Study Reveals Dolphins Super Long Memory

While we may all be familiar with the idea that elephants are the members of the animal kingdom with the longest memory apart from humans, a new study conducted with information regarding captive dolphins in both the United States and Bermuda has revealed that it is, in fact, those sea mammals that have the longest non-human memories – especially where social interaction is concerned.

Headed up by University of Chicago researcher Jason Bruck, the study took a look at information that dates back more than 40 years pertaining to 56 dolphins that have lived in six different unnatural environments in the two countries. The focus of the study was to better understand the social interaction that takes place between the animals, with a particularly hard look at what role memory plays in helping them to remember friends, allies, playmates, and adversaries.

While the study touched on several aspects of interaction between the animals, the main question that those behind the study wanted to answer was that of just how long two dolphins could remember each other after being separated. To achieve this, researchers identified dolphins who had lived together at some point in the past; as the logistics of reintroducing them from faraway locations were overwhelming, they instead played recordings of the lost friends’ signature whistles to each dolphin, measuring their reactions in order to determine whether or not memory allowed for familiarity.

Surprisingly, even to those who are well aware of dolphins’ proficiency at recall, some of the animals remembered lost playmates from many years ago, speeding towards the source of the recorded whistle playfully in order to interact without hesitation.

Allie and Bailey

The study uses the example of two dolphins in particular to highlight their findings. The animals, named Allie and Bailey, lived together in captivity in the Florida keys more than 20 years ago, when they were very young, before being separated when Bailey was transported to Bermuda. When researchers played Allie a recording of Bailey’s signature whistle, she responded immediately, despite the long gap since the time that she had last heard that whistle under natural circumstances.

As a control, researchers would intersperse the playing of Bailey’s call with that of other dolphins, both those familiar and unfamiliar to Allie, allowing them to better gauge and judge her reactions.

Researchers’ Conclusions

While their propensity for long social memories isn’t exactly a surprise to those who have worked with dolphins, the length of time and speed of recall demonstrated in this study are both astounding, highlighting just how capable the sea mammals are of establishing lifelong relationships, both within family units and with complete strangers. Combined with other recent studies that indicate that the signature whistles in question may function as “names” in the dolphin social spectrum, there obviously remains much to be learned about our intelligent cousins.

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Category: All, Environment