Discover strange facts about marine mammals: whales, dolphins, seals, sea lions, walruses, manatees, and sea otters, the warm-blooded giants of the ocean.

Explore the world of marine mammals from blue whales and orcas to dolphins, seals, and narwhals. Expert-written guide covering biology, behavior, deep-diving adaptations, echolocation, and the conservation threats facing ocean-dwelling mammals.

Orcas hunt great white sharks and blue whales. Expert guide to the killer whale's intelligence, cultural diversity, hunting tactics, and why they have no natural predators.

Complete guide to the common bottlenose dolphin: size, habitat, diet, cognition, echolocation, signature whistles, unihemispheric sleep, and the strange facts that make Tursiops truncatus one of the most intelligent animals on Earth.

Everything about the orca: size, ecotypes, diet, hunting, social structure, intelligence, lifespan, conservation, and the strange facts that make Orcinus orca the ocean's apex predator.

Everything about the walrus: size, tusks, whiskers, piston-suction feeding, Arctic habitat, mass haul-outs, subspecies, lifespan, conservation, and the strange facts that make Odobenus rosmarus the most recognisable pinniped on Earth.

Everything about the narwhal: the spiraled tusk, Arctic habitat, deep diving behaviour, echolocation, sensory biology, medieval unicorn horn trade, lifespan, conservation, and the strange facts that make Monodon monoceros the unicorn of the sea.

Everything about the Weddell seal: the southernmost-breeding mammal on Earth, the pinniped dive champion at 600 metres and 80 minutes underwater, an underwater singer with 34 distinct call types, and the Antarctic fast-ice specialist named after James Weddell.

Everything about the leopard seal: size, habitat, diet, hunting, vocalisations, the Paul Nicklen encounter, and the strange facts that make Hydrurga leptonyx the apex predator of Antarctic waters after the orca.