2023-11-15 07:51:47
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[EN VIDÉO] In video: The birth of a little beluga at the Georgia Aquarium The Georgia Aquarium in Atlanta celebrated a happy event a few weeks ago….
We are north of the Pacific Ocean. To the east, on our right, the frozen plains of Alaska. To the west, the Siberian lands. Very close, further north, the Arctic Circle and its expanses of pack ice as far as the eye can see. Here, the Bering Strait separates two giants, America and Eurasia. It’s summer, the mild temperatures announce the retreat of the ice. But for now, white and silence dominate. The sea is so calm that no one could guess what is happening today. We have an appointment with a phenomenon that only occurs once a year. An exceptional phenomenon. But to see it, you have to switch to the other side, behind the gray mirror-mirror of the water. In these seemingly inhospitable cold waters, thousands of species live to the rhythm of the seasonsseasons. They are there. We hear them before we see them. The sea is not silent. By calming your breathing, by letting yourself be lulled by the waters, you can hear the life around us.
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Their white silhouette reflects the lightlight of the sunsun. They swim slowly, twirl, brush against each other. With their appearance of large dolphins dressed all in white, you may have recognized them: they are belugas. While a first group advances towards us, another, a little further away, emerges from the depths of the ocean. We are suddenly surrounded by a hundred white whales. The little ones are easily recognizable: they still have gray skin. They are the babies of the group. Looks like they made a date. And it’s an appointment that owes nothing to chance… but we’ll come back to that later. Because the spectacle is breathtaking. All around us, these sea giants, measuring up to 5 meters long and weighing more than 1,000 kilos, float gracefully, as if weightless, in the cold waters of the Arctic. At birth, babies already weigh 80 kilos, the weight of an adult human!
Nunavut belugas seen by Florian Ledoux
The beluga is, like the whale or the dolphin, a marine mammal, belonging to the cetacean family. It lives in the northern waters of our Planet. Its scientific name, Delphinapterus leucasDelphinapterus leucas, means “wingless dolphin”, in ancient Greek. Because, unlike common dolphins or sharks, its silhouette, white as ice, has no fins. Instead, it is topped by a thin crest, which runs along its back. Its beak, split into a broad smile, reveals sharp teeth, very useful for crunching the fishfish and crustaceanscrustaceans that it eats. On each side of its head, small eyes give the beluga a large field of vision. Like all marine mammals, our cetacean comes to the surface to breathe, thanks to its blowhole, this small hole located at the top of its skull. And its vent is also used to make bubbles!
The “canary of the seas” lives in a universe of sound
The beluga’s real trump card is neither its field of vision nor its sharp teeth. No, its major asset is its sonar. Like its cousin the dolphin — who gives first names to its friends, remember, we talked about it in a previous episode — like the dolphin, therefore, the beluga is capable of taking sound photographs of its environment. To find its way in the water, at depths where sunlight is rare, it emits sounds by vibrating membranes located in its nosenose, and which are more or less comparable to our vocal cordsvocal cords. These sounds are amplified by an organ, the melonmelon, this big bump on the beluga’s forehead which makes it recognizable among thousands, and (we’re not going to lie) which makes it look a bit funny.
The sounds emitted by the beluga, made more powerful by its melon, travel through the water, and it is then that they bump against what they encounter: the ice floe, a boat, fish. When they reach an obstacle, the sounds bounce back to the beluga, vibrating through its jaw, to its inner ear to inform it that something is there, in that direction. The beluga’s brain then creates a sort of map, an instantaneous photograph of what surrounds it. Quite a superpower, isn’t it?
“The beluga communicates with its conspecifics by emitting hisses, clicks, squeaks and grunts”
The beluga is perfectly adapted to life in the sonic realm of the ocean. And as you will have noticed, it’s a real chatterbox! It communicates with its conspecifics by emitting hissing, clicking, squeaking and grunting sounds. It is even nicknamed the sea canary, because of its incessant cackles! Their vocal repertoire is so varied that it takes several years for baby belugas to express themselves perfectly. Because communication is essential for these animals, which live in groups and maintain deep bonds with their peers. Belugas are social animals. Look at them, they traveled together, and hardly strayed from each other! They will spend the summer here. Because like every year, at the same time, cetaceans migrate from their winter territories, a little further north, towards the coastal waters where they will splash around all summer. They make their way through the ice floe for several months, sometimes traveling thousands of kilometers. This phenomenon is called “summer migrations”. From year to year, they take the same path, follow the same underwater route and find the same bay. Everywhere, from north to south of the Bering Strait, thousands of belugas are doing the same.
But why are they meeting here? How do they manage to find themselves, year after year, in the same place? As you can imagine, this extraordinary behavior quickly piqued the curiosity of scientists, and you will see that they made a surprising discovery about the extraordinary intelligence of the beluga.
A migratory culture passed down from generation to generation
A team of researchers from around the world followed the movements of more than 1,600 belugas living in the Arctic waters of Siberia and Alaska for 30 years. They brought together the research done by their predecessors and followed the belugas to access essential information: their DNADNA. DNA is the information contained in each cell of our body. This information is a kind of biological code, specific to each person, totally unique, and which will dictate the colorcolor of our eyes, our hair, but also certain aspects of our character for example. Our DNA is a bit like our biological identity card, or rather genetic, to be precise. All living things have one. And this is therefore crucial information for researchers! It allows them to know if the belugas they study belong to the same family: are they cousins, brothers and sisters, parents or children?
By comparing these genetic identity cards with the marine paths followed by belugas during their migrations, the researchers made an exceptional discovery. They realized that the belugas that come together belong to the same family and all migrate towards the place of their birth. So of course, lots of animals migrate: fish, birds, or even turtles… But what makes beluga migration so extraordinary is that they don’t use chemical or magnetic cues. to find their way: among belugas, migration can be learned.
Grandmother orca ensures the survival of her grandchildren
In fact, beluga mothers pass on their knowledge of marine routes to their young. They teach them to find their way in the immensity of the Arctic waters and to find their way back to the place where they were born. When knowledge is transmitted socially in this way, we speak of culture. Belugas are therefore not simply migratory animals, they have a migratory culture. And that changes everything ! Researchers believe that these migrations allow them to adapt to seasonal changes, for example to find food. This is evidence of surprising social intelligence and complex cognitive abilities. Another way of saying they’re really smart.
Narwhal adoptions and imitation of human voices
And the extraordinary abilities of belugas don’t stop there! Do you remember the bubbles they were blowing earlier? Well, scientists have discovered that they produce them alone or in groups, without them having any real use, quite simply… for fun. These little pranksters also have a big heart: on several occasions groups of belugas have adopted narwhals. Narwhals are also called sea unicorns, because of the long, needle-shaped tusk that they sport and which can measure up to 3 meters! They are cousins of belugas, but they do not belong to the same species, which makes their understanding, even rare, exceptional.
And you may have heard of Noc, a beluga who became famous thanks to a most astonishing ability. Noc was a captive beluga whale living in a pond in San Diego, United States. He was unfortunately one of the belugas torn from their natural environment, but today, things are changing, and more and more voices are being raised against this type of practice. During these long years spent in the pool, Noc rubbed shoulders with belugas, dolphins and humans.
Noc, the beluga who talks to humans
And one day, while going about their business near Noc Pond, the scientists heard strange noises. Noises that sounded suspiciously like human conversation. When they realized that it was Noc himself who produced them, everyone was shocked. In Noc’s speech, we don’t really distinguish any words, more of a sort of mumbled conversation. But it is already a real feat for the beluga, which makes the effort to produce much deeper sounds than usual, by contracting the muscles of its nostrils differently. Noc had found a hobby: he imitated the way humans spoke. Extraordinary, isn’t it?
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