A horrified TV crew working on Planet Earth II saw 150,000 antelope killed off by disease in just three days as they filmed at calving grounds.
Fans of the David Attenborough series will see scenes featuring the Saiga Antelope of Kazakhstan in Central Asia on Sunday.
But Chadden Hunter, producer of the Grasslands episode, told how he thought he was witnessing the “extinction of the species” as the animals started to die.
He said: “When we were out there in the calving grounds, with hundreds of thousands of females all giving birth at the same time, a very ­virulent disease swept through the population and killed around 150,000 of them in a matter of three days.
“At the time we thought we were watching the greatest natural catastrophe that I’d ever heard of. We watched 150,000 of these magnificent animals die in front of us.
“At the time we didn’t know if it was the …