Dolphins give birth to live calves while staying in relatively shallow waters. Normal delivery results in a calves being born tail (or fluke) first.
As marine mammals, dolphins gestate live young and give birth to live calves that are prepared to breathe and swim shortly after birth. Gestation periods vary for different dolphin species; bottlenose dolphins gestate their young for 12 months, while spinner dolphins give birth after 11 months. Typically, dolphins give birth to only one young at a time. According to the University of Utah, a healthy adult female bottlenose dolphin will have one calf every 2 to 4 years. Similarly, spinner dolphins have one calf every two years, according to Texas Tech University.
Many dolphin species engage in mating in summer months; because gestation periods are about a year long, most dolphins are born in the summertime as well. After birth, mothers nurse their young calves. The calves will then swim with their mothers' pods, which are dolphin social groups.
Though mothers may not nurse their young for the entire duration, most dolphin calves will stay with their mothers for 3 to 6 years. Newborn dolphins are relatively small, usually three or four feet long, and they measure 8 to 12 feet once fully grown.