Researchers from St Andrews found that bottlenose dolphins use unique whistles to address each other. In other words, they use signature whistles like “names”. The study is another proof that marine mammals have sophisticated cognitive abilities like self-recognition and a sense of identity. User grosbigranou, in the Everything Science subreddit, 09 Sep 2021
TIL: Bottlenose Dolphins are the only discovered non-human mammals that have names for one another in their own natural communication system. User 3slyfox, in the Today I Learned (TIL) subreddit, 12 Jul 2019
TIL that the bottlenose dolphins can use learned vocal labels to address each other. AKA knowing each other by names! User lexypax, in the Today I Learned (TIL) subreddit, 15 Oct 2013
TIL that dolphins are so advanced that they actually call each other by name User a1c4pwn, in the Today I Learned (TIL) subreddit, 24 Jul 2013