Pacific white-sided dolphins do not mate for life. Gestation is about 12 months. The mothers nurse their single calf for about one year. Longevity Longevity varies depending on environmental factors, but may range from 10 to 25 years in the wild. Social Organization Pacific white-sided dolphins are among the most gregarious of all dolphins and may form huge temporary herds of a thousand or more, although groups of a hundred or less are more common.
Herds usually contain individuals of both sexes and all ages.
As predators, Pacific white-sided dolphins control populations of their prey. Because dolphins are small and extremely fast, humans have not directly exploited them. Incidental deaths of nearshore animals occur by drinftnet and gillnet entanglement, pollution and boat traffic. Shedd Aquarium is presently involved in several marine mammal research projects throughout the world.