The bowhead whale ( Balaena mysticetus), sometimes called the Greenland right whale, Arctic whale, and polar whale, is a species of baleen whale belonging to the family Balaenidae and is the only living representative of the genus Balaena. It is the only baleen whale Endemism to the Arctic and subarctic waters, and is named after its characteristic massive triangular skull, which it uses to break through Arctic ice.
Bowheads have the largest mouth of any animal representing almost one-third of the length of the body, the longest baleen plates with a maximum length of , and may be the longest-lived mammals, with the ability to reach an age of more than 200 years.
The bowhead was an early whaling target. Their population was overfishing before a 1966 moratorium was passed to protect the species. Of the five stocks of bowhead populations, three are listed as "endangered", one as "vulnerable", and one as "lower risk, conservation dependent" according to the IUCN Red List. The global population is assessed as of least concern.
Taxonomy
Carl Linnaeus named this species in the tenth edition of his
Systema Naturae (1758).
It was seemingly identical to its relatives in the North Atlantic, North Pacific, and
, and as such they were all thought to be a single species, collectively known as the "right whale", and given the binomial name
Balaena mysticetus.
Today, the bowhead whale occupies a monotypic taxon genus, separate from the , as proposed by the work of John Edward Gray in 1821.[
]
For the next 180 years, the family Balaenidae was the subject of great taxonometrics debate. Authorities have repeatedly recategorized the three populations of right whale plus the bowhead whale, as one, two, three or four species, either in a single genus or in two separate genera. Eventually, it was recognized that bowheads and right whales were different, but there was still no strong consensus as to whether they shared a single genus or two. As recently as 1998, Dale Rice listed just two species – B. glacialis (the right whales) and B. mysticetus (the bowheads) – in his comprehensive and otherwise authoritative classification.[
]
Studies in the 2000s finally provided clear evidence that the three living right whale species comprise a phylogenetic lineage, distinct from the bowhead, and that the bowhead and the right whales are rightly classified into two separate genera.[
]
The right whales were thus confirmed to be in a separate genus, Eubalaena. The relationship is shown in the cladogram below:
The earlier fossil record shows no related cetacean after Morenocetus, found in a South American deposit dating back 23 million years.
An unknown species of right whale, the so-called "Swedenborg whale", which was proposed by Emanuel Swedenborg in the 18th century, was once thought to be a North Atlantic right whale. Based on later DNA analysis, those fossil bones claimed to be from Swedenborg whales were confirmed to be from bowhead whales.[
]
Description
The bowhead whale is among the largest baleen whale species and is distinguished by its round body with an exceptionally curved rostrum, a large head, and long, dark
Baleen. Relative to its size, the bowhead whale has the largest head of any
cetacean,
measuring nearly 40% of the total body length.
Two blowholes are situated atop its head, and help propell a stream of water up to in the air.
The lower lips encompasses the baleen racks and resembles a curved circular shape when viewed from the side. It also has wide, trigonal flukes and fairly large, oar-shaped flippers. The skin is mostly black with white patches around the flukes, tail, eyes, and chin. These patches develop throughout life, with the exception of the patch surrounding the chin, which is usually visible in newborn calves, and increases in size at the same rate with the whale's overall growth.
An adult whale usually measures in length and in weight. The fluke of this species measures long and the 230 to 360 baleen plates are thought to grow to long, which is longer than that of any other whale by more than a meter. This species is sexually dimorphic as females usually reach lengths of , while males average . There are, however, some specimens that exceed these sizes. In one instance, a female killed off the waters of Pond Inlet in the 1800s allegedly measured . Some estimates put the total maximum length higher at about .
Analysis of hundreds of DNA samples from living whales and from baleen used in vessels, toys, and housing material has shown that Arctic bowhead whales have lost a significant portion of their genetic diversity in the past 500 years. Bowheads originally crossed ice-covered inlets and straits to exchange genes between Atlantic and Pacific populations. This conclusion was derived from analyzing maternal lineage using mitochondrial DNA. Whaling and climatic cooling during the Little Ice Age, from the 16th century to the 19th, is supposed to have reduced the whales' summer habitats, which explains the loss of genetic diversity.
A 2013 discovery has clarified the function of the bowhead's large palatal retial organ. The bulbous ridge of highly vascularized tissue, the corpus cavernosum maxillaris, extends along the centre of the hard plate, forming two large lobes at the rostral palate. The tissue is histologically similar to that of the corpus cavernosum of the mammalian penis. This organ is thought to provide a mechanism of cooling for the whale (which is normally protected from the cold Arctic waters by or more of fat). During physical exertion, the whale must cool itself to prevent hyperthermia (and ultimately brain damage). This organ becomes engorged with blood, and as the whale opens its mouth cold seawater flows over the organ, thus cooling the blood.
In one study, the brain size of two males that measured in total length, were recorded at , respectively. With a gyrencephalic index of 2.32, the brains of the two males were found to exhibit extreme gyrification. Compared to other cetaceans, their brain had a lower level of gyrification in the cerebral cortex, more vertically-aligned gyri, and a relatively dull temporal pole region.
Behaviour
Swimming
The bowhead whale is not a social animal, typically travelling alone or in small pods of up to six. It is able to dive and remain submerged under water for up to an hour. The time spent under water in a single dive is usually limited to 9–18 minutes.
[Würsig, B. and C. Clark (1993). "Behavior". In Burns et al.] The bowhead is not thought to be a deep diver, but can reach a depth down to . It is a slow swimmer, normally travelling around .
When fleeing from danger, it can travel at a speed of . During periods of feeding, the average swim speed is increased to .
Feeding
The head of the bowhead whale comprises a large portion of its body length, creating an enormous feeding apparatus.
The bowhead whale is a
filter feeder, and feeds by swimming forward with its mouth wide open.
It has hundreds of overlapping
baleen plates consisting of
keratin hanging from each side of the upper jaw. The mouth has a large, upturning lip on the lower jaw that helps to reinforce and hold the baleen plates within the mouth. This also prevents buckling or breakage of the plates from the pressure of the water passing through them as the whale advances. To feed, water is filtered through the fine hairs of keratin of the baleen plates, trapping the prey inside near the tongue where it is then swallowed.
[ Bowhead Whale . American Cetacean Society. Retrieved on 16 November 2015.] The diet consists of mostly
zooplankton, which includes
krill,
copepods,
,
amphipods, and many other
crustaceans.
About of food are consumed each day.
While foraging, bowheads are solitary or occur in groups of two to 10 or more.
[Lowry, L. F. (1993). "Foods and Feeding Ecology". In Burns et al.]
Vocalization
Bowhead whales are highly vocal
and use low frequency (<1000 Hz) sounds to communicate while travelling, feeding, and socialising. Intense calls for communication and navigation are produced especially during migration season. During breeding season, bowheads make long, complex, variable songs for mating calls.
Many tens of distinct songs are sung by a population in a single season.
From 2010 through to 2014, near
Greenland, 184 distinct songs were recorded from a population of around 300 animals.
Reproduction
Sexual activity occurs between pairs and in boisterous groups of several males and one or two females. Breeding season is observed from March through August; conception is believed to occur primarily in March when song activity is at its highest.
Reproduction can begin when a whale is 10 to 15 years old. The
gestation period is 13–14 months with females producing a calf once every three to four years.
[Koski, William R., Rolph A. Davis, Gary W. Miller, and David E. Withrow (1993). "Reproduction", p. 245 in Burns et al.] Lactation typically lasts about a year. To survive in the cold water immediately after birth, calves are born with a thick layer of
blubber. Within 30 minutes of birth, bowhead calves are able to swim on their own. A newborn calf is typically long, weighs roughly , and grows to within the first year.
Health
Lifespan
Bowhead whales are considered to be the longest-living mammals, living for over 200 years.
In May 2007, a specimen caught off the
coast was discovered with the head of an explosive
bomb lance of a model manufactured between 1879 and 1885 lodged in its body, so the whale was probably bomb lanced sometime between those years, and its age at the time of death was estimated at between 115 and 130 years.
Spurred by this discovery, scientists measured the ages of other bowhead whales; one specimen was estimated to be 211 years old.
Other bowhead whales were estimated to be between 135 and 172 years old. This discovery showed the
longevity of the bowhead whale is much greater than originally thought.
Researchers at
CSIRO, Australia's national science agency, estimated that bowhead whales' maximum natural lifespan is 268 years based on genetic analysis.
Genetic benefits
A greater number of cells present in an organism was once believed to result in greater chances of
mutations that cause age-related diseases and
cancer.
Although the bowhead whale has thousands of times more cells than other mammals, it has a much higher resistance to cancer and aging. In 2015, scientists from the US and UK were able to successfully map the whale's
genome.
Through comparative analysis, two
alleles that could be responsible for the whale's longevity were identified. These two specific gene mutations linked to the bowhead whale's ability to live longer are the
ERCC1 gene and the proliferating cell nuclear antigen (
PCNA) gene.
ERCC1 is linked to
DNA repair and increased cancer resistance.
PCNA is also important in DNA repair. These mutations enable bowhead whales to better repair DNA damage, allowing for greater resistance to cancer.
The whale's genome may also reveal physiological adaptations such as having low metabolic rates compared to other mammals.
Changes in the gene
UCP1, a gene involved in
thermoregulation, can explain differences in the metabolic rates in cells.
Ecology
Range and habitat
The bowhead whale is the only baleen whale to spend its entire life in the Arctic and subarctic waters.
[Moore, S. E., and R. R. Reeves (1993). "Distribution and Movement". In Burns et al.] The
population spends the winter months in the southwestern
Bering Sea. The group migrates northward in the spring, following openings in the ice, into the
Chukchi Sea and
Beaufort Sea seas.
The whale's range varies depending on
and on the forming/melting of ice.
Historically, bowhead whales' range may have been broader and more southerly than currently thought. Bowheads were abundant around Labrador, Newfoundland (Strait of Belle Isle) and the northern Gulf of St Lawrence until at least the 16th and 17th centuries. It is unclear whether this was due to the colder climate during these periods.
Population
Generally, five stocks of bowhead whales are recognized: 1) the Western Arctic stock in the Bering, Chukchi, and Beaufort Seas, 2) the Hudson Bay and Foxe Basin stock, 3) the Baffin Bay and Davis Strait stock, 4) the Sea of Okhotsk stock, and 5) the Svalbard-Barents Sea stock. However, recent evidence suggests that the Hudson Bay and Foxe Basin stock and the Baffin Bay and Davis Strait stock should be considered one stock based on genetics and movements of tagged whales.
Western Arctic
The Western Arctic bowhead population, also known as the Bering-Chukchi-Beaufort population, has recovered since the commercial harvest of this stock ceased in the early 1900s. A 2019 study estimated that the Western Arctic population was 12,505; although it was lower than the 2011 value of 16,820, the surveyors believed there was no significant decline in 2011–2019 due to the unusual conditions of whale migration and observation in 2019.
The yearly growth rate of the Western Arctic bowhead population was 3.7% from 1978 to 2011. These data suggest that the Western Arctic bowhead stock may be near its precommercial whaling level.
Migration patterns of this population are being affected by
climate change.
Alaskan Natives continue to hunt small numbers of bowhead whales for subsistence purposes. The Alaska Eskimo Whaling Commission co-manages the bowhead subsistence harvest with the National Oceanic and Atmospheric Administration. The Alaskan villages that participate in the bowhead subsistence harvest include Barrow, Point Hope, Point Lay, Wainwright, Nuiqsut, Kaktovik, Gambell, Savoonga, Kivalina, Wales, and Little Diomede.
Baffin Bay and Davis Strait
In March 2008, Canada's Department of Fisheries and Oceans stated the previous estimates in the eastern Arctic had undercounted, with a new estimate of 14,400 animals (range 4,800–43,000).
[ Eastern Arctic bowhead whales not threatened. Cbc.ca (16 April 2008). Retrieved on 15 September 2011.] These larger numbers correspond to prewhaling estimates, indicating the population has fully recovered. However, if climate change substantially shrinks sea ice, these whales could be threatened by increased shipping traffic.
[Laidre, Kristin (22 January 2009) "Foraging Ecology of Bowhead Whales in West Greenland." Monster Jam. Northwest Fisheries Science Center, Seattle.]
The status of other populations is less well known. About 1,200 were off West Greenland in 2006, while the Svalbard population may only number in the tens. However, the numbers have been increasing in recent years.[Norwegian Polar Institute. Bowhead whale ( Balaena mysticetus). npolar.no]
Hudson Bay and Foxe Basin
The
Hudson Bay –
Foxe Basin population is distinct from the
Baffin BayDavis Strait group.
The original population size of this local group is unclear, but possibly about 500 to 600 whales annually summered in the northwestern part of the bay in the 1860s.
[ Species Profile (Bowhead Whale) – Species at Risk Public Registry . Registrelep-sararegistry.gc.ca. Retrieved on 5 November 2016.] It is likely that the number of whales that actually inhabit Hudson Bay is much smaller than the total population size of this group,
[ Hudson Bay-Foxe Basin bowhead whales, Stock status report E5–52. DFO Science, Canada] but reports from local indigenous people indicate that this population is increasing over decades.
Larger portions of the bay are used for summering, while wintering is on a smaller scale. Some animals winter in
Hudson Strait, most notably north of
Igloolik Island and north eastern Hudson Bay. Distribution patterns in these regions are affected by the presence of
orca, and bowheads can disappear from normal ranges in the presence of atypical numbers of orca. Increased mortality caused by orca attack is a possible outcome of
climate change, as reduced ice coverage is expected to result in fewer areas that the bowheads can use for shelter from attack.
Whaling grounds in the 19th century stretched from
Marble Island to Roes Welcome Sound and to
Lyon Inlet and
Fisher Strait, and whales still migrate through most of these areas.
Distribution within Hudson Bay is mostly restricted to the northwestern part
Congregation within Foxe Basin occurs in a well-defined area of north of Igloolik Island to Fury and Hecla Strait and Kapuiviit and , and into Gulf of Boothia and Prince Regent Inlet. Northward migrating along western Foxe Basin to eastern side of the basin also occurs in spring.
Sea of Okhotsk
Not much is known about the endangered Sea of Okhotsk population. To learn more about the population, these mammals have been regularly observed near the
Shantar Islands, very close to the shore, such as at
Ongachan Bay.
Several companies provide
whale-watching services, which are mostly land-based. According to Russian scientists, this total population likely does not exceed 400 animals.
Scientific research on this population was seldom done before 2009, when researchers studying
Beluga whale noticed concentrations of bowheads in the study area. Thus, bowheads in the Sea of Okhotsk were once called "forgotten whales" by researchers. The WWF welcomed the creation of a nature sanctuary in the region
Possibly, vagrants from this population occasionally reach into Asian nations such as off Japan or the Korean Peninsula (although this record might be of a right whale[ ホッキョククジラか、知床沖遊泳 国内観察は極めてまれ. Asahi Shimbun (23 June 2015)] Fossils have been excavated on Hokkaido,
Genetic studies suggest Okhotsk population share common ancestry with whales in Bering-Chukchi-Beaufort Seas, and repeated mixings had occurred between whales in the two seas.
Svalbard-Barents Sea
The most endangered but historically largest of all bowhead populations is the Svalbard/Spitsbergen population.
[Gross A., 2010 Background Document for Bowhead whale Balaena mysticetus. The OSPAR Convention and Musée des Matériaux du Centre de Recherche sur les Monuments Historiques. . retrieved on 24 May 2014] Occurring normally in
Fram Strait,
[Kovacs M.K., Bowhead whale ( Balaena mysticetus). Environmental Monitoring of Svalbard and Jan Mayen. retrieved on 27 May 2014] Barents Sea and
Severnaya Zemlya along
Kara Sea to
Laptev Sea and East Siberian Sea regions, these whales were seen in entire coastal regions in European and Russian Arctic, even reaching to
and
Norway coasts and
Jan Mayen in
Greenland Sea, and west of Cape Farewell and western
Greenland coasts.
Also, bowheads in this stock were possibly once abundant in areas adjacent to the
White Sea region, where few or no animals currently migrate, such as the
Kola Peninsula and
Kanin Peninsula. Today, the number of sightings elsewhere is very small,
[Ritchie B. (June 2013) Arctic shorts – bowhead whale. Vimeo. Retrieved 2 June 2014] but with increasing regularities
[Sala E. (2013) Franz Josef Land Expedition: First Look at Post-Expedition Discoveries. Pristine Seas Expeditions. National Geographic. retrieved on 24 May 2014] with whales having strong regional connections.
[WIIG Ø., Bachmann L., Janik M.V., Kovacs M.K., Lydersen C., 2007. Spitsbergen Bowhead Whales Revisited. Society for Marine Mammalogy. Retrieved 24 May 2014] Whales have also started approaching townships and inhabited areas such as around
Longyearbyen.
[Johannessen, R. (19 October 2011) Dette er en sensasjon!. The Aftenposten. retrieved on 27 May 2014] The waters around the marine mammal sanctuary
[Nefedova T., Gavrilo M., Gorshkov S., 2013. Летом в Арктике стало меньше льда . Russian Geographical Society. retrieved on 24 May 2014] of Franz Josef Land is possibly functioning as the most important habitat for this population.
[European Cetacean Society. Bowhead whales ( Balaena mysticetus) sighting in the Franz Josef Land area. . retrieved on 24 May 2014][Scalini I. (19 February 2014) Всемирный день китов. Russian Arctic National Park. retrieved on 24 May 2014]
It is unclear whether this population is a remnant of the historic Svalbard group, recolonized individuals from other stocks, or if a mixing of these two or more stocks has taken place. In 2015, discoveries of the refuge along eastern Greenland where whaling ships could not reach due to ice floes
Possible moulting area off Baffin Island
During expeditions by a tour operator 'Arctic Kingdom', a large group of bowheads seemingly involved in courtship activities was discovered in very shallow bays south of
Qikiqtarjuaq in 2012.
[Lennartz T. (29 April 2013) New Bowhead Whale Molting Location Found. Arctic Kingdom. retrieved on 9 June 2014] Floating skins and rubbing behaviours at sea bottom indicated possible
moulting had taken place. Moulting behaviours had never or seldom been documented for this species before. This area is an important habitat for whales that were observed to be relatively active and to interact with humans positively, or to rest on sea floors. These whales belong to
Davis Strait stock.
Isabella Bay in Niginganiq National Wildlife Area is the first wildlife sanctuary in the world to be designed specially for bowhead whales. However, moultings have not been recorded in this area due to environmental factors.[ Polar Bears and Glaciers of Baffin Island Webinar on Vimeo. Arctic Kingdom. 2014. retrieved on 9 June 2014]
Predation
In 1978 the International Whaling Commission (IWC) introduced a hunting strike quota for the Bering-
Chukchi Sea-
Beaufort Sea (BCB) bowhead.
The quota has remained at 67 strikes per year since 1998 and represents about 0.5 percent of BCB population.
The population of bowheads in West Greenland and Canada is estimated to be 6,000 and rising, and hunts in this are minimal (<0.001 percent).
Both stocks are rising, and the indigenous hunts seem to be self-sustaining.
Orca are also known predators.
[Philo, L. M., E. B. Shotts, and J. C. George (1993). "Morbidity and Mortality." In Burns et al.] There is no consensus on the number of deaths by orca.
Bowheads seek the ice and shallow waters' safety when threatened by orca.
The Inuit have a traditional word for this behavior to give historical context that this is not a new phenomenon.
Global warming is increasing the frequency that orca are observed in the far north. A once-rare event, orca are now seen more frequently.
There are no reports of attacks on bowheads by sharks.
Whaling
The bowhead whale has been
whaling for
blubber, meat,
whale oil, bones, and baleen. Like the right whale, it swims slowly, and floats after death, making it ideal for whaling.
Before commercial whaling, they were estimated to number 50,000.
[Woodby, D. A. and D. B. Botkin (1993). "Stock Sizes Prior to Commercial Whaling". In Burns et al.] Paleo-Eskimo sites indicate bowhead whales were eaten in sites from perhaps 4000 BC. Inuit people near the Pacific developed specific hunting tools, with the whales providing food and fuel.
Commercial bowhead whaling began in the 16th century when the Basques killed them as they migrated south through the Strait of Belle Isle in the fall and early winter. In 1611, the first whaling expedition sailed to Spitsbergen. The whaling settlement Smeerenburg was founded on Spitsbergen in 1619. By midcentury, the population(s) there had practically been wiped out, forcing whalers to voyage into the "West Ice"—the pack ice off Greenland's east coast. By 1719, they had reached the Davis Strait, and by the first quarter of the 19th century, Baffin Bay.[Ross, W. G. (1993). "Commercial Whaling in the North Atlantic Sector". In Burns et al.]
In the North Pacific, the first bowheads were taken off the eastern coast of Kamchatka by the Danish whaleship Neptun, Captain Thomas Sodring, in 1845.[Bockstoce, J. R., and J. J. Burns (1993). "Commercial Whaling in the North Pacific Sector". In Burns et al.] In 1847, the first bowheads were caught in the Sea of Okhotsk, and the following year, Captain Thomas Welcome Roys, in the bark Superior, of Sag Harbor, caught the first bowheads in the Bering Strait region. By 1849, 50 ships were hunting bowheads in each area; in the Bering Strait, 500 whales were killed that year, and that number jumped to more than 2000 in 1850.[Vaughan, R. (1984). "Historical survey of the European whaling industry". In Arctic Whaling: Proceedings of the International Symposium, pp. 121–145. University of Groningen.]
Bowheads were first taken along the pack ice in the northeastern Sea of Okhotsk, then in Taui Bay and Northeast Gulf (Shelikhov Gulf). Soon, ships expanded to the west, catching them around Iony Island and then around the Shantar Islands. In the Western Arctic, they mainly caught them in the Anadyr Gulf, the Bering Strait, and around St. Lawrence Island. They later spread to the western Beaufort Sea (1854) and the Mackenzie River delta (1889).
Commercial whaling, the principal cause of the population decline, is over. Bowhead whales are now hunted on a subsistence level by native peoples of North America.
In 2024, the Inuit hunters of Aklavik, Northwest Territories were permitted to hunt and kill one bowhead whale to distribute the whale meat, an important part of Inuit cuisine, to Inuvialuit and Gwich'in communities in the region.[ CBC News: For the first time in nearly 30 years, Aklavik, N.W.T., hunters can harvest a bowhead whale]
Conservation
The bowhead is listed in Appendix I by
CITES. While the global population is thought to be secure, thus assigned "least concern" status,
some populations are listed by the National Marine Fisheries Service as "endangered" under the auspices of the United States' Endangered Species Act. The IUCN Red List data are:
The Alaska Department of Fish and Game and the USA government list the bowhead whale as federally endangered.[ Bowhead Whale ( Balaena mysticetus). Alaskan Department of Fish and Game]
The bowhead whale is listed in Appendix I[" Appendix I" of the Convention on the Conservation of Migratory Species of Wild Animals (CMS). As amended by the Conference of the Parties in 1985, 1988, 1991, 1994, 1997, 1999, 2002, 2005, and 2008. Effective: 5 March 2009.] of the Convention on the Conservation of Migratory Species of Wild Animals (Bonn Convention), as this species has been categorized as being in danger of extinction throughout all or a significant proportion of its range. CMS Parties strive towards strictly protecting these animals, conserving or restoring the places where they live, mitigating obstacles to migration, and controlling other factors that might endanger them.
See also
Cited sources
External links
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A documentary by Bill Mason from 1974 following an expedition that searches out and meets the bowhead and Beluga whale.
