Why Did 150,000 Saiga Antelopes Die Within Just a Few Weeks?

In May of this year, more than half of the population of one of the world’s most endangered antelope species died within weeks of each other, apparently without explanation. The Saiga antelope, which resides largely on the plains of Kazakhstan, had their numbers decimated earlier this year when hundreds of thousands of animal carcasses were found.

Scientists are at a loss to explain why the population died off quite so quickly and in such large numbers. Now, extinction poses a tangible threat for the dwindling numbers of these animals.

Science Confounded

Normally, when such a mass decrease in animal population occurs, it is due to the transmittance of a fatal disease. However, leading experts on the topic have concluded that the epidemic occurred too quickly to be caused by a disease.

The last time such a sharp drop-off occurred in the Saiga population as a result of something other than a disease, poaching was identified as the culprit. However, these carcasses display no signs of physical trauma (and the bodies have been recovered), essentially ruling out poaching as the reason.

Furthermore, there are no obvious signs of contamination of the soil with toxins or radiation fallout, or the pesticides which have wreaked havoc on other animal populations around the globe. Meanwhile, malnutrition has also been ruled out as the reason for the drop-off in population.

A Latent Bacteria the Most Probable Cause

According to Professor Richard Kock from the University of London, a latent bacteria already present in the antelope’s system is the most likely factor in their mass death. The bacteria, known as pasteurella, resides in the throat of the antelope and is general harmless. However, an unknown factor may have acted as a catalyst for the bacteria to turn malevolent and cause the deaths of the unfortunate animals within weeks of each other.

Professor Kock believes this is most likely due to an environmental factor. It is true that the temperatures in Kazakhstan plummeted from 30°C to a frosty -5°C in the days leading up to the deaths, but the Saiga are renowned for their ability to withstand both hot and cold temperatures and have endured similar changes in the past.

Another theory has suggested that climate change could be responsible, not only for the Saiga die-off, but for mass extinction of many other animals as well. In addition to the hike in temperatures, the knock-on effect on soil and vegetation in the area could have triggered the pasteurella bacteria into action.

Saiga on the Brink

Whatever the cause, the Saiga antelopes are now staring down the barrel of extinction. Prior to this latest disaster, their worldwide population was estimated at anywhere between 250,000 and 320,000 specimens. With a confirmed figure of 150,000 carcasses already buried – not including calves, which are also thought to be in the hundreds of thousands – and many more bodies not being counted in the tally, the Saiga population has been well and truly decimated by this setback.

Professor Kock is not optimistic about their chances, especially if global warming played a part in the catastrophe. “If climate change is involved, the frequency [of deaths] will increase and if that’s the case then extinction could be inevitable,” he predicted.