Beluga Whales (Delphinapterus leucas)
Delphinapterus leucas. © 2005 beluga1
Once upon a time in a frigid land of ice and snow, there lived a pleasant beluga named Bertha. Bertha was born after her mother, Bessie, held her within the confines of her womb for 15 months, in which she playfully swam with other pregnant mothers as they prepared to welcome the next generation into the sea. During this time, Bertha’s father, Bartholomew, was having meetings with the other fathers in the open sea.
On the warm spring morning that Bertha was born, Bartholomew and the other fathers protected the expectant mothers that all lived in a shallow estuary off of Baffin Bay. Bertha was born a brownish-grey colour, weighing 50kg and measuring 1.5 metres in length. When she was born, Bertha came out of her mother’s womb tail first, in shallow, warm waters, near the surface of the ocean. Her umbilical cord quickly snapped away from her mother and she was finally released into the waters of her new icy life. Bertha was free to swim up to the water’s surface to take her first breath – with her mother’s help, of course. Bessie and Bertha stayed close as Bertha nursed milk from her mother’s abdomen. This close relationship continued until Bertha’s first birthday, when her teeth began to form.
After Bertha’s teeth became fully formed, she was free to go out hunting to catch her own food all by herself, without her family’s help. Usually this hunting job was taken care of by her older brother, Benjamin, but today was Bertha’s turn to learn (just in case). On one bright, adventurous morning, Bertha set out with her best friend, Betty, in search of some food for lunch.
As the two whale friends traversed the cool coastal waters of their home, they kept watch for any unsuspecting mollusks, fish, or benthic invertebrates that crossed their paths. Suddenly, Betty spotted Mark the mollusk swimming with a few of his friends. Utilizing great stealth, Bertha and her friend managed to sneak up on Mark from behind and gobble him and his friends up for a most appetizing lunch.
Satisfied by her accomplishments, Bertha set off on the journey home. However, this adventure was tainted with peril. While swimming around a bend on her way to the home estuary, Bertha encountered Kenneth, the Killer Whale. With a menacing grin, he set off at full speed toward Bertha, determined to gobble her up for HIS lunch. Ever so smooth, Bertha managed to quietly swim behind an ice floe and with her bluish white skin, camouflaged by the frigid obstacle. She arrived home safely, with many stories to account to her fellow Beluga whales.
As Bertha began to mature into a grown up Beluga, her colouring gradually turned from a bluish-brown, grey colour into the pure white of an adult Beluga. By the time she was five years old, Bertha the Beluga weighed 1 360 kg, measured 4 metres in length and was considered a sexually mature adult. Bertha was now able to search for a man with whom she could start a new generation of whale families. At the age of 28, after living a long, prosperous, and fulfilling life, Bertha passed away peacefully, with the hope that humans learn to protect their environment and respect the animals that they share it with (especially the Belugas).
After reading the story about Bertha, try answering the following questions to test what you have learned about Beluga Whales.
1) How long is a Beluga mother pregnant for?
a) 5 months
b) 9 months
c) 15 months
d) 29 months
2) What colour are baby Beluga’s born?
3) What colour are adult Belugas?
c) Pure white
4) What do Belugas like to eat?
a) Mollusks, crabs, cheese
c) Sushi, sashimi, pine nuts
d) Mollusks, fish, benthic invertebrates
5) About how much do adult female Belugas weigh?
a) 500 kg
b) 1 360 kg
c) 1 500 kg
d) 1 2400 kg
Answers: 1) c 2) b 3) c 4) d 5) b
Beluga whales, Delphinapterus leucas, are also known as the white whale, Belukha, Sea Canary (1). Full-grown belugas range between 3-4 metres in length and weigh between 1300-1500 kilograms (1). They have a stout, robust body with no dorsal fin, a short, broad neck, and a round head with a noticeable bump (or melon) on top of their small head (2). Their neck bones are not fused together, unlike other whales, and they can turn their heads from side to side (2). The melon allows them to crack through ice to allow access to the surface in order to breath (3). Belugas have 32-40 teeth altogether in both jaws, which they use to feed on fish, mollusks, and benthic invertebrates (1). They have small, dark eyes, located behind the corners of their mouths, and ears located behind the eyes, with no external flaps or lobes (3). They have a single blowhole, on top of their head, which is covered by a water-tight, muscular flap, that contracts to allow the beluga to breathe (1). Belugas are rather slow swimmers, swimming at 3-9 kph, but are capable of short bursts of speed of up to 22 kph (4). They can also swim backwards and forwards to avoid obstacles (1). Belugas make high-pitched chirping sounds to communicate with each other, which gave them the name, Sea Canary (4). Adults are almost pure white in colour, which allows them to avoid predators as they resemble many ice floes that dot their ocean habitat (5).
Habitat & Predators
Beluga whales live in entirely Arctic and Sub-Arctic, aquatic environments (1). Belugas live in the Arctic Ocean and its adjoining seas, including the Sea of Okhotsk, the Bering Sea, the Gulf of Alaska, the Beaufort Sea, Baffin Bay, Hudson Bay, and the Gulf of St. Lawrence (1). Belugas prefer living near the coast of continents and islands, rather than in the more open parts of oceans (3). Belugas are generally found in shallow, coastal bays, estuaries and river openings, often in water barely deep enough to cover their entire bodies (4). Belugas migrate to more southern waters during the winter months, as if the ice freezes too thickly, they will not be able to come to the surface for air (3). They move freely between salt and fresh water and swim into rivers to feed, especially when salmon is spawning (1). They live in groups of 5 – 10, called pods, but may cluster in groups of up to 100 during migration season. Beluga’s predators include Killer Whales and Polar Bears, but increasing human interference with their habitat, and illegal hunting is decreasing Beluga populations (5).
Specific Adaptations to the Environment
Belugas are highly adapted to live in their icy environment. They can swim backwards and forwards in order to avoid icy and other obstacles they may encounter in the Arctic regions (1). Belugas swim slower than most other whales, about 3-9 km/h, lower their heart rate while diving, which helps conserve energy (1). They breathe through a single blowhole, which opens and closes muscularly to keep out water, which is key to living in an aquatic environment (1). They also have a long breath-hold, which entails more air to enter their lungs when they breathe, allowing them to survive underwater for extended periods of time (1). Moreover, belugas store most of their body fat in the form of blubber just below their skin (1). This layer streamlines the beluga’s body, insulates vital organs and also functions as an energy reserve (3). Belugas have no dorsal fin, which reduces heat loss and avoids interference with ice and obstacles (1). In addition, their neck vertebrae are not fused together which allows them to rotate their head and neck more freely (1). Most interestingly, belugas have a melon, which is a thick skin with a thick layer of blubber underneath, which forms a bulbous shape on the top of their head (1). This allows the whales to ram through thick ice, should they need to create a breathing hole (1).
Reproductive Characteristics and Life Cycle:
Male belugas become sexually mature around 8-9 years of age and females around 4-7 years of age (1). They mate between March and May in small bays and river openings, and are born in the same area (3). A single male may impregnate several females in one breeding season with the gestation period lasting between 14 and 15 months (2). A female may give birth to a single baby every 2-3 years, with twins being a rare occurrence (4). Baby belugas are generally 1.5 metres in length and about 80 kg (1). They are born brown, become darker grey or bluish, then yellowish, and turn almost pure white around sexual maturity (1). Beluga calves can swim at birth and the mother beluga’s nurse the calves until around 1 year of age, when their teeth come in (1). Mothers and claves often group together, away from the males of the group where the calves earn survival behaviors by observing and mimicking the actions of the adults in their pod (4). They reach full size around 10 years of age and have a lifespan of between 25 and 30 years of age (1).
Information on the Internet
- Beluga Whales An extensive link providing scientific information, data and graphs about beluga life, research and habitat.
- Belugas This simple children’s website provides simple and concise information, most interestingly about beluga’s communication through echolocation.
- Beluga Whales A fairly extensive link that provides very interesting information about the threats and protection about belugas.
- Canadian Beluga Whales A Canadian Government link with information surrounding the movement, habitat, threats and behaviors about belugas living in Canada.
- Beluga Whales A fairly extensive site defining the beluga’s physiological structure in addition to their habitat and environmental adaptations.