Before Moko the dolphin turned up, the beached whales were in clear distress. But when Moko arrived at Mahia beach on the east coast of New Zealand's North Island, their mood changed and they followed him to safety. The ability of some animals to communicate is well known. What's less well documented, however, is the communication between species. Justin Gregg, vice president of the Dolphin Communication Project, said it is possible that a dolphin and a whale could communicate in some way. "But it wouldn't be instructions like 'Hey, buddy, the open ocean is over here. Follow me,'" he says. Dolphins use three forms of signaling to other dolphins—whistles, clicking and postures. A whale might have signals in common with a dolphin, just as different species of dolphins are known to share signals which might theoretically allow a form of basic inter-species communication. But just as it's possible that Moko the dolphin and the stranded whales shared a signal, it is also possible that the whales just saw a vaguely similar creature and followed it. There are many reasons why different species communicate, says Vincent Janik, lecturer at the Sea Mammal Research Unit at St Andrew's University. "The animals exploit the systems of others for their own benefits. Sometimes the benefits are the same for each, therefore they share information. Sometimes they are trying to take advantage of the other. Getting food may not be to the advantage of the one giving up the food. "