Flying high above the dry, sweeping plains of southern Sudan, Paul Elkan is a man on a mission.
The director of the region's Wildlife Conservation Society, he is tasked with surveying a wilderness that has been off-limits to international researchers for the best part of 30 years.
"It's one of the last wilderness areas in Africa, one of the last great wilderness areas in the world," Elkan told CNN. "You have a very large savannah ecosystem that is adjacent to the largest wetland in Africa. So there are a lot of superlatives here in southern Sudan."
For many years, conservationists feared the distinctive wildlife documented by researchers in southern Sudan before the conflict had been hunted to extinction.
But recent surveys in the region have revealed that not only did many animals survive, they are thriving.
CNN filmed exclusive footage in Sudan of the wildlife that inhabits a wilderness largely unseen by the world before now
Elkan told us of the euphoria when and his colleagues rediscovered large numbers of elephants.
"We were ecstatic and moved, really. People were saying elephants were finished in southern Sudan, so initially it's people cheering and yelling in the plane. A bunch of scientists, normally very focused people everyone just whooping and hollering - can you believe there's elephants here?
"Then you get your composure back and start taking your photographs to count them. We came across 150 elephants, there were people writing articles saying there are no more elephants in so Sudan, so hey, what about these 150? We saw a big bull elephant, and you know it's a celebrity elephant, a survivor of 25 years of civil war."
Both sides in the war killed elephants for meat and for their ivory but several thousand escaped the tanks and bullets and disappeared into the vast expanses of bush.
And it's not just elephants -- the region boasts the largest savannah in Africa, immense fresh water wetlands, soaring plateaus and a million-strong antelope migration.
Not all animals survived as well as the elephants and antelope. Thirty years ago the area was thickly populated with wildlife including 30,000 zebra. Now, they have counted just seven.
Elkan can see the day southern Sudan is mentioned alongside the Serengeti, the Masai Mara, Kruger National Park. The Wildlife Conservation Society is working with the Government of Southern Sudan to try and secure key wild spaces. The U.S. Government, through USAID, provides substantial funding to the project, but the task ahead is immense.
"It could be just as significant as the Serengeti," said Elkan. "In many ways it's more special because it's more isolated. You have species here which are found nowhere else in Africa and nowhere else in the world."
"I certainly think it can be viable wildlife area. If you're looking for revenue, there's a lot of oil in southern Sudan, so tourism doesn't need to generate all the wealth."
But viable tourism could be at least a decade away, admits Elkan. And, in peace, animals face more immediate threats.
Southern Sudan has 80 percent of Sudan's oil and oil companies are moving into the upper White Nile areas to explore drilling options. Logging companies want to exploit the teak forests. Road construction and water diversion projects are under way.
Human encroachment could be the greatest threat. Nomadic tribes are pushing into wildlife areas, bringing with them cattle -- which compete for limited grazing areas and water -- in the past they used bows and arrows to hunt --now, they have automatic weapons.
Nyanyo, a Murle herdsman toting an AK-47 puts the conflict in stark terms, "I have a question for you: You say we must not kill the wildlife because otherwise they will be finished. Now I have to slaughter one of my cows. So in a few years I will have no cows. So you want me to kill all my cows and have nothing?"
To protect the wildlife zones, fighters from the civil war are being turned into rangers tasked with protecting the land and stopping poachers. They are being set up in remote outposts with radio communication. Often, they are the only law-enforcement in the area for miles.
But they are usually outmanned and outgunned, and for the people here -- among the poorest in the world -- protecting wildlife comes a distant second to survival.
"When I was young I was used to eating meat from wildlife but now people give me conditions," says Nyanyo, "If you kill animals we find you, we take your gun, with which I'm also defending my life. It looks like you want to finish me."
The conservationists argue that without the wildlife they will have nothing. Elkan says that the Southern Sudan has a brief window of opportunity to come up with a strategy for conserving the land and, ultimately, helping the people.
"They will be much more poor if they don't have a wildlife resource base. The poorest people in the world are those who live in environmentally degraded places."