Saiga antelopes are steppe specialists that experienced one of the most catastrophic wildlife die-offs ever recorded in 2015, when more than 200,000 individuals died within weeks from a normally harmless bacterium that became pathogenic under unusual climatic conditions.
Mass mortality events of this scale cause individual suffering on an enormous scale: saiga calves were found dead beside their mothers across thousands of square kilometres of steppe within days. The rapid systemic nature of Pasteurella septicaemia causes acute fever, respiratory failure, and death within hours of symptom onset. Preventing future events requires continuous environmental monitoring to identify conditions that may trigger Pasteurella pathogenicity shifts, and protected area management that maintains habitat quality and reduces additional stressors such as poaching pressure that leave populations more vulnerable.