cannibalism

thumb|A slug, Arion vulgaris, eating a dead individual of the same species Cannibalism is the act of consuming another individual of the same species as food. Cannibalism is a common ecological interaction in the animal kingdom and has been recorded in more than 1,500 species. Human cannibalism is also well documented, both in ancient and in recent times.

The rate of cannibalism increases in nutritionally poor environments as individuals turn to members of their own species as an additional food source. Cannibalism regulates population numbers, whereby resources such as food, shelter and territory become more readily available with the decrease of potential competition. Although it may benefit the individual, it has been shown that the presence of cannibalism decreases the expected survival rate of the whole population and increases the risk of consuming a relative. Other negative effects may include the increased risk of pathogen transmission as the encounter rate of hosts increases. Cannibalism, however, does not—as once believed—occur only as a result of extreme food shortage or of artificial/unnatural conditions, but may also occur under natural conditions in a variety of species.