Rodent Harakiri

AMAZING LIVING WORLD

THE lemming is a small rodent which lives in the Arctic tundra region. It is 8-15 cm long and is well-adapted to the cold, with dense, silky fur, small ears, short feet and an almost invisible tail.

Lemmings browse on the sparse tundra grass and roots, using their strong claws to dig tunnels. In winter, the collared lemming even develops two peculiar, large forked claws on the front feet to help it dig burrows in frozen ice and snow.

Lemmings, especially the Norwegian species, are famous for their sudden, spectacular mass migration, which happens once in around four years. Overpopulation is the main reason for the lemmings to begin moving. Sometimes, when food is abundant, the females give birth to eight babies in a litter instead of the usual five. The young ones mature quickly, sometimes breeding when they are just six weeks old! There is a population explosion.

Millions of them rush madly down the hills like a river in flood, in search of new grazing land. On the way, when they come across rivers or fjords or reach the sea, they plunge in and try to swim across. Thousands drown and are washed up on the shore. To the casual observer, it may seem that the lemmings all move in one direction, led by one animal, to the sea, where they jump off the cliffs in droves in a manic mass 'suicide'.

In reality, there is no one 'leader' and most wander aimlessly for miles. Lemmings are good swimmers and drown only because they panic and the smallest waves can overwhelm them. Or they are so exhausted that they cannot go any further. Once the population is reduced to a manageable size, the survivors settle down in a new place and start new families.