9 Beguiling Facts About Belugas

The Arctic can seem quiet compared with lower latitudes, where there are often more birds and other animals to fill the air with sound. It does have music of its own, though — including the underwater hullabaloo of belugas, sometimes referred to as the "canaries of the sea."

Beluga whales live in and around the Arctic Ocean, and they're abundant in some parts of Alaska, Canada, Greenland, and Russia. More than 200,000 may exist in the wild, but due to their remote and inhospitable habitat, many people know them only from aquarium exhibits, wildlife documentaries, or "Finding Dory."

While belugas are generally beloved around the world, they are even more interesting and impressive than some casual fans may realize. Here are a few things you might not know about these magnificent marine mammals.

1. Belugas Belong to a Tiny Taxonomic Family

Belugas are toothed whales, a diverse group of cetaceans that includes dolphins and porpoises, as well as a few larger species like orcas and sperm whales. Within that group, however, belugas belong to Monodontidae, a tiny family of just two living species: narwhals and belugas.

Both belugas and narwhals inhabit the Arctic Ocean, along with some nearby seas, bays, fjords, and estuaries. Narwhals mainly ply the Arctic and North Atlantic, while belugas are scattered across parts of the Arctic, North Atlantic, and North Pacific. Belugas have also adapted to both fresh and saltwater, allowing them to venture inland through rivers, sometimes relatively far. The two species do coexist in some areas, and there is at least one known case of a beluga-narwhal hybrid found in the wild.

2. Up to 40% of Their Body Weight Is Blubber

Belugas swim among ice floes in and around the Arctic Circle, which means they have to endure incredibly cold water. Despite seasonal journeys into warmer estuaries and river deltas, they still need to spend long periods in water as cold as 32 degrees Fahrenheit (0 Celsius), according to the U.S. National Oceanic and Atmospheric Administration (NOAA).

That calls for a lot of blubber, the thick layer of body fat that insulates marine mammals from cold environments. In belugas, blubber may account for as much as 40% of total body weight, according to NOAA.

3. A Dorsal Fin Can Be a Liability in the Arctic

Blubber is just one way belugas have adapted to life amid the sea ice. They also lack dorsal fins, for example, those prominent upright fins on the backs of some toothed whales, like orcas and many dolphins.

A dorsal fin helps with stability and making turns while swimming; it's so useful it has emerged multiple times through convergent evolution (such as in fish and cetaceans). Yet despite its potential benefits, a dorsal fin can have drawbacks in the Arctic. It contributes to heat loss, which is a big deal in such a cold environment, and since belugas often need to swim under ice, a dorsal fin could also make it harder to maneuver and navigate.

4. Belugas Are Among the Chattiest Cetaceans

Whales and dolphins are famous for their intelligence and their loquacity, since many species produce a wide variety of sounds for social communication, as well as echolocation. Belugas are believed to have especially sophisticated hearing and echolocation skills, and their vocal range has inspired comparisons to songbirds.

The ebullient sounds of belugas can sometimes be heard out of the water, or even through the hulls of boats. These include echolocation clicks along with various whistles, trills, bleats, chirps, mews, and even bell-like tones. Belugas are known to produce at least 50 different identifiable calls.

5. They Can Imitate Human Speech

Some toothed whales excel at vocal learning, helping them become impressive mimics. Orcas can learn to imitate the language of bottlenose dolphins after living together, for instance, and bottlenose dolphins have been known to emulate the songs of humpback whales.

Belugas, however, are particularly talented impersonators — and they've even hinted at an ability to mimic human speech. Researchers have reported wild belugas making sounds like "a crowd of children shouting in the distance," for example, and some captive belugas have even spoken human words, at least once well enough to fool an actual human.

"Who told me to get out?" a diver asked after surfacing from a tank that held a captive beluga named NOC. As researchers would later report in Current Biology, the diver was responding to a "command" from NOC himself. The young male beluga had reportedly learned to produce unusually low-frequency sounds, with an amplitude and frequency (200 to 300 Hz) similar to human speech, sometimes clearly enough to sound like words. NOC stopped imitating humans once he reached maturity, the researchers noted, although he remained highly vocal in adulthood.

6. A Shape-Shifting Melon Helps Them Talk

Despite being such vocal animals, belugas don't have vocal cords like we do. They instead make sound with nasal air sacs and phonic lips, then focus that sound through a mass of fatty tissue called the "melon" at the front of the head. All toothed whales have some version of this organ, which may help transmit sound waves from a whale's head into the water.

While it's normal for toothed whales to have these fatty melons in their heads, a beluga's melon is substantially larger, more bulbous, and more prominent than in other species. And, unlike other cetaceans, belugas are able to change the shape of their melons, presumably offering more control as they aim or otherwise modify their outgoing sounds.

7. They're Head-Turners

Stiff necks are common among whales and dolphins — some species have as many as seven neck vertebrae fused together — but this adaptation is still not entirely understood. It might provide more stability when swimming, among other possible perks, but it also limits an animal's ability to turn its head independently from the rest of its body.

Not so for belugas, however, who are among the few cetaceans with fully unfused neck vertebrae. This allows for a wider range of head movement, and it's why belugas can nod or look left and right with relative ease. A freer head could be useful for communication, hunting, escaping predators, or just general maneuverability in shallow or icy water.

8. They Form Broad Social Networks

Each summer, belugas swim back to their own birth areas to hunt, breed, and calve. Belugas are highly social animals, typically seen in pods that can vary widely in size, from as few as two whales to hundreds.

Belugas were once thought to use a matrilineal social system, like orcas, centered around female relatives. While they do socialize with family, however, a 2020 study published in Scientific Reports suggests belugas also form broader social networks beyond their close relatives. Belugas might have a fission-fusion society, where size and makeup of social groups depends largely on context, according to lead author and Florida Atlantic University research professor Greg O'Corry-Crowe.

"Unlike killer and pilot whales, and like some human societies, beluga whales don't solely or even primarily interact and associate with close kin," O'Corry-Crowe said in a statement. "It may be that their highly developed vocal communication enables them to remain in regular acoustic contact with close relatives even when not associating together."

9. The Loss of Sea Ice Poses a Few Problems

Returning to the same estuaries every summer has long made belugas vulnerable to overexploitation by humans, according to the International Union for Conservation of Nature (IUCN), which listed the species as Vulnerable in 1996. Legal protection has helped some populations rebound in recent decades, leading the IUCN to reclassify belugas as Near Threatened in 2008, then down to Least Concern in 2017.

About 200,000 belugas now live in 21 subpopulations across their range, but there are still far fewer belugas today than there were just 100 years ago, according to the IUCN, and there is still concern about their future. Some subpopulations are small and endangered, and the species itself faces the daunting challenge of adapting to high-speed climate change, namely the decline of Arctic sea ice. Belugas use sea ice to help them hunt fish and evade orcas, for example, and less sea ice also invites outside threats into their home, such as noise and collisions from ships, pollution from the oil and gas industry, and even competition for food from other whales.