Dolphins Remember Friends’ Whistles For Decades [Study]

A new study suggests that dolphins can remember their friends’ whistles for decades, even if they haven’t seen each other in years.

The research was published on Tuesday in the journal Proceedings of the Royal Society B. In it, researchers suggest that dolphins could have a better long-term memory than humans, at least when it comes to friends and acquaintances.

Until recently, scientists believed that very few animals besides humans had long-term memories, reports Live Science. A few studies have found that monkeys have memories four years or longer.

Reports also suggest elephants remember their kin for up to a decade. But dolphins reunited with their long-lost friends appear to pick up right where they left off — just like us.

Despite the apparent good memory, scientists wanted to know if the animals truly remembered each other, or if they were simply very social creatures.

A recent study already showed that dolphins have their own names, or a specific whistle that is unique to each individual. Using that, NBC News notes that researcher Jason Bruck, a biologist with the University of Chicago, was able to find that dolphins really do remember their old friends.

Bruck played tapes for several dolphins in captivity of their former playmates, including bottlenose dolphins Allie and Bailey. The pair were together when they were four and two, but had been separated for more than 20 years.

But when Bailey heard Allie’s whistle played over a set of speakers, she swam quickly to them and hung around a while to listen in on the sound she remembered from decades before. And considering how much humans change through the years (remember that 20-year high school reunion?), the study suggests bottlenose dolphins have longer social memories than even humans.

With the exception of very young dolphins, all of the animals in Bruck’s study responded to familiar whistles of former playmates when played through a speaker. That included Semo, a 45-year-old dolphin currently the longest living male in captivity. Even he responded to the whistles of friends from years before — well, as long as he wasn’t chasing the four females in his current tank.

While the study shows dolphins can remember each other for years using their unique whistles, Bruck is not sure if they are picturing the individuals in their heads or not. But, he aims to find out.

[Image via ShutterStock]