Wildlife photographer Norbert Rosing was taking photos in northern Canada when a polar bear arrived on the scene. Most of the tethered dogs went crazy, barking and jumping, and Rosing thought it was going to be the end of dog breeder Brian Ladoon's Canadian Eskimo sled dogs. But one dog, Hudson, remained calm and wagged his tail, and to Rosing’s astonishment, the bear nuzzled the dog and in return, the dog licked the bear’s face.

Then another polar bear arrived and began walking toward Ladoon’s dog Barren, but the dog simply rolled onto his back and he and the bear began tumbling in the snow. Amazed, Rosing began snapping photos from the safety of his vehicle, and he witnessed the bears return for more playtime and cuddling sessions with the dogs every afternoon for 10 days in a row.

The heartwarming photographs of the dogs and polar bears can be viewed in Rosing’s book “The World of the Polar Bear,” in which he recounts the charming story of these natural enemies’ unexpected friendship.

Also on MNN: 16 unlikely animal friendships