The white whale; the sea canary; the melonhead. These three terms may seem random and unrelated, but they all refer to a fascinating species of cetacean – the beluga (Delphinapterus leucas). Like its closest living relative, the narwhal, the beluga is a medium-sized whale found in Arctic waters. Belugas are easily distinguished by their all-white colouration, unique amongst marine mammals, hence the alias ‘white whale’.
Extremely social creatures, belugas live in pods of around ten individuals. Although, during the summer months, these pods can contain hundreds of whales. Adapted to living in groups, belugas have evolved a complex language of communication. This includes a variety of clicks, chirps, whistles and squeals. Their repertoire of bird-like sounds earned them the wonderful name ‘sea canaries’.
However, these vocalisations are not just used for communication, they also give belugas the incredible power of echolocation. They produce a series of clicks that pass through the large budge on its head that houses an echolocation organ known as the melon (giving them the name ‘melonhead’). These sounds waves are then projected through the surrounding water. When the sound waves hit an object, they are reflected and return as echoes that are heard and interpreted by the beluga. This skill serves a variety of uses from targeting prey to finding breathing holes in the frozen ice.
The beluga’s diet mainly consists of a wide range of fish species, but also includes crabs, squids, octopuses and clams. The beluga’s varied diet and relatively large abundance means that they play a vital role in the ecology of the Arctic Ocean. These mammals are highly adapted to Arctic life. Beside their all-white camouflage, belugas also lack a dorsal fin which enables them to swim under ice with ease.
Many beluga populations migrate south in the autumn as the sea freezes over. Then, in the spring, they return north as the ice breaks apart. Their annual migration may take them as far south as Scottish and Japanese waters. Once listed at ‘vulnerable’ by the IUCN (International Union for the Conservation of Nature), they are now considered ‘least concern’, although questions still surround their status. Some populations are in far more trouble than others.
There is so much more that can be said about the beluga, from its remarkable senses to its playful behaviour, but hopefully I have shown you a snippet of the brilliance of the beluga.
Hennessy, K., Wiggins, V. (2014) Animal Encyclopedia: The Definitive Visual Guide. 2nd edn. London. Dorling Kindersley.