Quite possibly the ocean’s most expressive cetaceans, beluga whales get their nickname, the “sea canaries”, from their extraordinary propensity for vocalisation. Their extensive range of sounds includes whistles and squeaks, chirps and tweets, and more melodious, bell-like noises.
Name etymology and distribution
The name “beluga” is derived from the Russian word for white, for these charming whales inhabit the frozen waters of the Arctic and its adjoining seas. They also venture into estuaries and rivers – slightly warmer, sheltered waters where they typically calve and mate – though their migratory patterns vary between populations.
Gestation period and life expectancy
With a gestation period of up to 15 months, belugas typically give birth to one calf every three years. Calves are just over a metre long and grey in colour, becoming a little darker after the first month or so. The calf will nurse for up to 20 months, and will reach sexual maturity at between four and nine years of age, by which point it will have lost its darker, juvenile colouring. Studies on belugas’ life expectancies have given different estimates, from 30 to 80 years.
Belugas are highly social cetaceans, forming pods of up to 20 whales that are led by a dominant male. Pods are “unstable” and individuals may move between pods. These whales are playful and affectionate, often seeking physical contact, rubbing against each other, and playing with bubbles or objects they may find.
Diet and predators
These are not the fastest of cetaceans, but are adapted for manoeuvrability, with flexible necks, and short, powerful tails. Spending most of their time just below the surface, and under or around pack ice and ice floes, belugas are prey to polar bears and orcas. Belugas themselves have a varied diet that includes various species of fish, molluscs, and crustaceans. They can dive for up to 20 minutes at a time in search of food, and have been recorded diving to more than 800 metres.
On IUCN’s Red List, beluga whales are listed as Near Threatened, though some sub-populations are Endangered and one sub-population in Alaska is currently listed as Critically Endangered. They have an estimated total population of around 150,000.
Belugas face a number of anthropogenic threats, including intensive hunting, chemical contaminants, habitat modification (such as hydroelectric dam and oil and gas developments), disturbance from shipping traffic and noise pollution.
Beluga whales are commonly captured and used as exhibits in aquaria and marine parks around the world. The opinion that it should be illegal to keep cetaceans in captivity is rapidly gaining ground, as more is understood about the intelligence of this order of animals.
In captivity, belugas may suffer as a result of not being able to function as they would in the wild; confined in tanks that can in no way emulate the conditions of their natural habitats, through which they would normally regularly swim long distances and engage in complex social relationships. Being kept in close confinement with other large whales, unable to move away should conflicts develop, is also a source of stress for these highly developed, self-aware creatures.
This article featured in SD OCEAN PLANET (Issue 6/2014)