Information and Research by Becci Jewell
Dolphins produce “whistles” that are thought to be used for communication. They last for 1 to 2 seconds and it is also thought possible that they are used as social calls, and even used as a individual “name tags” to identify a mother and calf for example.
Some dolphins have whistles that are individually distinctive, and typically made when the dolphin becomes isolated from the group. Another proposed use for signature whistles is to prevent inbreeding. It had been observed that signature whistles of male offspring are often similar to their mothers signature whistle. This could aid recognition of knowing who belongs to your family if you were a dolphin.
Dolphins can actually echolocate and whistle at the same time, which means they can look for food and communicate with other dolphins in the area.