"But beneath the harmony lies a darker side of dolphins. Gangs of strong males pick on younger or smaller dolphins. Bottlenose dolphins are even known to kill for reasons other than hunger.

Cinematographer Paul Atkins, diving in the Bahamas with wild dolphins, heard the first sign of trouble before a particularly intense fight. “Jaw clapping” is a bone-chilling, audible threat to those around. The encounter that ensued–including head ramming, biting, and blows from powerful flukes–is surprisingly violent.

In another hemisphere, Dr. Richard Connor, studying dolphins in Shark Bay in Western Australia, has documented cases of males kidnapping and holding females captive, sometimes for months at a time. “Dolphins are complex, intelligent, social animals and that carries with it a range of behaviors from the nice to the not-so-nice. Just like in our own species.”

Dr. Connor is especially intrigued by relationships between the males. To him it’s like cracking the code of a secret society. These alliances can last for a dozen years or more. The strategy is designed to keep females from mating with other males so that the alliance will have the most offspring."

Nobody can explain why dolphins display aggressive behavior, particularly against their own young; though there are mutterings about some ”evolutionary“ reason for it, it appears to be irrational, serving no survival purpose. Unlike most mammals, dolphins don’t eat what they kill (though they do eat squid and fish for nourishment). They seem to be driven by what Samuel Taylor Coleridge called ”motiveless malignity,“ battering smaller creatures, smashing their skulls and vertebrae, and biting them to death for the fun of it.