Red foxes do not usually prey on Arctic foxes, but this can happen occasionally owing to their overlapping hunting territories, as captured in this winning photograph by Don Gutoski, who bagged the title of Wildlife Photographer of the Year 2015-16.
In this instance, the red fox chased the small Arctic fox, killed it in the snow and fed on the carcass for three hours.
It then dragged away the remains to store for later.
The photograph was taken in Wapusk National Park, near Cape Churchill in Canada.
Both species usually hunt small rodents, such as lemmings, but when their territories overlap, the red fox has been observed to prey on the Arctic fox and compete with it for food.
As rising temperatures in the Arctic allow the red fox to move north and cross paths with the Arctic fox, conflicts between the two are likely to become more common.
London's Natural History Museum owns and organises the Wildlife Photographer of the Year competition. This time, the judges sorted through 42,000 entries submitted from almost 100 countries.
The contest, which has been running for more than 50 years, is divided into 18 categories, each with its own best in class.