Natural World: Cuckoo

Behind the magical call of the cuckoo is a bird that is a cheat, a thief and a killer. Just how does the cuckoo trick other birds into accepting its eggs and raising its young? And why do they work so relentlessly to feed a demanding chick that looks nothing like them and will soon dwarf them? New photography is combined with archive footage and the latest scientific findings to solve a puzzle which, as narrator David Attenborough explains, has perplexed nature-watchers for thousands of years.