For many people, fall evokes the roar of the football stadium, pumpkin harvest or the closing-up of a summer home. On the prairie in the fall, the sky begins to fill with big V formations of geese and brittle stalks of grass rasp in northerly winds. For a dedicated few individuals, the shortening days of fall also signal a return to their nocturnal roamings. These people live their lives between the slivers of morning and evening light in some of the most remote parts of the country, where a distant light might belong to a lonely ranch 20 miles off. These people are not characters from Twilight or a gothic novel. They are ferret chasers. Fall is the time that the caretakers of America’s endangered black-footed ferrets take to the field to study how their tiny populations have fared over the past year, including which ferrets have mated and how many babies were born the previous spring. These census-takers have to adjust to an inverted work schedule because ferrets are most active at night, and they must learn how to navigate the night’s darkness with few landmarks, stripped of daylight’s color. To find ferrets, these teams develop “spotlight squint” — they stare down the powerful beam of a spotlight that can reach up to 300 yards, and look for a ferret’s green eyeshine reflecting back at them.
I once counted myself among this fraternity, but these days, I am a dilettante. I show up to wave the flag and cheer, spending a few nights helping out here and there with these real night owls. Travis Livieri, of Prairie Wildlife Research, a nonprofit partner of Defenders devoted to this work, spends nearly a third of the year chasing eyeshine.
In September, I joined him and a team of Forest Service biologists led by Randy Griebel on a midnight search for ferrets living in Conata Basin, an area on the Buffalo Gap National Grassland in southwestern South Dakota. This is one of just 22 sites in the country where black-footed ferrets have been reintroduced as part of the species’ recovery program.
Black-footed ferrets require large prairie dog colonies for survival; ferrets live in prairie dog burrows and eat prairie dogs. Conata Basin once had more than 30,000 acres of prairie dog colonies, but plague recently wiped out two thirds of the colonies. This year, heavy rains finally ended South Dakota’s long drought. The grass and sweet clover grew so fast and tall this summer that the remaining prairie dogs were overwhelmed. Normally, prairie dogs clear the grass away from the entrances to their burrows, making it easier to spot predators. This year, unable to keep up with the mowing required to keep their colonies well-groomed, they were forced into small pockets where their combined munching carved out tiny islands amidst forests of tall grasses. Ferrets, who depend on large, connected colonies of prairie dogs, find themselves exposed to predators when they have to travel long distances between prairie dog colonies – which is exactly what we think happened when the Conata Basin prairie dog colonies contracted further in size due to the tall vegetation. Our crews there found that ferret counts were down from previous years, a disappointing trend at what has historically been one of America’s premier ferret recovery sites.
Unfortunately, the ferret recovery program has been encountering different, but equally challenging, problems at nearly all of the 22 existing sites. Drought is as bad or worse as monsoon rains, as it leave less grass for prairie dogs to eat and maintain their health. While rains change the landscape this year in Conata Basin, drought seems to be taking its toll on prairie dog and ferret populations in Mexico and Kansas.
Unlike Goldilocks, it’s tough to find a year that’s “just right” for ferrets. Even when the weather is just right for growing grass, it might be just the wrong combination for ferrets because it grows fleas — the carriers of sylvatic plague which kills both prairie dogs and ferrets. Plague was introduced to North America around 1900, arriving on ships and impacting many species of wildlife that had never experienced this disease before. Sadly, even at low levels, plague is active at nearly every ferret recovery site.
Of course it wasn’t always like this. Prairie dog colonies were once 100 million acres strong; there was always someplace that was “just right” for ferrets somewhere nearby on the prairie. But today, after a century of poisoning, plowing and plague, prairie dog colonies cover far less land, and black-footed ferret recovery sites make up only a tiny fraction of the species’ historic range – perhaps one thousandth of one percent of what was available only a short 100 years ago. Managing these postage stamp recovery sites when climate and plague act over huge areas can be a discouraging proposition. What’s happening at Conata Basin, like almost every other site, is a continuing struggle to maintain ferret populations as prairie dogs dwindle.
A few days after the survey at Conata Basin, I found myself on the Fort Belknap Indian Reservation in north central Montana with Russ Talmo and Kylie Paul from Defenders’ Missoula, Montana field office. This time, we didn’t have to look far for ferrets. John Hughes with the U.S. Fish and Wildlife Service Ferret Recovery Program had brought a truckload of endangered ferrets from the captive breeding program in Colorado. This visit was not about finding ferrets; it was an opportunity to celebrate the arrival of these new additions, which will add much needed genetic diversity to the group established here in 2013. Delighted squeals of schoolkids carried across the prairie as the cheeky new ferret recruits popped out of prairie dog holes only feet away from a large group of people from the Fort Belknap community that had come to see their release.
This reservation has a unique history when it comes to ferret recovery. Fort Belknap’s ferrets disappeared a decade ago after their prairie dogs were wiped out by plague in the early 2000s. Slowly, the prairie dogs came back. But, it took over a decade for the prairie dogs to recover. In 2013, Defenders and World Wildlife Fund helped the Assiniboine and Gros Ventre Tribes of Fort Belknap renew the ferret program by bringing ferrets back to the Reservation. This day’s efforts were to bolster that reintroduction with some fresh ferret recruits from the captive breeding program in Colorado. It’s inspiring to me that the Fort Belknap Tribes have not given up hope, and are eager to continue efforts to bring ferrets back after a decade absence. This is the kind of perseverance that shines as brightly as the spotlights at the 21 other ferret recovery sites across the range, and speaks volumes of the dedication that the biologists leading each of these projects bring to the recovery program.
Tonight, while you sleep, there will be ferret caretakers logging miles in trucks, 4-wheelers, and on foot, at North America’s 22 recovery sites, and John Hughes will be showing up in his ferret wagon hauling ferrets to promising new sites. If it means that even one young future biologist is made by seeing his or her first ferret scamper across the darkening prairie, and it inspires them to change the world someday, all of the lost sleep will have been more than worth it. And this hope will inspire the rest of us to keep looking down the beam of the light, chasing eyeshine.
Steve Forrest is the Senior Rockies & Plains Representative at Defenders of Wildlife