The beluga whale (Delphinapterus leucas) inhabits areas centered on the Arctic Ocean and appears widely from sea-ice regions to near estuaries. Males measure about 3.1–5.2 m, females are somewhat smaller. They are characterized by a flexible neck and a dorsal ridge in place of a dorsal fin. They feed on fish, cephalopods, crustaceans, and other prey. Groups vary widely in size from a few individuals to several thousand. They have a rich repertoire of vocalizations and are called “sea canaries,” producing distinctive squeaks involved in individual recognition. Reproduction begins in spring with births in summer; gestation lasts about 12–15 months. Population numbers are relatively large and assessed as Least Concern, but climate change and hunting can pose threats.