Discovering the Narwhal - Amazon Web Services · Web viewSuch behavior might help determine social rank and maintain dominance hierarchies, similar to the antlers of a stag. Narwhals

Discovering the Narwhal

Unicorn of the Sea

Lara Arbach

12/3/2009

Narwhal, Monodon monoceros, and Qilalugaq qernartaq are three descriptions of an arctic

whale characterized by its legendary tusk (Nweeia and Meehan). Narwhal translates from Old Norse, the

prefix “Nar” means “corpse” and “hval” means “whale” (Laidre and Heide-Jørgensen). Thus “corpse-

like,” the animal’s grayish, mottled pigmentation resembles that of a drowned sailor (Narwhal). The

narwhal was one of the many species originally described by Linneaus in 1758 in his book, Systema

Naturae (Narwhal). Carl Linnaeus was a Swedish botanist, physician, and zoologist who laid the

foundations for the modern scheme of binomial nomenclature. He is known as the father of modern

taxonomy, and his main contribution to science was to establish conventions for the naming of living

organisms that became universally accepted in the scientific world (Carl Linneaus). He documented the

species name for the narwhal’s most unique feature, its unicorn-like single tusk found on most males

(Nweeia and Meehan); Monodon monoceros, means “one tooth, one horn” (Laidre and Heide-

Jørgensen). The Inuit name, Qilalugaq qernartaq, translates to mean “the one that points to the sky,”

describing the narwhal’s unique behavior of pointing the tusk straight upward out of the water (Nweeia

and Meehan).

The Inuit people of Northern Canada and Greenland have respected the ancient narwhals for

thousands of years, and have honored them in their traditions and culture. An Inuit legend of how the

narwhal came to be started with a wicked woman who lived with her daughter and her blind son. As the

son got older, his sight improved, even though the mother tried to convince him of his helpless state.

Time passed and an old man came to the house for a visit, and told the young girl how she could help

her brother regain his sight. In the spring, he told them to watch for a red throated loon at a nearby lake

who would swim trustingly towards them. Once the loon was close enough, the blind brother wrapped

his arms around the loon's neck and took him to the bottom of the lake. Once they emerged from the

water, his sight returned. The loon told the young man not to mention his regained sight until later in

the summer when the loon would send a pod of belugas to their campsite. When summer came and the

ice began to break, the belugas began to move. One morning, a pod was closer to land than usual. The

young man grabbed his harpoon and told his sister to accompany him to help him aim. They went to the

shoreline, and the mother seeing the son with a harpoon became concerned and followed them. Once

she was close to them, the son gave the end of the line from the harpoon to his mother, asking her to tie

it around her waist to hold the harpooned animal. The son aimed for the largest whale and harpooned

it. The mother was cast into the sea, and as she submerged into the water she spiraled around the line

transforming into the whale, with her long hair twisting in the water until it became the characteristic

spiral narwhal tusk (Nweeia and Meehan).

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The narwhal has been a long fascination for sea explorers and scientists by its unique physical

characteristics. Infant narwhals, called calves, are gray or dark bluish-gray. After two years, the skin

becomes more mottled with overlapping white patches, and the gray color becomes more blackened.

Adults are white on the ventral side, and light brown and mottled on the dorsal side (Nweeia and

Meehan). The patchy discoloration resembles livor mortis; a settling of blood underneath the skin when

death occurs (Lambert). Older adults have only a narrow dark triangular band extending from the back

of the neck at its widest portion to a point ending on the midline of the back (Nweeia and Meehan).

About four inches of fat insulates the narwhal from the cold Arctic waters (Narwhal: Arctic Animals).

Males can reach a length of five meters (approximately 16 feet) and weigh up to 1,600 kg (about 3,500

pounds). Females are somewhat smaller, reaching a length of four meters (approximately 13 feet) and

1,000 kg (2,200 pounds) (Laidre and Heide-Jørgensen). Compared to other cetaceans, marine mammals

such as whales and dolphins, narwhals have a small head, blunt snout, short rounded flippers, and

convex rather than concave tail flukes. They have no dorsal fin, but have a ridge about five centimeters

high that runs along the posterior end on the dorsal side, which measures 60 - 90 centimeters (24 – 35

inches) long (Narwhal, Monodon monoceros). There is currently no reliable method for determining the

age of narwhal, (Nweeia and Meehan) however, narwhals have been recorded to live 50 years or more

(Laidre and Heide-Jørgensen).

The narwhal is a gregarious species commonly found in groups, or “pods,” sometimes up to 20

individuals varying combinations of males, females, and calves (Narwhal Whales), but are mostly found

in groups of three to eight, which are regularly segregated by sex. (Laidre and Heide-Jørgensen). The

male narwhal reaches sexual maturity at eight to nine years old, and the female at four to seven years

old. Narwhal are seasonally estrous, typically breed in mid-April (Narwhal Whales), and mate in the

water belly to belly (Narwhal, Monodon monoceros). The female is able to give birth to a single calf once

every three years with a 15-month gestation period (Narwhal Whales), however, in rare cases the birth

of twins have been recorded. Calves are born tail first and measure 1.5 - 1.7 meters (approximately 5

feet) long and weigh 80 kg (176 pounds), with about a 25 millimeter thick layer of blubber (Narwhal,

Monodon monoceros). Narwhal calves are usually born in July, are rarely born outside deep bays and

inlets, and remain with the female for up to 20 months after they are born. Newborn calves are dark

blue-gray, but as they mature the back transforms to an olive brown and begins to develop the mottled

spotting, which is most often seen in adult narwhals.

One of the most distinguished characteristic traits of the narwhal is a tusk protruding from its

forehead. The narwhal is an odontocete, a toothed whale, but is different from other toothed whales

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because it has no teeth in its mouth (Laidre and Heide-Jørgensen). Calves initially develop six pairs of

maxillary teeth and two pairs of mandibular teeth. Only one pair from the maxillary jaw develops and

the others are vestigial, or functionless (Nweeia and Meehan). The male develops a long, straight tusk

that projects two to three meters (roughly nine feet) from its head, grows in a counter-clockwise spiral,

and can weigh up to 10 kg (22 pounds) (Laidre and Heide-Jørgensen). The tusk is the left incisor tooth

protruding out of the upper left side of the jaw through the lips, and is variable in length, girth,

morphology, wear, and coloration depending on the whale and age (Nweeia and Meehan). The tusk is

flexible, able to bend about a foot in any direction without breaking (Lambert). The right tooth remains

embedded in the jaw and measures roughly one foot (Nweeia and Meehan). About one in 500 males can

produce two tusks, which occurs when the right incisor tooth also grows out (Narwhal). On rare

occasions, females can produce a tusk, which are shorter, straighter, and have a more regularly defined

morphology (Nweeia and Meehan). The narwhal tooth is the only straight tusk in the world, and also

one of the only spiral tooth (Lambert).

Narwhals can be found in the Atlantic portion of the Arctic Ocean; concentrating in the Canadian

high Arctic, Baffin Bay, Davis Straight, and northern Hudson Bay. They can also be found in less numbers

near Alaska, and in the Greenland Sea extending to Svalbard to Severnaya Zemlya off Russia (Nweeia

and Meehan). The most northern sighting of narwhals has occurred north of Franz Joseph Land, at about

85° North latitude (Narwhal). Narwhals are one of the northernmost cetacean species with a smaller

range. They stay near the loose pack ice, where they maintain breathing holes, and prefer deep water,

migrating with the seasonal advance and retreat of the ice (Narwhal, Monodon monoceros). In the

summer, they occupy deep bays and fjords in the Canadian high Arctic and Greenland. During the

summer migratory season, smaller groups combine with other groups to form large pods. As winter

approaches, narwhals migrate into the pack ice of Baffin Bay, the northern Davis Strait, and adjacent

waters. During months when ice is forming, narwhals are in danger of being trapped beneath the ice.

Such entrapments are known to have killed hundreds of narwhals. Narwhals have predictable migration

patterns and are creatures of habit. Even though they spend a large amount of time offshore far from

humans, they still move along the coast, and pass certain promontories, bays, or fjords at precisely the

same time each year (Laidre and Heide-Jørgensen).

Most notable of the narwhal’s adaptations is their ability to perform deep dives. In summer,

narwhals often dive to depths between 30 and 300 meters (approximately 98 – 980 feet), although they

spend most of their time at or below 50 meters (Narwhal). In fall, dive depths and durations increase

when narwhals migrate towards their wintering grounds. When at their wintering grounds, they stay in a

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fairly limited area for six months and make small movements with the shifting leads and cracks in the

pack ice (Laidre and Heide-Jørgensen). Narwhals typically dive to at least 800 meters (around 2,600 feet)

between 18 and 25 times per day, every day for six months. Many of these dives are even deeper of at

least 1,500 meters (roughly 4,900 feet) (Narwhal); some of the deepest diving ever recorded for a

marine mammal. Dives to these depths last around 25 minutes which includes the transit down, time

spent at the bottom, and back to the surface. In addition to making remarkably deep dives, narwhals

also spend a large amount of their time below 800 meters greater than three hours per day. This is an

incredible amount of time at a depth with an enormous amount of pressure exceeding 2,200 PSI

(pounds per square inch) and lack of air, which requires special adaptations for survival. Narwhals have a

compressible rib cage which is flexible and can be squeezed as the water depth increases. They have a

high concentration of myoglobin in their muscles (a molecule which binds oxygen); twice as much as

some seal species and eight times as much as terrestrial mammals, even those specialized in fast

running. An average-sized narwhal can carry 70 liters of oxygen in its lungs, blood, and muscles meeting

oxygen demands for more than 20 minutes underwater at swim speeds of one meter/second.

Furthermore, the narwhal does not have fast-twitch fibers in its skeletal muscles (like a dolphin), but

instead has muscles suited for endurance swimming (less oxygen demanding). During its dive, a narwhal

can save oxygen by shutting off blood flow to selected organs or non-critical body parts. Finally,

narwhals have streamlined bodies and can glide easily through the water column towards the bottom.

This helps minimize oxygen consumption to work the muscles and ultimately saves energy (Laidre and

Heide-Jørgensen).

It is thought that narwhals produce sounds in their nasal passages (Hebridean Whale and

Dolphin Trust). The melon, a fatty organ located at the cranial portion of the head, focuses these sounds

into a beam before sending them out. The sound waves travel until they hit something, at which point

the echoes bounce back to the whale (Lambert). The whale receives these echoes either in the lower

jaw or directly in the skull, depending on the frequency of the sound (Hebridean Whale and Dolphin

Trust). Each sound wave has a different range of frequencies, depending on what the whales need

echolocation for; low-frequency sounds go farther, while high-frequency sounds are suited to short

distances (Lambert). Narwhals whistle and produce a combined pulsed/tonal sound (Institution). A wide

variation of clicks and whistles are used, with click rates varying from three to 150 clicks per second

(Nweeia and Meehan). Researchers suspect the narwhals use echolocation to communicate as well as to

hunt (Lambert).

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Identifying what narwhals eat has proven to be a difficult task for researchers. Narwhals

navigate polynyas, which are pools of open water in otherwise iced-over environments. The polynyas

are rich in organisms, such as phytoplankton and copepods, that serve as the feeding grounds for

biodiverse marine animals (Lambert). However, narwhals mostly prefer waters far offshore covered in

sea ice where they eat at great depths in complete darkness. Because of this, no direct observations of

narwhal feeding has ever been made. An alternate method is used to discover the eating habits, by

examining the stomachs of dead whales. The results of examining hundreds of narwhal stomachs over

the past ten years have identified patterns implying they are carnivores, and have a very restricted and

specialized diet. Narwhals eat only a few prey species; primarily Greenland halibut, the polar and Arctic

cod, shrimp, and Gonatus squid. Occasional exceptions have been wolffish, capelin, skate eggs, and

sometimes rocks are accidentally ingested when the whales feed near the bottom (Laidre and Heide-

Jørgensen).

Narwhals change their diet seasonally. In winter, they feed intensively on Greenland halibut or

Gonatus squid. They eat a lot of Greenland halibut, because the bulk of their energy uptake occurs on

the wintering grounds in Baffin Bay where the narwhals spend more than half of the year. The many

deep dives also indicate the narwhals feed mostly on the bottom. The summer ice-free season, between

July and September, is not used for intense feeding and whales have very little in their stomachs except

for the Arctic cod. The narwhal’s concentrated winter feeding period is likely an adaptation to relatively

low productivity in the high arctic summering areas, or a behavioral trait to avoid competition with

lower latitude whales feeding in summer (Laidre and Heide-Jørgensen).

The purpose of having such a large tooth has been discussed by scientists for centuries. Many

suggestions have been made, such as narwhals using their tusk to dig up the seafloor, spear prey,

making holes in sea ice, or to determine sea ice thickness. It cannot serve a critical function for survival,

because females rarely have a tusk and live longer than males (Laidre and Heide-Jørgensen). It is

thought to play a strong role in the mating activity of the whale, as they have been seen with their tusks

crossed to possibly determine dominance. Additionally, the tusk is known to experience a growth-spurt

at sexual maturity in males; this has been interpreted as suggesting there is a possible breeding function

tied into the narwhal tusk (Narwhal Whales). During the summer in the northern Canadian high Arctic

bays and fjords, male narwhals can be seen carefully crossing their tusks as though they are practicing

sword fighting, called “tusking,” and making a strange, sad whistle. Such behavior might help determine

social rank and maintain dominance hierarchies, similar to the antlers of a stag. Narwhals have not been

observed using their tusk for fighting or other aggressive behavior (Laidre and Heide-Jørgensen).

[6]

Often associated with the mythical unicorn, the narwhal’s tooth has found its way into the

books of scientific rarities and fantasy tales (Nweeia and Meehan). Some medieval Europeans believed

narwhal tusks to be the horns from the legendary unicorn. As these horns were considered to have

magic powers, such as the ability to cure poison and melancholia, Vikings and other northern traders

were able to sell them for many times their weight in gold. The tusks were used to make cups that were

thought to negate any poison that may have been slipped into the drink. During the 16th century,

Queen Elizabeth received a carved and bejeweled narwhal tusk worth £10,000, around the cost of a

castle (approximately £1.5 million; $2.5 million worth in 2007) (Narwhal).

The truth of the tusk's origin developed gradually during the Age of Exploration, as explorers

and naturalists began to visit Arctic regions themselves. In 1555, Olaus Magnus, Swedish ecclesiastic and

writer, published a drawing of a fish-like creature with a horn on its forehead, correctly identifying it as a

narwhal. The author, Herman Melville wrote a section on the narwhal in Moby Dick, in which he claims

that a narwhal tusk hung for “a long period” in Windsor Castle after Sir Martin Frobisher had given it to

Queen Elizabeth (Narwhal). Artists know the narwhal for its unique association to the famous Unicorn

Tapestries; six from the Lady and the Unicorn hanging at the Cluny Museum in Paris and seven from the

Hunt of the Unicorn at the Cloisters Museum in New York, are among the most renowned and well

known works of art of all time. The tooth is revered by many cultures around the world. In Japan, two

crossed narwhal teeth adorn the entrance to the Korninkaku Palace. In Denmark multiple teeth decorate

the frame of the Danish throne. The royal scepter in England is made from the rare tusk. The unicorn

and the narwhal tooth continue as an endless source of fascination in modern culture (Nweeia and

Meehan).

The Narwhal Tusk Research, founded in 2000, is a multinational collaboration with an

interdisciplinary approach that crosses the borders of biologic, chemical, physical, and social science to

discover the purpose and function of the erupted tusk of the narwhal. 27 Institutions worldwide and

over 48 scientists with a myriad of backgrounds in cellular biology, histology, anatomy, marine mammal

science, dental medicine, evolutionary genetics, and mathematics, have combined their insights with 32

experienced Inuit elders. The Inuit elders have extensive skills as hunters and guides from the Eastern

Canadian high Arctic and Western Greenland are continuing to provide traditional knowledge, guide,

and direct current findings and past studies about the behavioral and social characteristics of the

narwhal and its tusk (Nweeia and Meehan).

The Tusk Research was successfully able to discover the results of the function of the tusk, as

revealed by Dr. Martin Nweeia, a clinical instructor at the Harvard School of Dental Medicine (Lambert).

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The bottom end of the tusk appears clean and polished, however, the remaining tusk is often covered in

algae. The tusks are made up of an outer layer of cement, an inner layer calcareous hard tooth material

called dentine, and a pulp cavity rich in blood that holds the tusk in place. Narwhals often break tusks,

however, they are able to repair the damage with new dentine growth (Narwhal, Monodon monoceros).

According to a Press Release from the Harvard Medical School dated December 13, 2005:

"Dr. Nweeia has discovered that the narwhal's tooth has hydrodynamic sensor capabilities. Ten

million tiny nerve connections tunnel their way from the central nerve of the narwhal tusk to its

outer surface. Though seemingly rigid and hard, the tusk is like a membrane with an extremely

sensitive surface, capable of detecting changes in water temperature, pressure, and particle

gradients. Because these whales can detect particle gradients in water, they are capable of

discerning the salinity of the water, which could help them survive in their Arctic ice

environment. It also allows the whales to detect water particles characteristic of the fish that

constitute their diet. There is no comparison in nature and certainly none more unique in tooth

form, expression, and functional adaptation" (Narwhal, Monodon monoceros).

This sensitive quality does seem to cancel out some of the theories about the tusk, such as the idea male

narwhals use them to duel, although some scientists still argue the tusk is a way of establishing

dominance. Narwhals do touch tusks, but observers have reported them to be nonviolent. Researchers

are unsure, but suggest perhaps it is a form of communication. One theory which still holds is the tusk is

used as a sex characteristic for mating purposes (Lambert).

About 50,000 narwhals are estimated to live in Greenland and Canada, but recent research

suggests the numbers have declined by about 6% since the 1980’s. Three possible causes have been

suggested: hunting, development of inshore fisheries, and climate change (Laidre and Heide-Jørgensen).

Their natural enemies include orcas, polar bears, and rarely walruses. Narwhals have been traditionally

hunted by the Inuits, who are allowed to hunt a certain number of narwhals a year in accordance with

their traditions and culture (Lambert). The Canadian government instituted the Narwhal Protection

Regulation under the Fisheries Act in 1971. This made hunting narwhals illegal for anyone other than the

Inuits. There is a catch limit of five narwhals a year per subsistence hunter, and hunters are required to

utilize every part of the narwhal (Narwhal - Wildlife). Almost all parts of the narwhal, meat, skin, blubber

and organs, are consumed (Narwhal). Inuits dine on the top layer of skin and blubber, called muktuk or

maktaaq, for vitamin C, a scarce commodity in the Arctic (Lambert). The narwhal’s bones are used for

tools and art (Narwhal), and their tusks are also valued commercially in Canada and Greenland,

however, international efforts to control the global ivory trade may have reduced tusk sales in recent

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years (Laidre and Heide-Jørgensen). The narwhal has been deemed particularly vulnerable to climate

change, due to their narrow geographical range and specialized diet (Narwhal). Because narwhals are

wedded to their pack ice environment, changes in sea ice have a huge impact on their migration

patterns and survival. If the ice is too thick, narwhals can get trapped under it and cannot surface to

breathe. If the ice is too thin, predators may find it easier to hunt them and their prey may move

elsewhere (Lambert).

As a consequence of the whale’s elusiveness, scientists can only identify a few infestations the

narwhal can harbor, such as whale lice located on the base of the tusk, and certain nematodes, or

roundworms (Narwhal: Arctic Animals). Narwhals can also be susceptible to new diseases, as a result of

climate change. Ole Nielson, a researcher with the Federal Department of Fisheries and Oceans, is

concerned that climate change may introduce new diseases that could decimate the North’s narwhal

and beluga whale populations. Diseases such as distemper and brucellosis could trigger dramatic die-offs

among northern whale groups. Distemper, similar to the disease that affects household pets, can cause

seizures and ultimately death in aquatic mammals. As the oceans warm with climate changes, animals

known to carry the disease, such as dolphins, will come north. The disease produced by bacteria, can

cause weight loss in animals, infertility, and lameness. It can also spread to humans, which is why

Nielson is recommending whale harvesters take care when butchering animals. While none of the

narwhals or beluga whales Nielson have tested has distemper, he said those animals would

be defenseless against the disease if they came into contact with it (CBC News - North). About 6% of the

Arctic beluga whale samples tested up to the mid-1990’s was positive for brucellosis, a disease that can

cause reproductive failure and late abortions. Since then, the infection rate has been rising. At best,

natural immunity will protect most species from diseases that have until now been kept in check by cold

temperatures, or by climatic conditions that prevent disease-carrying animals from expanding their

range northward (Disease, the Scariest Threat).

Integrating scientific needs and objectives with habitat preferences and diving abilities of

narwhals will allow for new investigations to be made. Due to harsh winter conditions in the Arctic,

scientists have employed the use of narwhals as part of a research project to determine global warming

conditions in the waters, and also provide researchers the opportunity to observe narwhals in their

winter habitat. The purpose of the exploration project is to improve understanding of climatic changes

occurring in an offshore ecosystem of Baffin Bay, and how these changes may affect narwhal

populations who are part of that ecosystem. Satellite tags are attached to narwhals inserted through the

dorsal ridge on the whale’s back. These satellite-linked, time-depth-temperature recorders track

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narwhal whale movements, diving behavior, and ocean temperature structure in Baffin Bay. The

instruments collect water column temperature profiles in the pack ice to more than 1,500 meters in

depth when narwhals make a fall migration from north Greenland to their wintering grounds in Baffin

Bay (Laidre and Heide-Jørgensen). With success, scientists will have a better understanding of narwhal’s

winter habitats, along with rising water temperatures in the Arctic.

Narwhal whales have given rise to countless myths and legends over the ages. Existing in their

domain beneath the cold, deep waters, they have fascinated artists, philosophers, and storytellers.

Being one of the ocean’s most intriguing creatures, narwhals have evolved to take advantage of a world

dominated by ice. The Inuit’s hunting techniques and skills gave them access to the narwhal’s tusks,

which were subsequently traded to European explorers, who used the delicate spiral teeth to keep alive

the fable of the unicorn. Today, the narwhal is part of the Inuit diet in both Canada and Greenland,

where it is known respectively. In the early 21st century, researchers replaced the countless myths and

legends with biological descriptions and population survey data. In some cases, what we have learned is

reassuring, but in others the news is troubling. The narwhal’s habitat is changing, and the evidence is

growing that unless we do our part in protecting its fate, the narwhal could drift back into the realm of

legend.

[10]

Range of narwhal sightings in Canada and Greenland. (Hrynyshyn)

[11]

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"Disease, the Scariest Threat." 2 December 2007. Canada.com. 18 November 2009 <http://www.canada.com/edmontonjournal/features/thebigthaw/features/thebigthaw/story.html?id=bae648e5-3533-49a0-9947-7f7f3a2d22d5&amp;k=57488>.

Hebridean Whale and Dolphin Trust. 2008. 22 November 2009 <http://www.whaledolphintrust.co.uk/index.asp>.

Hrynyshyn, James. "Canada's Narwhal Whale." (2004): 2.

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Laidre, Dr. Kristen and Dr. Mads Peter Heide-Jørgensen. "Tracking Narwhals in Greenland: Biology." 7 December 2007. NOAA Ocean Explorer. 18 November 2009 <http://oceanexplorer.noaa.gov/explorations/06arctic/background/biology/biology.html>.

Lambert, Katie. "Meet the Narwhal." 30 October 2008. How Stuff Works. 18 November 2009 <http://animals.howstuffworks.com/mammals/narwhal1.htm>.

"Narwhal." November 2009. Wikipedia, the Free Encyclopedia. 21 November 2009 <http://en.wikipedia.org/wiki/Narwhal>.

"Narwhal - Wildlife." 2009. Defenders of Wildlife. 18 November 2009 <http://www.defenders.org/wildlife_and_habitat/wildlife/narwhal.php>.

"Narwhal Whales." 2009. Narwhal: A Real Life Fairytale. 21 November 2009 <http://www.narwhalwhales.com>.

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"Narwhal: Arctic Animals." 1998. Animals of the Arctic. 18 November 2009 <http://library.thinkquest.org/3500/Narwhal.html>.

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