David Attenborough series on the natural history of the polar regions; Attenborough appeared on screen and authored the final episode, in addition to performing voiceover duties. Attenborough introduced and narrated the Unit's first 4K production "Life Story." For "Planet Earth II" (2016), Attenborough returned as narrator and presenter, with the main theme music composed by Hans Zimmer. In October 2014, the corporation announced a trio of new one-off Attenborough documentaries as part of a raft of new natural history programmes. "Attenborough's Paradise Birds" and "Attenborough's Big Birds" was shown on BBC Two and "Waking Giants", which follows the discovery of giant dinosaur
David Attenborough the BBC to consider a follow-up, and five years later, "The Living Planet" was screened. This time, Attenborough built his series around the theme of ecology, the adaptations of living things to their environment. It was another critical and commercial success, generating huge international sales for the BBC. In 1990, "The Trials of Life" completed the original Life trilogy, looking at animal behaviour through the different stages of life. The series drew strong reactions from the viewing public for its sequences of killer whales hunting sea lions on a Patagonian beach and chimpanzees hunting and violently killing a colobus monkey.