystems and all the other plant and animal species who live there.

Breeding Programs

Black-footed ferrets have captive breeding efforts to thank for their second chance, and new or future technologies could stand to help them even more.

The U.S. Fish and Wildlife Service teamed up with conservation partners at the Association of Zoos and Aquariums to explore solutions to some of the genetic diversity issues facing the world’s remaining black-footed ferret population. A huge milestone came in December of 2020, when scientists successfully cloned a black-footed ferret baby using the frozen cells of a female who’d lived over 30 years before. (The picture above shows Elizabeth Ann, the first cloned black-footed ferret at the USFWS National Black-footed Ferret Conservation Center.)

Since all black-footed ferrets in existence today are descendants of the same seven individuals, cloning could address some of the genetic diversity and disease resilience challenges facing additional populations.

Vaccines

The development of effective sylvatic plague vaccines for endangered black-footed ferrets and the prarie dogs they’re dependent on could help stop disease-related complications within sub populations. Or, at the very least, vaccines could create less severe symptoms should infection occur.

The U.S. Geological Survey and Colorado Parks and Wildlife have conducted field trials using peanut butter flavored bait laced with a vaccine against sylvatic plague to prairie dogs in Colorado. They found that wild prairie dogs are less likely to succumb to the disease and that the vaccine also helped reduce widespread outbreaks within prairie dog colonies.

Another study that included colonies in seven different western states from 2013 to 2015 found that the odds of survival in vaccinated prairie dogs was 1.76 times higher for adults and 2.41 times higher for juveniles.

Raise Awareness

One of the best ways that individuals and landowners can help save the black-footed ferret is by staying conscious of what they are putting in the environment, especially in the case of rodenticides and poisons. Finding alternatives to these poisons that don’t release toxic chemicals into the ecosystem has the potential to help protect prairie dogs and black-footed ferrets alike.

It is recommended to contact the U.S. Fish and Wildlife Service before initiating any activities that could potentially affect prairie dog colonies and reporting any black-footed ferret sightings to a wildlife agency.

Studies show that livestock performance may not be as negatively affected by grazing competition with prairie dogs as previously thought. Research ecologists have found that, while prairie dog grazing reduced the amount of grass in cattle pastures, it enhances the quality of the forage both in protein content and in vitro dry matter digestibility.