Names are pretty important to humans, but do dolphins use them too?

 

Scientists have known for some time that dolphins use distinctive signature whistles.

 

Now researchers in Scotland have found that dolphins respond differently to recordings of their personal signatures in the same way that a human students might react hearing their name called out in class. 

 

In experiments with wild bottlenose dolphins off the Scottish coast, scientists recorded their signature whistles, then played them back using a hydrophone (a sort of underwater loud-speaker).

 

The scientists also played back recordings of unfamiliar signature whistles. The dolphins recognised their own signature whistles, and whistled back. When they heard other signature whistles, they didn't react in the same way. 

 

When dolphins hear their signature called, they sometimes simply repeat their signature; a bit like saying “I’m here!” 

 

Others repeat their signature and then add a lot of other whistles, which scientists can still only guess the meaning of.

 

When groups meet, they often announce their presence with their own signature whistle, telling the others they are there.

 

If dolphins recognise their own signature whistles, then they probably know a number of signatures of different individuals as well. That makes scientists wonder if they remember things about each other, and associate those memories with a name. It also suggests that dolphins may be self-aware like humans are.

 

Scientists want to carry out more experiments to see whether signature whistles are really like names. With human infants, scientists can play the name of a familiar person, and then show the baby a photo of that person, or someone else. If the baby matches the face to the name, then they really recognise the name. That kind of experiment may not be so easy with dolphins, who don't rely on 'faces' for recognition.

 

Source: “Bottlenose dolphins can use learned vocal labels to address each other.” By Stephanie L. King and Vincent M. Janik. Proceedings of the National Academy of Sciences, 22 July 2013 as reported in Wired.