Here’s why 60 percent of the world’s saiga antelopes were wiped out in 2015

In May 2015, researchers in central Kazakhstan witnessed something really strange: thousands of saiga antelopes began acting a bit weird, becoming unbalanced, and then just plopping on the ground within a few hours — dead. Over the course of just three weeks, more than 200,000 saigas died, or about 60 percent of the global population.

“I had never seen anything like it,” says Richard Kock, a wildlife veterinarian and professor at the Royal Veterinary College in the UK. “It was very concerning because it was so unnatural, outside of the realm of my experience.”

The saiga antelopes were later found to be infected with a bacterium that causes blood poisoning and internal bleeding, or hemorrhagic septicemia. Now, a new study shows that unusually wet and hot weather played a key role in causing the outbreak. How exactly that happened, though, remains a bit of a mystery.

Researchers analyzed historical data related to other mass die-offs of saigas from the 1980s, and found that when the outbreaks occurred, it was warmer and more humid than normal, according to a new study published today in Science Advances. That doesn’t bode well for the future of this critically endangered species. A warmer world could make such outbreaks more likely, and if that happens, the saiga antelopes could go extinct.

Saiga antelopes, whose bulbous noses recall the tauntaun creatures in Star Wars, live in the grasslands of central Asia, from Hungary all the way across Mongolia. They’ve been around for thousands of years, since the time of the mammoths, but they’re now at risk of disappearing because of hunting and habitat loss. “Extinctions took out other animals, but the saiga persisted through modern time,” says Kock, one of the authors of the study. With thick furs and unusual noses that warm up cold air before it gets to the lungs, the animals are highly adapted to extreme environments, and being able to survive harsh winters.