The Sino-UK documentary Earth: One Amazing Day features 38 wild species from 22 countries. [Photo provided to China Daily]

"China has an amazing biodiversity. The topic of endangered species in the country is also important," says Fan.

The film's Mandarin version is being narrated by Hong Kong action hero Jackie Chan. Chinese-American novelist Yan Geling has added local flavor to the script.

Chan, who voices a wildlife documentary for the first time in his career spanning four decades, says he worked for hours on it, and almost "performed animal roles" during recording sessions.

In a scene where a penguin trips on a rock after an exhausting journey to hunt fish, Chan says he added an "whoops" that was not written in the script he was reading.

"He became very engaged with it personally and emotionally," Nightingale says of the Chinese actor.

"The funniest moment is the dancing bear. When Jackie first saw the footage, he started dancing … He comes across (in) the movie like your favorite uncle who is telling an amazing story about the natural world," says Stephen McDonogh, another producer.