Beluga whales are the only whales, other than narwhals, a closely related species, that live exclusively in arctic and subarctic waters. Like many other arctic animals, belugas are white. In fact, the word ‘beluga’ comes from ‘bielo,’ the Russian word for white.
But belugas aren’t born white, notes Ragen Davey, Alaska marine representative for the conservation group Defenders of Wildlife. Calves are dark gray and gradually get lighter as they age, becoming totally white upon reaching adulthood.
Beluga whales are listed as Least Concern on the IUCN red list, though they do face challenges.
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Beluga’s Have Melon Heads
Beluga’s heads are called melons. Really. The melon is a protrusion on a beluga’s forehead, made up of fatty tissue and muscle. A study published earlier this year documented and quantified what beluga experts already knew: Belugas can alter the shape of their melons, creating a variety of facial expressions.
Though the study did not indicate whether or not these expressions were intentional, the researchers said they seemed to be a form of communication. But that’s not all the melon does. It also helps these highly social animals project sounds.
“Because they have muscular control over their melon, they can create a wide range of clicks, whistles, squeals, chirps, and other vocalizations,” explains Jenn Odell, director of zoological operations, mammals, and birds, at the Georgia Aquarium in Atlanta.
These delightful calls have earned belugas the nickname “canaries of the sea.”
Beluga’s Are Adapted for Ice
Belugas are well-adapted to their glacial environment. Unlike many other whales, such as orcas and blue whales, belugas have no dorsal fin. Instead, they have a low ridge where the dorsal fin would be. The lack of a dorsal fin prevents heat loss and makes it easier for the whales to swim under ice. It also aids in breaking through the ice above them when they need to surface to breathe.
Also unlike other whales, belugas’ neck vertebrae are not fused, so they can move their heads up and down and from side to side, explains Davey. This likely aids in hunting and finding their way around under the ice. However, Davey adds that belugas primarily use echolocation to navigate and locate prey.
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Threats to the Beluga Whale
While belugas aren’t a vulnerable species on the IUCN red list, their greatest threat right now is global warming, according to Odell.
“Because the ice caps are melting, previously frozen-over channels are now accessible to shipping traffic, which creates a lot of underwater noise and disturbances that greatly impact the whales’ ability to forage and communicate with one another,” says Odell.
The loss of ice also allows one of the beluga whales’ major predators, the killer whale, to hunt them more easily, she adds.
Some belugas are in serious trouble, however. Davey studies a critically endangered sub-population of belugas that live in the Cook Inlet of Alaska.
“They just don’t have as much food as they used to,” Davey says.
Salmon populations are down, and even though belugas are opportunistic feeders, other fish, or even smaller salmon, don’t provide the calorie density to make up for the energy spent hunting them.
Another problem is noise. Cook Inlet belugas live “in downtown Anchorage, Alaska, right in our backyard,” as Davey puts it. Oil and gas development takes place in the middle of Cook Inlet. There’s constant noise and human activity. And for animals that depend on sound to communicate and to locate prey, this is a serious problem.
In addition, Davey says, “Cook Inlet is not a super healthy body of water, and we know that the contaminants are affecting the whales,” pointing to a decrease in birth rates and survival rates. All of this has a cumulative effect, she says.
Living in humans’ backyard has almost driven the Cook Inlet belugas to extinction. However, living so close to humans just might help save them. Anchorage residents and visitors to the city can watch the calves following their moms and learning to swim, Davey says. This could be good news for the whales because the more people get to know these whales, the more motivated they will be to help them and perhaps become more aware of threats facing other animals.
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Article Sources
Our writers at Discovermagazine.com use peer-reviewed studies and high-quality sources for our articles, and our editors review for scientific accuracy and editorial standards. Review the sources used below for this article:
Avery Hurt is a freelance science journalist. In addition to writing for Discover, she writes regularly for a variety of outlets, both print and online, including National Geographic, Science News Explores, Medscape, and WebMD. She’s the author of Bullet With Your Name on It: What You Will Probably Die From and What You Can Do About It, Clerisy Press 2007, as well as several books for young readers. Avery got her start in journalism while attending university, writing for the school newspaper and editing the student non-fiction magazine. Though she writes about all areas of science, she is particularly interested in neuroscience, the science of consciousness, and AI–interests she developed while earning a degree in philosophy.
Source : Discovermagazine
