Why 200,000 Antelope Dropped Dead in 3 Weeks

By Stephanie Pappas, Live Science Contributor | January 23, 2018 11:01am ET

Credit: Courtesy of the Joint saiga health monitoring team in Kazakhstan (Association for the Conservation of Biodiversity, Kazakhstan, Biosafety Institute, Gvardeskiy RK, Royal Veterinary College, London, UK)

One day in May of 2015, a handful of critically endangered saiga antelope dropped over, dead. This wasn't necessarily alarming to the scientists in the area who were busy monitoring the herd; the saiga antelope (Saiga tatarica tatarica) of the Central Asian steppe are stressed in springtime, which is calving season, and deaths happen every day. But the next day, more antelope died. On day three, they were dropping by the hundreds.

Within three weeks, 200,000 saiga antelope — 62 percent of the world's population — were dead. And now, scientists have learned that the killer was lurking inside the animals all along.

A new study reveals that the ruminants were killed by a bacterium that normally lives in the antelopes' tonsils without causing any problems. But unusually warm, moist weather apparently triggered the overgrowth of the bacteria, Pasteurella multocida, which subsequently found its way into the antelopes' bloodstream and killed them. [Photos: Mass Death of the Saiga Antelope]

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