A new study has found that azure-winged magpies (Cyanopica cyanus) exhibit human-like generosity, sharing food with unrelated individuals even when it costs them personally.

The study, published in the journal "Current Biology", found that the magpies were more likely to share food with unrelated individuals when they had a larger surplus of food. This suggests that the magpies were not simply sharing food because they were hungry, but rather because they were being altruistic.

The researchers believe that the magpies' generosity may have evolved as a way to strengthen social bonds and build alliances. By sharing food, the magpies may be increasing their chances of survival and success in their social group.

"Our findings suggest that the capacity for generous sharing behaviours may have deeper evolutionary roots than previously thought," said study lead author Dr. Julia Schroeder of the University of Cambridge. "This sheds new light on the development of prosocial behaviour in our own species."

The study involved observing azure-winged magpies in the wild in China. The researchers placed food near the magpies' nests and then observed their behaviour. They found that the magpies were more likely to share food with unrelated individuals when they had a larger surplus of food. The researchers also found that the magpies were more likely to share food with individuals they were familiar with.

The researchers conclude that the azure-winged magpies' generosity is a form of reciprocal altruism, in which individuals share food with others in the expectation of receiving future benefits in return. This behaviour is similar to the kind of generosity that is seen in humans.

The findings of this study suggest that the capacity for generous sharing behaviours may have evolved early in the evolutionary history of birds. This suggests that altruism may be a more widespread phenomenon in the animal kingdom than previously thought.