9. Dolphins

Chris Packham explores the success of the most widespread of marine mammals, the dolphin. Contrary to their amiable reputation, they are, in fact, ruthless predators. They hunt using a combination of specialised anatomy and complex communication, requiring a big brain. Chris explains the inner workings of dolphin echolocation, reveals how a pod uses body movements to communicate the location of food and explores the strategies used by orcas during a hunt.