Transcript for 2 conservationists' quest to save the lions in the wild
Reporter: They are the kings of the jungle. Immortalized in the Disney classic "The lion king." Everything the light touches is our kingdom. We are all connected in the great circle of life. Reporter: And beautifully remastered in the newly-released live action film. Everything you see exists together in a delicate balance. Reporter: But for lions, that delicating real-world balance is under threat. Eric and Beverly have dedicated their lives to lion conservation and in their lifetimes aloin have seen the population drop from 450,000 to 20,000. It's a decline. "The lion king" came out and we've seen a drastic reduction since then. Reporter: The husband-wife team say many aren't aware of the significant loss. When you see lions, you sigh a lot of lions, they cluster. You'll get a pride of lions, there will be 18, 12. People get a sense that there are a lot, but there are not. And if you kill one lion, you're not just killing one, there will be a new male come in, but the new male will kill the cubs. Reporter: While not yet endangered, lions are listed as a vulnerable species, but they say the endanger the designation two be beneficial for the lions' cause. It just makes good common sense that if animals are heading in the direction of extinction you back up before they become extinct. Reporter: They talk about the misunderstanding about the vulnerability. The hunting of big cats sent shockwaves around the globe. In 2015, a legend lion was killed by American dentist Walter palmer on a recreational, big game hunt, launching a firestorm. A warning to our viewers, the image you are about to see might be disturbing to some. Reporter: And last week, that same fire reignited when a trophy-hunting couple posted a picture kissing over a lion they had just slain. Of the 20,000 lions left on the planet, few of them are males, and the males are targeted by trophy hunters. Reporter: And it's not just the poachers that pose a threat. The general encroachment of humans on their territory has been detrimental to their future survival. The goal is to double the lion population, and about 60% have no protection at all. If we can increase the protection we can regrow the population. Reporter: They have been at the forefront of the conservation effort in Africa, producing documentaries. In 2009, starting the big cats initiative, alongside national geographic in the hopes of halting the decline of one of the world's most recognizable and beloved creatures. It's already imperative to get the right messaging. And if they go through the emotional drive we've gone through, they will want to protect them. Reporter: Now they're hoping another film will bring renewed attention to their cause. The re-imagine nation of the 1994 classic has a new star-studded cast, but its powerful themes remain the same. The movie has an incredible spirit. It opens you up. It talks about the struggle of standing up and fighting for what you love. And it takes you on so many emotional rides. Reporter: And now, with a call to action. Disney is partneringith the world's leading lion experts to help defend African wildlife. To double the number of lions in the world by 2050. Reporter: And an opportunity for a new generation to feel an emotional connection to the animal they care so deeply about. Movies are great influences, that's why a film like lion king does so much more. And next, the moon landing
This transcript has been automatically generated and may not be 100% accurate.