Beluga Whale (Delphinapterus leucas)

Marine MammalArcticToothed Whale

Overview

The beluga (Delphinapterus leucas) is a small white toothed whale of Arctic and subarctic seas, and the narwhal's closest living relative. Adults are uniformly white; calves are born grey or brownish and pale over several years.

Belugas have no dorsal fin — replaced by a tough dorsal ridge, an advantage under sea ice — and, unusually among whales, unfused neck vertebrae, which lets them turn the head to the side rather than moving the whole body.

The rounded forehead, or melon, is a fatty structure used to focus sound for echolocation, and in belugas it is visibly deformable: the animal can change its shape. Belugas are so vocal that whalers called them the 'canary of the sea'.

Habitat & Range

Belugas live in Arctic and subarctic waters around Alaska, Canada, Greenland, Svalbard and Russia. They are strongly associated with coastal waters, estuaries and river mouths in summer, where large numbers gather to moult, and move to areas of pack ice and open leads in winter. Some populations are highly migratory while others, such as those in the St Lawrence estuary, are resident.

Diet

Belugas take a broad diet of fish and invertebrates — cod, salmon, herring, capelin, flatfish, squid, octopus, shrimp and marine worms — varying with region and season. They have relatively few, peg-like teeth and often feed by suction, and they forage both near the surface and on deep dives to the seabed.

Behavior

Belugas are highly social and travel in pods that can merge into large aggregations. They are exceptionally vocal, producing whistles, clicks, chirps and creaks used for communication and echolocation, and their flexible neck and mobile facial tissue give them an unusually expressive appearance. Each summer they gather in shallow estuaries to moult, rubbing against gravel to shed the outer skin layer.

Human Interaction & Conservation

Belugas are hunted for subsistence in parts of the Arctic under management, and are among the whale species most often kept in aquaria — a practice that remains contested. Wild populations face pressures from underwater noise, shipping, contaminants, prey shifts and sea-ice change; some populations, such as Cook Inlet in Alaska, are far more threatened than the species as a whole. Verify current status at the IUCN Red List and NOAA Fisheries.