Polar bears often stand on their hind legs. In this photo, an adult male rises to get a better look at a newcomer in his territory. Photo © Nikita Ovsyanikov

Wrangel Island. A mixed family of polar bears – a mother with a two-year-old cub and a young female possibly from a previous litter – walk along a shingle spit on Cape Blossom. There are quite a few such mixed families, which is evidence of how social polar bears are. Photo © Nikita Ovsyanikov

Wrangel Island. A female polar bear with a cub from her latest litter in the tundra. Polar bears are very good mothers. When the ice melts off Wrangel Island in summer, they live on the island until winter. Adult males prefer to live on the shore, while females go deeper into the tundra, where they feel more comfortable. Photo © Irina Menyushina

Wrangel Island, Somnitelnaya Spit. A standoff between two polar bear families over the remains of a walrus pup. One family has two-year-old cubs, while the cubs in the other family are a year old. Polar bears are social animals who usually settle disputes by demonstrating aggression without actually causing each other harm. Photo © Irina Menyushina