Eavesdropping

MIT/WHOI graduate student Ari Shapiro takes a break from listening to the vocalizations of narwhals. His computer screen shows a spectrogram—a plot of sound frequency versus time— of one of the Shapiro and colleagues found evidence that narwhals produce certain vocal signatures to help them recognize and reunite with family members nearby and at a distance. (Photo by Tom Kleindinst, Woods Hole Oceanographic Institution)