As the Planet Warms, What Happens to the Reindeer?

It’s a frigid Tuesday morning in April, and Steve Albon is riding on the back seat of a snowmobile below white peaks on the Arctic island of Spitsbergen, in the Norwegian archipelago of Svalbard. He clutches the side of the speeding vehicle with one hand. In the other, he holds a pole fixed to a square net the size of a studio apartment. A rider on another snow machine holds a pole at the net’s opposite side. It drags on the snow as they rush toward three goat-size animals sprinting out in front of them.

These shaggy gray and white creatures are known as Svalbard reindeer, after this island group nearly 500 miles north of the European mainland, east of Greenland. A close relative of Alaska’s caribou and the semi-domesticated reindeer of Scandinavia, this sweet-faced, stubby-legged subspecies looks part ungulate and part teddy bear. With no natural predators here, and accustomed to snowmobile traffic, they’re not particularly afraid of people. But that doesn’t mean they’ll walk right into a trap.

The two racing snowmobiles close in on one of the three reindeer, a young female with a collar and white ear tags. Each passenger quickly lifts his pole, then lets go. As the poles fall, the net wafts down atop the deer and catches her antlers. She tries to buck it off.

A third snowmobile, the one I have been riding, along with a Norwegian veterinarian named Erik Ropstad, has been following the action. When we reach the reindeer, Ropstad dives at her, and soon White 150 is pinned on the snow.

White 150 is just one in a long line of reindeer that have occupied Albon almost every April since 1995. A 59-year-old ecologist from the southwest of England whose hair has tinges of the reindeers’ white and gray, Albon got started with hoofed animals in the 1970s, first during a summer trip to study antelope in Kenya and then as a research assistant at Cambridge University, when he became involved in a decades-long study of red deer on the Isle of Rum, off the west coast of Scotland.

Albon, now at the James Hutton Institute in Aberdeen, has spent his career tracking wild populations. Here in Svalbard, he races up near-vertical slopes on a machine that feels as if it may flip at any moment. But he’s not in it for the rush. He’s snowmobiling for science, to collect as much data as possible about the hundreds of reindeer that wander the valleys of central Spitsbergen.

After catching up with White 150, he and his team record her weight, leg length and antler points (both sexes have antlers), and take samples of her hair, blood and feces for analysis. The biological tidbits tell the story of White 150’s life. When combined with data from other deer, they also trace the rises and falls in reindeer population across generations, a Nordic saga based on some 3,000 encounters with more than 800 reindeer. “I’m committed to long-term research projects on individuals,” Albon says. “That’s the way we unravel the natural history.”

Albon and his snowmobiling colleagues have recently honed in on weather, which appears to be behind much of the recent action in the Svalbard saga. It is perhaps the single biggest factor determining how Svalbard reindeer will fare as the planet warms. We have all imagined a grim fate for the polar bear, left behind in an Arctic without enough ice. Svalbard reindeer could be in trouble too, but, perhaps surprisingly, for the opposite reason: too much ice.

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Anyone can buy a plane ticket on a regular commercial airline from mainland Scandinavia to Longyearbyen on the island of Spitsbergen, which is what I did. A stuffed polar bear watches over the baggage claim at the airport, a ten-minute bus ride from the tiny town. From there, it’s about an hour on snowmobiles along well-traveled paths to the bare-bones cabin where the scientists spend about ten days every spring, crammed inside with bunk beds, a paraffin stove and several bottles of scotch.

Anyone leaving Longyearbyen carries a rifle, in case of running into polar bears. A week and a half before I arrived, a couple shot and killed a male that had worked his way partway through the window of their cabin, after throwing heavy mittens and a cup and shooting off signal flares didn’t deter him. Scientists go to a shooting range on the hillside above the airport every year before heading out into the field. “The Norwegians are always much better than me,” Albon says. If a polar bear ever did attack, “I would hand the rifle to one of them and say, ‘Here, you do it.’”

Albon first came to Spitsbergen in 1989 when a colleague he’d known in Cambridge clued him in to the reindeer that wander its valleys in groups of three to five, nibbling on herbs, grass and dwarf shrubs. Though Svalbard is high in the Arctic, vegetation does grow in lowlands near the coasts and in ice-free valleys during the short summer, thanks to warm Atlantic currents. The reindeer pack on fat while they can, and in the fall join up in bigger groups for the rut, when males use their antlers to battle over who gets to mate with females.

No one knows exactly how many reindeer live in all of Svalbard; they’re small and spread out, in unusually inhospitable terrain. It’s believed that most survive around ten years. Even if it were possible to get an accurate count for any given year, the population oscillates widely. If you had to make a bet at any one time, pick a number between 1,000 and 10,000, says Brage Bremset Hansen, a population ecologist at the Norwegian University of Science and Technology in Trondheim and the guy on the other end of Albon’s reindeer-catching net. Exactly how the animals got to this now-remote island isn’t clear either, but a founding population must have walked over the sea ice thousands of years ago, possibly from North America or Russia. Any such link is long gone, leaving the reindeer isolated even in winter.

It’s cold in April in the Arctic—the temperature was 5 degrees Fahrenheit the day White 150 was caught, right around the average winter temperature near Longyearbyen between 1961 and 1990. But the weather is warming. For the last three decades, average winter temperatures have hovered closer to 10 degrees Fahrenheit. Warmer weather might sound like a good thing for the reindeer. After all, a longer summer means a longer growing season. But Albon and his colleagues think that the more important factor for reindeer health is not how much they eat in the summer but in the winter. And, unfortunately for these ungulates, warmer winters lead to more rain.

During the winter, Svalbard reindeer paw through the snow to get at lichen and plants. But after a rain the water freezes, encasing the vegetation in a hard ice shell and making it impossible for the deer to obtain dinner. In a rainy winter, animals starve. “Although they’ve got capacities to put fantastic quantities of fat on in the summer, they can’t actually survive the nine months of winter on that,” Albon says. “It’s not enough.”

The year 2012 was particularly rough. Nearly two inches of rain fell over a four-day period in late January and a six-inch-thick layer of ice formed on the ground under the snow. The famine conditions were reflected in data collected that winter by Albon and his team, who found that the average weight of female adults (which the team concentrates on) was 103 pounds—around 20 pounds lower than in good times. Fifty-nine percent of female reindeer were pregnant, a lower than usual rate, and one in ten of those fetuses was already dead when the researchers made their rounds. Though the animals can rebound from a bad year if a better year follows, two bad years in a row (a situation that hasn’t yet occurred, at least not since Albon started his study) could be a serious blow to the population. Early in the study, bad years were rare, with one in 1996 and the next not until 2002. But they seem to be coming more often: 2008, 2010 and 2012 were rainy.

The year I went out, 2013, was colder, and the scientists found no measurable ice on the ground. The average weight of female adults was 126 pounds, one of the highest weights ever recorded, and almost all of those females were pregnant, with no dead fetuses. “In general,” though, Albon says, “things have been getting tougher and the reindeer have been getting smaller.”

Not just reindeer are at risk. Last year, Hansen, the Trondheim population ecologist, published a paper in the prestigious journal Science showing that a warm winter with a lot of rain also leads to declines in a vole, a plant-eating bird known as the Svalbard rock ptarmigan and the Arctic fox (with a year lag), suggesting changes in weather could crash multiple populations simultaneously, threatening an entire self-sustaining Arctic community.

Scientists have generally agreed that a warming globe means animals will move if they can, following their comfort zones. Populations of everything from butterflies to fish have been observed shifting toward the poles or up mountainsides. But the details of such climate-induced migrations—which species will move when and why—are challenging to study, because most ecosystems are incredibly complex.

One of the charms of studying reindeer in Svalbard is the simplicity. It’s a sort of desktop terrarium version of an Arctic ecosystem. The reindeer inhabit one of the world’s simplest food webs. They have no predators, other than people authorized to take part in a small annual hunt. Wolves and wolverines don’t live here. Polar bears chase marine mammals, and Arctic foxes go for smaller prey or carcasses. What’s more, there’s little development to interfere with the reindeers’ lifestyle; the oil industry’s roads and pipelines don’t reach this far. Even coal mines are absent from Albon’s study area.

That leaves one variable: weather. “The thing that’s going to kill you is the winter,” says Perry Barboza, a scientist at the University of Alaska-Fairbanks who studies how food availability and quality affect the survival and growth of animals. “Svalbard gives you this wonderful opportunity to get reliable data every year.” And because of the ecosystem’s streamlined nature, Svalbard can serve as a kind of baseline for what’s happening in places with much more complexity, and more animals.

Still, it’s too soon to know exactly how the reindeer would react to a series of rainy winters. Albon doesn’t bet on extinction: “Not everywhere would be iced to the same degree,” he says. “They can move.” He suspects the reindeer will head to the eastern part of the island first, away from the North Atlantic Current’s warming influence. But will the entire ecosystem shift intact? Will the eastern slopes support as many reindeer?

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In Fardalen, a valley with the equivalent of a snowmobile highway that runs out from Longyearbyen, the team seeks another deer, the sixth of the day. The valley walls rise steeply, then level off for a few hundred feet before the start of a peak that appears to be made of fondant. On that broad shelf, the scientists chase down and net White 78.

Ropstad, the vet, and Larissa Beumer, a German graduate student who has come out for some field experience, tie White 78’s ankles with a loop of rope called a hobble and take a blood sample. Most deer stay still during the scientists’ tests, resigned to the poking and prodding, protest showing only in their eyes. Some struggle awkwardly. “Some are a bit stroppier than others. They’re like people,” Albon says. White 78 kicks, snorts and groans as Ropstad does an ultrasound. There’s a moving fetus in there. “Pregnant, live,” Ropstad calls to Vebjorn Veiberg, an ecologist from the Norwegian Institute for Nature Research in Trondheim, who records the data. Veiberg has heard the phrase many times this week.

We’re huddled around the tied-up deer, like a nomadic camp in the white vastness: snowmobiles parked in a semicircle, people in matching black suits with fur-lined hoods, kneeling or standing, a few working efficiently through the series of measurements and sample collection. After several days in a cabin with no running water, everyone looks a bit ragged.

It’s still well below freezing, but with the right apparel—a thick coat of fur for reindeer, multiple layers of wool and an insulated snowmobile suit for humans—it is perfectly comfortable to be outside all day. Sandwiches and thermoses of warm black currant juice will come out after this deer’s data are collected, and when the wind isn’t blowing, the sun warms the air next to your skin. There is time to admire the landscape and reflect on the day. “I’ve always thought this stuff, for a real job, is not bad,” Albon says. It beats sitting in a cubicle.

Albon and Veiberg catch the hobble between the deer’s hoofs on a set of scales that hang from the center of a pole. They heave the pole’s ends to their shoulders, then to the tops of their heads, so her antlers don’t drag on the snow. “Fifty-seven point zero,” Albon says. That’s 126 pounds, a good weight.

Before freeing White 78’s legs, Leif Egil Loe, an ecologist at the Norwegian University of Life Sciences, sprays a red “X” on each of her flanks so the team won’t accidentally catch her again too soon—the color wears off after a week. Some deer shoot off across the snow in a wild galumph, but White 78 stands up and walks away, down the slope, across the snowmobile highway and up the other side, off to dig for food under the snow.

Helen Fields | | READ MORE

Helen Fields is a freelance writer based in Washington, D.C. She will write about more or less anything, but she focuses on biology. She last wrote for Smithsonian about Panamanian tree frogs.