by Steve Forrest
When I received a text from Travis Livieri on June 2, 2024, my heart raced. Travis is the Director and lead researcher for Prairie Wildlife Research, which has been the lead organization spearheading recovery efforts for the highly endangered black-footed ferret on National Grassland and National Park lands in western South Dakota. Managed by the US Forest Service’s Buffalo Gap National Grassland and Badlands National Park, the “Conata Basin” is America’s last stronghold for the ferret, a secretive nocturnal predator of the prairie dog, a once-ubiquitous member of the ground squirrel family. The prairie dogs themselves began to run into trouble around the turn of the last century, as European settlers new to the continent began to claim land that would ultimately be converted to uses that conflicted with the prairie dog’s burrowing and grazing habits, ultimately resulting in large-scale poisoning campaigns to eradicate them. Unknown to many of us until much later, prairie dogs were also likely falling victim to an introduced disease, the plague, the killer of much of the human population in the Middle Ages, which had arrived on North America’s shores about the same time the poisoning campaigns were ramping up. By the time I started working on ferrets in the early 1980s, ferrets were known only from one small population, and remaining prairie dogs were a mere 5% of their former abundance. In a stunning reversal, involving the efforts of hundreds of people from many state and federal agencies, Indian tribes, nonprofits, and universities, ferrets were rescued from the brink of extinction, ultimately over the last 30 years restored to the last remaining vestiges of prairie dogs scattered throughout the Great Plains and intermountain west.
While the demand for destruction of the prairie dog from mostly ranchers and lessees of public lands has diminished, due to the success of the poisoning campaigns, the threat of plague has lurked prominently in the background of recovery efforts for the ferret. It is now the most critical threat impacting recovery of the ferret. The primary transmitter of plague to prairie dogs are specific kinds of fleas of the Oropsylla genus. These fleas are themselves infected by the bacteria Yersina pestis, which causes the symptoms of plague: lethargy, poor appetite, vomiting, fever, and in prairie dogs particularly, death from massive bacterial infection. Once in an “epizootic” state-an epidemic in wildlife populations-few if any prairie dogs survive. Even today, plague is poorly understood, in that we know the route of transmission from flea to prairie dog, but have less information about how flea populations suddenly erupt in some years, or where the plague goes when there are no fleas…as plague kills infected fleas as well as the flea host prairie dogs. The text that Travis broadcast to me an others was to announce that it had been discovered that this was one of those years, a year where seemingly out of nowhere plague had erupted in the Conata Basin. Several colonies of prairie dogs evidenced the ghostly abandonment typical of rapid and catastrophic collapse typical of a plague epizootic and several dead prairie dogs found at colonies had tested positive for plague.
Travis was probably aware the impact of this news would have on me, and that I, among just a handful of people, would appreciate the anxiety racing through his mind. In 1985 a similar situation had presented itself to me, and my colleague Dean Biggins, who were studying that last previously mentioned ferret population at Meeteetse, WY. Over the course of a year, we watched in disbelief as, not only prairie dogs disappeared at an alarming rate, but also the ferrets themselves, who we would only learn later can also contract plague. The result at Meeteetse was the heroic salvage effort that resulted in a captive breeding effort to bring the ferrets back, but in the meantime, over the course of two years, the prairie dog population at Meeteetse totally collapsed. Ferrets would not return to Meeteetse for nearly 30 years.
It was only two decades later that our colleague Randy Matchett’s reintroduction site in northcentral Montana at the CM Russell National Wildlife Refuge suffered the same fate. We had better tools by then to fight back against the inevitable and insidious decline of the prairie dogs, but the fighting back involves a major financial and logistical commitment. Travis and I had both worked to keep a remnant of prairie dogs intact alongside Randy following an outbreak there, but eventually prairie dogs dwindled to numbers too few to support ferrets, and the effort was abandoned as the prairie dogs, and then the ferrets, disappeared.
Throughout the ferret program, expertise has evolved as a result of this omnipresent threat as experience battling plague has grown. Dean Biggins would go on to study plague and its impacts for the rest of his professional career at the US Geological Survey (USGS), illuminating the scope and nature of the threat. He was later joined by Dave Eads, also at USGS, who has rigorously tested the efficacy of various treatments and new technologies at many sites throughout the western US. Dan Tripp, at Colorado Parks and Wildlife continues to perfect the means to efficiently apply insecticides to kill fleas. Randy Matchett with the US Fish and Wildlife Service has committed a multi-year effort since the loss of his site to reduce the costs of insecticide treatment through the development of an ATV-mounted delivery system and an insecticide bait called “fipbits.” Toni Rocke at the USGS National Wildlife Health Center spent many years developing an oral plague vaccine. Land managers, like Eddie Childers at Badlands National Park, and Randy Griebel, Phil Dobesh, and Brooke Fricke at the Forest Service pushed their agencies to cover the cost of innovation and maintenance of plague management. Other site managers, like Sean Grassel at Lower Brule Reservation, and Angela Jarding at Wind Cave National Park find the resources to battle plague on an annual basis, as do the private land, managers at sites in Colorado and Wyoming. Backstopping all of this are non-profits, with Kristy Bly at World Wildlife Fund negotiating deals with insecticide companies and funding research, Lindsey Sterling Krank at Humane World funding crews to apply dust and translocate prairie dogs into plagued-out areas, and Chamois Anderson at Defenders of Wildlife providing support to all of these efforts. And finally, in addition to the site managers that include private, state, federal and tribal land and wildlife management agencies, and perhaps most importantly, are the financial supporters of recovery, the National Fish and Wildlife Foundation, the Smithsonian Conservation Biology Institute, the Cheyenne Mountain, Louisville and Phoenix zoos, and most critically, the federal government—the insecticide treatment program at Conata Basin may well run in excess of $100,000 annually, a cost borne largely by the Forest Service and Park Service.
While these singular efforts have advanced our understanding of plague and kept the specter of plague across the entire range of ferrets at bay on many fronts, the emergency at Conata presented one of the most significant threats to the recovery program since the near extirpation at Meeteetse. While range-wide recovery now involves a new generation of hundreds of people involved in every step of the recovery process, from captive breeding to the field biologists who keep track of ferrets in the wild at some of the 13 currently active sites, most of the sites are unfortunately small, a legacy of the poisoning era and the continued modern-day intolerance of prairie dogs from some key private landowners. Conata is literally the beating heart of the nationwide recovery effort, with nearly half of all ferrets in the wild found there. Loss of Conata, on the scale that we were confronted with at Meeteetse and Montana, would be catastrophic, and a possible death blow to the national recovery effort.
Travis would begin mobilizing to confront this epic threat in the days to follow. Conata has followed a rigorous regime for well over a decade, involving contracted insecticide applicators, who scurry over the colonies with four-wheelers, small all-terrain vehicles, to put insecticidal dust at burrow entrances. The insecticide, deltamethrin, kills plague-carrying fleas living on the prairie dogs and in the burrows, and effectively keeps flea numbers so low that any plague harbored in them is not a problem. Typically, however, these contractors have a lot on their plate…to be effective, every single burrow in a colony must be dusted, because any burrows that escape treatment could be the source for an irruption of plague. It typically takes the better part of a summer season for a crew of 5 or 6 dusters to dust the 6,000 or more acres usually treated. The clock was ticking, the contracting schedule needed to be moved up, but more importantly, more dust and dusters would be needed to get ahead of the moving wave of plague that was washing over the Basin, and more of the area was at immediate risk.
Understanding what was at stake, the response within the ferret community was swift. Volunteers from agencies and nonprofits committed equipment and labor in short order. The Forest Service organized training and permitting for volunteer dusters on an expedited basis. The additional resources that flowed in doubled the capacity to meet the threat head on, and teams were in the field in a matter of weeks, doing the grinding work of laying down dust.
I arrived the third week in June. Training of dusters was still ongoing, and Travis had not yet had time to see what, if any, impact the epizootic had had on ferrets. Assuming any ferrets were likely already impacted in the areas where prairie dogs already had disappeared, we were most interested in learning what was happening at the leading edge of the plague outbreak…were ferrets still there, and if so, could we build a wall of resistance around them with spot dusting and hope that we had not arrived too late. A few nights in the field proved fruitful…ferrets were still there. As we searched for ferrets by night, dusters arrived where we had pinpointed ferrets by day, and blanketed the immediate areas with dust. We were going on the offensive, trusting that years of experience had improved our chances of beating back a major epizootic.
As the summer progressed, the volunteer and professional dusting teams kept a relentless schedule under Travis’ watch. Government employees, like Matt Schwarz of the US Fish and Wildlife Service, worked tirelessly to keep the effort moving forward. Randy Matchett arrived from Montana, bringing a new formulation of edible insecticide, fipronil, and his “triple-shooter” machine, capable of treating hundreds of acres a day. By August, 11,000 acres had been dusted, 2,000 acres of fipronil grain, and 2,000 acres treated with fipbits– nearly 90% of the ferret-occupied habitat at Conata that was not impacted by plague. No place that was known to have ferrets was left untreated. As in any effort of this kind, so many give freely of their precious time, expecting no reward but their own satisfaction of helping a cause larger than themselves. Too numerous to mention here, their hard work in the field was inspiring, their sweat through the summer heat sprinkled over the thousands of acres covered. Finally, and somewhat ironically, while teams were doing their best to knock back plague, elsewhere in the Conata, as a measure of goodwill to private landowners, another team from Humane World were capturing prairie dogs scheduled for poisoning. Again, going on offense against the ravages of plague, the HSUS crews moved over 800 prairie dogs to safety, moving them to previously collapsed colonies where the epizootic had already burned out.
The visual inspection of prairie dogs by late August and early September seemed to suggest that the dusting had thrown up a wall of resistance. No evident collapse of colonies around the places where ferrets had been found in June seemed evident. Finally, the moment of truth: had any of this worked? The only way to know was to begin the annual surveying for ferrets. Immediately we were rewarded with visual confirmation that ferrets had not only survived, but had successfully produced kits, even in those areas in the crosshairs of advancing plague. As it would turn out, it was in fact a banner year for ferret kit production, one of the best in many years. It was possible that the same environmental conditions that set the table for plague, had also resulted in high pup production in prairie dogs. We believe that prairie dog pup production is key for quality ferret habitat, and there was apparently plenty to go around for the survivors.
In the end, Conata Basin lost several thousand acres of high-quality ferret habitat…maybe about 15% of the existing habitat base. This is not trivial. Several thousand acres could result in the loss of habitat for 6-8 ferret families. When so few ferrets exist in the wild today, each of these families lost represent a loss of scarce genes, unique adaptations, and is a setback for recovery of the species generally, which is literally counted in the tens of animals. But the efforts of the dozens of biologists and managers had clearly checked what could have been a catastrophic failure and a much worse outcome.
The story doesn’t end here, however. Plague is an insidious killer, and as prairie dogs retreat to their burrows for the winter, hibernating in close proximity to one another, remaining vestiges of the previous summer’s virulent outbreak could be still active at low levels at Conata. We won’t really know where we stand until a couple of months from now, when the prairie dogs emerge, and we can take stock of what was lost over the course of the winter. No doubt, there will be additional loss, but our collective hope is that it is small, and that the previous summer’s work will have thrown up a strong barrier that will result in plague retreat. There will be a need for increased vigilance, and a continued aggressive campaign of treatment in the coming year to ensure plague will not rear up with a vengeance. Unfortunately, this very crucial time comes at a time of great uncertainty for our federal partners who played such a critical role in the plague response, many of whom worry that their jobs and budgets could vanish as quickly as the plague-impacted prairie dogs. Federal funding that supported the annual treatment regime could be held up or pulled back, which makes planning for the safety of ferrets tenuous. It would be the height of tragedy if, having won a critical hard-fought battle, we were to lose the plague war at Conata on the cusp of victory, but for the lack of support from a carelessly executed federal policy. What we do know, is that folks like Travis and the hundreds of biologists and volunteers who won the first round with plague, and continue to keep the ferret’s torch burning, won’t go down without a fight.
Steve Forrest is a prominent figure known for his expertise and extensive work related to black-footed ferrets and their conservation.Key contributions and roles:
- He has been working with black-footed ferrets since the 1980s.
- Forrest is a biologist deeply involved in the efforts to recover this endangered species.
- He has contributed to research on black-footed ferrets, including studies on their habitat, ecology, and the challenges of conservation efforts. Notably, he is a co-author of the chapter “Conserving Endangered Black-Footed Ferrets: Biological Threats, Political Challenges, and Lessons Learned” in the Encyclopedia of Conservation.
- Forrest has highlighted the precarious situation of black-footed ferret populations, emphasizing the importance of conservation efforts and the challenges they face, such as the potential impact of outbreaks like the sylvatic plague.