Dolphins are known to show signs of curiosity and intelligence, but their sensitive behaviour continues to surprise researchers. A sighting in the Algarve, in 2021, during a field survey by AIMM - Associação para a Investigação do Meio Marinho, indicates that these mammals are also able to exhibit behaviour associated with the mourning process when loved ones die.
According to a new scientific article and cited by CNN Portugal, a group of 50 or 60 bottlenose dolphins were along the coast of Albufeira when researchers noticed that one of the adults showed signs of tension and seemed to be left behind. The researchers found that It was a female interacting with a dead calf, carrying the inanimate body with her head and propelling it several times to the surface.
Subsequent investigation of photographs allowed them to identify the calf as being a male about three weeks old and the female as the probable parent, based on abdominal distension that showed a recent delivery. The corpse was not yet in the process of decomposition, but it had some marks that were probably caused by the mother when transporting it. The researchers refer to having observed this phenomenon for about an hour and conjecture that it continued even after the team left.
A group of dolphins stayed close by, although they did not interact with the calf. According to the report resulting from the observation, the group appeared "calm" - despite the successive interactions of the mother, who repeatedly swam in the direction of several members before returning to the small male, as if in an attempt to capture the attention of the others.
The ability to experience complex emotions - in particular mourning, which requires an understanding of the finitude of death - is generally associated with Humanity and is still "controversial" when applied to non-rational animals, as the scientific article recognises. Still, this type of behaviour "has been particularly associated with intelligent animals such as cetaceans", and the pattern exhibited by the female is "consistent with typical reactions associated with grief in humans" and even other mammals.
Successive attempts to propel the tiny dolphin to the surface could represent an "effort to stimulate it, for the purpose of resuscitation".
The circumstances of death are uncertain, but it is the mother's behaviour that makes this moment so special, the researchers emphasise.
"Although it was a rather sad sighting, it is a behaviour that demonstrates these animals' capacity for feeling", writes AIMM, in a note sent to CNN Portugal. "And for us, colleagues in our area, it is very important to deepen our knowledge about this behaviour."