Walrus

The walrus (Odobenus rosmarus) is a large pinniped marine mammal found near the North Pole in the Arctic Ocean and subarctic seas of the Northern Hemisphere. It is the only living species in the family Odobenidae and the genus Odobenus. There are two subspecies: the Atlantic walrus (O. r. rosmarus), living in the Atlantic Ocean, and the Pacific walrus (O. r. divergens), living in the Pacific Ocean.

Adult walrus are known for their big tusks and whiskers, and they are very heavy. Males in the Pacific can weigh more than 2,000 kilograms (4,400 pounds) and are among the biggest pinnipeds, only smaller than the two types of elephant seals. Walrus mostly live in shallow waters above the continental shelves and spend much of their time on the sea ice searching for benthic bivalve molluscs. They are long-lived, social, and clever animals and are important to the Arctic marine region as a keystone species.

Walrus have been very important to many indigenous Arctic peoples, who hunt them for food, fat, skin, tusks, and bone. In the 19th and early 20th centuries, walrus were hunted a lot for their blubber, walrus ivory, leather, and meat. Because of this, their numbers dropped quickly all around the Arctic. Their populations have grown again some, but the Atlantic and Laptev walrus groups are still smaller than before people started hunting them.

Etymology

The word walrus may seem Latin-like, but it actually comes from older Germanic languages, likely from either Dutch or Old Norse. The first part of the word comes from the Old Norse word hvalr, meaning 'whale', and the second part from hross, meaning 'horse'. For example, the Old Norse term hrosshvalr means 'horse-whale' and may have been passed to Dutch and northern German dialects as walros and Walross.

Another idea is that the word comes from Dutch words wal (shore) and reus (giant). The scientific name rosmarus is Scandinavian, appearing in old Norwegian writings. Some place names in Iceland, Greenland, and Norway might come from old walrus sites. An older English word for walrus, morse, likely came from Slavic languages and even older languages from Northern Europe. The scientific genus name Odobenus comes from Greek words for 'teeth' and 'walk', because walruses use their tusks to pull themselves out of the water onto land.

The Inuttitut name for the walrus is aivik, and a similar word, aiviq, is used in Inuktitut.

Taxonomy and evolution

The walrus is a mammal that belongs to the order Carnivora. It is the only living member of the family Odobenidae, which is one of three groups in the suborder Pinnipedia, along with true seals (Phocidae) and eared seals (Otariidae). Scientists believe all three groups came from a common ancestor that was closely related to modern bears.

There are two subspecies of walrus: the Atlantic walrus, O. r. rosmarus, and the Pacific walrus, O. r. divergens. These two groups separated from each other between 500,000 and 785,000 years ago. The walrus originally lived in warmer areas but moved to colder Arctic regions over time. Fossils of walrus have been found in places like San Francisco, Vancouver, and even as far south as North Carolina.

Anatomy

While some large Pacific male walruses can weigh up to 2,000 kg (4,400 lb), most weigh between 800 and 1,700 kg (1,800 and 3,700 lb). Male Atlantic walruses weigh an average of 900 kg (2,000 lb), while females weigh about two-thirds as much as males. Walruses are the third largest pinniped species, after the two elephant seals. Their thick blubber keeps them warm in cold water and gives them energy.

Walruses have large tusks, which are long upper teeth, used mainly for fighting, showing dominance, and helping them climb out of the water onto ice. Both males and females have tusks, but they are slightly longer and thicker in males. Walruses also have many sensitive whiskers around their tusks, which help them feel their way while searching for food. Their skin is wrinkled and mostly bald, except for these whiskers.

Life history

Reproduction

Walruses can live up to 20–30 years in the wild. Males can start mating as early as 7 years old but usually wait until they are fully grown around 15 years. Females can start having babies as young as 4–6 years and are fully grown by 10–12 years. Breeding happens from January to March, with most mating in February.

Babies are born between April and June after a pregnancy of about 15 months. At birth, they weigh between 45 and 75 kg and can swim right away. Mothers nurse their babies for over a year, and young walruses can stay with their mothers for up to five years. Because females can only have a baby every two years, walruses have one of the lowest birth rates among sea animals.

Migration

For most of the year, walruses gather in huge groups on rocky beaches. In the spring and summer, many travel long distances from the Bering Sea to the Chukchi Sea through the Bering Strait.

Vagrancy

Walruses sometimes travel far from their usual areas, especially moving south. Over the years, a few have been seen in places like Scotland, England, and Ireland. Recently, some famous walruses have traveled across Europe, being tracked and named by people who see them.

• 'Wally'. First seen in Ireland in 2021, then traveled along Wales, France, Spain, and back to Ireland and Iceland.
• 'Freya'. First seen in 2019, then appeared in the Netherlands in 2021, and was later seen in Norway.
• 'Stena'. Seen in Norway in 2022, then traveled through Denmark, Sweden, and Germany, finally reaching Finland, where it died after struggling to find food.
• 'Thor'. Seen in the Netherlands in 2022, then traveled through France, England, and back to Iceland.

Ecology

The Pacific walrus mainly lives in the Arctic waters north of the Bering Strait, especially in the Chukchi Sea near eastern Siberia and Alaska. In spring and fall, they gather in the Bering Strait, and in winter, they move to the Bering Sea. Atlantic walruses live around the Canadian Arctic, Greenland, Svalbard, and western Russia.

Walruses usually stay in shallow waters, hunting for food like bivalves on the sea floor. They can dive deep but often stay close to the surface. Their diet includes many sea creatures, but they especially like clams. Walruses use their sensitive whiskers to find food and powerful suction to pull it in.

Because of their size and strong tusks, walruses have few predators. The main threats come from orcas and polar bears, who mostly target younger walruses. Even then, walruses can defend themselves and sometimes hurt their attackers.

Relationship with humans

Conservation

People have used many parts of the walrus for years. They eat the meat, especially in winter. They use the tusks and bones to make tools and art. The oil from walruses gives warmth and light, and their hides are used to make ropes and coverings. Even today, walrus meat and carvings are important to some communities.

In the past, many walruses were hunted, which greatly reduced their numbers. Now, hunting is controlled, and only some groups are allowed to hunt a small number each year. Scientists are watching walrus populations closely because changes in sea ice affect their homes and families.

Culture

Folklore

The walrus is important in the stories and beliefs of Arctic peoples. It appears in many legends and ceremonies. For example, in some tales, a girl turns into a walrus after falling from a cliff. These stories help keep the traditions of these cultures alive.

Literature

The walrus is also a character in many books and poems. One famous example is in Lewis Carroll’s poem "The Walrus and the Carpenter", where the walrus and a carpenter talk to oysters on the beach. Another appearance is in a song by the Beatles called "I Am the Walrus". The walrus also appears in stories like "The Jungle Book" by Rudyard Kipling.