Approximately 6 hours after dolphin calves are born, the mothers will begin to nurse their young below the water but close to the surface for at least 4 times each hour for the first 4 to 8 days. Each period lasts anywhere from 5 to 10 seconds, and the mothers will nurse their calves for up to 18 months. The milk is produced at the abdominal mammary gland sites, and the milk contains approximately 33 percent fat, 6.8 percent protein, traces of lactose and 58 percent water.
The mother dolphins will stay close their calves, and the calves will swim with them in their slip stream, which is a hydrodynamic effect that develops as the mother swims in order to ensure that the calves stay close to their side, and close to the pod so that they do not get lost.
The mothers and the calves will typically develop an extremely strong bond, and the calves will generally stay with their mothers for around 3 to 6 years before going out on their own.
At times, other dolphins in the pod will help the mothers with raising their calves. These dolphins are referred to as assisting dolphins and can be either male or female.