Scientists since Darwin have wondered why animals like these perform cooperative behaviors that may be detrimental to their own evolutionary fitness. One key to understanding such altruistic ...

The benefit of an altruistic behavior is ultimately measured in its effect on an animal’s lifetime reproductive success. Evolutionary biologists and animal behaviorists have sought to identify ...

Description and analysis This study sheds light on the enduring question of whether altruistic behaviours exist in animal societies by capturing rare and notoriously difficult-to-observe events.