Broadcast 15 January 2003, this episode concentrates on marine dwellers. Astride an elephant, Attenborough highlights their love of water, before moving on to those that are completely at home in it. In proportion to their size, sea otters probably have the biggest appetites of any mammal, and Attenborough swims with them off the Californian coast. Their adaptations include webbed feet, which in one way or another (as flippers) are common to all sea-going mammals. Sea lions are shown leading their young into the water for the first time, and navigating entangling beds of kelp. In Antarctica, the differences between true seals and sea lions are illustrated: the former don't have the external ears or the mobility on land of the latter. Meanwhile, in the Arctic, ringed seal pups are prey to polar bears. Other pinnipeds shown include hooded seals and harbour seals. The manatee is a grazer descended from land-living herbivores and spends its entire life in the water. Near south-eastern America, there live dolphins that specialise in synchronically 'herding' fish on to the river banks before feeding. With the aid of computer animation, Attenborough walks the length of a blue whale — the largest creature on the planet — to demonstrate its vast physiology, and then travels alongside one in the open ocean. Whale song, and particularly that of humpback whales, is examined. The tumultuous breeding habits of southern right whales are shown off the shores of Patagonia.
The Life of Mammals is a BBC nature documentary series written and presented by David Attenborough, first transmitted in the UK from 20 November 2002. A study of the evolution and habits of the various mammal species, it was the fourth of Attenborough's specialised surveys following his major trilogy that began with Life on Earth. Each of the ten episodes looks at one (or several closely related) mammal groups and discusses the different facets of their day-to-day existence. All the programmes are of 50 minutes' duration except the last, which extends to 59 minutes. The series was produced in conjunction with the Discovery Channel. The executive producer was Mike Salisbury and the music was composed by Dan Jones and Ben Salisbury. It was later shown on Animal Planet. Part of David Attenborough's 'Life' series, it was preceded by The Life of Birds (1998), and followed by Life in the Undergrowth (2005). However, in between the former and this series, David Attenborough presented State of the Planet (2000) and narrated The Blue Planet (2001).