Transcript for Jouberts Film 'The Last Lions'
They sit atop the food chain but human encroachment has managed to drive lions in the wild. To the edge of extinction. For the most part their ordeal is invisible but tonight we -- -- extraordinary couple who have devoted their lives to documenting. The lions majestic struggle by filming them day after day and week after week. The results of breath take. Here's -- Cohen bill -- Storm is building for the planes Botswana. -- -- -- a single mother threats. Her name is -- -- and it's been weeks since invading pride mortally wounded her remains. After ending his long rain we'll try to wipe out -- -- -- by hunting moderates house columns. She now has the most primal of decisions flights or flights. Decision complicated by the crock infested water surrounds. College to -- travel fast established being stalked. The big invading males and that same -- rival lioness from the fateful night. Fight that gave her signature wound in the name silver. The last lines include some of the most incredible wildlife footage ever -- But equally fascinating is a love story the audience never -- The one behind the camera. They are Derek and Beverly -- -- Filmmakers big -- protectors and partners in every conceivable way. Sometimes -- jumps into the plane to get supplies. Folks that -- to -- from the occupied attempt. Occasionally Beverly will cook for guests in her -- kitchen. But almost every day for almost thirty years these high school sweethearts have been alone together. In the wild. The longest period without seeing anybody at all was certainly concerned -- says. And then we needed to do yeah. -- should do a film on. Marriage. I don't know a lot of couples they could live out here for 270 days. Since her stay together. Well maybe that's the odds that you see you do have to Jane you have to have -- -- time without advise you around -- A lifetime ago that left bustling South Africa in search of adventure became smitten with the big cats. And never went back and -- each dog they load up their four wheel drive office got a hold your breath as we've got -- And take that swampy commutes across the park event at delta and they had -- monitor lizards around the -- -- Take a left at the adorable baby elephant because he's so back into -- he could -- painful -- And Begin looking for the clues that will lead us alliance very often they kill them. Bob -- into the throat but you know and in here. And -- -- -- through to block orf. The veins during and after the brain after decades out here every bird -- -- meaning every moving shadow makes sense. -- -- -- -- I -- for the month couldn't it. And they -- the quiet patients needed to capture sequence like this. Money sour on the run from Silverado and the others swims for safety to -- follow -- the littlest one hesitates. Which is exactly what the hungry crocodiles hoping for. Considering the pure brutality of this place seems unlikely we'll ever find the stars -- last lions but wouldn't you know it's the first cat we see. -- -- -- The movie on the street yeah. And just around the bed right next to a big key cuddle while. Is -- out dozing in the sun he can't help but marvel at the sound of their breath sighs. Chasing cape buffalo through water makes the most muscular lines in Africa and to the show bears -- -- sold. -- I think too often people see non says he said her -- -- -- We hear they benefit they -- have struggled through some sort of a working mother. Different. Every story its Olympic image that captures an effort to create a global uproar because these are quite literally the last lines. Lose your bears were born there were 450000. Of them and Africa now they say -- -- twenty. And each year other countries and Africa sell 600 lion hunting permits. The vast majority. To Americans rethink -- of these these long lines were reached in. -- ten or fifteen -- that's really. You know hunting. Has been part of the human condition for thousands of years. Do you think we can -- and eliminated entirely. When it comes to species like this there's always going to be somebody is gonna pay a lot of money -- -- alliance. So that's the key and in species like this we have to we have to contain those urges that we have. You know during not to shoot from a parked -- and -- should -- managers here were -- you do that. That's a completely different from recession shift in the -- -- the -- thousand and civilians -- dramatic. We have to ten safari hunting into this -- that this shooting taking a camera and CNN sports -- captain. Because if we tenant the images that we have -- can it be enough of this species to have children. Now he's there to -- That's with a conscious and the system that -- -- Brady and beyond as we started exploring and we realized that who wouldn't be able to do with kids. And so -- cannot -- as a selfless decision but actually eccentric scientist I think we've been able to duplicate lives. To what we truly believe in what -- compassionate in. Homes as we see that the kind of phone or the animals in Africa we -- to -- Taunton. This game with Tampa. -- -- -- -- To have an extraordinary. And so forward -- can't. What gorgeous animals big cat -- begins this Sunday on Nat geo wild.
This transcript has been automatically generated and may not be 100% accurate.