Saiga antelopes almost wiped out 6 years ago, then there was a baby boom
Pastruela killed 90% of the species in 2015. Scientists have 2 theories. One, the bacteria, already in the animal (it exists in healthy Saigas at least sometimes, scientists have found), is triggered to grow by something and it kills them. Two, there is an amoeba in the environment that is infected by the bacteria, and then in the wet season the bacteria becomes active, and meanwhile it is somehow consumed when the antelopes grazes.
Saiga populations recover quickly, though. Females at age 1 have one calf. Older females have twins, and the most mature, larger females can have 3.
The current population is estimated at 250,000, just like before the endemic on the Kazakh steppe. People in 2015 worried they might become extinct.
They are now returning to the same grazing ground, though. Experts have little doubt the same plight will affect them again.
They also face a possible new highway through their migration ground, which would connect the Caspian Sea (at Aktau) and the Nur-Sultan (the capital city).