Whether by land or sea, spotted seals have excellent hearing, a new study finds. Scientists had suspected that seals use sound to hunt in dark Arctic waters. But spotted seals (Phoca largha) also spend time above the water, while giving birth or nursing their pups on ice floes. Researchers trained two orphaned spotted seal pups from Alaska—Amak and Tunu—to touch a target with their noses when they heard a tone. By testing a range of frequencies, they found that seals detect seven octaves of sound underwater. But they have surprisingly good hearing in the air as well, researchers reported online yesterday in The Journal of Experimental Biology. The seals hear four octaves, with sensitivity similar to land carnivores, such as cats.  The research is the first step to understanding how human noise in the Arctic from commercial shipping and the use of seismic air guns for undersea oil exploration may be affecting the seals’ sensitive hearing.
ScienceShot: Spotted Seals Have Amphibious Ears