saiga antelope drinking

The saiga is perhaps most recognizable for its unique, elephant-like nose. (Photo: Saiga Conservation Alliance)

The saiga antelope, an ice age relic, once roamed alongside woolly mammoths and saber-toothed tigers. Today, the population of this ancient species is in collapse. In just a 15-year period, their numbers have dropped by 95 percent, which represents the sharpest collapse for a mammal species ever recorded. Poaching and habitat loss are historically the main culprits, but over the last several years a new scourge has arrived: a mysterious disease that has wiped out more than 120,000 saiga in a matter of weeks, nearly half of the remaining worldwide population, reports Nature.

It's difficult to comprehend the loss that this species has suffered in such a short time. "Apocalyptic" is not too strong a word.

“I’m flustered looking for words here,” Joel Berger, a senior scientist at the Wildlife Conservation Society, told the New York Times. “To lose 120,000 animals in two or three weeks is a phenomenal thing.”

So what could cause such a mass die-off? Scientists still aren't entirely sure, but there are some clues. Here's what they do know: Autopsies of dead saigas have revealed that they were infected with two species of bacteria, Pasteurella and Clostridium, and that these infections contributed to their deaths. But this knowledge hardly solves the mystery because these bacteria are present in most healthy antelope too. In other words, it's likely that some other unknown ailment is crippling their immune systems, allowing the bacterial infections to take hold.

Scientists are also considering whether the cause is from something other than viral or bacterial pathogens. For instance, Central Asia has experienced heavy chemical pollution over the decades from factories and farms. Climate change could also be at fault. Heavier than normal rainfall has led to lush plant growth in the region, and saigas are known to overeat, become bloated and get sick. But so far these are mere speculations.

Whatever this disease is, it strikes with alarming quickness. Animals typically die within hours of developing symptoms, which include depression, diarrhea and frothing at the mouth. The only good news is that the mass die-off appears to be over, as few new deaths have occurred since the initial collapse. But unless scientists can identify exactly what is killing the antelope, there could be no stopping another catastrophe.

One reason for optimism is that the saiga is a resilient animal, and the species has survived population collapses in the past. Though not as severe as the recent die-off, similar events also occurred in 1984, 2010 and 2012, and the species was able to recover. Part of the reason the saiga is so well-adapted to such population collapses is that the animals have a high reproductive rate. They regularly produce triplets and have the highest fetal biomass of any mammal.

Still, it's a long uphill climb for a species that has been so utterly decimated in such a short period of time, and there are heavy hearts for the conservationists who have worked so diligently to protect this beautiful antelope.

The fossil record reveals that the prehistoric range of the saiga stretched from the United Kingdom to Alaska, though today their range is limited to pockets in Kazakhstan, Mongolia, Russia, Turkmenistan and Uzbekistan. The species is most recognizable for unusual noses, which look roughly like rudimentary elephant trunks. Though the noses look goofy, they represent remarkable adaptations. They act as filters, protecting the animals from breathing in rising dust from the dry ground in summer, and warming the air during the cold of winter. 

“It’s a remarkable structure, really,” said Dr. Kühl-Stenzel, a saiga expert, to the New York Times. “In the rutting season, the male’s nose swells even more, and then they shake their heads and it makes a squishy sound.”

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