Beluga - White whale
The beluga (Norwegian: hvithval; Greenlandic: Qilalugaq qaqortaq; Faroese: Hvítfiskur; Icelandic: Mjaldur) or white whale, is a medium-sized toothed whale that belongs to the family Monodontidae. The only other member of this family is the narwhal. The English name “beluga” comes from the Russian word belukha, which means “white”. Beluga whales have stout bodies, flexible necks and a disproportionately small head with a well defined beak and a prominent forehead bulge or "melon". They have short but broad paddle-shaped flippers, no dorsal fin, a narrow ridged back and a broad tail fluke with a deeply notched centre. The name “delphinapterus”, meaning “dolphin-without-a-wing” reflects the absence of a dorsal fin. Adult beluga whales grow to lengths of 3-5 m, and can weigh up to 1,500 kg. Males grow slightly larger than females. Newborns are brown or slate-grey in colour and average 1.6 m in length and 78 kg in weight. They become bluish-grey as they mature, then progressively lighten in colour, fading to white after 6 years of age. Most females mature sexually while still light grey, while males become white before maturing. Older males have a marked upward curve at the tip of their flippers.
Beluga mate in the early spring, and calving occurs a little over a year later. Calving for beluga in the Canadian High Arctic population occurs mainly during early July to early August, although calves have been reported there as early as May 31, and as early as late March off west Greenland (Koski et al. 2002).
Distribution and stock definition
Beluga whales have a discontinuous circumpolar distribution, and in general occur only in seasonally ice-covered parts of Arctic and sub-Arctic seas (Fig. 1). Some isolated populations, however, extend into subarctic regions as far south as the St. Lawrence River in Canada. Throughout their range belugas inhabit cold Arctic waters, living amongst pack ice, in leads and polynyas in winter and migrating to shallow bays and estuaries of large northern rivers in the summer. Their seasonal movements depend on both oceanographic conditions (primarily the dynamics of ice cover) and the distribution of their primary prey species (Boltunov and Belikov 2002). Belugas usually travel in pods of 2 to 10 whales, although larger pods are not uncommon. Females with young are found in calm shallow waters along reef edges, close to islands and in large bays. These areas have a warm surface temperature and sand, gravel or mud bottoms that support molluscs, crustacea and bottom fish. Adults and weaned young prefer areas where the water depth varies, where surface temperatures are cold, and where there are reef bottoms of sand and gravel or deep bottoms of sandy mud and coarse material.
|Beluga - White whale|