The Beluga Whale, or White Whale, is an Arctic and sub-Arctic cetacean. It is one of two members of the family Monodontidae, along with the narwhal and the only member of the genus Delphinapterus. This marine mammal is commonly referred to simply as the beluga or sea canary due to its high-pitched twitter. Using the term «white whale» to refer to belugas is, in the strictest sense, erroneous as the term whale is usually applied to the Mysticeti (baleen whales) and not to toothed cetaceans which belong to the suborder Odontoceti, which also includes dolphins and porpoises.
From a conservation perspective, the beluga was placed on the International Union for Conservation of Nature’s Red List in 2008 as being "near threatened"; however the subpopulation from the Cook Inlet in Alaska is considered Critically Endangered and is under the protection of the United States' Endangered Species Act. Of seven Canadian beluga populations, two are listed as endangered, inhabiting eastern Hudson Bay, and Ungava Bay.
Belugas are one of the cetaceans that are most commonly kept in captivity in aquaria and wild life parks in North America, Europe and Asia, they are popular with the public due to their colour and expressivity.
Its body is round, particularly when well fed, and tapers less smoothly to the head than the tail. The sudden tapering to the base of its neck gives it the appearance of shoulders, unique among cetaceans. The tailfin grows and becomes increasingly and ornately curved as the animal ages. The flippers are broad and short—making them almost square-shaped.
These cetaceans are highly sociable and they regularly form small groups, or pods, that may contain between two and 25 individuals, with an average of ten members. Pods tend to be unstable, meaning that individuals tend to move from pod to pod. Radio tracking has shown that belugas can start out in one pod and within a few days be hundreds of miles away from that pod. These pods contain animals of both sexes, and are led by a dominant male. There can be many hundreds and even thousands of individuals present when the pods join together in river estuaries during the summer. This can represent a significant proportion of the total population and it is the time when they are most vulnerable to being hunted.
They are cooperative animals and they frequently hunt in coordinated groups. The animals in a pod are very sociable and they often chase each other as if they are playing or fighting and they often rub up against each other.
Belugas play an important role in the structure and function of marine resources in the Arctic Ocean as they are the most abundant toothed whales in the region. They are opportunistic feeders as their feeding habits depend on their location and the season. For example, when they are in the Beaufort Sea they mainly eat Artic cod (Boreogadus saida) and the stomachs of belugas caught near Greenland were found to contain Rose fish (Sebastes marinus), Greenland halibut (Reinhardtius hippoglossoides) and Northern shrimp (Pandalus borealis), while in Alaska their staple diet is Pacific salmon (Oncorhynchus kisutch). In general the diet of these cetaceans consists mainly of fish; apart from those previously mentioned, other fish they feed on include: capelin (Mallotus villosus), smelt, sole, flounder, herring, sculpin and other types of salmon. They also consume a great quantity of invertebrates, apart from shrimp, such as squid, crabs, clams, octopus, sea snails, bristle worms and other deep sea species.
Belugas exploit a varied range of habitats, they are most commonly seen in shallow waters close to the coast but they have also been reported to live for extended periods in deeper water where they feed and give birth to their young.
In coastal areas they can be found in coves, fjords, canals, bays and shallow waters in the Arctic Ocean that are continuously lit by sunlight. They are also often seen during the Summer in river estuaries, where the feed, socialise and give birth to young. These waters usually have a temperature of between 8 and 10 ℃. The mudflats of Cook Inlet in Alaska are a popular location for these animals to spend the first few months of summer. In the eastern Beaufort Sea female belugas with their young and immature males prefer the open waters close to dry land; the adult males live in waters covered by ice near to the Canadian Arctic Archipelago, while the younger males and females with slightly older young can be found nearer to the ice shelf. It is generally agreed that the use of different habitats in summer reflects differences in feeding habits, risk from predators and reproduction factors for each of the subpopulations.