The highly intelligent and sociable creatures are known to use their own signature whistle to introduce themselves to others.
Now experts have shown that a calf separated from its mother mimics her short, sharp whistle in what is thought to be a way of trying to trigger a reunion. A male will use the same method to try to find its best friend of the same sex.
Researchers at St Andrews University analysed recordings of bottlenose dolphins from Florida which were periodically caught for health checks. During these checks the animals could normally hear, but not see, each other.
Information on captive dolphins at Walt Disney World, also in Florida, was factored in. The data showed that when two close male friends were separated, one would often mimic the whistle of the other.
Source: Daily Mail