Say that, in 1993, you were at a bar having some beers with a dolphin. Say that the dolphin said, "I've got the tab," and you said, "Okay, thanks -- I've got the next one." Say that you proceeded to forget about that promise, and that -- not because you didn't like the dolphin, or anything, just because life got in the way -- you never saw the dolphin again. Now say that, this morning, you ran into the dolphin, at the bank or in a tank or in the pool of some terrible resort in the Bahamas.
Here's the awkward thing: The dolphin may well remember you. And maybe the debt, too.
Yep. Dolphins, it turns out, have the longest social memories of any species besides humans. And we're learning more and more about how lengthy those memories can actually be. The researcher Jason Bruck, a biologist at the University of Chicago, wanted to test whether bottlenose dolphins in particular can, indeed, remember each other after a long stretch of separation.
So he took advantage of something else about dolphins: the fact that they seem to have something like names. Sometime between their first 4 months and their first year of life, dolphins will develop a distinct whistle -- one that will remain the same for the rest of its life. According to research published last month in the Proceedings of the National Academy of Sciences, dolphins use these whistles in pretty much the same way we humans use names: as ways both to identify themselves and to call each other.