Best known as the media mogul who founded CNN, Ted Turner is also a conservationist, dedicated to restoring native wildlife in the United States. CNN
Turner owns 16 ranches in the United States, and three in Argentina. They cover a total of almost 2 million acres, making him the second-biggest landowner in North America. CNN/Beau Molloy
Each ranch is a refuge for native species, especially his beloved bison. Turner says that aged 10, he read about how the North American bison had come close to extinction. "I decided then that I would do what I could to help bring the bison back and preserve them," he said.
More than 50,000 bison now roam the Turner ranches. It's thought to be the biggest private herd in the world. CNN/Bryan Kane
His ranches operate on the principles of "eco-capitalism" -- the idea of using the free market to promote sustainability. The bison reared on Turner's ranches are sold for meat, some of it through his "Ted's Montana Grill" chain of restaurants. CNN/Bryan Kane
At the start of the 20th century, only 1,000 bison remained in the United States -- even fewer by some counts. The species has made a remarkable recovery and there are now up to 500,000 bison in the US, mostly in private herds. CNN/Beau Molloy
He has also helped conserve other important native animals, including the black-footed ferret and the prairie dog.
"Prairie dogs are considered pests by a lot of people because they eat grass and they eat a lot of it," says Turner. "But I feel like the prairie dogs are entitled to some. I'm willing to share my grass with the prairie dogs and the bison." JULIAN STRATENSCHULTE/DPA/AFP/Getty Images
One of North America's largest Gray Wolf packs lives on Turner's Flying D ranch, in Montana. Courtesy: Turner Endangered Species Fund
For Turner, reintroducing bison is also about restoring his ranch land to its former glory. Research has shown that bison can improve biodiversity in prairie ecosystems. CNN/Beau Molloy
Given enough land to roam, bison grazing patterns can support the return of many native plant species. CNN/Beau Molloy
Turner has founded a number of conservation organizations, including the Turner Endangered Species Fund (TESF). It says it has contributed towards helping 36 specific native imperiled species in the US.
He also founded the Captain Planet Foundation, which has directly funded 1.6 million children to develop projects to improve their local environment -- including tree planting, clean ups and recycling programs. TBS/Captain Planet Foundation
The back deck of Turner's house at his Flying D Ranch. Now aged 80, this 113,000-acre ranch is where family say he feels most at home, among the bison, elk, antelopes, wolves, bears, and eagles. CNN/Beau Molloy