From Wolf of Wall Street to American Wolf. From the story of a broker to the life of a Yellowstone wolf. Leonardo DiCaprio steps out of his role as an actor and into that of producer to tell, through an investigative film, the story of 832F, a female wolf (Canis lupus) welcomed into Yellowstone park and quickly becoming a favourite of hikers and researchers alike.

Her fame stemmed from her charisma: 832F was an alpha female and led a large pack — an unusual occurrence among wolf packs, which are typically led by a male. The animal, nicknamed 0-Six after her birth year of 2006, faced a harsh winter in December 2012 that turned the park into a frozen wasteland; prey was scarce, but her cubs needed food. She made a decision: to leave the park's protected area and venture outside, into an alien and hostile world. There, the wolf was shot dead by a hunter, a year after the US Environmental Protection Agency had decided to remove wolves from the list of endangered species.

The wolf's death deeply affected the media and public opinion in the United States; the New York Times even ran an obituary for the animal. DiCaprio, through his production company Appian Way Productions, has acquired the rights to the book of the same name written by Nate Blakeslee, a staff writer at Texas Monthly.

The American actor thus reaffirms his love and concern for the environment and animals. The Hollywood star has taken many initiatives in defence of the planet: last year, for example, he donated three million dollars to WWF for the protection of tigers in Nepal. Just days ago, DiCaprio was appointed "messenger of peace" by the United Nations with the aim of raising global awareness of climate change.