What might dolphins be saying with all those clicks and squeaks? Each others’ names, suggests a new study of the so-called signature whistles that dolphins use to identify themselves. Whether the vocalizations should truly be considered names, and whether dolphins call to compatriots in a human-like manner, is contested among scientists, but the results reinforce the possibility. After all, to borrow the argot of animal behavior studies, people often greet friends by copying their individually distinctive vocal signatures. “They use these when they want to reunite with a specific individual,” said biologist Stephanie King of Scotland’s University of St. Andrews. “It’s a friendly, affiliative sign.”