Delphinapterus leucasbeluga

Geographic Range

Habitat

Belugas are commonly found in arctic or subarctic waters. Generally, they stay near pack ice along coastlines but they will travel out to more open areas to depths of about 800m or more to hunt. In the summers, they are generally found in shallower waters (1-3m) such as estuaries or even large river mouths. (Jefferson, et al., 2012; Laidre, et al., 2000; Shaffer, et al., 1997; Shirihai and Jarrett, 2006; Stewart and Stewart, 1989; Watson, 1981)

  • Range depth
    >800 to 1-3 m
    to ft

Physical Description

The beluga has been nicknamed the “white whale” because, as an adult this whale, has a very distinct bright white color covering its entire body. However, as a calve, the whale can have a pale grey or almost blue-toned coloring to its body that will fade to the well-known pure white coloring anywhere between 5 and 12 years old. Another distinguishing characteristic is its lack of a dorsal fin but presence of a prominent dorsal ridge. The beluga also has a small bulbous head and a very short beak with a cleft upper lip. The beluga has a large body mostly consisting of a large layer of blubber. It can have large folds or wrinkles covering most of its body, with a blubber layer about 15cm thick. A feature that is unique only to this species of cetacean is its visible, somewhat flexible neck. A beluga will have 8-9 teeth in each row of the top and bottom jaws, and these may appear heavily worn down in older whales. On average, a male beluga is about 25% larger than a female. An adult can be anywhere from 3-7m in length but on average; a male beluga can grow up to about 5.5m long while a female is generally only 4.3m. A male beluga will also have slightly curled tips to its flippers while a female’s flippers remain flat. Adults can weigh anywhere from 400-1,600kg with the average being 1,500kg. At birth, a calf can weigh from 80-100kg and be about 1.6m long. The beluga is often confused with another species of cetacean, the narwhal (Monodon monoceros). The beluga and narwhal have very similar body structure. Each whale can grow to about the same size, neither have a dorsal fin, and a beluga calf has the same grey color of the narwhal. However, a male narwhal will have a protruding long tusk, which is lacking in the beluga, distinguishing the two from one another. (Shirihai and Jarrett, 2006; Stewart and Stewart, 1989; Watson, 1981)

  • Sexual Dimorphism
  • male larger
  • sexes shaped differently
  • Range mass
    400 to 1,600 kg
    881.06 to lb
  • Average mass
    1,500 kg
    lb
  • Range length
    3 to 7 m
    9.84 to 22.97 ft
  • Average length
    4-6 m
    ft

Reproduction

Belugas will mate during late autumn into early spring so that in the warmer months they can migrate into shallow estuaries to give birth to their calves. Belugas are normally in polyandrous groups, meaning there is a group of males centered on one female with calves of many ages. (Lydersen, et al., 2001; Watson, 1981; Weigl, 2005)

Belugas can reach sexual maturity as early as 4 years old, but the age for females ranges from 4-7 years with the average being 5 years, while the range for male belugas is 7-9 years with the average being 8 years. Male belugas will normally reach sexual maturity in conjunction with the changing of their skin color from grey to white. Female belugas experience their first pregnancy around the same age sexual maturity is reached and they will give birth once every three years, having a total of about 10 pregnancies in one complete reproductive lifecycle. Gestation lasts about 12-15 months with, typically, one calf born per season. Weaning can take place anytime between 3 and 36 months but the average is about 2 years, the same time independence is normally reached. Mating will take place around late February into early May and calves are born during the summer months, usually April-September. This will vary geographically based on when different stocks migrate into warmer waters. (Kelley, et al., 2015; Lydersen, et al., 2001; Matthews and Ferguson, 2015; Shelden, et al., 2006; Stewart and Stewart, 1989; Weigl, 2005)

  • Breeding interval
    Once every 3 years, during warmer months (April-September)
  • Breeding season
    February-May
  • Range number of offspring
    1 to 2
  • Average number of offspring
    1
  • Average number of offspring
    1
    AnAge
  • Range gestation period
    12 to 15 months
  • Average gestation period
    14 months
  • Range weaning age
    6 to 36 months
  • Average weaning age
    25-32 months
  • Range time to independence
    1 to 2 years
  • Average time to independence
    2 years
  • Range age at sexual or reproductive maturity (female)
    4 to 7 years
  • Average age at sexual or reproductive maturity (female)
    5 years
  • Range age at sexual or reproductive maturity (male)
    7 to 9 years

A beluga calf is completely dependent on its mother for the first two years of life. The calf will rely on the mother’s milk as its only source of food for the first year. After two years, shrimp and small fish will begin to be introduced into the diet along with continuing its intake of the mother’s milk. Many studies have shown that the calf will stay close to its mother even after the first two years of life although it is no longer dependent. A female beluga will protect her calf during an encounter with a predator by swimming slowly and non-erratically so that her calf will not become separated from her. It is also common to see a calf riding on top of its mother’s back when swimming long distances. The male beluga provides no parental care. (Colbeck, et al., 2012; Kelley, et al., 2015; Stewart and Stewart, 1989; Weigl, 2005)

  • Parental Investment
  • altricial
  • female parental care
  • pre-weaning/fledging
    • protecting
      • female
  • pre-independence
    • protecting
      • female
  • post-independence association with parents
  • inherits maternal/paternal territory

Lifespan/Longevity

The longevity of the beluga whale in the wild is not well known but there have been accounts of the whale living to be at least 40 years old, with some individuals living to 60 or more years. In captivity, the longest a beluga has lived is about 5 years but the average is ca. 3 years. (Macdonald, 1985; Stewart and Stewart, 1989; Weigl, 2005)

Behavior

Belugas are commonly observed in groups ranging from 2-10 but during summer migrations the groups can range from hundreds to even thousands of whales. Most commonly, there are two groups, one consisting of females with several offspring varying in age and sex and a group of all mature males. In the group with the large female-offspring ratio, it is common for all younger, pre-weaning, calves to follow their mothers in a single-file line. Female calves tend to stay with the stock they were born into for the rest of their lives while male calves tend to leave their maternal stock, usually forming groups with other adult males.

Colbeck et al. (2012) report that because calves are dependent on their mothers for such a long time, both sexes will become accustomed to the migration patterns. Even after reaching the age of independence the calves will still follow the same migrations patterns as they did when they were younger.

Although other whales jump or breech, belugas do not. Instead, belugas swim very slowly in a smooth rolling motion, rarely raising their heads from the water. Belugas spend a lot of their time near ice packs in the winter and are commonly seen using their bulbous forehead to break through ice 10cm thick in order to make a hole for breathing. During the calving season, these whales will migrate into shallower warmer water (mostly estuaries) because there is an abundance of food and it will be easier to avoid most predators. Belugas can have dives lasting about 25 minutes at the most and can reach depths of 800-1,000m, sometimes being observed foraging close to the ocean floor. (Colbeck, et al., 2012; Lydersen, et al., 2001; Shaffer, et al., 1997; Stewart and Stewart, 1989; Watson, 1981; Weigl, 2005)

Home Range

The beluga whale does not have a home range.

Communication and Perception

Belugas are considered to be the most vocal species of cetaceans. They have been nicknamed the “sea canary” by many researchers because of their large repertoire of sounds, which can even be heard above the surface. They use many different clicks, chirps, and whistles (ranging from 3-9 kHz) to communicate with each other but they also use a very distinct “bell tone” that is unique to only this species of whale. Their clicks are often in short pulses and are used along with their melon like forehead as a type of echolocation to find cracks in the ice caps to surface to breathe. (Stewart and Stewart, 1989; Watson, 1981)

Food Habits

The beluga whale is primarily a bottom feeder and will normally hunt alone in waters about 300m deep. Its diet varies geographically but mostly consists of fish such as: salmon (Salmo salar), herring (Clupea harengus), and arctic cod (Arctogadus glacialis). The beluga may also consume cephalopods like squid or octopus, and crustaceans such as shrimps or crabs. Crustaceans and fish constitute about 25 kg of the daily diet in adults. Calves normally eat more shrimp and crab but for the first two years of life they are dependent on their mother’s milk. The beluga will use suction as a way to trap their prey because their teeth are not that large, and swallow most of their food whole. (Lydersen, et al., 2001; Shirihai and Jarrett, 2006; Stewart and Stewart, 1989; Watson, 1981)

  • Animal Foods
  • fish
  • mollusks
  • aquatic crustaceans

Predation

There are three predators of beluga whales, with killer whales (Orcinus orca) being the most common of the three. There have been recordings of belugas changing their chirp or whistle frequencies when killer whales are nearby in an attempt to warn the rest of their stock to avoid the area. Because belugas tend to return to same areas every migratory season, they are easy to track for hunting. Polar bears (Urus martitimus) and humans (Homo sapiens) use this to their advantage. Polar bears will wait near the breaks in ice caps, where the whales surface to breathe, and pull them out of the water and onto the ice. Humans have hunted belugas for centuries, and in some small areas the whales are still a major food source. (Lydersen, et al., 2001; Shelden, et al., 2006; Watson, 1981)

Ecosystem Roles

Belugas are known to be a host for three species of trematodes (Odhneriella seymouri, Leucasiella arctica, and Leucasiella mironovi) one cestode (Diphyllobothrium lanceolatum) and eight species of nematodes (Anisakis küikenthali, Corynosoma strumosum, Terrenova decipiens, Stenurus arctomarinus, Octophocaenurus oserskoi, Stenurus minor, Crassicauda giliakiana and Pharurus pallasii) with Pharurus pallasii being the most common. There have also been a few rare cases where belugas have been found with Pasacyamus nodosus, or whale lice, originally thought to be harbored by narwhals (Monodon monoceros). Beluga whales are known to be one of the main apex predators of the arctic waters. (Barbero and Thomas, 1960; Stewart and Stewart, 1989; Weigl, 2005)

Commensal/Parasitic Species
  • trematodes: (Odhneriella seymouri, Leucasiella arctica, and Leucasiella mironovi)
  • cestotode: (Diphyllobothrium lanceolatum)
  • nematodes: (Anisakis küikenthali, Anisakis simplex, Terrenova decipiens, Stenurus arctomarinus, Stenurus minor, and Pharurus pallasii)
  • whale lice Pasacyamus nodosus

Economic Importance for Humans: Positive

Beluga whales play an important role in the survival of the Canadian and Alaskan Inuits, also known as the modern day Inuvialuits. For centuries, the belugas have been a main food source for these small communities and their blubber has also been used for oil. These whales also bring ecotourists interested in whale watching because of the belugas large social gatherings, creating new jobs and allowing growth in the community. (Dressler, et al., 2001; Friesen and Arnold, 1995; Stewart and Stewart, 1989)

  • Positive Impacts
  • food
  • body parts are source of valuable material
  • ecotourism

Economic Importance for Humans: Negative

There are no known negative economic impacts that beluga whales have on humans.

Conservation Status

The beluga whale is listed under the IUCN red list as “Near Threatened” as of 2012. As of 2011, the US Fish and Wildlife Service federal list has a small beluga stock (375 whales in Cook Inlet, Alaska) listed as endangered. Along with all other cetaceans, the beluga whale is cited under Appendix II in CITES. This means that although the beluga is not necessarily threatened with extinction as of now, there still needs to be some sort of regulation on the hunting or capture of this species.

A common threat to the beluga population is being hunted for food, or captured for the aquarium trade. Humans pose a threat to the beluga for many reasons. Expansion of communities along the coast affect beluga feeding habits and migration patterns. Pollution from the communities negatively affect the health of the beluga. There have not been many conservative efforts put in place for the beluga whale because it is not endangered worldwide, but in Greenland and Canada the Joint Committee on Narwhal and Beluga/North Atlantic Marine Mammal Commission recommend a catch limit of about 10 whales per harvest year for this species.

The small stock in Alaska that is endangered is currently protected under the U.S Endangered Species Act and the Marine Mammal Protection Act of 1972. The recovery plan that has been put in place for this stock includes regulating the harvest of the beluga. The goal of this plan is to restore this stock’s population to a healthy level. The NOAA Office for Law Enforcement was put in place to stop illegal fishing of the beluga. (Jefferson, et al., 2012; Saxon, et al., 2013; Stewart and Stewart, 1989)

Contributors

Krista Zimmermann (author), Radford University, Cari Mcgregor (editor), Radford University, Zeb Pike (editor), Radford University, Karen Powers (editor), Radford University, April Tingle (editor), Radford University, Jacob Vaught (editor), Radford University, Genevieve Barnett (editor), Colorado State University.

Glossary

Arctic Ocean

the body of water between Europe, Asia, and North America which occurs mostly north of the Arctic circle.

Atlantic Ocean

the body of water between Africa, Europe, the southern ocean (above 60 degrees south latitude), and the western hemisphere. It is the second largest ocean in the world after the Pacific Ocean.

World Map

Nearctic

living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.

World Map

Pacific Ocean

body of water between the southern ocean (above 60 degrees south latitude), Australia, Asia, and the western hemisphere. This is the world's largest ocean, covering about 28% of the world's surface.

World Map

Palearctic

living in the northern part of the Old World. In otherwords, Europe and Asia and northern Africa.

World Map

acoustic

uses sound to communicate

altricial

young are born in a relatively underdeveloped state; they are unable to feed or care for themselves or locomote independently for a period of time after birth/hatching. In birds, naked and helpless after hatching.

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

brackish water

areas with salty water, usually in coastal marshes and estuaries.

carnivore

an animal that mainly eats meat

chemical

uses smells or other chemicals to communicate

echolocation

The process by which an animal locates itself with respect to other animals and objects by emitting sound waves and sensing the pattern of the reflected sound waves.

ecotourism

humans benefit economically by promoting tourism that focuses on the appreciation of natural areas or animals. Ecotourism implies that there are existing programs that profit from the appreciation of natural areas or animals.

endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

estuarine

an area where a freshwater river meets the ocean and tidal influences result in fluctuations in salinity.

female parental care

parental care is carried out by females

fertilization

union of egg and spermatozoan

food

A substance that provides both nutrients and energy to a living thing.

holarctic

a distribution that more or less circles the Arctic, so occurring in both the Nearctic and Palearctic biogeographic regions.

World Map

Found in northern North America and northern Europe or Asia.

migratory

makes seasonal movements between breeding and wintering grounds

motile

having the capacity to move from one place to another.

natatorial

specialized for swimming

native range

the area in which the animal is naturally found, the region in which it is endemic.

pelagic

An aquatic biome consisting of the open ocean, far from land, does not include sea bottom (benthic zone).

piscivore

an animal that mainly eats fish

polar

the regions of the earth that surround the north and south poles, from the north pole to 60 degrees north and from the south pole to 60 degrees south.

polyandrous

Referring to a mating system in which a female mates with several males during one breeding season (compare polygynous).

saltwater or marine

mainly lives in oceans, seas, or other bodies of salt water.

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

social

associates with others of its species; forms social groups.

tactile

uses touch to communicate

ultrasound

uses sound above the range of human hearing for either navigation or communication or both

vibrations

movements of a hard surface that are produced by animals as signals to others

viviparous

reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.

References

National Marine Fisheries Service. Conservation Plan for the Cook Inlet beluga whale (Delphinapterus leucas). none. Juneau, Alaska: National Marine Fisheries Service. 2008.

Barbero, B., L. Thomas. 1960. A record of Pharurus oserkaiae (Skrjabi, 1942) in an Alaskan whale. The Journal of Parasitology, 46/6: 726.

Colbeck, G., P. Duchesne, L. Postma, V. Lesage, M. Hammill, J. Turgeon. 2012. Groups of related belugas (Delphinapterus leucas) travel together during their seasonal migrations in and around Hudson Bay. Proceedings of the Royal Society B, 280/1752: 9.

Dressler, W., F. Berkes, J. Mathias. 2001. Beluga hunters in a mixed economy: Managing the impacts of nature-based tourism in the Canadian western Arctic. Polar Record, 37/200: 35-48.

Friesen, M., C. Arnold. 1995. Zooarchaeology of a focal resource: Dietary importance of beluga whales to the precontact Mackenzie Inuit. Arctic, 48/1: 22-30.

Hoover, C., M. Bailey, J. Higdon, S. Ferguson, R. Sumaila. 2013. Estimating the economic value of narwhal and beluga hunts in Hudson Bay, Nunavut. Arctic, 66/1: 1-16.

Jefferson, T., L. Karkzmarski, K. Lairde, G. O'Corry-Crowe, R. Reeves, L. Rojas-Bracho, E. Secchi, E. Slooten, B. Smith, J. Wang, K. Zhou. 2012. "Delphiapterus leucas" (On-line). IUCN Red List of Threatened Species 2012. Accessed January 28, 2016 at http://www.iucnredlist.org/details/6335/0.

Kelley, T., R. Stewart, D. Yurkowski, A. Ryan, S. Ferguson. 2015. Mating ecology of beluga (Delphinapterus leucas) and narwhal (Monodon monoceros) as estimating by reproductive tracts. Marine Mammal Science, 31/ 2: 479-500.

Laidre, K., K. Shelden, D. Rugh, B. Mahoney. 2000. Beluga, Delphinapterus leucas, habitat associations in Cook Inlet, Alaska. Marine Fisheries Review, 62/3: 27-36.

Lydersen, C., A. Martin, K. Kovacs, I. Gjertz. 2001. Summer and autumn movements of white whales Delphinapterus leucas in Svalbard, Norway. Marine Ecology Progress Series, 219: 265-274.

Macdonald, D. 1985. The Encyclopedia of Mammals. New York: Facts on File.

Matthews, C., S. Ferguson. 2015. Weaning age variation in beluga whales (Delphinapterus leucas). Journal of Mammalogy, 96/2: 425-437.

Moore, S., K. Shelden, L. Litzky, B. Mahoney, D. Rugh. 2000. Beluga, Delphinapterus leucas, habitat associations in Cook Inlet, Alaska. Marine Fisheries Review, 62/3: 60-80.

Recchia, C. 1994. Social Behavior of Captive Belugas, Delphinapterus leucas (Ph.D. Dissertation). Cambridge, MA: Massachusetts Institute of Technology.

Saxon, L., A. Sirovic, E. Roth. 2013. Effect of construction noise on the Cook Inlet beluga whale (Delphinapterus leucas) vocal behavior. Canadian Acoustics, 31/3: 14.

Shaffer, S., D. Costa, T. William, S. Ridgway. 1997. Diving and swimming performance of white whales, Delphinapterus leucas: An assessment of plasma lactate and blood gas levels and respiratory rates. Journal of Experimental Biology, 200: 3091-3099.

Shelden, K., D. Rugh, B. Mahoney, M. Dahlheim. 2006. Killer whale predation on belugas in Cook Inlet, Alaska: Implication for a depleted population. Marine Mammal Science, 19/3: 529-544.

Shirihai, H., B. Jarrett. 2006. Whales, Dolphins, and Other Marine Mammals of the World. Princeton, NJ: Princeton University Press.

Stewart, B., R. Stewart. 1989. Delphiapterus leucas. Mammalian Species, 336: 1-8.

Watson, L. 1981. Sea Guide to Whales of the World. London, United Kingdom: Hutchinson.

Weigl, R. 2005. Longevity of Mammals in Captivity; from the Living Collections of the World. Stuttgart: Kleine Senckenberg-Reihe.