Man-eater is a colloquial term for an individual animal that preys on humans as a pattern of hunting behaviour. This does not include the scavenging of corpses, a single attack born of opportunity or desperate hunger, or the incidental eating of a human that the animal has killed in self-defence. However, all three cases (especially the last two) may habituate an animal to eating human flesh or to attacking humans, and may foster the development of man-eating behaviour.
Although human beings can be attacked by many kinds of animals, man-eaters are those that have incorporated human flesh into their usual diet and actively hunt and kill humans. Most reported cases of man-eaters have involved tigers, leopards,lions and crocodilians. However, they are by no means the only predators that will attack humans if given the chance; a wide variety of species have also been known to adopt humans as usual prey, including bears, Komodo dragons, and hyenas.
Tigers are recorded to have killed more people than any other big cat, and tigers have been responsible for more human deaths through direct attack than any other wild mammal. About 1,000 people were reportedly killed each year in India during the early 1900s, with one individual tiger killing 430 people in India. Tigers killed 129 people in the Sundarbans mangrove forest from 1969–71. Unlike leopards and lions, man-eating tigers rarely enter human habitations in order to acquire prey. The majority of victims are reportedly in the tiger's territory when the attack takes place. Additionally, tiger attacks mostly occur during daylight hours, unlike those committed by leopards and lions. The Sundarbans are home to approximately 600 royal Bengal tigers who before modern times used to "regularly kill fifty or sixty people a year". In 2008, a loss of habitat due to the Cyclone Sidr led to an increase in the number of attacks on humans in the Indian side of the Sunderbans, as tigers were crossing over to the Indian side from Bangladesh.
A theory promoted to explain this suggests that since tigers drink fresh water, the salinity of the area waters serve as a destabilizing factor in the diet and life of tigers of Sundarbans, keeping them in constant discomfort and making them extremely aggressive. Other theories include the sharing of their habitat with human beings and the consumption of human corpses during floods.