An endangered black-footed ferret is shown on the Buffalo Gap National Grassland. The blue mark on his neck tells biologists and researchers that the animal has been examined and counted. (Image courtesy of Travis Livieri/Prairie Wildlife Research)

Editor's note: The following article was written by Kathryn Sosbe from the U.S. Forest Service's Washington Office of Communication. 

Wildlife Biologist, Phil Dobesh and the Conata Basin/Badlands National Park black-footed ferret recovery implementation team have been working overtime lately, worried about the black-footed ferret population. But Dobesh and multiple public and private partners are running against the clock as they face yet another plague outbreak found in prairie dog colonies.

“We have one of the greatest collaboration of partnerships out of every other wildlife recovery effort at the Conata Basin/Badlands National Park black-footed ferret recovery site,” said Dobesh, who works on the Buffalo Gap National Grassland in south-central South Dakota. “We have handled plague epidemics before, the last in 2008, on Conata Basin and the adjacent Badlands National Park. At that time, we had about 355 ferrets (2007 pre-plague) but that population went down to about 49 individuals (by 2013) because of the plague. That’s a big swing, and a big challenge.”

By late fall of 2023, the Conata Basin/Badlands National Park population of the endangered black-footed ferret (Mustela nigripes), had risen to 160, about half of the world’s wild population of ferrets. But in recent weeks, the re-emergence of the plague among prairie dogs increased the worry about the U.S. population once again. Prairie dogs, especially the weaker, sicker or younger of the species, are ferret food. If the black-footed ferrets eat a sickened prairie dog, the ferret population could take another big hit.

Brooke Fricke, wildlife biologist on the Buffalo Gap National Grassland in South Dakota, releases a male black-footed ferret during the Spring 2024 biomedical survey. The endangered mammals are captured, examined and inoculated as part of the multi-partner effort with the Conata/Badland National Park recovery site to save the most endangered mammal in North America. Before being released, the black-footed ferrets are sprayed with a blue dye as one method of tracking./USDA Forest Service, Ashley Merkel)

“We are working hard to minimize the spread of plague at Conata Basin/Badlands by dusting the prairie dog colonies with DeltaDust, which has the active ingredient of deltamethrin,” Dobesh said, referring to an insecticide used on lawns, gardens and golf courses. “We will treat every last burrow in the prairie dog colony to help control flea populations in the recovery site.”

The black-footed ferrets do not seem adversely affected by the pesticide.  

The black-footed ferret population, once numbering as high as 1 million, is listed as endangered and was thought to have gone extinct on two separate occasions between 1950 and 1980. The acres of natural grasslands where they could thrive also are dwindling. Historical estimates put grasslands and tallgrass prairies at nearly 1 billion acres before the European migration. Today, the country loses an average of 2 million acres annually to land conversion, land once home to many tribes and millions of wildlife species, including the bison, which also had faced extinction due to unregulated overhunting.

The Forest Service manages 20 grasslands and one tallgrass prairie across 13 states for multiple purposes, such as clean water, minerals, wildlife, grazing, recreation and other uses. Each grassland has similar yet unique attributes.

The Buffalo Gap National Grassland is uniquely positioned adjacent to the Badlands National Park, the Pine Ridge Indian Reservation, and the Rosebud Indian Reservation, lands that likely will never be converted to other uses. The Conata Basin, an area shared with the Badlands National Park, is where the federal government’s most successful black-footed ferret reintroduction is centered.  

The collective work has helped make the 600,000-acre Buffalo Gap with its wind-swept rolling hills, nutrient-rich soils the most successful Forest Service unit. Roughly half of the world’s wild population of black-footed ferrets exists at the Conata Basin/Badlands reintroduction site. This site has also provided several wild born ferrets to help establish or supplement ferret populations on other recovery sites.

Black-footed ferrets are essential because of their dynamic relationship with prairie dogs which influences prairie dog behavior on the landscape. Known as a keystone species, prairie dogs provide habitat for many other native grassland species by building expansive burrow systems.  

But those stocky rodents that weigh 2-3 pounds cause a lot of trouble. People and animals are sometimes injured by unknowingly stepping into a burrow hole. Prairie dogs can also cause erosion and water loss in some areas by weakening levees or dams, leading to seepage or failure. They also can weaken roadbeds or gnaw through underground cables and irrigation tubing and clip or remove potential forage for livestock.

Dobesh spent his early career focused on other endangered species, such as the blowout penstemon (Penstemon haydenii), a flowery, short-lived perennial found in clumps and the American burying beetle (Nicrophorus americanus), a carrion beetle that helps to speed up the decomposition process of dead animals and return nutrients to the soil.  

Prairie dogs are a food source for the endangered black-footed ferret and the Prairie dog underground burrows are used by the ferrets./Image courtesy of Travis Livieri/Prairie Wildlife Research.

But his focus – and his heart – seemed to change with the black-footed ferret.

“The ferret? This cute, charismatic animal from the weasel family (Mustelidae)” he said with a grin. “There is so much history in this program from where they started, to get to the point where successful reintroductions were possible. Finding the Meeteetse, Wyoming, population, learning from past failures to developing the current captive breeding and rearing program and the development of conditioning protocols for the release of captive bred ferrets into suitable recovery sites to enhance the wild populations. But it’s the partnerships, too. That is a great selling point. We’re all working together for the same cause.”

As a nocturnal animal, the black-footed ferret is a creature that must be studied at night.

“You stay up all night looking for ferrets, but you see nothing, and that is terrible,” he said. “But when the sun rises, and you see it shining off of the Badlands formations, you realize that you’ve learned something that is still important to help with the species recovery. You are accepting the challenge and trying to solve the puzzle, setting it up and trying to pull together all of the pieces for the next biologist that comes after you so they can learn from the mistakes we made and to continue to do the things that have been successful.”

“We are still going strong, and it doesn’t happen because of me or any other single person. It’s every person and organization in the cooperative partnership that goes out to every recovery site, sharing information and working to make a difference.”

So, how did the ferrets go from being extinct to surprising biologists again? Thank a ranch dog named Shep.

In 1974, the last known population was about 81 miles from Badlands National Park. Then, they were just gone, and ruled as extinct. Until 1981, when Shep killed a black-footed ferret and took it to its owner on a ranch in Meeteetse, about 420 miles from the Badlands. The rancher took the dead animal a taxidermist to be stuffed, not knowing what Shep had caught. The learned taxidermist understood the importance of the dead animal, and that led to the discovery of 130 black-footed ferrets on the ranch, planting the seed for the recovery effort.

“A dog name Shep. Imagine that,” Dobesh said. “Everyone thought the black-footed ferret was gone forever. That dog changed everything.”