The Saiga Antelope
Saiga antelopes used to have widespread populations throughout the northern hemisphere. Today’s saiga antelope populations are mainly isolated to Kalmykia and Kazakhstan.
In May of 2015, the already endangered saiga antelopes faced huge die-offs, killing half of their populations in a few months.
This picture shows one heard that died off
The die-offs have now ended but the cause of the deaths is still unknown, many speculate that a bacterial disease was at fault.
Here's a link to a cute baby saiga antelope video