Outside the car window, a large rodent called a blacktailed prairie dog stands guard over what looks like a ruined world. As far as the eye can see, the land is dry and scabby, cratered with prairie dog burrows and hatched with a meagre growth of sage and grass. On the horizon, the blue rim of the Frenchman Valley, in the west block of Grasslands National Park, shimmers in the haze of a midsummer afternoon.
No matter which way you turn, you see rodent after rodent after rodent, all of them a-twitch. Some, like my bowling pin of a neighbour, keep watch, ready at the first hint of danger to throw their heads back in a yip-yipping alarm. Others, meanwhile, get on with the serious work of digging and denudation, as if their sole mission in life were to reduce the rangeland of southern Saskatchewan to desolation.
But first impressions can be deceiving and seldom more so than here. This apparently barren landscape — a 15-minute drive from the village of Val Marie, Canada’s proud “Prairie Dog Capital” — is actually an exceptionally biodiverse place. And the plump little rodents that are responsible for this biological enrichment are not vermin, as one might at first suppose, but an animal that, through its activities, creates habitat for dozens of insects, amphibians, reptiles, birds and mammals, including some of the most vulnerable creatures on the planet.
I swing my binoculars up to scan the margins of the colony, hoping to catch sight of one of the rare species that find refuge here. What a treat it would be to see a family of endangered burrowing owls standing beside the prairie dog hole in which they’ve made their nest or to watch a group of endangered male sage grouse performing their strange, gobbling dance or to glimpse an endangered greater shorthorned lizard basking in the warm dirt.
“Endangered” is not a cheery word, but it certainly beats “extinct.” Whether I see these critters (and, today, I appear to be out of luck), it’s reassuring to know that they are out there, taking advantage of whatever opportunities the prairie dogs happen to offer. Until recently, that’s more than could have been said about another member of the prairie dog ecosystem, a beguiling baby-faced carnivore called the black-footed ferret (Mustela nigripes). Once found in almost every prairie dog colony across the length and breadth of the North American plains, from the Rio Grande north to the Frenchman Valley, this mid-sized member of the weasel family was extirpated from Canada in the mid-1930s and globally extinct in the wild by the late 1970s.
But now, thanks to the presence of these busy rodents — and to a recovery effort that has tested the limits of human dedication — the black-footed ferret is being given a chance to get re-established right here, on the northernmost edge of its range. Come next spring, if all goes well, wild black-footed ferrets will produce offspring, or kits, in Canada for the first time in 70 years. This scruffy, dried-out, dug-up, gnawed-over piece of prairie is about to witness a rebirth.
Although southern Saskatchewan is where these hopes will play out, it’s not where the story begins. To follow the ferrets on their journey home and to glimpse what’s involved in bringing a species back from the dead, we must shift our gaze halfway across the continent, to the Toronto Zoo. Here, in an unassuming building on a back lot, carefully secluded from the madding crowds, specialist zookeepers have been breeding the black-footed ferret in captivity for almost two decades. As the only Canadian partner in a multi-faceted, multi-institution captive-breeding program overseen by the U.S. Fish and Wildlife Service (USFWS), the Toronto facility has, over the years, contributed hundreds of kits to reintroduction attempts in northern Mexico and across the western states. The results have been heartening.
Mapping ferret communities (Map: Steven Fick/Canadian Geographic; Source: United States Fish and Wildlife Service)
Mapping ferret communities (Map: Steven Fick/Canadian Geographic; Source: Parks Canada)
“They now estimate, south of the border, that they have about a thousand ferrets living in the wild,” says Maria Franke, curator of mammals, when I visit the zoo in June. “When you think that they were extinct, that’s pretty incredible.”
And that number, though still modest, becomes all the more impressive when you hear about the successive calamities the ferrets and their human champions have faced and overcome. We sit in the staff area of the breeding facility, with our feet encased in hospital-style plastic booties and the ferrets in quarantine on the other side of a closed door, as Franke (herself a former keeper of the Toronto ferrets) and current incumbent Paula Roberts fill me in on the tortuous backstory.
The saga begins at least one million years ago, when black-footed ferrets and Siberian polecats evolved from a common ancestor, either in North America or across the Bering land bridge in Asia. Eventually, the ferrets took up residence in prairie dog colonies. Here was everything a ferret could ask for in one convenient package: food (prairie dogs constitute 90 percent of the black-footed ferret’s diet), protection from predators (simply scoot down a prairie dog hole) and den sites for resting and rearing kits (ditto).
And so things continued until the late 19th century, when the plains were suddenly overwhelmed by an influx of agricultural settlers, armed with plows, strychnine and guns, who set about ridding the country of what they saw as pestiferous rodents. With prairie dogs reduced to two percent of their historic range, the ferrets (which, as territorial animals, were always sparsely distributed) began to diminish toward the vanishing point.
As early as 1900, Manitoba naturalist Ernest Thompson Seton was sounding the alarm. “The Blackfoot,” he warned, “always rare, is becoming rarer. Now that the big Demon of Commerce has declared war on the Prairie-dog … the Ferret, too, will pass.… Does [that thought] inspire you to some action? If so, what? There is but little time left in which to do it.”
But no action was taken then or for decades afterwards. “It’s human nature, I guess,” says Franke with a rueful laugh. “We still haven’t learned. We don’t do something when there are several thousand left. We wait until there are only a handful.”
The black-footed ferret reached the handful stage in South Dakota in the late 1960s, when the only known members of the last known wild population were brought into captivity in a dicey attempt to save the species. Without a safe vaccine for canine distemper (several ferrets were killed by their shots) and unable to get the survivors to reproduce, state biologists were forced to stand by and watch a species disappear.
And so the story might have ended were it not for a Wyoming ranch dog named Shep that went out hunting one night in 1981 and came home with some sort of slinky, masked, black-footed, weasel-type carcass. Intrigued by this unusual trophy, Shep’s owner took the skin to a taxidermist, who must have thought he was seeing a ghost. And that’s how the Meeteetse, Wyoming, population of 129 ferrets was discovered. Tragically, in a few short years, both the Meeteetse ferrets and their prairie dog landlords were struck down by epidemics, and the black-footed ferret seemed doomed to extinction for a second time.
From fall 1985 to spring 1987, with the ferret population in free fall, the USFWS, in collaboration with the Wyoming Game and Fish Department, again began bringing in the survivors — 18 in all — in the distant hope of establishing a captive population. This time, against the odds, they succeeded. Equipped with improved vaccines and a growing knowledge of the animal’s reproductive physiology, researchers helped enable 15 of the captive ferrets to mate and produce offspring, although only seven were genetically varied enough to be called “founder” animals.
“The whole world population of ferrets, including the ones we have here, is based on those seven founders,” says Franke, nodding toward the room next door. “We [humans] have increased the rate of extinction — and of animals becoming endangered — exponentially. We’ve sped it up so fast, we have an obligation to do what we can to help.”
There’s a lull in the conversation, and Roberts suddenly leaps from her chair. “There, can you hear them?” she asks as a commotion of muffled thumps emanates from the adjoining room. “They’re up. Even though they’re mostly nocturnal, they often get up to play.”
She leads me to an observation window where, like a doting parent gazing into a hospital nursery, I find myself peering into the ferrets’ maternity suite. The well-lit space is furnished with rows of elegant wooden cages, each with upper and lower decks that are linked, in lieu of a stairway, by flexible plastic tunnels. “Like prairie dog burrows,” points out Roberts.
Of the 280 ferrets held in captivity for breeding, 18 are housed in this room, 8 males and 10 females. (As a precaution against disease and other disasters, ferrets are also bred at zoos in Arizona, Colorado, Kentucky and Washington, D.C., with the majority at a USFWS facility north of Denver.) In 2009, the Toronto population produced 17 young, enough to make up about half of the Grasslands reintroduction.
“It’ll be nice to have some Canadian-born animals living in Canada,” says Franke with a happy laugh. “True Canadian citizens.”
On the other side of the window, four of those Canadian citizens are having a wild rumpus, wrestling with one another, whipping up and down their tube and scrapping genially over the carcass of a white rat. I think of all the work that has gone into producing this litter, recalling the elaborate protocol that Franke and Roberts had described to me a few minutes earlier: the vaginal smears to check females for breeding condition; the testicular palpations and electroejaculations to test the males for sperm; the round-the-clock video monitoring of young litters. Plus the mundane routine of feeding and cleaning. “It’s poop up to here right now because it’s birthing season,” says Roberts.
All of this to save a single species. Could we conceivably multiply this effort almost 600-fold in Canada, or 17,000- fold in the world, to save all the species that are currently known to be threatened or endangered?
Before I can voice this discomfiting question, one of the kits in the nursery notices an unexpected shape at the window, stretches up on its hind legs and fixes me with a round-eyed stare. It’s a face to melt away reservations, a face that has launched a thousand captive-bred animals out into the wild world. These little guys are not just cute — they are exquisite.
If the pioneers of the black-footed ferret program thought their troubles were over when the captive ferrets produced their first litters, they were sadly mistaken. Getting those hand-reared youngsters re-established in the hardscrabble world has proven to be an even more difficult challenge. Within nine months of the first reintroduction in Wyoming in 1991, for example, more than 90 percent of new releases had succumbed to predators, principally coyotes and badgers. The coddled, cage-reared ferrets didn’t know what to fear.
Through the early 1990s, researchers tried everything they could think of — even hazing with a robotic badger — but nothing seemed to help. In the end, the solution turned out to be remarkably simple. If the ferrets are “preconditioned” in outdoor pens, with real burrows for shelter and real prairie dogs to hunt, they quickly develop most of their natural wariness. With this approach, the population’s survival rate jumped 10-fold, and more ferrets managed to breed in the wild.
Which explains why, in early July, the 17 kits from Toronto, together with a few adults that had been selected for release, were packed into pet crates, provided with bedding and a length of plastic tunnel to keep them comfortable and put on board flight AC1037, heading for “boot camp” in Colorado. At journey’s end lay a handsome, low-slung structure on a secluded stretch of prairie between Denver and Cheyenne, Wyoming, almost due south of the ferrets’ ultimate destination in Saskatchewan.
The USFWS National Black-footed Ferret Conservation Center offers what manager Paul Marinari jokingly calls “the ultimate ferret experience.” Inside the quarantined facility, captive breeding occurs on an impressive scale, with four large wards filled with cages and a near-record production of 269 kits in 2009 alone. Outside, on the grounds east of the building, animals intended for reintroduction are housed in a long, barrackslike rank of roofed-in runs, the kind you might find at a particularly well-appointed boarding kennel. Here, provisioned with food as needed and kept under a watchful eye, the new recruits have a chance to see how it feels to go wild.
When I visit on a sultry afternoon in August, the Toronto ferrets are already a month into this apprenticeship. Under a sky towering with thunderheads, Marinari and I crunch along the gravel lane that services the pens, pausing at each enclosure, peering through the mesh, scanning the ground for movement. Nothing — nobody stirring. And then, at the third stop down the line, a small, round-eared head pokes out of a hole, and I find myself, for a second time, caught by a dark-eyed stare. A split second later, down periscope, and the ferret is gone.
“That’s Barb,” says Marinari, “one of the Toronto adults.” As a 23-year veteran of the recovery effort, he not only is on a first-name basis with the breeding stock in the program but, given half a chance, will also reel off their pedigrees for generations back. Still, he knows full well that some of the animals in boot camp will not pass the test. “It’s sad when an animal dies,” he says. “But if they can’t make it here, where there are no predators and all they have to do is kill prairie dogs for themselves, they are probably not going to make it in the wild.”
A few weeks hence, with this arduous trial behind them, individuals that have qualified for the Canadian reintroduction will receive a full course of vaccinations and two microchips (the same kind that are used for pets) before being packed back into their travel crates and driven across the border. “Historically, ferrets occurred in three countries, the United States, Mexico and Canada,” says Marinari. “Our partners in Toronto have been breeding ferrets for a long time, sending animals south to us, so it’s time to put that final piece back into the puzzle.”
The possibility of reintroducing black-footed ferrets in Canada first came up for serious consideration in the 1990s, when the Toronto Zoo became involved. At that time, the USFWS concluded that the available habitat in this country — the prairie dog colonies in and around the Frenchman Valley — was too limited to make any significant contribution to the recovery effort. Since then, the prairie dog towns have grown from 1,030 hectares in 1998 to 1,275 hectares in 2007, not enough to make much difference to the ferrets. When all the relevant factors are taken into consideration — the natural social spacing of the predators, the density of prey, and so forth — the evidence suggests that Grasslands National Park and its surroundings can support a breeding population of about 20 to 30 adult ferrets.
In the words of the “Recovery Strategy for the Black-Footed Ferret,” released in June 2009 under the aegis of Canada’s Species at Risk Act, a population of this size will remain “highly vulnerable to extinction” and will “likely require ongoing supplementation” in order to persist. Even if the prairie dogs can be encouraged to expand into adjacent areas within the park, in the limited spots where this may be possible, the Canadian ferrets are never likely to be numerous enough to get by entirely on their own.
“Frankly, I needed a little convincing at first,” concedes Pat Fargey, the species at risk/ecosystem management specialist for Grasslands. “Do we wish we had more habitat? Of course we do.” But is it important to get the ferrets out of captivity and back into the wild, throughout their range, wherever quality habitat still exists? The answer, as Fargey now sees it, is obvious.
What makes this fragile population important is not only what the Frenchman Valley has to offer but also what it lacks. These days, the major threat to the continental recovery effort is active outbreaks of plague. Yes, that plague (see sidebar below). Likely introduced to San Francisco via ship-borne rats from Asia at the turn of the last century, the disease has established itself in rodent populations across the North American plains. There, it lies quiescent until, following a microbial logic that nobody yet understands, it breaks out with full cataclysmic force in the ecosystem. In its active form, the disease is almost 100 percent fatal to both prairie dogs and black-footed ferrets.
Until recently, the future of the ferret-recovery program seemed to lie in the Conata Basin/Badlands area of South Dakota, a region with thousands of hectares of prairie dogs, hundreds of self-sustaining ferrets and no sign of the deadly pestilence. Then, in 2008, plague (which previously had been confined to the western and central plains) extended its reach to the east and put the ferrets’ last, best hope in jeopardy.
That summer, when field staff set to work dusting the South Dakota colonies with deltamethrin, to kill infected fleas, it was a tacit acknowledgement that no populations of ferrets will ever again be entirely self-sustaining. Although an oral vaccine for prairie dogs is in the works and may bring the disease under control, it will also necessitate an annual intervention. (Captive-bred ferrets receive a vaccine that provides them, though not their young, with a lifetime of protection.)
Plague is present on the Canadian prairies — researchers have found evidence of recent exposure in coyotes and farm dogs — but the incidence and the severity of the disease are both low. Best of all, no sign of plague has been detected in the Frenchman Valley prairie dogs. So while the Canadian ferrets may eventually require additional releases to bolster the population or prevent genetic collapse, there is a reasonable chance that they will be spared the Black Death. Such is the face of the wild in 2010.
“I think we can succeed with a small managed population of a species that has been gone from this part of the world for decades,” says Fargey. “I don’t mind admitting that I’m excited.”
As for myself, I don’t mind admitting that my heart is torn. As I’ve pieced this story together, I’ve often found myself replaying a snatch of conversation I overheard at the Toronto Zoo. I was making my way back from the ferret house toward the main entrance, by way of the public displays — here an endangered rhino, there a threatened kangaroo or an imperilled frog — when I found myself next to a woman with two curly-headed little girls in tow. “Well,” I heard her say to the children, “have you had enough trauma for one day then?”
Popping a couple dozen ferrets into the Frenchman Valley is not going to heal the ecological trauma of the Canadian plains. It won’t restore the periodic superabundance of insects and mice that are needed to maintain healthy populations of burrowing owls. It won’t reduce the incursion of the oil and gas industry into the habitat of sage grouse, a species that is seismically sensitive to human disturbances. It won’t bring about a significant increase in the range of prairie dogs, themselves a “species of special concern,” or even ensure the long-term survival of black-footed ferrets on Canadian soil. It won’t heal my grief about what looks like a ruined world.
I do not have ready solutions to these problems, nor do I know of anyone who does. However, at a cost of $565,000 in public funds (to cover monitoring and management over the next five years), we have been presented with a relatively inexpensive opportunity to make a small but meaningful contribution to the recovery of a species that, through human mismanagement, has come within a whisper of oblivion. The ferrets were standing ready, the prairie dog habitat was there, and it only remained for us to put the pieces back together.
That is exactly what happened on October 2, when a minivan loaded with ferrets headed up the Frenchman Valley ecotour road and, after stopping, members of the reintroduction team hiked a few kilometres to a prairie dog town. A plump rodent, standing sentinel, yip-yipped and dived down its hole as a crate was placed in the dirt. The door was opened, and a small black-masked face peered out into the wide prairie sky. Against the trends of a calamitous century, the black-footed ferret was back.