Show of the week

Planet Earth II

Ten years ago, the BBC’s Planet Earth raised the bar on nature documentaries to dizzying new heights, and the series was rewarded with the largest audiences cable TV had ever recorded. Now, the network’s brilliant Natural History Unit has done it again, assembling hour after hour of close-up high-definition footage that reminds us all of nature’s astonishing fecundity. The always charming David Attenborough, now 90, returns as narrator for the six-part series, which opens with a focus on islands, and how they can intensify the interspecies struggle for survival. Saturday, Feb. 18, at 9 p.m., BBC America

• All listings are Eastern Time. ■