From the depths of the South American jungles to the frozen peaks of Asia, a new BBC nature series co-produced with Chinese partners is now being aired, Xu Fan reports.

On an icy corner of Antarctica, two male elephant seals are violently biting and crashing into one another to compete over the mating rights of the 60 or so females.

For most people, it's such a rarely-seen sight that they would have the chance to encounter at such close quarters.

It's a moment captured by BBC cameramen and featured in the first episode of BBC's latest nature documentary series, Seven Worlds, One Planet, which started broadcasting simultaneously in China and the United Kingdom on Oct 28.

From the depths of the South American jungles to the frozen peaks of Asia, and from the cities of Europe to the vast plains of Africa, the seven-episode documentary features extraordinary scenes of animal behavior and untold stories of wildlife that shape the remarkable diversity of our planet.

More than 1,500 people worked on the project, which assigned four teams to 41 countries, filming for nearly 1,800 days and capturing more than 2,260 hours of footage. The entire documentary spans seven hours.

The Chinese premiere of the documentary-made by the BBC Natural History Unit production team with Tencent Penguin Pictures and China Media Group CCTV 9 as co-producers-was recently held in Beijing. This collaboration helped the BBC cameramen to trek to the mountains of Sichuan province to retrace the footsteps of snub-nosed snow monkeys for the episode about Asia.

Scott Alexander, the series producer who attended the event, says the production marks the first time that BBC has created a natural history series which classifies its episodes by continent-a departure from previous titles that normally divide the natural world by habitat.

"The important thing for any documentary is to make it feel new and surprising. So we spent at least a year researching the wildlife and looking for new stories. As well as this new angle, in the series you'll see new species, new behaviors and new filming techniques," says Alexander.

The development of drone technology-which can now install 4K miniature cameras onto unmanned aerial devices-helped the team to capture some of the most eye-catching scenes.

One scene shows a gentoo penguin swimming at speeds of around 35 kilometers per hour to outrun a pod of orcas in the Antarctic Ocean. Another scene captures 150 great whales feasting on krill off the coast of Elephant Island, the largest group of whales ever caught on film, according to the BBC.

"The drones gave us a lovely, unique view of these areas. Unlike helicopters that are noisy and intrusive, drones are small and quiet. It gave us a top-down view, enabling us to observe the wildlife without disturbing it while holding the shot," Alexander continues.

According to the BBC, the crew trained six team members to operate drones and also recruited a range of freelance pilots. Drones were guided to locations that were virtually impossible for humans to reach, traversing volcanoes and diving into underground caves along the way.

At the same time, high-definition long-range thermal imaging cameras helped the team to reveal the behavior of European wolves at night, and used new telescopic lenses to shoot the flight patterns of wandering albatrosses, one of the world's largest birds.

Other animal behaviors that have never been captured on film before include a jellyfish being caught and eaten by sea anemones in Antarctica, and a puma successfully hunting an adult guanaco in South Africa.

One interesting facet for the audience is the segment at the end of each episode where the cameramen share their approach to the shoots. And while there is always a danger when the camera teams get into close proximity of large animals, an encounter with a troop of baboons left them with their rooms ransacked for food.

But when it comes to safety concerns, Alexander says teasingly: "The most dangerous thing we often do is to take a taxi to the airport. When you step into a taxi, you never know the driver."

He says ahead of every trip, the production teams would meticulously prepare for any eventuality-from researching the animals' habits to taking enough provisions and the right equipment to planning their routes in detail.

Most of the cameramen are also wildlife specialists, who feel "a lot happier out in the remote world than they are in cities", adds Alexander, who graduated from the University of Bristol with a major in zoology.

As a veteran with more than 20 years experience with the BBC Studios Natural History Unit, Alexander also says he is still very excited about finding new stories.

"Filming documentaries is my passion. Hopefully, we can show more people documentaries that spark an interest in them for wildlife," he adds.

And there were also some emotional moments in the documentary. In the first episode about Antarctica, the impact brought about by climate change and its effect on animals in their struggle for survival was highlighted.

But the series also offers hope in how environmental protection efforts are working, exemplified by the protection of whale sharks in Asia and the Iberian lynx in Europe, which was once at the brink of extinction and has seen its population rise from less than 100 to more than 700, thanks to local protection measures.

"Ultimately, we do want to offer people hope," adds Alexander.