### Delphinapterus leucas: The Luminous Sea Canary
Identification
Unmistakable and ghost-like, the adult Beluga is the only cetacean to sport a pure, brilliant white coloration. Measuring 13 to 20 feet, they possess a robust, fusiform body that lacks a dorsal fin—an evolutionary adaptation for swimming easily beneath thick sea ice. Instead, look for a toughened dorsal ridge. Their most distinctive field mark is the "melon": a bulbous, protruding forehead that is remarkably squishy and mobile. Unlike most whales, Belugas have unfused neck vertebrae, allowing them to nod and turn their heads with uncanny, human-like flexibility. Juveniles are born slate-gray, gradually lightening as they mature over five to eight years.
Habitat & Range
These are the spirits of the far north, circumpolar in distribution across the Arctic and sub-Arctic. You’ll find them navigating the fractured ice leads of the Beaufort and Bering Seas or congregating in massive numbers in Hudson Bay. While they love deep offshore trenches, they are famous for frequenting shallow coastal bays and murky river estuaries. A relict, endangered population also resides much further south in the Saguenay-St. Lawrence Marine Park in Quebec.
Behaviour
Belugas are the most vocal of all whales, earning the nickname "Sea Canaries." An observer near the surface may hear a cacophony of whistles, trills, and bell-like chirps even without a hydrophone. They are intensely social, traveling in pods that can swell into the thousands during summer migrations. In the field, watch for their unique "molting" behavior: they congregate in shallow river mouths to rub their bodies against coarse gravel, sloughing off old, yellowed skin to reveal the snowy white layer beneath.
Diet
Opportunistic and clever, Belugas are primarily suction feeders. They use their flexible lips to create a vacuum, pulling prey from the seafloor or out of rocky crevices. Their diet is diverse, consisting of Arctic cod, salmon, flatfish, shrimp, crabs, and even octopuses.
Fascinating Fact
The Beluga’s melon is actually an acoustic lens. By blowing air through its sinuses, a Beluga can physically change the shape of its forehead to focus outgoing echolocation clicks, allowing it to "see" through murky water or find breathing holes in miles of solid ice with pinpoint accuracy!