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Common Name:
Beluga
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Belugas are exclusively northern hemisphere species and inhabit fjords, estuaries, and shallow water in Artic and Subartic oceans. They are also known to migrate up rivers in the summer months, although reasons for this are not certain. |
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Mass: 500 to 1500 kg Belugas are a white-colored whale with a fusiform body shape and a large melon on the head. This melon is thought by some to focus echolocation tones, although this is in question. The melon can also be used as an indicator of health (poorly nourished belugas have low flat melons while well fed individuals have round melons) and of emotional state--agressive individuals raise their melons forward. The tail is strongly forked. There are no dorsal fins. Thirty-eight spoon shaped teeth are present. Males are larger than females. |
Belugas eat a wide variety of prey, more diverse than most cetaceans. Many fish species, such as herring, cod, and salmon, as well as invertebrates such as octopus, squid, crab, and snails are taken. In addition, stomachs of belugas have been found to contain bottom-dwelling organisms. Echolocation is thought to aid in the search for food. Feeding dives last from 3 to 5 minutes, although one individual was seen to remain underwater for 20 minutes and dove to a depth of 647 meters. |
One young per birth is the rule for belugas. Calving occurs between April and September. Females give birth every 2-3 years. Gestation lasts about one year and the young are 70 kg. at birth. When born, young are a dark brown or black, reach a blue stage between one and two years, and then have a lighter yellow phase until they reach sexual maturity when the white color typical of this species is achieved. Young are weaned in 1.5-2 years. |
Most parts of the year, belugas live in social units of about 10 individuals led by a single large male. During migration or periods of great food abundance, groups of up to 10,000 belugas have been reported. Wintering sites can be either north or south of summering sites, and either closer to or farther from shore. Prey distribution and pack ice are two factors in determining seasonal movements. Belugas can swim up to 22 km/hr. |
Belugas have
been hunted for centuries for a variety of products. More recently, it
has been harvested by the commercial fishing industry.
The fishing industry often views belugas as competitors, and play killer whale vocalizations underwater to keep belugas from their nets. Current populations are estimated at about 60,000 individuals. Populations have been seriously overhunted and extirpated in many regions. Recovery of many populations is hindered by human activities such as river diversion or harbor contruction. Beluga fertility in some areas is low due to chemical pollution. |