Why Are Belugas Called Sea Canaries? Beluga Sounds Explained

What sounds do belugas make?

A beluga whale has one of the largest sound repertoires of any whale. Researchers usually sort its sounds into three broad groups.

Belugas also clap their jaws, slap the water and blow bubbles, which can add to the noise. NOAA Fisheries lists whistles, squeals, “moos”, chirps and clicks among their calls.

Two of the first scientists to listen to wild belugas underwater, William Schevill and Barbara Lawrence, published their observations from eastern Canada in 1949. They described a mix of whistles, squeals and clicks and compared some passages to children shouting in the distance. Later researchers found that belugas are vocal almost all the time, day and night.

How do belugas make sounds without vocal cords?

Belugas, like other toothed whales, do not call with vocal cords. Instead, they push air through the nasal passages that lead to the blowhole. Pairs of fatty structures called phonic lips sit in these passages and vibrate as air moves past them, much like the lips of a trumpet player.

The air does not leave the body. Belugas can shuttle the same air back and forth between air sacs inside the head, so they can keep calling for long periods underwater without breathing out. The sound then passes forward through the melon, the soft, rounded bump on the forehead, and out into the water.

Belugas can change the shape of the melon as they call, which is easy to see in aquariums. This flexible forehead, together with the unfused neck vertebrae that let them nod and turn their heads, gives belugas their famously expressive faces.

The melon and echolocation

The melon is packed with special fats that conduct sound and work like an acoustic lens. When a beluga echolocates, it sends rapid clicks through the melon in a narrow beam and listens for the echoes, picking them up mainly through fat-filled channels in the lower jaw. The echoes tell it the distance, size and shape of objects ahead. Bats use the same basic system in air, as explained in how do bats use echolocation?

Belugas hear an extremely wide range of pitches, roughly 1.2–120 kHz, compared with about 0.02–20 kHz for a young human. Echolocation is vital in their world. Arctic water is dark for months, river mouths are muddy, and a beluga under sea ice must find cracks and breathing holes before its air runs out.

In a classic experiment in the 1980s, a beluga moved from San Diego Bay to Kaneohe Bay in Hawaii shifted its echolocation clicks to much higher frequencies, apparently to avoid the loud crackling of snapping shrimp in its new home. It was an early sign that belugas adjust their calls to background noise.

NOC, the beluga that imitated human speech

The most surprising beluga sounds came from NOC, a male taken as a juvenile in Manitoba in 1977 and kept by the US Navy’s marine mammal program in San Diego. In 1984, researchers began hearing what sounded like two people talking in the distance near the whale pens. One diver even surfaced to ask who had told him to get out of the water. The voice turned out to be NOC.

Recordings showed that NOC produced sounds with the rhythm and pitch of human speech, several octaves lower than normal beluga calls. Pressure sensors revealed that he changed how he used his nasal passages and over-inflated an air sac near the blowhole to make them. He stopped after about four years, around the time he became mature, and he died in 1999. The study by Sam Ridgway and colleagues was published in Current Biology in 2012.

NOC was not talking in the sense of using words. But his imitation shows that belugas are excellent vocal learners, one of the few groups of animals, along with songbirds, parrots, bats, elephants, seals and some other whales, that can copy new sounds.

How belugas communicate with each other

Belugas live in groups that constantly split and merge, often in murky water where they cannot see far. Calls help them stay together. Mothers and calves exchange contact calls, and studies of captive belugas suggest that individuals may have distinctive calls that work a little like names, similar to the signature whistles described in how do dolphins communicate?

Calls also seem to vary from place to place. Recordings from different populations show differences in call types, which may help belugas recognize members of their own group, much like regional accents.

Talking in a noisier Arctic

Because belugas depend on sound, noise from ships can disrupt them. In the St. Lawrence River estuary, belugas call less often when large ferries pass and may change their call types or repeat calls more. In the Canadian Arctic, belugas have been seen reacting to approaching icebreakers tens of kilometers away, moving off along the ice edge to avoid them.

As sea ice shrinks, more ships are traveling through Arctic waters, raising concerns about how much space remains for belugas to hear one another. Even so, belugas are not the loudest whales: that title goes to sperm whales and blue whales, featured in our list of the loudest animals. The beluga’s fame comes from how often and how varied it calls, not from sheer volume.