Mautam

Mautam (Mizo for "bamboo death") is a cyclic ecological phenomenon that occurs every 48 years in the northeastern Indian states of Mizoram and Manipur, which are thirty percent covered by wild bamboo forests, as well as Chin State in Burma, particularly Hakha, Thantlang, Falam, Paletwa and Matupi Townships. One of its stages involves a rat boom, which in turn creates a widespread famine in those areas.

During Mautam, Melocanna baccifera, a species of bamboo, flowers at one time across a wide area. This event is followed invariably by a plague of black rats in what is called a rat flood. This occurs as the rats multiply in response to the temporary windfall of seeds and leave the forests to forage on stored grain when the bamboo seeds are exhausted, which in turn causes devastating famine. Famines thus caused have played a significant part in shaping the region's political history. The most recent spate of flowering, on the bamboo species' genetically-linked timetable, began in May 2006, and the state government and the Indian Army attempted to prevent a famine.

After flowering, the bamboo dies and regenerates from the seeds. The rodents feast on these seeds which are available in plenty. In consequence, there is a sudden boom in the rat population. The action of the rats is thought to be an ecological control mechanism. The seeds of any culm of bamboo that might flower off-cycle are all eaten up by rodents, thus reinforcing the rhythm of this extreme version of a mast year. Some experts believe that the flower has a positive effect on the fertility of the rats, as well as on increasing the viable size of a rat litter. All available explanations point to the fact that the increase in their numbers during the peak year is a natural after-effect of the flowering of the bamboos. However, once they exhaust this temporarily abundant food supply, the rats turn their attention to cultivated crops.

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