Over the last 30 years, Dereck and Beverly Joubert have made more than 25 wildlife films, amassing awards and accolades for their conservation documentaries about African animals, most recently the big cat films "Eye of the Leopard," "The Last Lion" and "Game of Lions." With their latest effort, "Soul of the Elephant," they revisit the subject of four of their early films, one in danger of disappearing due to ivory poaching. Premiering Oct. 14 on PBS "Nature," the film is an intimate look at the lives of the endangered giants.

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"We're losing 30,000 elephants each year — that's five an hour," Dereck Joubert said in an interview at the Jackson Hole Wildlife Film Festival, where the film was shown as part of the Elephant Conservation Summit to enthusiastic response. "We got a standing ovation and there were tears in the audience," said Beverly Joubert. "This is a tough audience because these are our peers, and acknowledgement of the craft is very gratifying — like the family has accepted this work," her husband added.

The Botswana-based filmmakers — he films while she records sound and takes still photographs — have attended all 12 of the biennial festival's editions, winning multiple awards including a Lifetime Achievement Award in 2013. "It's become an intersection point for serious conservation discussion as well as how filmmakers can make a difference. It's a meeting place of concerned, like-minded individuals and important conversation," Dereck said.

He pointed out that in light of the overwhelming onslaught of dire statistics, "we sometimes forget what we will be losing" if elephants disappear. "We wanted to do a film about the soul of the elephant, the soul we will lose if this slaughter keeps going."

A couple of years ago, the Jouberts stumbled upon the skulls of two bull elephants with their tusks intact, which meant they weren't killed but died of natural causes. Intrigued by the mystery of their deaths, the filmmakers spent the next two years following elephants in the area to try to reconstruct the deceased pachyderms' lives. Part of the journey included a 2-and-half-month canoe trip on a river in the Selinda Reserve in Botswana, home to more than 7,000 elephants (over one-third of the world's wild population), which allowed them to film elephant behavior up close.

"We probably shot 120 hours of footage. You can do a film on lions with much less, but with elephants you have to wait and wait for something to happen," explained Dereck. That meant adjusting their own pace and expectations. "We had to take on their energy," added Beverly. "They taught us to zone in and be more meditative and reflective and live a more peaceful existence with them. Looking at their nature, their personalities, you understand they are so much like us and we are so much like them, the compassion and the altruism and I think that’s what drew us in."

Dereck Joubert photographs elephants in BotswanaDereck Joubert photographs elephants in Botswana. The filming for 'Soul of the Elephant' had plenty of dangers for the Jouberts. (Photo: Beverly Joubert/Wildlife Films)

The trip was not without dangers. "We got on the river with all our gear, with no protection at all," said Beverly. "As we started the adventure we were nervous that something would topple us over, like canoeing into a hippo or that an elephant would approach us with aggression. In the early part of the film where we were at places that elephants had been poached and hunted, those elephants were angry and whenever they saw us they came charging at high speed. There's one scene in the film where a bull elephant comes right up to the canoe. Of course my heart was pounding like crazy, but we had to remain calm."

"We were on the river so they didn't associate us with humans or even mammals. So we kept still and quiet to exude confidence and fake them out," added Dereck. Other elephants ran away, clearly fearful of humans. It's easy to see why. A scene showing elephants inspecting the remains of dead relatives or friends with their tusks ripped away, and appearing to mourn over them, indicates their emotional and intellectual capacity.

"They can come up to a fallen companion with a bullet in the head and thoroughly and intuitively understand what that means," Dereck said. "I have no doubt at all that elephants are at least as intelligent as an adolescent human being. They're incredibly smart. They have knowledge and wisdom about their own culture and societies that are far more advanced than we think."

Although hunting is illegal in Botswana — thanks in large part to the Jouberts lobbying for the ban on behalf of lions, leopards and elephants — poaching continues in other African countries. "Ivory is collected as a status symbol, kept on mantelpieces and carved and revered, there’s some religious connotations as well. A large component is banking on extinction — people hoping that the animals will disappear and the value will increase," explained Dereck. He's encouraged by the U.S.-China agreement to ban the trade of ivory, but thinks all existing ivory should be destroyed so it loses its value as currency.

Rhinos are also victims of poaching for their horns, with one animal being killed every 7-and-half hours in South Africa. The Jouberts are raising funds to airlift 100 rhinos to safety in Botswana. "We've moved 10 and have another 15 in captivity. The good news is of the 10, one of the females just had a calf," said Beverly, noting that a film about the project is in the works, with a projected release in 2017. They'd like to do more films about big cats in the future, and in their role as National Geographic Explorers-in-Residence, they're planning a film about cheetahs for Nat Geo Wild's annual Big Cat Week in 2017.

The Jouberts embrace in a field of elephantsThe Jouberts share a moment in a field of elephants. (Photo: Val Joubert/Wildlife Films)

"We've always been fascinated by tigers but have never had the opportunity to work in India," said Derek, lamenting that there are so many endangered species, and so little time to spread the conservation message. "Rhinos will be extinct by 2020 if we don't do something about it. There are 20,000 left. Lions are at 20,000 and we're losing five of them a day. We're worried about those numbers, too. We hope there's a changing tide, and we're encouraged by a new generation of young people who are putting their foot down and saying no to hunting. But there's no limit to our capacity as a species to be greedy and corrupt so we have to be watchdogs."

The Jouberts' passion for life, the planet and each other is evident. "We've been together all our lives, and we're just passionate about everything, from dancing to going into the bush," said Dereck. In addition to their films, they've published 11 wildlife books, including several for children, and they're encouraged by letters from young people eager to follow in their footsteps and help conserve species. "We never had kids but now we get the chance to inspire young people," said Beverly, who met Dereck in high school and has no regrets about not having children of her own. "If we had had kids we wouldn't have been able to achieve what we have," she said. "The films are our children."