Fight!

This fight is a battle of the sexes for the bear necessity of life, food. These pictures taken by a British nature photographer, Nathan Harrison, show how the larger male brown bear starts the fight until his sister gains the upper hand by giving him a clip round the ear. They later wonder off as friends once again. The twins from Lake Clark National Park in Alaska are known for being of one minded and in this case the twin three-year-old bears are only thinking of their stomachs. (Nathan Harrison / Barcroft)