This story originally ran in bioGraphic, an online magazine about nature and sustainability powered by the California Academy of Sciences.
Story by Skylar Knight | Photographs by Carl Jan Risberg and Pål Hermansen
As the 65-foot Nanny rolls 20 degrees to port and then to starboard, the half dozen or so hunting dogs aboard look alarmed. It’s hard to blame them. The wooden boat is making a rough winter crossing from Torekov, a small Swedish fishing village-turned-getaway for the well-to-do – including actor Hugh Grant – to Hallands Väderö, a speck of an island off the country’s southwestern coast.
But when we arrive, the dogs tug at their leashes in anticipation of their task: hunting a subspecies of mountain hare called the heath hare, or mohare in Swedish. The 30 or so people who debark belong to the Väderö Hunting Club, which aims to preserve the island’s natural beauty, in part by keeping its mix of species in balance. The hunting party divides into three groups, and I join the one moving south through a rare old-growth beech forest. The towering, moss-covered silver trees shelter us from heavy wind, blowing over ground that’s bare of snow and strewn with rain-dampened leaves.
“The fact that this forest is here is one of the reasons it is important to keep the hares down to a reasonable number,” says Magnus Tenfält, a physician and the leader of the hunt. “If food gets rare in the winter, they start chewing on the bark,” which hurts the trees.
The forest isn’t the only evidence that the 100-plus-year-old club’s conservation efforts are working. Despite the island's size – just a hair smaller than New York City’s Central Park – it remains so rich in wildlife that the Swedish government has maintained it as a nature reserve since the 1950s. The dense forests support a number of threatened insects and lichens, while the rocky coastlines and sandy beaches shelter nesting shorebirds. And sprawling scrublands provide protection and sustenance for finches, warblers, and wagtails.
Heath hares are among the island’s handful of native land mammals. Their powerful back legs are so long and sinewy that when they hop, the animals slope forward like runners crouching at the starting line of a race. Under the hunters’ watch, the hares here have thrived despite disease outbreaks and the arrival of invasive predators. The hunters like the hares – larger and less social than rabbits – in part because they nest on the surface of the ground in thickets and brambles rather than in burrows, making them excellent game.
We emerge from the forest, slog through marsh, and scramble over centuries-old stone walls that shepherds still use during the milder months to contain grazing sheep. The clouds part to reveal a pale January sun near the apex of its arc for the day – just an outstretched hand’s height above the horizon—and the hunters fan out to form a loose pentagon around a patch of juniper. The handlers release the dogs into the middle of the tangle. After 15 minutes, there’s a bark, then a shout, then a shot.
When I approach, I see a hare laid out on a rock, a cold breeze ruffling its unusual fur. Most mountain hares in Sweden belong to the northern subspecies, Lepus timidus timidus, which turns from brown to white in winter for camouflage on snow. But heath hares like the ones on Hallands Väderö belong to the southern subspecies, Lepus timidus sylvaticus, and they turn from brown to blue-grey. That’s an increasingly important distinction. As climate change leads to shorter winters with less snow on the ground, the heath hare’s darker colour allows it to hide better in plain sight, while white hares blaze like beacons against the snowless ground, which makes them easier targets for eagles, foxes, and other predators.
Heath hares, then, have become unwitting reservoirs of genetic resilience. Sweden’s climate has already warmed by 1°C and could warm by as much as 7°C by century’s end. Recent studies have found that climate change has already shrunk the range of snowshoe hares, a distant North American cousin of the heath hare, and also threatens the survival of other animals that seasonally change colour, such as the alpine rock ptarmigan. If the country’s winters become so snowless that winter-white mountain hares can no longer survive, the genetic adaptability of the heath hare could provide a pathway for the species’ persistence as a whole.
Unfortunately, both subspecies of mountain hare have been displaced across mainland Sweden and elsewhere by non-native European brown hares (Lepus europaeus). Mountain hares now exist only in remnant populations in high-altitude locations in the Alps, fragmented forests in Poland, small pockets of the Scottish Highlands and English countryside, and a sub-Arctic band of habitat from Scandinavia across Finland to eastern Russia. And those are likely to become even more vulnerable to displacement by brown hares as snowpack retreats. In Sweden, the heath hare subspecies, once widespread across the southern part of the country, has likely been extirpated from the mainland. Today it remains mostly on a smattering of small islands, including this one. And island populations are much more vulnerable to extinction.
Carl-Gustaf Thulin, a biologist at the Swedish University of Agricultural Sciences in Uppsala who has studied Sweden’s mountain hares for nearly three decades, sees one potential way forward. In a 2021 paper, Thulin proposed a “reservoir island” strategy that would enlist hunters like Tenfält to periodically capture and translocate heath hares from one island to another. By limiting inbreeding, they would preserve genetic diversity across all of the islands – and preserve the heath hare’s status as a potential fur-based insurance policy for the entire mountain hare species.
“You could combine this geographic feature of being remote from the mainland and remote from the brown hares with the enthusiasm that is among the hunters for this subspecies,” Thulin says. “Allow them to hunt these populations, but also allow them to move them around and make good for the hares.”
On a grey January day, I meet Thulin at his office in Uppsala. Wearing jeans and cowboy boots, he looks more like a rancher than an academic. A lifelong outdoorsman and nature lover, he’s as comfortable talking about shooting a wild boar as he is discussing the intricacies of hare biology. Among the books and papers heaped on his desk, a book on the conservation status of the European buffalo edges up against a copy of the Swedish hunting code.
Thulin began studying mountain hares by accident. “I more fancy rabbits,” he had joked during a previous conversation. But as a student, he was interested in what genetics can reveal about animals, and his PhD studies in the 1990s gave him the opportunity to apply those interests to the mountain hare.
Mountain hares have a long history in Sweden. Fossils show that they’ve lived there for at least 10,000 years, arriving from central Europe after the glaciers of the last Ice Age receded from Scandinavia. As glacial meltwater raised sea levels, inflows of water stranded some populations of hares on islands big and small, from Ireland to Hallands Väderö.
The animals were already struggling when Thulin began to study them. His review of prior research and decades of hunting records revealed that brown hares were likely the primary cause of the decline, alongside other factors. Native to central and southern Europe, the European brown hare once coexisted with the mountain hare, each in its own ecological niche. Brown hares, which remain mottled brown in winter, thrived in open, low-altitude landscapes, while the mountain hares made their homes in forested and snowier high-altitude and high-latitude climes.
As humans converted European forests into farmland and rural and urban development boomed, the European brown hare expanded its range into that of the mountain hare. Wherever the two species overlapped, the brown hare’s generalist diet allowed it to outcompete the mountain hare. Worse, some hunters favoured the European brown hare because of its larger size and preference for open terrain. In the mid-19th century, those hunters started actively introducing the species to places where it had never been, including Sweden and Ireland.
Because the European brown hare's coat doesn't change in winter, snowy places remained refuges for northern mountain hares with their white camouflage. In the south, however, where snowfall was less steady, the heath hares found themselves quickly outcompeted by the wave of newcomers. By the 1990s, in the words of Thulin and his research collaborators, there had been a “complete niche replacement” of the heath hare by the brown hare in Sweden.
No one knows exactly how many islands harbour the last of the heath hares, nor how many of the animals remain. Conducting a comprehensive survey takes time and resources, which are as hard to come by in Sweden as they are anywhere else where conservation needs are great and budgets are thin. Thulin has yet to submit a formal proposal for his reservoir island approach to Sweden's Environmental Protection Agency, which oversees wildlife management and conservation efforts. But he says the idea has gotten only a tepid response from his contacts at the agency.
That may be because Sweden prefers a more hands-off approach. According to Robert Ekblom, a biologist at the Swedish EPA who works on species management plans, conservation in Sweden primarily focuses on habitat restoration and monitoring rather than on recovering specific species. Only in rare cases, when an animal is on the brink of disappearing altogether or is of particular importance to its ecosystem and other creatures, does the Swedish government intervene with actions such as captive breeding programs or translocations. Furthermore, it is much more likely to mount such efforts at the species level, with subspecies receiving formal management plans on a case-by-case basis.
The agency’s reticence is understandable. Short of culling the brown hare, which would be both ethically and logistically fraught, there is little hope of successfully reintroducing the heath hare to the mainland anytime soon. This means that the long-term survival of the subspecies would depend entirely on the island populations.
For now, at least, mountain hares remain relatively abundant across their global range. As a result, the influential International Union for the Conservation of Nature lists the species as a whole as of “least concern,” its lowest ranking. But that label obscures the worrisome downward trends at the local level. In Sweden, the heath hare is near extinction – and many local populations of its cousin, the northern mountain hare, are in decline.
This situation and others like it have led some scientists to argue that using species classification as a way to guide conservation isn’t always precise or useful enough. Climate research has revealed more information about what traits might be particularly beneficial to help species persist in the world we’ve given them. In addition, advances in technology have expanded scientists’ understanding of the genetic variation within species, which opens up new ideas and possibilities for conservation. Thulin and others wonder whether the calculus that agencies use to determine whether to help an animal like the heath hare should focus on a much more basic form of diversity.
Since Sweden’s most famous scientist, Carl Linnaeus, first set out to categorise the diversity of life on Earth, species have reigned supreme as the way Western science makes sense of nature. Known as the “Father of Taxonomy” – the branch of science dedicated to naming and classifying life into nested categories, including species – Linnaeus was convinced that there was a divinely ordained order to life on Earth waiting to be discovered. “If I only knew how many teeth and of what kind every animal had, how many teats and where they were placed,” Linnaeus wrote after stumbling upon the jawbone of a horse, “I should perhaps be able to work out a perfectly natural system for the arrangement of all quadrupeds.”
His Systema Naturae, published in 1735, provided the foundation for the formal process by which scientists still describe new species today, with a scientific paper and an official Latin name. Intentionally or not, it also gave scientists a species-based benchmark for protecting the planet’s life. “God creates and Linnaeus organises,” Thulin tells me, quoting a phrase Linnaeus himself is said to have used. “This is kind of a religious framework that we’re still working in, in a way.”
These days, though, with the advent of next-generation sequencing and machine learning algorithms, teeth and teats have given way to DNA and genes. Thulin believes the heath hare embodies the dilemma conservationists now face. Using traditional metrics, a struggling subspecies of a wide-ranging and relatively robust species might be passed over for conservation work, in favour of allocating scant resources elsewhere. But when considered at the level of mountain hare genetics, the heath hare becomes an important asset for a species that is likely to suffer in a warming world.
The heath hare isn’t the only unintended victim of conservation’s fixation on species over genes. Conservation policies have long lagged behind scientific advances, says Linda Laikre, an expert on conservation genomics at Stockholm University. There is even a term for the mismatch: the conservation-genetics gap. In theory, many national and international conservation efforts, including the United Nations Convention on Biological Diversity, which 196 countries have ratified, are intended to protect all levels of biodiversity, including ecosystems, species, and genetics. Yet genetics is often overlooked, Laikre says: “We have this knowledge from science, but it’s to a very limited extent used in practice.”
Laikre and her colleagues recently examined thousands of populations representing more than 900 species to determine their genetic health and how it corresponds with their IUCN conservation listing. Out of the 765 species for which they had sufficient data, the researchers found that more than 100 show alarmingly low levels of genetic diversity on at least one measure, despite being listed as “least concern.” For each of those species – yellow-bellied toads, white-backed woodpeckers, and silver-spotted skippers, for instance – their conservation listing, determined predominantly by their perceived abundance, may belie their real risk of extinction from inbreeding or an inability to adapt to our rapidly changing planet.
Sweden is further along than most countries when it comes to accounting for genetics in conservation. In a series of EPA-funded pilot studies, researchers, including Thulin with the mountain hare, have worked to better understand genetic variation between different populations of the same species. “The idea is, in the long term, to be able to identify functionally important genetic variation and to monitor how such variation is maintained in the population over long time periods,” says EPA’s Ekblom. He acknowledges that the heath hare's conservation status in Sweden could evolve as more information comes to light. Presently, though, the Swedish EPA is hesitant to commit further resources to help the animal’s case.
Back in Uppsala, Thulin flips through photos from a recent hare hunt on Hallands Väderö. In one, Thulin and another researcher lean over a heath hare that they’ve spread on a picnic table turned makeshift lab, taking tissue samples. Thulin grabs a small test tube and shows me the pale pink pellet of skin and muscle inside. Relying on this and other preserved tissue samples stacked in his filing cabinet and stored at another facility, Thulin and his collaborators sequenced the genomes of three heath hares, two northern mountain hares, and two European brown hares. In 2022 they published a paper sharing their results and identifying the places where the genetic code of each group differs. Using this as a guide, scientists may eventually be able to zero in on which genes are responsible for heath hares' unique colouration, as well as find other functional adaptations that the northern mountain hare lacks.
Thulin is also working with county-level government biologists to gain a better understanding of which islands currently have heath hares and which might be well-suited for translocations to start new populations or reseed old ones. Anna Karlsson, a regional county administration ecologist in western Sweden, tells me that a small island called Hållö used to have around 250 heath hares until a 1970s population crash. In their absence, maintaining the island’s meadow ecosystem has largely fallen on regional land managers, who use prescribed burns and manual labour to thin the heather and spur new growth. Translocations would be beneficial on Hållö, Karlsson says. “If you have a population that is big enough, they can do the grazing on the island,” she explains. "This means you don’t have to do any manual work to keep the flora intact.”
As for the hunters, Thulin says they remain ready to help translocate the hares if the Swedish EPA approves the reservoir island project. “It’s nostalgia,” he says of himself and the other hunters. “There is something about our identity that connects to the hare.”
The hunting party boards the Nanny for the return trip from Hallands Väderö to Torekov around three in the afternoon – almost sunset this time of year. Low-angle light illuminates the thin marine layer of clouds, giving them the uncanny appearance of tufts of blue-grey fur. Twelve dead hares, legs outstretched, lie in several tight lines scattered around the deck. A typical winter hunt can bring twice as many, but Tenfält isn’t disappointed. “That is hunting,” he says simply, chuckling. “It is non-negotiable.” As we hunch into our coats against the cold, he recounts the history of the island and the plight of the heath hare with a depth of knowledge that rivals that of the academic experts I’ve spoken with. He’s excited about the prospect of a new “genetic refreshment” that he hopes the Swedish EPA will approve.
Later, when I’ve thawed in my hotel room, I flip through a book given to me by Lars Isacson, another of the hunters on the trip. It was written by his father, who was also a member of the hunting club. Part natural-history text, part record of hunts past, the book is a physical embodiment of how dearly those in the Väderö Hunting Club hold both the heath hare and the island.
Near the beginning, a poem by a former hunting club president reads like a wish for Hallands Väderö’s future:
[Y]ou are still full of living life.
We can still rejoice at neighboring pheasants and the blue-white wool of hares.
May Flora and Fauna enjoy together, our fellow hunters, to their heart’s content.
Every biodiversity loss – be it at the level of ecosystem, species, or gene – makes nature less resilient. But for the people tied to a particular animal, plant, or place, such losses are harder to define – a rearranging of identity that reveals the ways one’s world can depend on something as simple as a blue-white hare.
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