When the seals heard the roar of a beta male, they approached aggressively. But when the male heard the call of a male higher in the dominance hierarchy, he turned tail and fled.
That suggested the seal knew the male's identity and that recognizing the call enabled him to decide how to respond.
In a follow-up experiment, the researchers went to a beach about 150 miles (240 kilometers) south and played the same calls to a group of elephant seals that weren't familiar with them.
The males didn't respond at all to the unknown calls. "This was a very anti-climactic field trip for us," Casey said.
That nonresponse suggests the elephant seals use prior knowledge of the pecking order to decide when to pursue or retreat from a fight. The scientists aren't sure whether the seals have to learn through painful personal experience which male is the alpha, or whether they can observe other fights to know when to steer clear, Casey said.
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