Among the odontocete cetaceans we find the White Whale or beluga. Its correct scientific name is Delphinapterus leucas, and belongs to the family Monodontidae next to the narwhal. The first thing that catches your eye is the white of their skin, a trait they acquire when they reach maturity; at birth they are grayish or bluish-brown. In addition, they have a rounded head with a prominent melon (key organ in echolocation) and lacks dorsal fin, features that make it unmistakable.
Beyond its appearance, this species accumulates unique adaptations to the Arctic, an amazing vocal repertoire for which she is known as “sea canary", and a very marked social behavior. Want to learn more about the white whale? We'll tell you all about it here.
Key features
Among its distinguishing features it stands out that It does not have a dorsal fin; instead it presents a tough dorsal crest which makes it easier for it to navigate under the ice and even break through thin crusts to breathe. It also doesn't have the extremely slender appearance of other cetaceans; its body is robust and fusiform, with short, rounded pectoral fins and a caudal fin with characteristic lobes. They usually form groups of around 10 individuals, and in summer they can meet in aggregations of hundreds or thousands in estuaries and shallow coasts.
It presents a clear sexual dimorphism: Males are, on average, 25% larger than females. The length of males is usually between 3,5 and 5,5 meters (with maximums close to 6 m) and its weight is around 1.100-1.600 kg, while females reach 3-4 m y 700-1.200 kgBoth sexes grow to approximately 10 years, at which point they usually reach their maximum size.
One of its great keys to survival in icy waters is its fat layer (subcutaneous fat), which can represent between the 40–50% of body weight and reach up to about 15 cm thickThis reserve acts as a thermal insulator and as an energy store. Being robust, it can be seen fat folds in the ventral area, especially in well-fed adults.
White is not present at birth. The young are dark grey to brown and gradually lighten to white, effective camouflage between snow and sea ice. This coloration is not only aesthetic: it reduces visibility in predators like orcas and polar bears.
Su longevity natural often exceeds the four decades and individuals have been documented reaching the 70–80 years, although classical estimates suggested a lifespan of around three decades. Age has historically been estimated using the counting layers of dentin and cementum on the teeth.
Use of the senses
The beluga has a extraordinarily acute hearing, with sensitivity to very high frequency ranges (tens of kHz), far above humans. Like other odontocetes, sound conduction to the middle ear can be done through fat deposits in the lower jaw, which optimizes perception in the water. This auditory performance supports its extremely powerful echolocation: emits trains of clicks that, when crossing the melonThey focus like an acoustic beam, bounce off objects, and return as echoes to reconstruct the environment, locate prey, or distinguish pollinia (openings in the ice) through which to breathe.
His vision is functional in and out of the waterThe eyes secrete a substance gelatinous and oily which protects the ocular surface from pathogens and airborne particles, and helps keep them lubricated. Although their acuity doesn't match that of some dolphins, belugas are well adapted to low light conditions, and there are indications that they could distinguish certain colors.
In the language they have been identified chemoreceptors able to distinguish flavors, which suggests a sense of taste functional. On the contrary, as in most odontocetes, they lack a olfactory system developed. The touch is remarkable: they show preference for physical contact among peers, rubbing frequently; the layer of fat does not reduce their sensitivity.
Their vocalizations are especially rich: they combine whistles, squeals, trills, chirps and cackles, audible even on the surface when they are close. This exceptional repertoire has earned them the nickname of “canaries of the sea”In addition to communicating, with these sounds they also perform tasks of search for prey by echolocation. They have been documented geographical variations in certain calls between subpopulations, suggesting regional “accents.”
White whale feeding
The beluga is a opportunist with a variable diet depending on the area and season. It mainly consumes fish (e.g. Arctic cod, herring, salmon, capelin, halibut and others), and invertebrates such as shrimp, crabs, clams, snails, squid and octopusIn captivity, it has been estimated that they ingest 2,5–3% of your body weight per day, a useful reference to understand its high energy demand.
Although it has teeth, these are blunt and relatively small; they do not crush or tear large prey. Their main strategy is suction: they generate negative pressure to attract food and swallow wholeIn soft bottoms they dig with their mouths, alternating suction and jets of water to expel sediment and reveal buried dams.
The search for food is carried out both individually and in groups. cooperationIn shallow waters they can surround a booth de peces and push it into shallow areas to reduce its escape capacity, taking turns capturing it. When food is required, they are able to dive frequently and reach great depths within the mesopelagic range.
In Arctic ecosystems, and especially when they congregate, belugas can exert a noticeable pressure on local resources, although this function is balanced within food webs where they also play the role of pinch (made with three fingers) of large predators.
Behavior
Although its bulky body is not the most hydrodynamic of the order, the beluga compensates with maneuverability. Your cervical vertebrae are not fused, allowing you to rotate the head up, down and sideways with a freedom uncommon in cetaceans, useful for stalking prey in complex seabeds or among ice. Its typical cruising speed is around 3 – 9 km / hand can raise it for short periods.
What does make it special compared to other whales is the ability to swim backwardsThey spend a good part of their time in active waters and shallow, and rarely perform aerial displays comparable to dolphins or orcas. They are, however, excellent divers: easily overcome the hundreds of meters in specific dives, and maintain ranges of about 20-40 m in repeated background searches.
During diving, they reduce the heart rate and prioritize blood flow to the brain, lungs, and heart. Their muscles store a large amount of oxygen thanks to the myoglobin, and his blood presents a high oxygen content dissolved. This, together with efficient reserve management, allows them stay underwater many minutes without coming out to breathe.
They are animals highly social: they chase each other, play, rub against each other and even make “toys"with floating objects. In addition, they show great curiosity about humans and they frequently approach boats, so responsible observation is essential.
Distribution, habitat and migrations
Belugas inhabit a wide stretch of the Arctic Ocean and its adjacent seas, extending to subarctic zones and even occasionally to temperate latitudes of the northern hemisphere. They are found mainly in Alaska, Canada, Greenland and Russia, with presence in Arctic archipelagos such as Svalbard. They can use from offshore deep waters to shallow coasts, lagoons and estuariesSome populations go up freshwater rivers during the summer, traveling hundreds of kilometers upstream.
Many subpopulations are migratoryIn winter, they endure ice cover and use canals and polynyas to breathe. When the ice retreats, they move towards estuaries and coasts where they molt, reproduce and socialize. Migratory routes can be transmitted from mother to baby, a cultural learning that reinforces loyalty to key areas. Other subpopulations are more Residents and maintain relatively stable environments throughout the year.
White fur and seasonal shedding
The beluga's iconic white fur is not static. With age, the greyish pups become progressively paler until they reach the characteristic ivoryThe epidermis shows a pattern of seasonal molt: after winter, the skin may become yellowish due to superficial thickening; during the summer, when entering estuaries and rivers, belugas rub against gravel and rough substrates for exfoliate and reveal a new, shinier layer. This process supports both the thermoregulation such as the integrity of the skin against microorganisms.
Reproduction and life cycle
Sexual maturity in males is usually reached between 4 and 7 years, and in females it can take up to around 9 years. The copulation It takes place mainly from end of winter to spring, and the gestation hard to 12 to 15 months (somewhat higher values have been recorded under controlled conditions). On average, females give birth to a single offspring every 2–3 years, with a peak birth rate that varies by region.
The babies are born with about 1,5 m and approximately 80 kgThey are able to swim immediately and they feed underwater within a few hours. lactation Exclusive dependence usually lasts for about a year, and dependence can extend up to 20 months or more. Cases of have been observed alloparental care by other females, a cooperative behavior typical of social species.
Classical estimates spoke of a half-life of around 30 years, but subsequent studies have shown that many belugas easily exceed the 40 and some reach the 70–80 years. The edad Historically it has been calculated by counting layers of dentin and cementum in the teeth, although techniques have been refined to improve accuracy.
predators and threats
Belugas have two large natural predators: The orcas and polar bearsOrcas hunt both calves and adults in many regions of their range. Polar bears, for their part, may stalk belugas. trapped by ice in winter or surprise them when they emerge from vents; even captures of large individuals have been documented.
Human activity adds additional pressures: Regulated subsistence hunting is part of the culture of several indigenous peoples in the north; in some estuaries, contamination by heavy metals and persistent organic compounds has raised concerns for the health of certain subpopulations; the underwater noise from ships and industrial activities interferes with communication and echolocation; and sea ice disturbances They can modify access to key areas and exposure to predators. Therefore, adaptive management and population monitoring are essential.
Appearances outside of their usual range
Although its core distribution is Arctic and subarctic, they are occasionally recorded wandering individuals far from its typical geography. These sightings have occurred in European estuaries, coasts of the Atlantic and Pacific of North America and in Eastern AsiaCauses can include storms, health issues, or exploration, and are often isolated events that generate a great deal of interest.
Conservation and status of populations
Globally, the beluga whale is not considered to be in the highest risk category, although its official status may vary depending on the source and revisionWhat is consistent is that some subpopulations discreet are threatened or in a delicate state, such as in certain estuaries or inlets, where historically accumulated factors (such as past catches, pollution or acoustic disturbance) have limited their recovery. In contrast, other subpopulations show large and stable sizes. This requires a unit-based conservation approach, with tailor-made measures for each group.
Responsible observation and interaction with humans
Belugas are curious and in some regions they approach the boats, which encourages fishing activities ecotourismObserving them has enormous educational value, but it demands responsibility: maintaining sufficient distance, avoid sudden changes in speed or direction, do not intercept its trajectory, limit the noise and, of course, do not feed or touch to animals. These principles reduce stress and promote safe encounters for all.
In accredited facilities, some belugas live in captivity for educational and research purposes, although ex situ reproduction has had limited results. Current programs emphasize the people's wellbeing, applied research (e.g., acoustics or diving physiology) and raising public awareness about Arctic conservation.
Elegant, vocal and perfectly adapted to the ice, the White Whale encapsulates the ingenuity of life in an extreme environment. Its migrations, its summer moult, its social intelligence And her "sea canary" voice makes her one of the great protagonists of the Arctic. With constant research and protection measures By subpopulations, we will continue to enjoy their presence in polar seas for generations.