Polar bears eating a walrus on Wrangel Island. Although they hunt alone, polar bears usually share walrus carcasses. Such behaviour increases the chances of their survival and of the survival of the population as a whole in the harsh Arctic environment

An adult polar bear on Vilkitsky Island near a walrus rookery. After feeding on a walrus, a polar bear’s face and head is bright red with blood. The blood washes off for the most part after entering the water, but the fur on their heads remains a yellowish-pink colour for several days. It is easy to spot a polar bear that recently fed

Polar bear versus walrus. Walruses use their tusks to defend against polar bears if they have no time to retreat into the sea. Vigorous thrusts with the tusks and a forceful show of resistance are almost always enough to stop an attacking bear

A young polar bear finds a walrus carcass. On Wrangel Island polar bears find walrus carcasses very quickly and leave nothing to waste. A polar bear that finds a dead walrus is usually shortly joined by others, as the wind spreads the smell fast

Walruses group together before exiting the water. To reach a rookery, first walruses group together near the shoreline and watch the coast for polar bears for a long time. When they feel safe, the stronger adults start leaving the water. Their sounds attract all the other walruses in the area and the rookery starts to grow rapidly

A walrus rookery on Wrangel Island. Walruses calmly lie close to each other until a polar bear approaches

Formation of a rookery on Wrangel Island. Walruses carefully choose the location of their rookeries. They should have certain features and be near their feeding grounds on the seabed

Hunting on the rookery. At first the polar bear walks toward the rookery but then starts to run as it closes to within a couple dozen metres. At that point, walruses rush into the water in panic. The bear’s success depends on luck and choice of tactic