Offering up another remarkable nature series, presenter David Attenborough considers the quest for survival faced by mammals the globe over, and how they must adjust and adapt to a changing biosphere. Cutting-edge camerawork captures how nocturnal creatures thrive and how increasing number of species are foregoing a daylight existence, to how they function in both forests and aquatic environments, to how they contend with climes of extreme heat and extreme cold. 6 episodes on 2 discs. 6 hrs. Widescreen; Soundtrack: English.