Are dolphins self-aware?
Most animals will react to danger by running away, but scientists argue that they are not aware of what they do, and live only in the moment.
Signature whistles, and the mirror test, suggest that dolphins are self-aware, which is a sign of higher intelligence:
Signature whistles: Dolphin's signature whistles suggest that they have a sense of self. Not only that, but they recognise the signature whistles of other dolphins and even use them.
The Mirror test: Human babies between 18 and 24 months old don't realise when they are looking in a mirror; they think they are looking at another child.
Scientists argue that you don't recognise yourself in a mirror until you are aware of yourself as an independent, self-conscious being.
Scientist Ken Marten put a spot on a dolphin called Keola, so that he could only see the spot when looking in a mirror. Keola clearly twisted and maneuvered himself while looking in the mirror in order to see the spot. This behaviour was quite different to how Keola would react to a new member of the group.
Scientist Diana Reiss conducted a similar experiment with mirrors and zinc spots on the backs of dolphins. After the scientists started removing the zinc spots from the backs of the dolphins, they would swim back to the mirror to check that the spot had gone.
The dolphins did not react to their reflection as if they were seeing another dolphin.
It's worth remembering that dolphins do not recognise each by their 'face' and they also use a sort of sonar to 'see', which would not work using a mirror. So dolphins looking in the mirror is all the more remarkable.