Naturally, lions do not prey on humans. This is a fact that has puzzled researchers since the 1898 incident where two lions in the Tsavo purely feasted on human flesh. It is estimated that the man eaters could have devoured over 100 Indian workers. Many theories have come up as to why this could have taken place. The most common once are that there was an outbreak of rinderpest at the time. This could have killed many of the animals the lions preyed on. These included wildebeests, gazelles, buffaloes and other herbivores. As a result, food was scarce and the two lions resulted to hunting humans who were readily available in the area. This argument is not fully supported because only two lions hunted humans, what about the rest of the lions in the Tsavo.
The other argument which makes more sense than the first one is that the lions were used to coming across the dead bodies of the natives. Most of the natives did not bury their dead and they would throw them in the bushes for the animals to eat. The lions might have developed a liking to human flesh from these encounters. Indians too could have invited the lion scavengers as they cremated their dead. Slave caravans bound for Zanzibar usually crossed the river and they would throw the dead bodies in the Tsavo.
Another argument indicates that the first lion had a severely damaged lower right canine. This could have stopped it from being able to actively hunt down big and mighty animals thus resulting to hunting humans. The Indians who set camp in its territory became a dietary alternative for this lion.