Male elephant seals compete fiercely for access to females during the breeding season, and their violent, bloody fights take a toll on both winners and losers. These battles are relatively rare, however, and a new study shows that the males avoid costly fights by learning the distinctive vocal calls of their rivals. When they recognize the call of another male, they know whether to attack or flee depending on the challenger's dominance status.

Source: Male elephant seals use 'voice recognition' to identify rivals