The food that walruses like to eat is usually in waters no more than about 80 meters / 263 feet deep, and a walrus usually doesn't dive deeper than this - making short dives of 5 to 8 minutes.

However, they can go deeper and stay down longer. One observation confirmed a dive of 113 meters / 371 feet - staying underwater for about 25 minutes!

Walruses, like other marine mammals, have special adaptations to help conserve oxygen when diving. They slow their heartbeat, and during deep dives, their blood is pulled away from parts of the body that do not need high oxygen levels. It's re-directed to more important organs, such as the heart and brain.

Their warm blood also shifts away from the skin surface to inside the body. This helps to keep their body temperature stable at about 99°F / 37°C. When the walrus moves ashore, blood flows back to the skin.

The rounded walrus shape comes from a layer of blubber, or fat, that can be nearly 6 inches / 15 cm thick and it provides a layer of insulation under the 1 inch / 2.5 cm thick hide. This huge bulk keeps them warm in Arctic waters by blocking out the cold.

Although the walrus' great bulk makes them awkward on land, when they hit the water - watch out! Walruses are very strong, and with their short strong foreflippers and triangular-shaped hind flippers, they can really move!