Reindeer on the run in Norway. Photo credit: zetson Running via photopin (license).

It was inevitable, given the timing, that Andrey Petrov’s latest research would get some unusual treatment.

At the Fall Meeting of the American Geophysical Union in San Francisco last week, Petrov presented a report showing that one of the world’s largest reindeer herds is contracting. After reaching a peak population of around a million in 2000, the pack has fallen to around 600,000 in the Taimyr Peninsula, its home territory and one Russia’s northernmost parts.

With Christmas just days away, some websites relayed the news with a tongue-in-cheek approach.

At Gizmodo, the headline was “400,000 Reindeer Vanish in Ongoing War on Christmas.”

LiveScience introduced its piece with “Santa’s Reindeer Feel the Heat as Numbers Shrink Worldwide.” The lead goes on with “Santa Claus better stock up on reindeer, because he may have trouble scrounging up replacements in the not-too-distant future, new research suggests,” before continuing with a serious and thorough report.

The BBC, meanwhile, played it straight.

I’ll admit: the Christmas time peg is one reason I’m also jumping on this study. But there are serious reasons and ramifications for the worldwide reindeer decline.

I wrote about Petrov and his project in 2014, when it received a National Science Foundation grant. Called Arctic-FROST (Arctic Frontiers Of SusTainability: Resources, Societies, Environments and Development in the Changing North), the five-year effort seeks to understand Arctic communities and how they can enhance their development, health and well being while preserving societies and ecosystems.

Reindeer are one of the things the indigenous communities in northern Siberia rely on to survive. Local people hunt them for meat, hides and other needs. Reindeer in Taimyr are “the fundamental element of the subsistence economy,” Petrov told a press conference at the AGU meeting. “That’s why it’s so critical to understand” what’s happening to them.

You can watch his statement in this video, starting at about 17:30.

The Taimyr herd comprises about a quarter of the world’s 2.5 million reindeer and caribou, their North American cousins. According to a slide Petrov showed at the press conference, the herds of both species are shrinking in most areas of their Arctic Circle habitat.

This map of the Arctic shows reindeer and caribou herd status, with red marking regions of declining population. Taimyr is on the right, in northern Russia. Image courtesy of Andrey Petrov.

Soviet game management policies helped keep the Taimyr herd stable for years. In the 1990s, the numbers began to rise, reaching about a million in 2000 before the population “crashed,” Petrov said, falling drastically over the last 16 years.

Russian scientists know this because they’ve monitored the herd since at least 1969, first counting reindeer via aircraft and more recently supplementing that with satellite images. Satellite images also helped Petrov and his colleagues from Russia, Colorado College, the U.S. Fish and Wildlife Service, and the University of California, Santa Barbara, measure the herd’s impact on vegetation. They used radio collars to track its movements.

The record shows reindeer typically go to the same places every year, migrating from winter habitat in the south to summer pasture in the north, where calves are born, and back again.

But over the last 20 years, the researchers have seen “a dramatic shift,” Petrov said, with the herd’s summer habitat moving east and north and into higher elevations.

Historic reindeer migration in the Taimyr Peninsula. Courtesy of Andrey Petrov.

Historic reindeer migration in the Taimyr Peninsula. Courtesy of Andrey Petrov.

The researchers blame the shift on, as you might guess, global climate change. Average temperatures in the region have risen by 1.5 degrees over the last several decades. The herd probably is relocating to find cooler weather and to avoid harassment from mosquitoes, whose numbers also have increased with warmer weather.

The change in summer habitat means the reindeer must travel farther between summer calving grounds and their winter ranges. Calves are more likely to die during the longer treks, especially when crossing open rivers that, in the past, would have been frozen.

The higher temperatures also lead to unstable winter conditions, producing more ice storms and thawing-refreezing episodes that make it difficult for the herd to find ground cover to eat.

The researchers speculated that a decrease in available vegetation, due to overgrazing when the herd size peaked, might have contributed to the population decline. They used satellite images from 2000 to estimate the amount of available plant matter and found that while the herd’s presence reduced the available biomass at their summer grounds, it quickly rebounded after the pack moved on.

“Which tells us maybe wild reindeer are actually managing the territory. There’s no real evidence that in this case there was overgrazing,” Petrov said in the press conference. Some researchers theorize that a million reindeer may be close to its natural size, he said in an email, because much of its growth was attributable to reduced pressure from humans. But since hunting has affected the population since before observations began, it’s unclear what its natural level would be.

Other factors besides climate probably have also cut into reindeer numbers, the researchers said. Human activity and population growth may be blocking migration routes and disturbing and polluting pasture. (The reindeer herd has shrunk the most at the west edge of the Taimyr Peninsula, where human population growth has been strongest.)

The number of predators, like wolves, also has increased. Petrov said he and his colleagues believe this is because the same Soviet wildlife management policies that kept reindeer populations steady also held down wolf numbers. Those policies have largely vanished.

Size of the Taimyr Peninsula reindeer herd over time. Courtesy of Andrey Petrov.

Finally, the very communities that rely on reindeer also may be damaging the herd.

“A big, big number of reindeer are being killed every year for subsistence, and some of my Russian colleagues will tell you that this is the primary cause of decline, along with climatic changes,” Petrov said.

The herd is likely to continue shrinking, Petrov said in an email. “We see negative trends in reindeer demographic composition,” like fewer young reindeer and lower fertility. “So the numerical decline is not the only sign of problems in the population.”

To help preserve the herd, the researchers recommend regulating hunting more closely while giving priority to indigenous people. They also suggest continued monitoring and study “of this unique wild reindeer herd,” Petrov wrote.

Perhaps most importantly, they recommend safeguarding the herd’s pastures. “We know where they’re going to be, most likely,” Petrov said at the AGU meeting, “and we need to make sure to protect those areas – that those areas are not being damaged, either by pollution or by other human activity.”

My take: The study provides another example of global climate change’s negative impact on some of the world’s most vulnerable communities. But as these remotely located, indigenous people have little money or education, their plight is easy for politicians to ignore. More’s the pity.