Marine mammals include cetaceans and pinnipeds. Dolphins, whales and porpoises are “cetaceans.” Walruses, sea lions and seals are “pinnipeds”. While they must breathe air like all mammals, marine mammals can stay underwater for up to two hours before surfacing for air. Dolphins and whales breath air through blowholes, while walruses, seals and sea lions breath through their nose and mouth.
Seals have scored better than adult humans at logical reasoning tests. Ringed seals build snow caves above their breathing holes in the ice to protect their young from predators.
Orcas brains are more emotionally developed than those of humans. The limbic system — the layers of interconnecting tissue that processes emotions — have grown elaborately compared to those in the human brain. They have a level of social culture that rivals humans.
Dolphin brains are larger and, in some ways, more complex than human brains. Dolphins have been taught to speak human words. Their own language allows them to trace other dolphins up to six miles away. They even have names for one another. They have such significant brain power it stops them from sleeping. They use tools and pass their knowledge through a family line. They reason, problem-solve and comprehend ideas. They use nonlinear math formulas when catching prey. They blow bubbles that vary in exact amplitudes to detect fish, then subtract values found with their echolocation to confirm the target. They follow ships to collect fish churned up their wake, and ride bow-waves like human surfers. They play catch, tag and other games with each other, and also enjoy playing with other animals. Dolphins swim onto the nose of humpback whales, who then raise themselves out of the water so the dolphins slide down their heads – both animals enjoy the game. Dolphins form complex social groups. They plan ahead. They crave physical attention and stroke each other with their flippers.
Dolphins and whales communicate with a variety of low sounds that humans cannot hear. They also use echolocation – sending sounds through water to bounce off objects to determine their shape, size and distance.