Requiem for a Dolphin

Dolphins are social animals, living in pods and engaging in what seems to be fairly sophisticated communication. It's likely that such behaviour is part of the reason for their success, with well over 30 species spread across the world's oceans... and that's excluding porpoises, and some other "dolphin-like" animals outside the dolphin family proper.

Sociability involves a number of different traits and behaviours, but one that's known to exist in cetaceans and relatively little else, other than primates, is what's technically known as epimeletic behaviour. This is, in essence, the act of helping other members of your species when they are in trouble, typically due to an injury of some kind. (For what it's worth, this compares with etepimeletic behaviour, which is acting in such a way as to make it easier for others to care for you).

Whales in Mourning

Dolphins are social animals

Mammals are by no means the only animals to give their young extended parental care, but it is a feature associated with them more than with most other animals (birds being an obvious exception). This is, in part, due to the fact that young mammals require milk to survive, and that the production of milk is one of the key defining features of mammals. The complex social lives of some mammal species, and the long maturation required for the development of features such as high intelligence are also relevant, and it's no surprise that humans have just about the longest period of juvenile development of any animal - and require significant parental care for a large part of that.

Parental care naturally involves things such as suckling the young, protecting them from predators, and so forth, and it can also include helping them to survive injury. Without the advent of first aid, this may often be ineffective, but it has been observed in a number of species. It becomes particularly dramatic - and, from a human perspective, distressing - when it is apparent that the juvenile is already dead. Here, there is no possible benefit to the young, and likely at least some apparent detriment to the mother in wasted effort, if nothing else.