Behavior
Vocalization
Some species, such as the humpback whale, communicate using melodic sounds, known as whale song. These sounds can be extremely loud, depending on the species. Sperm whales have only been heard making clicks, while toothed whales (Odontoceti) use echolocation that can generate about 20,000 watts of sound at 163 decibels and be heard for many miles.Whale vocalization is likely to serve many purposes, including echolocation, mating, and identification.
Reproduction
Males are called 'bulls', females, 'cows' and newborns, 'calves'. Most species do not maintain fixed partnerships and females have several mates each season.
The female delivers usually a single calf tail-first to minimize the risk of drowning. Whale cows nurse by actively squirting milk, so fatty that it has the consistency of toothpaste, into the mouths of their young. Nursing continues for more than a year in many species, and is associated with a strong bond between mother and calf. Reproductive maturity occurs typically at seven to ten years. This mode of reproduction produces few offspring, but increases survival probability.
Male genitals retract into body during swimming, reducing drag and preventing injury.
Socialization
Whales are known to teach, learn, cooperate, scheme, and even grieve.
Sleep
Unlike most animals, whales are conscious breathers. All mammals sleep, but whales cannot afford to become unconscious for long because they may drown. It is thought that only one hemisphere of the whale's brain sleeps at a time, so they rest but are never completely asleep.