Odontocetes

Odontocetes are the toothed whales: a suborder of 71 species that includes Porpoises, river and ocean Dolphins, Beaked whales, Killer whale, and Sperm whale. Their defining contrast with Mysticetes is not merely anatomical. They pursue prey through the ocean, while baleen-feeding whales take food in mouthfuls; the book uses that difference to show how varied cetacean life is, even within the broad category of whales.

Classification and Feeding

The word cetacean derives from the Greek ketos, meaning sea monster, but the book presents cetaceans as a group divided into two clear suborders. Odontocetes feed on fish and squid. Mysticetes, of which at least fourteen species are identified, filter plankton and smaller fish through Baleen. The contrast separates hunters following prey through the water from grazers taking in dense mouthfuls of food.

The distinction is made concrete in the fertile waters of Cape Cod, where Mysticetes are described as dominant. Minke whale, Humpback whale, Right whale, and Fin whale represent different sizes and habits within that local community. Their feeding by filtering contrasts with the odontocetes’ fish-by-fish pursuit, while the Fin whale’s speed and scale underline that the book’s account of whales ranges across strikingly different forms and ways of life.

Sperm Whales and Social Knowledge

Among the odontocetes, Sperm whale society receives particular attention. Hal Whitehead describes culture as information learned through social interaction, and argues that sperm whales use it to adapt to demanding ocean environments. Groups form ocean-wide clans with distinctive patterns of movement and repertoires of clicks. Even genetically similar groups living close to one another may communicate in different dialects.

The clicks are not all alike. Usual clicks, made about twice a second, accompany foraging. Faster sequences called creaks indicate a whale homing in on prey or scanning whales at the surface. Codas—patterns of clicks separated by pauses—may function as conversations, although what information they convey remains unknown. Mature males also make slow clicks or clangs. The account can distinguish these sounds and suggest their functions, but it does not claim to translate them; the gap between identifying communication and understanding its meaning remains central to the book’s treatment of whale intelligence.

Whaling and the Cost of Extraction

The history of whaling bears directly on the Sperm whale. As hunting depleted the species, its pursuit became commercially unviable; the discovery of oil at Titusville in 1859 further marked the decline of the sperm-whale fishery and the beginning of a new form of extraction. Later technology shifted attention toward other whales: Sven Foyn’s patented grenade harpoon helped whalers pursue large, fast rorquals, including Blue whale and Fin whale. The book thus distinguishes the pressure placed on odontocetes such as the Sperm whale from the later industrial assault on those great baleen whales.

The damage, however, is not measured only in animals killed. The book warns that hunting may have fatally disrupted sperm-whale societies by removing matriarchs and the knowledge they carried, as well as large males with whom females mate. The loss of experienced individuals threatens the transmission of learned behaviour between generations, making a population’s social organization part of what commercial killing can destroy.

Extinction and the Limits of Knowledge

The book broadens this warning from sperm whales to cetaceans and the wider natural world. During the writing of the book, one cetacean species was declared extinct; the text also reports an average disappearance of one hundred species of flora and fauna each day and warns that many more could follow. These figures are presented as signs of a crisis already underway, not as evidence that all odontocetes face identical risks.

For the Sperm whale, the future remains uncertain partly because it breeds slowly and may continue to suffer delayed effects from earlier hunting. At the same time, the most detailed scientific study does not close the question of what a whale is. Whitehead cautiously proposes that sperm whales may possess emotions and abstract concepts, perhaps even religion. The suggestion is not a settled finding, but it sharpens the book’s central tension: human beings can classify, track, and exploit odontocetes while still not knowing the full nature of their social lives or minds.