Why Do Narwhal’s Have a Horn?


narwhal

Narwhals have a horn or tusk that protrudes from their front. In this article we look at why narwhal’s have a horn and what they use it for.

Narwhals use their horns for echolocation, sparring, mating rituals, and other uses.

For more information on how narwhal’s use their horn, please read on.

Narwhals are medium-sized marine mammals that have a characteristic tusk or horn that protrudes through the top of their heads. It resembles a unicorn’s horn, which made them known in the past as the “unicorns of the sea.” 

narwhal

The name narwhal is derived from the Norse word “nar” which means corpse, and “hval” which means whale. The reason for this name is that the body of the narwhal, which is dappled gray, looks like that of a drowned soldier. Its scientific name, which is Monodon monoceros, means “one tooth, one horn.”

The shape of a narwhal’s body is like a sausage. They have a round head but without a beak. They have a ridge on their backs instead of a fin and short blunt flippers with uncurled edges. They have tail flukes that are odd-shaped. This makes the tail flukes look like they have been put on backwards.

The narwhal is a mysterious creature that has a reclusive nature. They live in the remote Arctic areas. They are shy creatures that are notoriously skittish. They live in groups but come together in the summer.

Want to know more about narwhals. Check out 101 facts I have compiled.

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You can find hundreds or even thousands of them migrating, travelling together, swimming fast and close to the surface. There are times when they simply float on the surface, motionless, but sometimes they will all leap out of the water at the same time. 

What Do Narwhal’s Use Their Horns For?

There are many speculations brought forth as to the use of the narwhal’s horns. Some say that the horn is used to spear food. Others think that it is an acoustic probe for detecting sound, a temperature regulator, or a breathing organ. Still, others say that it is a weapon used for battles against other narwhals or for fending off predators. It has been said to be an icebreaker, a digging tool, or a way to show off to females. 

Because narwhals live in remote regions, it has been difficult to ascertain the use of their tusks. However, studies and research have shown that the narwhal tusk is used in many ways.  The tusk is a multipurpose appendage. 

Here are some of its known uses.

Is A Narwhal’s Horn Used To Catch Food?

People used to think that narwhals used their tusks to catch food by spearing them. However, this would be difficult for them as they don’t have any other appendage to retrieve the food from its tusk.

Recent footages of narwhal activity, however, show they use their tusks to stun their prey by hitting them with quick jagged movements. These movements immobilize the fish so that they become easy prey to the narwhal, who then suck the fish into its mouth since they do not have teeth to chew. This is one of the newly discovered uses of a narwhal’s horn. But there are other purposes of a narwhal’s horn.

Is a Narwhal’s Horn Used As A Sensory Organ?

The tusk of a narwhal is covered in thousands of nerve endings and pores. This helps the narwhal sense and feel the environment around them. With their tusk, they are able to feel their surroundings.

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The tusk acts like having a giant antenna-like sensor. They are able to detect water pressure, temperature, and salinity. The tusk can even detect barometric pressure when it is above the water’s surface.

The heart rate of a narwhal changes when the tusk is exposed to different levels of salt in the surrounding water. They are able to taste chemical concentrations in the water. This helps them to find food, but also females that are ready to mate.

Is a Narwhal’s Horn Used For Echolocation?

Researchers have discovered that narwhals use echolocation. They have the most directional sonar ever detected. They are able to navigate through dark and murky waters by producing clicking sounds.  These sounds are made up to the rate of up to 1000 clicks per second.

They are able to reconstruct their surrounding be using the echoes as the sound waves bounce off nearby rock formations or prey.

Echolocation also helps them find food. Narwhals eat flatfish, shrimp, cod, squid, and crabs. These can be found on the seabed during their long dives. Narwhals have an interesting way of eating. They suck up their food as they create a vacuum in their mouth. 

Narwhals have the edge over all other echolocating species since they are able to sense the tiniest of stimuli. This is because their tusk has no protection of external enamel and so are very sensitive.

The tusk plays an important role in echolocation when seawater enters through the pores in its tip. Bubbles then travel through the shaft exciting nerve endings at the base of the tooth near the head. Signals are then sent to the brain about the narwhal’s surroundings.

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Do Narwhal’s Use Their Tusks As Weapons?

Male narwhals do use their horns to intimidate other males. They go side by side, crossing tusks and rubbing them together in a type of combat. This action is known as tusking. In their territorial battles, narwhals use their tusks to hit their enemies. It is very costly to do this, as their appendages are very sensitive.

Many adult males have dueling scars from these encounters. Some animals have even been found to have tusk-tips lodged in their skulls. 

Do Narwhal’s Use Their Horns To Attract Females?

The narwhal tusk is said to be a sexual trait in males. This is similar to the antlers of a deer, a lion’s mane, or the feathers of a male peacock. The tusk is used as social rank and in competing  for females. During the summer, you can find males crossing their tusks and making whistling noises. Normally, in between them, there is a female narwhal.

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Narwhal tusks can also be a visual indicator used by females for selecting males. This behavior can also help young males develop skills necessary for performing in sexual roles when they become adults.

Do Female Narwhal’s Have Tusks?

Normally, females do not have horns. Horns are mostly a male feature. Occasionally, however, female narwhals grow one. Since only a few females grow horns, it shows us that these tusks are not really meant for survival or feeding since females manage to live longer than males. The tusk has more to do with courtship and mating.

Scientists consider the tusk a male sex characteristic. Only 15% of female narwhals grow a tusk. The tusk is smaller than the males and does not become as prominent as a male’s tusk. Many times, the female tusks simply fall off.

Although many females do not grow tusks, looking inside the upper jaw of a female narwhal and removing sections of bone, you can find two, small, tusks that haven’t broken the surface. Scientists have studied a few skulls of female narwhals in their collection. These small, unerupted tusks serve a purpose that is yet to be discovered.

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What Is A Narwhal’s Horn Made Of?

Narwhal horns are made of ivory, and is similar to the tusk of an elephant.

The outer cementum layer of the narwhal’s tusk is porous. Its inner dentin layer has microscopic tubes that are found in the middle section. The pulp is in the center and has nerve endings that are connected to the brain of the animal. Because of this structure, the tusk is very sensitive to temperature and chemical differences in the environment. 

Cross-section of narwhal tusk

Unlike human teeth, the narwhal’s tusk is built from the inside out. It is soft on the outside and gradually gets hard and dense on the inside. This makes them the opposite of our teeth. On the surface of the tusk are millions of holes.

We also have these holes in our teeth, which make it sensitive to cold food or drinks. However, our teeth are covered with hard enamel. The tusk of a narwhal is sensitive, and scientists believe this would be similar to having your nerves exposed. Since narwhals live in the Arctic, these nerves are always exposed to these icy waters. 

Where Does The Horn Of A Narwhal Come From?

The narwhal horn is actually the left canine tooth that protrudes from the head of a male. The horn can grow as long as nine feet. A male narwhal normally measures about 15 feet long at maturity.

The right canine stays embedded, and no other teeth protrude from the mouth. Narwhals do not have any other teeth. Instead of chewing their prey, they use suction to swallow them whole.

Narwhal tusks are unique since it is the only straight tusk in the world. Tusks of other animals such as elephants and rhinos are usually curved. 

The horn is also unique in that it is the only animal with spiral teeth. The left tooth comes out of the jaw like a corkscrew through the lip. 

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Sometimes you can find a male narwhal with two tusks. This happens when the right tooth grows into a tusk also. However, when the right tusks grow, it usually does not look like the first tusk.

It is usually shorter, although it spirals in exactly the same way to the left. Narwhal’s tusks are very flexible and not as hard as you would imagine. The tusk can be bent about a foot in any direction, and it would not break.

Want to know where you can watch whales in North America? Check out this guide I wrote here.

Bryan Harding

Bryan has spent his whole life around animals. While loving all animals, Bryan is especially fond of mammals and has studied and worked with them around the world. Not only does Bryan share his knowledge and experience with our readers, but he also serves as owner, editor, and publisher of North American Mammals.

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