‘Lemming year’ about to explode
March 30, 2011
Norwegian researchers are predicting that a new “lemming year” will break out this spring in the mountains if current weather conditions persist – the first such year since 2007.
The small rodent, renowned for its violent temperament, enjoyed excellent breeding conditions beginning last November, with a stable environment and enough snow coverage to avoid the biting winter cold and the threat of predators. Living under the snow, the lemmings eat moss and other vegetation, building elaborate networks of tunnels in which to sustain their populations.
“It is a little society with hallways and tunnels. They are very productive,” Per Gustav Thingstad of the Norwegian University of Science and Technology (NTNU) told Norwegian Broadcasting (NRK).
Unique population boom
Lemmings breed remarkably quickly, as they become sexually mature after just three weeks and also have a gestation period of three weeks. Their populations in Norway rise and fall as part of a cycle every three to four years, when “lemming years” see an eruption in population, rising to unsustainable levels before falling to very low ones again. The Norway Lemming, which is not the only type of lemming found in the country, is part of a small group of vertebrates who display such stark population booms. During population booms, lemmings spread over large areas in order to find new sources of food and shelter, usually moving to higher ground with the retreat of the snow.
There are hundreds of different species of lemming living in various environments in or around the Arctic tundra, including parts of North America. The Norway Lemming is found in Scandinavia and some parts of Russia, and is the only vertebrate endemic to the region it inhabits, meaning it does not live in any other region in the world. The animal is active both day and night, making use of alternating periods of activity and sleep.
Mass suicide myth
There are a number of myths about lemmings, most notably the idea that they commit mass suicide, often by accident, as part of mass migrations. This myth is believed to have been propagated in particular by Disney, whose 1958 Oscar-winning documentary White Wilderness staged the jumping of a large number of lemmings over a cliff; it was further developed as part of an early, legendary computer game franchise called Lemmings, now one of the most popular computer game franchises of all time, in which players must build and clear obstacles in order to avoid the creatures running blindly into committing acts of mass suicide.