The Arctic is changing unnaturally fast, and neither reindeer nor caribou can keep up with it.

Image in public domain.

Santa’s helpers need some help themselves — the magnificent Arctic reindeer numbers are in sharp decline, and the consequences can be devastating for their entire ecosystem. Since the mid-1990s, the size of reindeer and caribou herds has declined by 56%, from an estimated 4.7 million animals to 2.1 million. It’s the lowest number since monitoring began.

“Five herds,” out of 22 monitored “in the Alaska-Canada region, have declined more than 90 percent and show no sign of recovery,” according to the latest Arctic Report Card from the National Oceanic and Atmospheric Administration, out Tuesday. “Some herds have all-time record low populations since reliable record keeping began.”

Reindeer and caribou are the same species: Rangifer tarandus. These animals are known not only for their magnificent antlers, but also for their impressive journeys, in which they travel thousands of miles looking for food. They reshape the vegetation by grazing and are important not only to other animals in the same environment but also to local people, to whom they are a source of food and livelihood.

Normally, the decline of reindeer populations shouldn’t really be surprising — they can fluctuate greatly, researchers say. But this time, it’s different . The losses are simply too high to dismiss as a natural process.

“The fact that these herds are declining shouldn’t be a shock — they do it all the time,” Russell said by phone from the Yukon territory in Canada. “But they’re at such low levels, you start to be concerned. […] If we return in 10 years and [their numbers] have gone down further, that would be unprecedented.”

The reasons for this decline are complex are involve a combination of climate change, hunting, disease, and low food availability — a group of problems which go hand in hand. The final straw, it seems, might be that global warming is causing longer, hotter summers. These warmer summers facilitate the spread of disease and place extra stress on the caribou.

“Warmer summers also have adverse effects through increased drought, flies and parasites, and perhaps heat stress leading to increased susceptibility to pathogens and other stressors,” the report notes.

If we take a step back, what’s happening to these reindeer populations is representative of the large-scale problems faced by most wildlife on Earth. Earth’s wilderness has decreased at an alarming level, with recent reports showing that we’ve wiped out almost all the planet’s wild areas — the average vertebrate population has declined by 60% since 1970.

The Arctic, too, is changing — faster than any other ecosystem — and it’s not clear if the caribou can adapt in time.