100 Under 100

by Scott Leslie

  Under increased protection, the Bialowieza Forest population gradually increased to nearly 800 animals over the next century. Then World War I happened. German troops occupying the region killed almost 600 bison for their meat, horns, and hides, reducing the population to about 200 animals. A German naturalist warned the army that the species was on the brink of extinction, but in the end his warnings weren’t heeded: the rate of hunting may have slowed for a while, but in the atavistic spirit of sore losers throughout history, the defeated Germans wanted to make a statement, so they laid waste to the forest’s wildlife at the end of the war. All but nine wisent were killed. By 1919, the lowland subspecies was extinct in the wild, a fate that would befall the Western Caucasus Mountains subspecies less than a decade later. Fortunately, 54 wisent were living in zoos throughout Europe at the time of the species extinction in the wild. This small captive population had descended from just 12 original founder animals. They nevertheless represented the only hope for the survival of a magnificent species.

  Reintroductions of wisent into Bialowieza began in the early 1950s. The species has done well. A strictly protected habitat and a high survival rate of newborn young has enabled the species to come roaring back. Its numbers continue to grow, despite serious concerns about inbreeding after the species passed through that genetic bottleneck of a dozen individuals (low genetic diversity makes the wisent susceptible to hoof-and-mouth disease). Thanks to those Polish kings and Russian monarchs, a remnant of wild Europe remains. Today, about 800 wisent live in the 1,500-square-kilometre Bialowieza Forest straddling the border between Poland and Belarus. This lowland mosaic of deciduous and mixed woodland, bogs, marshes, thickets, and meadows is one of the continent’s most important biodiversity hotspots. More than 10,000 species of animals and plants live here, including wolves and European lynx. Some of its giant oak trees are over 500 years old and have trunks more than six metres around. In addition to the reintroduced wild population in the Bialowieza Forest, another 1,000 or so live wild in nature reserves in Russia, Lithuania, Slovakia, and Ukraine. Most recently, a small herd was sent to Moldova—where the wisent appears on the country’s coat of arms—for reintroduction. There are about 1,400 living in zoos in 30 countries around the world as well.

  Some 2,000 kilometres to the east on the Mongolian steppe, another species with a Polish connection, the Przewalski’s horse, is also enjoying a new lease on life as the result of an intensive, long-term captive breeding effort.

  PRZEWALSKI’S HORSE

  Only two species of wild horse survived into modern times, both living in central Asia. (Zebras, onagers, and asses, though members of the equine family, aren’t considered horses, whereas mustangs and other “wild” varieties are feral animals descended from escaped domestic horses.) One of them, the historically abundant tarpan, lived on the steppe grasslands of southern Russia. It was hunted to extinction for its meat in the late 19th century. The other is Przewalski’s (pronounced shuh-vall-ski’s) horse.

  The only wild ancestor of the domestic horse alive today, Przewalski’s horse has a slightly different genetic makeup than the current domestic species, although the two can still mate and produce fertile offspring. It was named for Nicholai Przewalski, a Russian geographer and explorer of Polish ancestry who noted the unique horse in 1879 as he passed through China on his way to Tibet as part of an expedition for Alexander II.

  It’s thought the species once lived on grasslands throughout eastern Europe and Asia, from Germany across the steppes of Russia to Mongolia and China. This stocky, little horse—it weighed only about 300 kilograms and was just 13 hands, or 132 centimetres, high at the shoulder—with its golden-brown coat, long black tail, and stiff black mane like a Mohawk haircut, lived in small groups of up to 10, called harems. It was the quintessential patriarchal arrangement: one dominant male bred with all the breeding-age females. Bullied by the alpha stallion, other males didn’t get to breed. By the time Przewalski saw the species in the late 19th century, its numbers were already thinning, the victim of meat hunting, pressure from agriculture, and competition with domestic grazing animals. It would survive on the vast Asian plains for less than a century longer.

  In the late 1960s, the very last Przewalski’s horse in the wild died in Mongolia’s Gobi Desert. But that wasn’t the end of its story. Seventy years earlier, a small number of the horses had been collected for zoos around the world. The process of capturing such high-spirited animals was difficult. Foals provided the best “return on investment” because they were still young and would live a long time in a zoo environment. Often captured at the expense of the rest of the harem, which would be shot, foals were left undefended, confused, and more easily taken by barbaric collectors.

  Ironically, these captive animals would ultimately save the Przewalski’s horse as a species. But extinction threatened even the early captive horses. Spread among zoos and collections across the globe, there was no single herd large enough to effectively increase the population. To make matters worse, an early group of captive animals in the United States didn’t survive and another important herd living in the Ukraine was shot by German soldiers during their occupation of the country during World War II. By 1945, about 30 captive Przewalski’s horses survived around the world. Only 13 of these were capable of breeding.

  In 1959, new breeding programs were established in Europe and the United States. These efforts were coordinated through the use of an international studbook to keep track of which animals bred with which. By the mid-1970s, there were 250 Przewalski’s horses living in captivity, despite passing through a genetic bottleneck of just 13 breeding animals a few decades before. Every Przewalski’s horse in existence today can thank the contribution made by that baker’s dozen of ancestors. It was a very close call.

  In 1992, a program to reintroduce Przewalski’s horses back into the wilds of Mongolia was begun. It was a success. The species is now protected across its range. Today, there are over 300 of these wild horses running free in three grassland reserves in Mongolia. Although it is still critically endangered, Przewalski’s horse is no longer listed as being extinct in the wild. Another 2,000 or so live in zoos and breeding facilities throughout the world.

  VANCOUVER ISLAND MARMOT

  Przewalski’s horses and wisents are large, distinctive hoofed mammals. Sharks and tigers are powerful and dangerous predators. Peregrine falcons and cheetahs are fast. Mountain gorillas and bonobos seem so human. These animals grab our attention. Then there’s cuteness. This is the realm of lemurs, pandas, marmosets, and monk seals. These animals endear us. You can add another to the list: the almost irresistibly adorable Vancouver Island marmot. It is hard to imagine anything cuter. In fact, it was one of the mascots of the 2010 Vancouver Olympics.

  These rotund, 70-centimetre-long members of the squirrel family are reminiscent of a giant woodchuck, but with chocolate brown fur and the added panache of a white nose, crown, and belly. They are generally thought to be a species unique to Vancouver Island that has evolved rapidly since the last ice age 10,000 years ago (although a few scientists have questioned whether they are a different species from their mainland British Columbia cousins). Found only in the island’s alpine meadows, they live in burrows, survive on a diet of plants, and undergo a long winter hibernation that lasts upward of six months. Probably never abundant, Vancouver Island marmots began plummeting toward extinction in the early 1980s—clear-cut logging; predation by wolves, golden eagles, and cougars; and possibly other environmental changes are to blame.

  Alpine areas, such as the kind the marmot inhabits, are known to be particularly sensitive to climate change. Montane environments around the world are expected to be impacted by warming temperatures more than almost anywhere else. Their typically high-altitude, subarctic-like ecosystems are at risk of getting swallowed up as more temperate species move up mountains into cooler temperatures to escape a warmer climate. But marmots and other species already living in the alpine zone near the tops of moun
tains have no such luxury: they have nowhere to go.

  Less than a decade ago, there were only about 30 Vancouver Island marmots left in the wild, giving them the dubious distinction of being Canada’s rarest mammal. But conservationists have been working tirelessly to ensure their survival. Since 2003, when a program to capture, breed, and reintroduce the animals into the wild began, their numbers had increased dramatically—to 300 at the end of 2010. The goal of the Marmot Recovery Foundation is to have a sustainable population of 600 marmots in the wild by 2012.

  BLACK-FOOTED FERRET

  The black-footed ferret, a svelte, buff-coloured, 40-centimetre-long member of the weasel family, with black feet, tail tip, and “bandit” mask is another cute burrowing mammal that refuses to disappear. It has lived for thousands of years on the North American plains in close association with its primary prey species, the prairie dog, a type of ground squirrel.

  Prairie dogs once thrived with numbers in the hundreds of millions, living in colonies that literally covered 10 to 20 percent of the Great Plains. Individual colonies, known as prairie dog towns, were sometimes dozens of square kilometres in area and consisted of a complex burrow and tunnel system for shelter and protection from predators, storage of food, and the rearing of young. Black-footed ferrets not only rely on the prairie dog colonies as their primary source of food (an adult ferret will eat one every three days, on average) but they also use their burrows as ready-made homes to provide shelter from the elements and the owls and coyotes that prey on them.

  Once human settlers arrived in the region, the prairie dog became a target of farmers and ranchers who saw the rodents as destroying valuable agricultural and grazing lands. A century-long war of poisoning and shooting prairie dogs ensued; it continues to this day in places. The result? Ninety-five percent of their population has been wiped out and with them went the black-footed ferret. By the 1950s, the ferret was thought to be extinct.

  But to everyone’s surprise, that wasn’t the end of the little predator’s story. A small colony was discovered in South Dakota in 1964. Unfortunately, this colony had disappeared by 1974. One ferret, captured earlier as part of an unsuccessful captive breeding program, survived in a wildlife facility in Maryland until it died in 1979. The species was presumed extinct, again.

  Jump forward two years to 1981, when a farmer in Meeteetse, Wyoming, was led by his dog to a colony of a black-footed ferrets. The species had risen from the “dead,” Lazarus-like, for the second time. Unfortunately, canine distemper broke out in the colony, killing many ferrets and threatening to wipe out the species’ last population. So all of the survivors were taken into captivity in the mid-1980s as a precaution. It is a good thing they were, because today’s entire black-footed ferret population is descended from just a handful of these animals that were able to successfully produce offspring in captivity.

  In 1987, one of the most concerted efforts in history for the recovery of an endangered species began. Since then, about 7,000 ferret kits (as the young are known) have been produced. Of these, 2,600 have been released into the wild as part of 19 reintroduction projects spread across eight US states, northern Mexico, and most recently Canada, where, in 2010, ferrets poked their bandit-masked, whiskered faces from their burrows to gaze on the Saskatchewan prairie for the first time in more than 70 years.

  As encouraging as its progress has been, today’s black-footed ferrets face two great challenges: disease and habitat availability. As unlikely as it may seem, sylvatic plague, caused by Yersinia pestis, the same bacteria that killed millions of Europeans during the Black Death of the 14th century, is a major threat to the species’ survival.

  Since arriving in San Francisco in the early 1900s on fleas living on ship rats—there’s those damned ship rats again—the disease has slowly spread eastward across the Great Plains, killing black-footed ferrets, prairie dogs, and other wildlife that becomes infected (and since you asked, yes, it is still deadly to humans if not quickly treated). One hundred percent of infected ferrets die of the disease. The largest outbreak yet happened in Conata Basin, South Dakota, site of the most successful reintroduced colony. About 100, or one-third of the total ferret population there, died in 2008. Plague also killed nearly two-thirds of the prairie dogs in Conata Basin.

  Recently, a vaccine has been developed that protects the ferrets against the disease. All captive animals are now injected with it before they are released into the wild. However, those already living in the wild must be captured to be given the vaccine, a difficult and expensive task for conservationists and stressful for the animals, but absolutely necessary. Yet vaccinating the ferrets is only half of the equation.

  Prairie dogs also suffer a high mortality from sylvatic plague, which may be the most serious hurdle to clear if black-footed ferrets are to survive in the long term, since they depend on their longtime prey species so intimately for survival. If prairie dogs decline even further owing to the disease, it will be increasingly difficult to recover the population of black-footed ferrets in any sustainable way. Unfortunately, there is currently no vaccine that works with prairie dogs, whose population is already reeling with the disease. So, in the short term, prairie dog burrows near ferret colonies are dusted with an insecticide to kill the fleas that transmit plague. This helps prevent infection but is expensive. A vaccine that is delivered in bait has been used successfully in the laboratory, and it is hoped that it will be ready for widespread delivery to prairie dogs in the near future.

  Today, in addition to the 290 in captivity, there are about 250 wild-born and 750 captive-reared ferrets spread among the various reintroduced colonies throughout the North American plains, including the newest one in Grasslands National Park in Saskatchewan. All in all, not a bad comeback for a species thought to be extinct as recently as 1981. But owing to the vicissitudes of nature, including cold winters, predators, disease, and the challenge of obtaining enough prey, only about half this number will survive to breed in the wild each spring, and just 3 of the 19 reintroduced colonies have self-sustaining populations. So the injection of a steady stream of captive-bred animals into the wild is currently required to simply maintain, never mind grow, the population.

  Nevertheless, it is hard to argue that the resurgence of the black-footed ferret isn’t a success, for its current situation is immensely better than it was a few decades ago and continues to improve. On the other side of the world, in Australia, the northern hairy-nosed wombat, yet another endangered burrowing mammal (this one a marsupial), is making a comeback of its own.

  NORTHERN HAIRY-NOSED WOMBAT

  Some stories have staying power. None is older than those of the Indigenous people of Australia, who arrived on that southern land mass 40,000 to 50,000 years ago—some say over 100,000 years—when gigantic marsupials still roamed the land.

  The aboriginal story of the bunyip, Australia’s most famous legendary creature, may have its origins in a real animal known as the giant wombat, the largest marsupial that ever lived. Though it became extinct 30,000 to 40,000 years ago, there is a chance it co-existed with the earliest Indigenous people. That’s a long time for a culture to remember something, but a rhinoceros-like, two-metre-high, three-tonne behemoth carrying a human adult–sized baby in a pouch (it was a marsupial, after all) would be hard to forget. The bunyip legend is as popular Down Under today as it ever was, and wombats, though much smaller now, still live in the Australian wilds. One of them has been almost sucked into the vortex of extinction itself.

  Among Australia’s rarest mammals, the northern hairy-nosed wombat is one of three surviving members of the Vombatidae family, which it shares with the less endangered southern hairy-nosed and common wombats. Though it pales in comparison with its megasized ancient predecessor, the northern hairy-nosed wombat is nevertheless a chunky, muscular animal, weighing over 30 kilograms and reaching more than a metre long. With its plushtoy look, fuzzy muzzle (“hairy-nosed”), silky brown fur, and roly-poly gait, this long-lived species rivals th
e distantly related koala for the title of cutest Australian mammal. And although it may look as slow as a koala, wombats can hit 40 kilometres an hour in a sprint, carried along on stubby legs with powerful feet tipped by long digging claws.

  And do they like to dig! Among the world’s largest burrowing mammals, the northern hairy-nosed wombat bucks the trend of other marsupials by having a backward-facing pouch for its young. This keeps dirt out as it excavates complex tunnel networks that can reach 20 metres in length and delve three and a half metres underground into multiple rooms. Up to 10 individuals might live in a single tunnel complex, known as a warren. They’ve adapted to the brutally hot temperatures found in their native habitat along dry creek beds in the semi-arid grasslands and open woods of central Queensland State by living in cool burrows during the day and coming out at night to feed on grass.

  The northern hairy-nosed wombat was once common, living in several locations in the states of Queensland, New South Wales, and Victoria before Europeans arrived in Australia. After centuries of habitat destruction owing to cattle and sheep grazing and predation by introduced dingoes and red foxes, the endangered wombats are today confined to just one small 500-hectare area within Queensland’s Epping Forest National Park, set up in the early 1970s specifically to protect the last few members of the species. Although its population began to slowly rebound, only 35 wombats survived by the 1980s.

  In 2000, between 10 and 15 percent of the wombats were killed by dingoes. To make sure this wouldn’t happen again, a 20-kilometre-long fence was built around the wombat habitat in the national park in 2002. Other measures were also taken. The fence is monitored twice daily by volunteers to make sure dingoes and foxes are kept out. Feeding and watering stations were set up for the wombats to use when they need it. Introduced plants, which out-competed the native grasses eaten by the animals, were removed. Prescribed fires eliminated excess fuel that might result in destructive natural wildfires. And even though a captive breeding program tried in 1996 was a failure, there are plans to try again in the future using knowledge gained during a successful breeding program for the closely related southern hairy-nosed wombat.