The adult polar bear is considered the top of the arctic food chain, with its only predators being other polar bears and humans. There is an increasing amount of polar bear cannibalism due to a lack of other foods to meet nutritional requirements.
Infants are most commonly the victims of cannibalism, falling prey to their mothers or adult males. Before reaching 1 year in age, polar bear cubs sometimes are prey for carnivores, such as wolves. When a polar bear dies from other causes, such as roundworms that consume muscle tissue, the bear becomes food for scavengers in the arctic food web.