Sir David Attenborough returns to screens tomorrow with gripping scenes of a mother puma fighting a bigger male to save her four cubs.
His Dynasties II shows Rupestre brawling with Carnasa, who wants to mate with her and will kill her cubs first.
She keeps him at bay by goading him into a fight as daughters Coiron, Dania and Daneska plus son Neneo, make a run for it.
Over the tense footage shot in the foothills of the Andes in Patagonia. Sir David Attenborough says simply: “She will die to protect her cubs.”
The heart-in-mouth scenes are just one of the many challenges facing Rupestre as she struggles to bring up her big litter alone, hunting endlessly for the large llama-like creatures guanaco.
Her hunts result in failure nine times out of ten because guanaco are so big - and one kick to the head can be fatal.
Producer Mary Melville, who followed the family over two years, said filming the fight with Carnasa was “very distressing”.
She explained: “He just came out of nowhere. From where we were standing, he looks a lot bigger than her and it all happened so fast. Obviously when we watched it back, we were like, oh no, she gave as good as she got.
“But when it was happening in the moment, it was really scary. We were really worried for her. And we knew that if she got really badly injured, then the cubs wouldn’t be able to make it.”
She added: “I had a level of panic.”
At the end of the hour-long BBC1 film, the producer is shown on location spending the entire night searching for Rupestre, who is searching for her scattered cubs following the fight.
Melville doesn’t mind admitting she felt emotional because Carnasa had also followed the cubs.
“You are there to do a job and we’ve got to find her. But in the back of your mind, you’re thinking through all the worst case scenarios. I think that always brings the emotions to the fore.
“When we started filming, I’d never seen a puma. And now I know a group of pumas by name. It blows my mind.”
Melville said that intervening to try and help Rupestre was out of the question.
“We do get to know these animals really well. We get really emotionally attached to them because we’ve obviously spent so much time with them. But, in most situations, intervening at all would be counterproductive.
“There’s just nothing we can do. We have to watch these processes unfold, especially the way that these guys have to live. They have a really tough life the whole time.”
Carnasa is not the only puma Rupestre has to see off - she also tussles with one-eyed puma Blinker, a fellow female who wants to take over territory for herself. Their battle is ongoing throughout the two-years,
Even though females fighting over territory is rare, and the BBC crew were the first to film this behaviour.
Series producer Simon Blakeney said that if Rupestre perished during filming, they would have just ploughed on with the story.
“When we describe making these shows, we do sometimes talk about it as putting all of our eggs in one basket. We don’t know what’s going to happen.
“And we’ve had situations on the last series where some of the key characters did have really serious things happen to them. Some of them died. And it’s just something we have to follow.”
Rupestre’s triumph over adversity story is particularly inspiring because she also faces an enormous battle with the elements - the area has regular winds of 100mph and it covered in snow for many months of the year.
The series also tells the stories of other feuding families from the animal kingdom, covering elephants, cheetah and hyena.
*Dynasties II, Sunday, 8pm, BBC1