23 Sep 2010

A Troubling Decline in the Caribou Herds of the Arctic

Across the Far North, populations of caribou — an indispensable source of food and clothing for indigenous people — are in steep decline. Scientists point to rising temperatures and a resource-development boom as the prime culprits.
By ed struzik

In late July, a group of Inuit hunters set off by boat along the west coast of Banks Island to search for Peary caribou, which inhabit the Arctic archipelago of Canada. Roger Kuptana, a 62-year-old Inuit who had grown up on the island, didn’t give his fellow hunters much chance of success in their hunt for the animals, the smallest caribou sub-species in North America.

“I think it’s a waste of gas,” Kuptana told me when I visited his modest home in Sachs Harbour, a traditional community of roughly 100 people on the island, not far from the Yukon-Alaska border. “There used to be a lot of caribou around here when I grew up. But now you have to travel pretty far north to find them on the island. It’s not just here. It seems like this happening everywhere.”

As it turned out, Kuptana was right; the Inuit hunters found no Peary caribou, despite three days of searching. The hunters’ predicament is familiar to the Eskimos of Alaska, other Inuit of Canada and Greenland, and the Nenets, Komi, Evenks, Chukotkans, and indigenous groups of northern Russia and Scandinavia. Throughout the Arctic, many of the great caribou and reindeer herds that once roamed the treeless tundra, providing an indispensible source of meat and clothing for aboriginal groups, are in free-fall.

Caribou in the Yukon
For caribou, less snow makes it easier to dig for vegetation.
Thirty-four of the 43 major herds that scientists have studied worldwide in the last decade are in decline, with caribou numbers plunging 57 percent from their historical peaks. Some populations have fallen precipitously: The Bathurst herd in Canada’s central Arctic has plummeted from a peak of 472,000 in 1986 to 32,000 today — a drop of 93 percent.

According to scientists, the causes of the global caribou decline are straightforward: rapidly rising Arctic temperatures are throwing caribou out of sync with the environment in which they evolved; oil and gas development, mining, logging, and hydropower projects in the Far North are impinging on the caribou’s range; and, though not a major factor, hunting is further depleting already beleaguered caribou populations.

In the 1.6 million years that caribou have roamed the northern hemisphere, their populations have risen and fallen with cycles of glaciation and deglaciation. In more recent millennia, populations have ebbed and flowed on a regional basis. But what concerns many caribou experts now is the rapid, global decline of caribou and reindeer (reindeer is the Old World name for the caribou, Rangifer tarandus) in the face of precipitous warming.

Two caribou experts from the University of Alberta, Liv Vors and Mark Boyce, have done extensive research showing that a host of factors related to warming are taking a heavy toll on caribou populations, which they say now “hover on the precipice of major decline.” These factors range from a growing incidence of extreme weather and ice storms, which prevent caribou from reaching lichen and other vegetation under the ice, to a significant increase in mosquitoes and flies, which torment the animals and prevent them from foraging and gaining the body mass needed to successfully reproduce.

Peary caribou have been particularly hard hit by weather-related events. Back in 1961, when the first aerial survey of the Arctic islands was done, biologists estimated Peary caribou numbers to be 24,000. Since then, at
Caribou are better adapted to cold than to warmer, moister weather.
least two catastrophic freeze-ups that were caused by early fall ice storms and rains and early, short-lived spring thaws resulted in more than 90 percent of the animals starving to death because they could not punch through the ice to get to food. Peary caribou populations have fallen today to about 2,000 animals. Scientists in the far-northern Norwegian archipelago of Svalbard told me earlier this spring that they are seeing the same kind of icing take a toll on reindeer in that region.

While there is evidence to suggest that these severe icings have happened in the past, there are also signs that they are likely to occur more often in the future. In recent decades, the Arctic has been heating up twice as fast as the rest of the northern hemisphere — with temperatures routinely rising by 4 to 5 degrees F — making fall rains, early thaws, and severe icing events increasingly common.

Both caribou and reindeer are better adapted to cold than they are to warmer, moister weather. In cold, dry winters there is less snow to slow them down and sap their energy while they’re on the move or being chased by wolves. Less snow, especially if it is not icy and hard-packed, also makes it easier for them to dig down to the vegetation they need in order to get them through to the summer months.

But the icing problem is only one of a host of warming-related effects now plaguing caribou. In a paper published last year in Global Change Biology, Vors and Boyce detailed these impacts. As spring arrives earlier and earlier, “the flush of highly nutritious plant growth” has advanced. Yet caribou reproduction and calving are not occurring earlier, meaning the calves are born past the peak of prime forage availability.

In addition, the lichen and other tundra plants favored by caribou are gradually being replaced by shrubs and trees that are advancing northward as the Arctic warms. Vladislav Nuvano, an expert on the history of reindeer herding in Chukotka, in the Russian Far East, told me recently that reindeer herders there are seeing woody shrubs expand at the expense of lichens and other reindeer food.

Vors and Boyce also reported that rising temperatures have led to an increase in mosquitoes and flies, whose harassment of caribou interferes with their ability to forage and ultimately means that the animals gain less weight. One study in southern Norway showed that rather than increasing foraging times to compensate for harrying by insects, the animals lost body
As more southerly animals invade caribou territory, they bring disease with them.
mass, which makes it harder for the calves to survive the winter and for adults to successfully reproduce.

As other, more southerly animals, such as deer, move north as the Arctic warms, they invade caribou territory, bringing with them disease, such as the meningeal brain worm, according to Vors and Boyce. The worm does not harm deer, but kills caribou. In addition, as moose arrive from the south, wolf packs follow them, and while the much-larger moose are more successful at fending off wolves, caribou succumb more easily to the predators.

Komi reindeer herders along the Kola Peninsula in Arctic Russia are already complaining that their animals are losing 20 percent of their weight by the time they take them to slaughter. Not only is heavy snow making it more difficult to move the animals, warmer temperatures are delaying the winter round-up by up to two months because the lakes the herders need to cross are not freezing over as fast as they once did.

The other major threat to global caribou populations is industrial encroachment — the roads, pipelines, drilling platforms, mines, dams, and other human development that is shrinking the size and quality of the habitat these animals can move to when they become stressed by climate changes and overhunting.

In northern Canada, French mining giant Areva is proposing a $1.5 billion uranium mine near the calving grounds of the Beverly caribou herd, located in Nunavut Territory. That herd’s numbers have fluctuated considerably in recent decades, going from an estimated 210,00 in 1971 to 110,000 in 1980, to 286,000 in 1994. Aerial surveys done in the past several years show a steep drop in both the number of cows and calves, indicating that the herd now contains far fewer animals than in the mid-1990s.

The Canadian government is backing the Areva project, which will include four open pit mines, one underground mine, and the construction of roads
Environment Canada has dragged its feet on creating reserves and migration corridors for caribou.
and bridges. The project promises to create 400 jobs, many of which will go to the chronically underemployed Inuit in the region. But indigenous hunters oppose the mine, saying it could seal the fate of the Beverly caribou herd and create a precedent that will endanger other herds in the Canadian tundra. Half of the world’s caribou populations live in Canada’s Far North, which also contains most of the world’s uranium.

Farther south in Canada, logging and other human activities have led to a steady decline in numbers of woodland and mountain caribou. Yet, according to University of Montana caribou expert Mark Hebblewhite, Environment Canada has dragged its feet for years on creating reserves and migration corridors for these caribou sub-species.

Across the Arctic, development — sometimes aided by warming that is increasingly opening up the once ice-covered Arctic Ocean — threatens caribou and reindeer. In the central region of the Russian Arctic, the reindeer-herding Evenks have been struggling to stop a $13 billion hydroelectric development that will flood an area ten times the size of New York City.


The Natural World Vanishes:
How Species Cease To Matter

The Natural World Vanishes: How Species Cease To Matter
Once, on both sides of the Atlantic, fish such as salmon, eels, and, shad were abundant and played an important role in society. But as these fish have steadily dwindled, humans have lost sight of their significance, with each generation accepting a diminished environment as the new norm, writes biologist John Waldman.
In Greenland, a 22-mile access road that was built in 2000 between the Kangerlussuaq airport and the Greenland Ice Cap has already caused a major habitat alteration for the Kangerlussuaq-Sisimiut herd. The road, which provides year-round access to tourists, day-trippers, and hunters, traverses what was once sensitive habitat for the herd during the calving and post-calving periods. Now, ALCOA, the world’s largest producer of aluminum, wants to build a giant smelter in the region, along with several hydro dams to power it.

Anne Gunn, a former biologist with the government of the Northwest Territories and now a scientific consultant, is concerned that the whittling away of caribou habitat is occurring just as the animals are feeling the effects of global warming. Unlike some scientists, Gunn, who has more than 30 years of field experience, believes caribou can adapt to the climate changes occurring now. She is most concerned that very little is being done to protect critical caribou habitat, especially the critical calving grounds and migration corridors. Of 24 large caribou herds being tracked by CARMA — the Circumpolar Rangifer Monitoring and Assessment Network — only the calving grounds of the Porcupine and Bluenose West herds are fully or largely protected.

“For caribou it is all about ‘space’ — their perceptions of what space they need, including the space needed to distance themselves from us,” said Gunn. “Climate change and overhunting are very serious factors that need to be addressed. But unless we give caribou the space they need, I’m afraid we’re going to see these declines continue.”


Canadian author and photographer Ed Struzik has been writing on the Arctic for three decades. He is the 2007 recipient of the Atkinson Fellowship in Public Policy and was a finalist for the Grantham Prize for Excellence in Reporting on the Environment in 2008. His latest book is The Big Thaw. In previous articles for Yale Environment 360, he has written about the need for an Arctic Ocean treaty and about the threats facing polar bears as Arctic sea ice disappears.

SHARE: Tweet | Digg | | Reddit | Mixx | Facebook | Stumble Upon


"Now, ALCOA, the world’s largest producer of aluminum, wants to build a giant smelter in the
region, along with several hydro dams to power it." Factually the melter will be build on an island without tuttu, and we have not had bad experiences with the hydrodams f.ex. in Kangerluarsunnguaq, an mayor caribou area south of Nuuk.

It's known that caribou populations collapse when they become too many, and that it can
take a long time to rebuild a new large population. It's a fact with or without "global
warming," since I find this story a part of the ongoing scaremongering!

Posted by Ole Heinrich on 24 Sep 2010

So much for the good old days when we had our heads in the sand and thought caribou would rub up against the Alaskan Pipeline and have babies. The argument that opening ANWR to oil production will have no affect on burgeoning caribou populations is dead.
Posted by Andy on 24 Sep 2010

I'm very sorry to hear this... I understand they are up against man & $$$ in the use of aluminium... in everyday modern living, both in the home and in vehicles : ( Too bad industry doesn't think about the Caribou as they could easily replace aluminum with copper, paper, glass, magnesium and titanium, which are apparently viable alternatives:

Posted by on 24 Sep 2010

The caribou are just one more example of what humans are doing to the creatures with which we share the planet. If global warming and loss of space are important factors in the decline of caribou herds, then expect matters to get worse.

The human population continues to grow out of all proportion to the ecosystems upon which we depend and within which we and all life on Earth must live. However, just since 1900 our numbers have more than quadrupled, from 1.6 billion to 6.9 billion. We continue to add more than 80 million people to the planet each year, mostly in the world's poorest places.

Our emphasis on economic growth complicates our impact on the environment and ecosystems even further because it means that each of us is consuming more resources each years and our numbers are becoming more numerous. Unless this pattern of economic and demographic is curtailed, we will see more and more species decline in numbers and spatial distributions as we take over their habitats, restrict their ranges, and replace them with our own domesticated species, whose numbers are growing steadily along with our own.
Posted by Gary Peters on 25 Sep 2010

Caribou herds all but vanished in the early part of the last century. Nobody knew why, but suspected overhunting, resource development and warming after the end of the Little Ice Age. These are much the same reasons given for the current declines. But from the 1950s through the 1990s, caribou populations soared--despite global warming and resource development in the North.

While I acknowledge the implications of global warming, and see the unique problems with the Peary caribou, I think what we're actually seeing happening with caribou is largely a natural population cycle. But unlike the short-term cycles of animals like snowshoe hare or sockeye salmon, this caribou cycle takes a century or so to reveal itself. That's far too long a period to be easily recognized by scientists and public, especially if they weren't there to observe the previous crash and recovery. But there's some evidence in historical records of the Arctic that suggest a similar crash happened a century ago..

Caribou largely eat lichen, which is very slow growing. A large population can strip the lichen from huge areas of tundra, causing a food shortage that can last for decades until the lichen can regenerate. The first thing that happens is the caribou start migrating further away from their "normal" routes in search of abundant lichen. Also, their numbers level off or start to decline. Scientists started observing these movements and peaks in numbers in the 1980s-90s. The second thing that happens is all the remaining lichen is stripped, and that leads to widespread population crashes. That is happening now. The low population then allows the lichen to regenerate, which takes several decades, which finally creates a food abundance which leads to rapid population growth.

Now, I don't know whether the Arctic climate in 50 years time will hinder the lichen's recovery or favour shrubs and herbs. But I will say that for now, we are guilty of looking at a short-term trend and pointing the finger at global warming and resource development as the cause of a one-way decline in numbers, without grasping the bigger picture over the long period of time--the real cause.

Folks, it's a cycle.

Posted by pmjwright on 01 Nov 2010

pmjwright, you sir are right! Common sense prevails.

Posted by Tony on 17 Nov 2010

I grew up in Labrador and if find it would have been interesting to talk about the Quebec-Labrador heard as well in this article.

Posted by Éric Cyr on 17 Apr 2011



An Unusually Warm Arctic Year: Sign of Future Climate Turmoil?
This year will almost certainly go down as the warmest on record in the Arctic, with autumn temperatures soaring 36 degrees F above normal. In a Yale e360 interview, climatologist Jennifer Francis explains why a swiftly warming Arctic may have profound effects on global weather.

Full Speed Ahead: Shipping Plans Grow as Arctic Ice Fades
Russia, China, and other nations are stepping up preparations for the day when large numbers of cargo ships will be traversing a once-icebound Arctic Ocean. But with vessels already plying these waters, experts say the time is now to prepare for the inevitable environmental fallout.

As Arctic Ocean Ice Disappears, Global Climate Impacts Intensify
The top of the world is turning from white to blue in summer as the ice that has long covered the north polar seas melts away. This monumental change is triggering a cascade of effects that will amplify global warming and could destabilize the global climate system.

Food Insecurity: Arctic Heat Is Threatening Indigenous Life
Subsistence hunters in the Arctic have long taken to the sea ice to hunt seals, whales, and polar bears. But now, as the ice disappears and soaring temperatures alter the life cycles and abundance of their prey, a growing number of indigenous communities are facing food shortages.

Northern Forests Emerge As the New Global Tinderbox
Rapidly rising temperatures, changes in precipitation, and increased lightning strikes are leading to ever-larger wildfires in the northern forests of Alaska, Canada, and Siberia, with potentially severe ecological consequences.


Donate to Yale Environment 360