Topic: Beluga or white whale
Published: 04.03.2020 Updated: 09.03.2020
There are large differences in summer and winter habitats of belugas, in particular regarding ice cover. The species has one fairly well-known distribution in the summer, and a different and more poorly known distribution in the winter. During the winter, belugas move out from the ice-covered coastal waters and feed pelagic along the edge of the pack ice. But when summer arrives, the belugas return faithfully to the same summer habitat year after year. The species is therefore divided into 22 management units according to their summer habitats. This site fidelity to their summer habitats has made belugas a reliable food source for Arctic people dependent on harvesting marine mammals for subsistence. However, this site fidelity has made local populations of beluga vulnerable to overexploitation. Many local populations are therefore severely depleted.
The beluga calves are born with a greyish-brown colour and they become gradually lighter with age. When 14 to 18 years of age, all individuals are creamy white. The name beluga is from a Russian word for white colour. The belugas shed their outer skin annually. During the moult they rub the skin against the sea floor, preferably on sites with coarse gravel. Belugas are lacking a dorsal fin, assumed to be an adaptation to a life under the ice. Another characteristic of the beluga is the flexible cervical vertebras and a hint to a neck. The beluga was one of the first species to be captured for public display in dolphinaria, and the flexible neck made them able to be trained to nod affirmative to certain signals from the trainer.
The belugas are very ‘talkative’. They can produce about fifty different sounds or signals in the frequency range of 0.1 to 12 kHz. Due to the strong site fidelity to summer habitats, we also anticipate that different ‘dialects’ occur.
Females become sexually mature between eight and thirteen years of age, males somewhat older. Females give birth to one calf in early summer and the lactation period lasts for up to two years. The interval between births is three years or more. The global population is assumed to exceed 200,000 individuals, and the International Union for Nature Conservation, IUCN, has classified the species as Least Concern.