Dolphins reproduce every one to three years, with the gestation period lasting approximately 12 months. Calves are born fully formed and are able to swim alongside their mothers immediately. They leave their mothers between the ages of 3 to 8, staying until they learn how to feed, forage and socialize. Dolphins reach reproductive age between the ages of 5 to 10 and have an average life expectancy of 40 years.
Dolphins have defined home ranges where they rest and feed and spend the majority of the day looking for food. However, they can swim hundreds of miles in a day, traveling back and forth, hunting prey or diving into the depths. They are extremely social creatures, hunting and living in large pods with rigid hierarchies. Large pods are mixed, but dolphins also form three different types of smaller pods: a nuclear pod, with a single male and female; a nursery group, with several females and young; and a bachelor pod, with males.
However, in captivity, dolphins have much shorter life spans, dropping to a half or third of their life span in the wild. Dolphins born into captivity often are unable to form the kind of social relationships they need to thrive, depressing them and causing health problems.