In May 2015, the die-off of almost 200,000 saiga antelopes in far-away Kazakhstan captivated the Internet, all the deaths occurring in a period of about three weeks.
Over 200,000 saiga antelopes suddenly died due to what is believed to have been a bacterial infection, and scientists think this was triggered by environmental factors, the BBC reports. Scientists blamed bacteria called Pasteurella multocida type B. But new research suggests the antelope already contained the organism in their bodies, and that unusual heat and humidity released the bacteria, causing them to multiply rapidly in the days leading up to the event. Even without the mass die-off, hunting and habitat loss have depleted its numbers so that the saiga is now a critically endangered species, according to the International Union for Conservation of Nature (IUCN). At first, one or two antelopes would die.
"The fact that P. multocida infection in saigas ... appears strongly linked to high humidity and temperature is of concern going forward, given that a climate change-induced increase in temperature is projected for the region over the short to medium term", the researchers wrote. Dr. Koch, who witnessed the "rapidly accelerating deaths", talked with National Public Radio recently, He said the antelopes showed clear signs of a form of blood poisoning called hemorrhagic septicemia. It normally lives in the antelope's tonsils, but during the event, they quickly spread to the bloodstream, causing the hemorrhaging. "It's so toxic and so devastating that the animal doesn't show a lot of pathology actually, other than the hemorrhage and rapid death", he added. This scene is from a research trip in 2013.
Back in 2015, Kock's multi-disciplinary team used statistical analysis to study the conditions in which the environment was the day after the antelopes died. "And by doing that we could really tease it out and get a significant correlation", says Kock.
"There's theoretically a possibility of extinction of the species entirely", Kock said.
Kock told NPR that the herd has recovered and continue to breed, but if another weather event happens they could be wiped out.
The scientists still don't know precisely how the weather created the bacterial infection, or how it affected the animals in those three different events.
What's more, evidence suggests that animals like reindeer and musk ox face similar risks due to abnormal weather patterns.