I know that dolphins have names for each other. Nat Geo News article that summarizes it. Basically, each dolphin seems to have a unique whistle that acts as an identifier, a name—they’ll introduce themselves to new dolphins by whistling it, and will respond to it when called. (I believe this is true for all dolphin species, including orcas.) Apparently at least one species of parrot, does, too. Cornell University Chronicle article. I know that other species, I’m thinking like penguins or seals, don’t have names per se, but parents and children will call for each other, and can recognize each other’s voices in the din…. I guess it’s kind of like when kids at a playground shout “Mom!” “Dad!” (especially if the parents were to shout “Child!” back). I’m interested to see what other people know about this. I’m sure those aren’t the other two other species with some sort of name use, I just don’t know of any others myself.