Like humans, dolphins, and a few other animals, North Atlantic right whales (Eubalaena glacialis) have distinctive voices. The usually docile cetaceans utter about half a dozen different calls, but the way in which each one does so is unique. To find out just how unique, researchers from Syracuse University in New York analyzed the “upcalls” of 13 whales whose vocalizations had been collected from suction cup sensors attached to their backs. An upcall is a contact vocalization that lasts about 1 to 2 seconds and rises in frequency, sounding somewhat like a deep-throated cow’s moo. Researchers think the whales use the calls to announce themselves and to “touch base” with others of their kind, they explained in a poster presented today at the Meeting of the Acoustical Society of America in Pittsburgh, Pennsylvania. After analyzing the duration and harmonic frequency of these upcalls, as well as the rate at which the frequencies changed, the scientists found that they could distinguish the voices of each of the 13 whales. They think their discovery will provide a new tool for tracking and monitoring the critically endangered whales, which number about 450 and range primarily from Florida to Newfoundland.