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3 Types of Walruses: Subspecies, Facts and Photos

Walrus is from a monotypic genus under the pinniped family. They are known for their size, whiskers, and long tusks. This article discusses different types of walrus subspecies to deepen your knowledge of these marine mammals further. 

Read on to learn their habitat range, physical feature differences, conservation status, and the debate about the third subspecies.

General Information about Walruses

walruses on seashore
Photo by Jay Ruzesky on Unsplash.

Walruses are large marine mammals, specifically pinnipeds or fin-footed mammals like seals and sea lions. They commonly have bristly and touch-sensitive whiskers and long tusks. 

Present in both male and female walruses, tusks are used to create breathing holes, defend against predators, and duel with other walruses.

Their massive size means they have few natural predators; only polar bears and killer whales attack them occasionally. Both the orca and polar bear hunt young walruses. Besides calves, the bears also prey on weak adults.

Their thick layer of fat insulates their bodies against the cold; it is also their energy reserve. Additionally, walruses are social animals, huddling together in large herds on sea ice or sandy beaches.

They are well-suited to the harsh conditions of the Arctic Ocean and its surrounding seas, where they spend most of their lives. 

However, the International Union for Conservation of Nature (IUCN) has listed walruses as vulnerable to extinction due to the rapid loss of their sea ice habitat caused by climate change. They cannot live anywhere else. 

The walrus belongs to the Odobenidae family, with three subspecies: Atlantic Walrus, Pacific Walrus, and Laptev Sea Walrus

The main ones are the Atlantic and Pacific subspecies, as the Laptev Walrus is still under debate. The following section discusses the distinguishable features and behaviors of each.

Related Read: Walrus Facts.

3 Types of Walrus Species

1. Atlantic Walrus (Odobenus rosmarus rosmarus)

atlantic walrus
Photo by Godot13 on Wikimedia Commons licensed under CC BY-SA 4.0 (Cropped from original).

The Atlantic walrus is one of the two recognized subspecies of walrus alongside the Pacific walrus. These two have genetic differences hinting at a relatively recent separation, dating back to 500,000 – 785,000 years. This timeline lines up with fossil-supported hypotheses of the animals’ tropical origins and subsequent Arctic adaptation2.

Male Atlantic walruses boast muscular necks under thick, cornified skin. While adult males average around 10 feet and 2400 pounds, mature females reach a more slender 9 feet and 1750 pounds. Interestingly, Pacific walruses share a similar length but often tip the scales a bit more. 

As their name suggests, they live in the Atlantic Ocean, ranging from central Canada’s Arctic to the Kara Sea in the east, Svalbard in the north, and Nova Scotia in the south. With a narrow ecological niche, they need shallow water rich in bivalves, nearby haul-out areas, and open water feeding zones, especially in ice-covered winters. 

Opportunistic feeders, walruses primarily feast on a bivalve buffet, including clams, using their sensitive whiskers to scrounge for snacks in soft substrates. They also indulge in various sea critters like worms, snails, crabs, and slow-moving fish. 

Their low reproductive rate makes them susceptible to hunting and environmental changes. A female matures between ages 5 to 10 and gives birth to only one pup.

Although declining harvest levels and newly adopted management measures promise a hopeful population trend, looming climate change endangers their key ice habitats. This anticipated loss may cause a population decline of more than 10% over three generations. 

An estimated 12,500 in 2015 placed it in the IUCN’s Near Threatened category. However, when they reach numbers below 10,000, they will have the vulnerable status.

The Committee on the Status of Endangered Wildlife in Canada (COSEWIC) granted Atlantic walrus Special Concern status in 2006. In 2017, it separated the population into three, declaring the Nova Scotia-Newfoundland-Gulf of St Lawrence group extinct while maintaining the Special Concern status for High and Central/Low Arctic walruses.

2. Pacific Walrus (Odobenus rosmarus divergens)

pacific walrus
Photo by Joel Garlich-Miller on Wikimedia Commons (Public Domain).

The next subspecies is the Pacific walrus. Male walruses average at 7 to 12 feet long, 4,400 pounds in weight, and females round out at between 5 to 10 feet long, 1,800 pounds in weight. 

They call the northern coast of eastern Siberia, Wrangel Island, Beaufort Sea along Alaska's north shore, and regions south to Unimak Island home. Being more migratory than the first type of walrus, the Pacific walruses travel the rocky beaches of the Bering Sea into the Chukchi Sea every summer.

Here, they feed off clams, snails, crabs, shrimp, worms, and sea cucumbers found on and beneath the seafloor. Seals and seabirds, although less frequent on the menu, can become part of the walrus diet. Since they are humongous, their primary predators are only polar bears and killer whales.

Seen resting in large groups, their nurturing side is evident in the strong mother/calf bond that lasts for about two years. This bond is so robust that female walruses will show aggressive behavior if their calves are under threat. 

In terms of population, the U.S. Fish and Wildlife Service (FWS) 2006 survey suggested numbers1 of around 129,000 individuals. A more recent study, published in 2022, based on data from 2013 to 2017, estimated the count to be significantly higher at 257,000 Pacific walruses.

Since climate change is likely to reduce the ice coverage they depend on, a declining population is to be expected. Additionally, they have a low reproduction rate. Due to limited data, IUCN reported them as Data Deficient. However, they deemed the whole walrus species vulnerable in 20163.

3. Laptev Sea Walrus (Odobenus rosmarus laptevi)

The Laptev Sea walrus is a disputed third subspecies, neither widely recognized nor wholly dismissed. Relative to the Pacific walrus, its tusk length and circumference fit within the measurement range. 

Additionally, DNA sequencing puts the Laptev Sea walrus with populations from the North Pacific. Thus, taxonomically, the designation does not hold up. The study proposed the Laptev walrus as simply the westernmost population of the Pacific walrus, suggesting more research regarding its ecological uniqueness.

Conclusion

Walruses play a crucial role in the Arctic ecosystem's food chain, but their survival is currently threatened due to the loss of sea ice caused by climate change. Regulations have curbed overhunting and the global trade for walrus ivory, a threat in the past. 

However, we must take a comprehensive approach to reducing greenhouse gas emissions and preserving the Arctic habitat. Learning more about walruses is necessary to protect them and preserve the Arctic's intricate web of life.

1

MacCracken, J. G., Beatty, W. S., Garlich-Miller, J. L., Kissling, M. L., & Snyder, J. A. (2017). Final species status assessment for the Pacific walrus. Odobenus rosmarus divergens.

2

Hoelzel, A. R. (Ed.). (2009). Marine mammal biology: an evolutionary approach. John Wiley & Sons.

3

Lowry, L. (2016). Odobenus rosmarus. The IUCN Red List of Threatened Species 2016: e.T15106A45228501.

Mike is a degree-qualified researcher and writer passionate about increasing global awareness about climate change and encouraging people to act collectively in resolving these issues.

Fact Checked By:
Isabela Sedano, BEng.

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