Beluga whales inhabit the Arctic and subarctic regions of Russia, Greenland, and North America. Some populations are strongly migratory, moving north in the spring and south in the fall as the ice forms in the Arctic. As the ice breaks up in the spring, the whales move north again feeding near river mouths and offshore. There are a few isolated populations that do not migrate in the spring, including those in the Cook Inlet, Alaska and the St. Lawrence estuary in Canada. Beluga whales are not considered an endangered species however some stocks are faring better than others
Belugas are born dark gray. They turn white as they mature sometimes taking 3-8 years to reach their adult coloration. Adult beluga whales can grow up to 16 feet (4.9 meters) long. Females are generally smaller than males. Belugas have large melons and very short snouts. Interestingly enough, unlike other cetaceans, beluga whales also have the ability to move their head independent of their body. Beluga whales do not have dorsal fins. Dorsal fins would be a major hindrance during the winter when they live in the loose pack ice of the Arctic. A dorsal fin would cause extra heat loss when Arctic animals, such as belugas, need to to conserve heat. They do have a tough dorsal ridge which, along with their head, can be used to break ice for breathing holes.
Beluga whales have well-developed, acute senses. They can hear a vast range of sounds and have excellent vision in and out of water. Belugas may have some sense of taste, but they do not have the brain receptors or olfactory structures for the sense of smell. Beluga whales are diverse eaters, with more than 100 prey species identified including salmon, capelin, herring, shrimp, Arctic cod, flounder, and even crab. They feed in both open water (pelagic) or on the bottom (benthic) and in shallow and deepwater habitats. Beluga whales are thought to live for 35-50 years. Beluga whales are prey to killer whales and polar bears. They can also die when entrapped by ice.
NOAA National Oceanic and Atmospheric Administration