"The sperm whale, for example, which has the largest brain on earth, weighing as much as 19 pounds, has been found to live in large, elaborately structured societal groups, or clans, that typically number in the tens of thousands and wander over many thousands of miles of ocean. The whales of a clan are not all related, but within each clan there are smaller, close-knit, matriarchal family units. Young whales are raised within an extended, multitiered network of doting female caregivers, including the mother, aunts and grandmothers, who help in the nurturing of babies and, researchers suspect, in teaching them patterns of movement, hunting techniques and communication skills. "It's like they're living in these massive, multicultural, undersea societies," says Hal Whitehead, a marine biologist at Dalhousie University in Nova Scotia and the world's foremost expert on the sperm whale. "It's sort of strange. Really the closest analogy we have for it would be ourselves."

Whitehead has even discovered distinct clan dialects using different codas, what he describes as a "Morse code-like pattern of clicks" that the whales make with their long head cavities and use to communicate with one another over many miles, reinforcing social bonds and declaring clan affiliation. Whitehead, who has been tracking and recording sperm whales around the globe since the early 1980s, has positively identified five distinct clan dialects and studied two extensively. "The regular clan," he told me in a phone conversation from his lab in Nova Scotia, "makes three to eight equally spaced clicks. And then there are the Plus-One clans. They have two to eight clicks and then a pause and an added click at the end, kind of like the Canadian 'eh.' We've also noticed that these clans ply the water differently. Regular groups move in wiggly tracks closer to shore, while the Plus-Ones swim further from shore in straight lines." ..."

From this remarkable article in the New York Times.