No. Walruses do not eat penguins, because the two animals live at opposite ends of the planet. Walruses live in the Arctic and subarctic seas of the Northern Hemisphere, and penguins live in the Southern Hemisphere. A walrus eats mostly clams and other animals that live on the seafloor.
Why walruses and penguins never meet
Walruses live around the Arctic Ocean and nearby seas. There are two subspecies. Atlantic walruses live in the North Atlantic region, including the Barents Sea. Pacific walruses live in the Chukchi, Bering and western Beaufort Seas and west to the Laptev Sea.
The Australian Antarctic Division says penguins are found only in the Southern Hemisphere, mostly on Antarctic coasts and sub-Antarctic islands. There are 18 species. The Arctic has none. The two groups are separated by the equator and thousands of miles of ocean.
Penguins do have predators, but not walruses. At sea, their main predators are leopard seals and killer whales, while skuas and sheathbills take eggs and chicks. Leopard seals, which live in the pack ice around Antarctica, chase or grab penguins in the water.
What walruses eat
Walruses are bottom feeders. Both subspecies feed mainly on invertebrates that live on or in the seafloor. Clams and other bivalves are the main item, but a 2011 Alaska Department of Fish and Game status review found more than 100 types of bottom-dwelling invertebrates in walrus stomachs.
Common prey includes:
- Clams and other bivalve mollusks. The largest part of the diet.
- Snails and worms.
- Crustaceans, such as shrimp and soft-shelled crabs.
- Sea cucumbers and tunicates.
Fish and other vertebrates are eaten only occasionally. Alaska Fish and Game notes that some males eat seals and seabirds. That is the exception. A walrus is not an active hunter of seals, and penguins are out of the question.
How walruses find and eat their food
Walruses forage in dark water on the seafloor, so they rely on touch.
- Whiskers. They root along the bottom with their muzzles and use their whiskers to locate prey.
- Digging. They use their fore-flippers, nose and jets of water to uncover prey buried up to 32 cm (about 12 inches) deep.
- Suction. They suck the soft parts of mollusks out of the shells and discard the shells.
Walruses usually forage in water 80 m (262 ft) deep or less, although they can dive deeper than 250 m (820 ft). Atlantic walruses in one study ate an average of 53 bivalves per dive. Foraging trips from a resting site on ice or land last from a few hours up to several days.
Tusks are long upper canine teeth that can grow to about 3 feet. Walruses use them to haul out onto ice, to defend themselves and in dominance displays, while the digging is done with the snout, flippers and water jets. For how tusks matter around people, see are walruses dangerous.
How much does a walrus eat?
An adult walrus needs about 29 to 74 kg (64 to 174 lb) of food a day, based on its energy needs, according to the Alaska review. Large male Pacific walruses can weigh more than 2,000 kg (4,400 lb), and females up to about 1,100 kg (2,400 lb). Adult males forage little during the breeding season.
Walruses and the seafloor
Walruses affect the seafloor as they feed. One estimate in the Alaska review put their consumption at about 3 million metric tons of bottom-dwelling animals a year in the Bering and Chukchi Seas. The review concluded that walruses play a major role in the structure and function of seafloor communities and may increase the flow of nutrients there.
Predators
Adult walruses have few predators. Killer whales (orca profile) are regarded as the Pacific walrus's principal natural predator and mostly take the youngest animals. Polar bears take walruses only occasionally. The Alaska review says they are typically no match for a healthy adult in a direct confrontation, though some bears become skilled at preying on walruses, especially at crowded land haul-outs.
Threats to walrus food and habitat
Sea ice is the main concern. Walruses use ice as a platform to rest between feeding trips. When summer ice retreats far from shallow feeding grounds, walruses haul out on land, and females with calves must travel long distances to feed. The NOAA Arctic Report Card notes feeding trips of 180 km one way from coastal haul-outs. Crowded land haul-outs also raise the risk of stampedes that can kill calves.
The same report says clam populations in the northern Bering Sea have declined as sea ice has fallen, which researchers call a concern. It found no evidence that ocean acidification is affecting walrus prey so far.
Fishing looks like a smaller factor. The 2011 Alaska review found that commercial fisheries did not appear to compete directly with Pacific walruses for food, and that bottom trawls took very little walrus prey as bycatch.
The best current estimate for the Pacific walrus population is about 257,000 animals, with a wide margin of error. The trend is unknown. Walruses are protected in the United States under the Marine Mammal Protection Act.
Sources
- Status Review of the Pacific Walrus (Alaska Department of Fish and Game)
- Pacific Walrus Species Profile (Alaska Department of Fish and Game)
- Walruses in a Time of Climate Change (NOAA Arctic Report Card)
- Penguins (Australian Antarctic Division)
- Pacific Walrus Stock Assessment Report 2023 (U.S. Fish and Wildlife Service)