The Mystery of the Disappearing Elephant-Seal Dialects

A northern elephant seal needs to remember the calls of his rivals. An encounter between two males, fighting to control female harems, can be bloody—skin marked by an opponent’s canines, chunks torn from the trunklike nose, wounds on the chest shield. Such battles are rather rare only because less violent cues are often enough to deter an adversary.

Vocal displays are fundamental in these ritualized confrontations, and each male in the population has his own unique call that serves as an ID. “You can think of them as drumbeats,” says Caroline Casey, a researcher at the University of California at Santa Cruz. If a male can remember and recognize the vocal signature—characterized by this drumming rhythm—of those he has previously confronted, he can avoid energy loss in the best scenario, and death in the worst.

In the late and his colleagues couldn’t help but notice that the threat calls of males at some sites sounded different from those of males at other sites. “It was just so obvious. It would be like me distinguishing a dialect from people who live in Alabama as opposed to people who live around Boston,” recalls Le Boeuf, who has studied the marine mammals ever since and is affiliated with UC Santa Cruz.