A group of Rhesus macaques making their way across Jaipur, India. Pic/ Fredi Devas, Copyright BBC

Not very long ago, renowned Australian wildlife biologist and filmmaker Dr Chadden Hunter and his crew were in Kazakstan to film the critically endangered Saiga antelopes for a documentary. The team, he recalls, went deep into the middle of nowhere, driving for days before they could see the calving herds. Little did they realise that they were about to witness one of the "biggest biological tragedies" of their lives. While the shoot was on, a virulent, mysterious disease swept through the population and killed around 1,50,000 of them in just three days. "That was the most upsetting thing I have ever seen in nature," Hunter says, during a telephonic chat from the UK. "We feared that we were watching the entire extinction of the species." Fortunately, this story did have a happy ending. The fragile, yet incredibly resilient animals bounced back the following year, Hunter tells us.