He starts his search by observing an Arctic fox in its minus 20 Celsius environment, and explains that warm-bloodedness is one of the key reasons for the mammals' domination.
In following episodes, Sir David looks at insect-eating animals and other diets (like hedgehogs' preference for fruit, and how bats in New Zealand forage by walking on their wrists), and uses the latest surveillance technology to observe the feeding habits of herbivores, such as elephants and sloths (who takes a month to digest each meal).
Rodents, leopards, tigers, lions, porpoises, dolphins, blue whales, apes and monkeys, and even humans are all featured, making The Life Of Mammals is the ultimate study of warm-blooded species ever made.
One iconic moment involves Sir David Attenborough's ascent into the canopy of a tropical rainforest. Using a catapult to fire a fishing line over a sturdy branch, a rope and pulley counterbalance was then used to act as a climbing aid. The finished sequence shows a 70-odd year old Attenborough proving he still has adventure coursing through his veins.
With each episode focusing on the evolution and behaviour of certain groups of mammals, The Life of Mammals displays the variety shown by one of nature's most successful groups.