A forest's synchronized death
In the hills of Mizoram, a state in northeast India, the dominant forest species is a bamboo called Melocanna baccifera. This species, known locally as Mautak, has a life cycle that dictates the region's ecology and has even influenced its political history. Approximately every 48 to 50 years, every single clump of this bamboo across the entire region engages in a biological event called gregarious flowering. Regardless of age or location, the plants produce flowers and then massive quantities of large, fleshy fruit before dying off completely.
This synchronized death, known as Mautam, has been recorded with eerie regularity, with major events occurring in 1863, 1911, 1959, and most recently around 2007. The phenomenon is not fully understood by scientists, but it appears to be controlled by an internal genetic clock. A second, less severe event called Thingtam occurs when another species, Bambusa tulda, flowers on its own cycle. The fruit of M. baccifera is unusually large for a grass, resembling a pear, and its sudden appearance in enormous quantities provides a massive food source on the forest floor.
The rat flood and famine
The sudden feast of bamboo fruit triggers a catastrophic ecological cascade. The region's population of black rats (Rattus rattus) undergoes an explosive increase in numbers, a phenomenon sometimes called a "rat flood". High protein does not cause this in the fruit, as once thought, but by its high sugar content, which provides an immense energy source. The rats gorge on the fruit and reproduce rapidly.
Once the bamboo fruit supply is exhausted, the massively inflated rat population turns from the forests to human settlements and farms. Hordes of rodents devour agricultural crops, especially rice and maize, and invade grain stores. The result is a devastating famine. The 1959 Mautam was particularly severe, destroying harvests and leading to widespread starvation. The perceived inadequate response from the government led to the formation of the Mizo National Famine Front, which later became the Mizo National Front (MNF), a political party that led a long insurgency before Mizoram became a separate state. For the 2007 event, authorities were better prepared, instituting programs to control the rat population and stockpile food grains.