Documentary. "Subtitles are a function of the disc and serve the same purpose as closed captions. Described video (for the visually impaired) is available as a secondary audio track." Originally produced as an episode of the television series: Nature. Program content: ©2019. "Based on the book 'The Serengeti rules' by Sean B. Carroll." Widescreen (16x9) Special features: Otters and orcas : an Alaskan mystery -- Bob Paine tribute -- Jim Estes portrait -- John Terborgh portrait -- Mary Power portrait -- Tony Sinclair portrait. TV Parental Guidelines rating: TV-14 (parents strongly cautioned; this program contains some material that many parents would find unsuitable for children under 14 years of age). Editor, Benedict Jackson ; director of photography, Tim Cragg ; music composer, Ty Unwin. Narrator, Campbell Scott ; commentator, Bob Paine, Matthiesen McCrae, Jim Estes, Jaime Excell, John Terborgh, Jonathan Newport, Mary Power, Ashlyn Lopez, Samantha Nugent, Tony Sinclair, Greg Kriek. English dialogue; English subtitles, descriptive video for the visually impaired.