What are lemmings?

The question on everyone's lips.

lemming* (lem'ing) n., pl. -mings or ming [L latrare, to bark, lamentum, LAMENT] any of various small, mostly arctic rodents (family Cricetidae) resembling chipmunks but having short stubby tails and fur-covered feet: some species (esp. genus Lemmus) undertake spectacular mass migrations at peaks of population growth, ultimately drowning while trying to cross the sea
 

In VICENZA , the year of the lemming

Because Adi was SOSOSO Good at school for the first half of the year, she got her Cricheetti..or creatures!!

If you go rambling in the mountains along Norway's long coastline this year you may be treated to the rare sight of hordes of Norwegian lemmings.

If scientists have their timing right, this is a "lemming year" and the mountainous scrublands should be teeming with the small, shy rodents. But don't expect to see them hurling themselves off cliffs.

Myth and legend have surrounded lemmings for hundreds of years. Say "lemming" and the mind conjures up images of thousands of vole-like creatures plunging headlong over cliffs into the waves below.

As early as the 1530s, the geographer Zeigler of Strasbourg published an account of how lemmings fell from the sky in stormy weather and how they died by the thousands when the spring grass began to sprout.

Scandinavia's indigenous Sami, or Lapp, people believed lemmings rained down from heaven, while other Nordic legend had it that they marched en masse to the sea where they willingly drowned themselves. Such folklore may be a convenient and romantic way to explain why lemmings undergo sharp fluctuations in numbers but modern scientists say the tales are untrue.

"It is this phenomenon that is a big challenge, the scientific community does not understand why," Nils Christian Stenseth, a professor at the University of Oslo and one of the leading experts on lemmings, told Reuters of the population fluctuations. "If you are a tourist in the mountains most years you will not see any lemmings and every three to four years you would see them everywhere."

The folklore was etched onto people's minds when Walt Disney released the 1958 film "White Wilderness" showing thousands of lemmings apparently hurling themselves from an Arctic cliff. But Stenseth said the film was wrong on two counts: Lemmings do not commit mass suicide and the film depicted the so-called collared lemming whereas such myths are confined to the Norwegian species, Lemmus lemmus.
 
 

Why these rodents are found in abundance and then suddenly die out is a question that has confounded scientists. Theories have abounded including stress and aggressive behavior caused by high numbers, food shortage and predation.

Stenseth, who began working on lemmings in 1970, says scientists are now closer than ever to a consensus pointing mainly to the impact of predators such as weasels, stoats and birds of prey on lemming population. Predators feast on lemmings in good years, helping cut back the population. Then they have difficulty finding food and consequently die out, providing a chance for the lemming population to rebound.

"We don't really know but there is a tendency to focus more and more on predators. There is quite a substantial amount of experimental and observational data that points to the predator interaction," Stenseth said. "There is more agreement now than there has been for the last 20 years."

Lemmings are found in wide areas of Norway, Siberia, Finland, Sweden, Arctic Canada, Alaska and parts of Greenland. Dramatic explosions and declines in population are also seen in other rodents such as the field vole.

Stenseth said data showed population fluctuations occurred every four to five years in northerly regions, probably because there were fewer predators in colder climates.

The Norwegian lemming is about three inches long with a black head dotted with two yellow spots on the crown and huge white furry cheeks. The secretive rodent is unlikely to go looking for trouble but can give a nasty bite if disturbed.

Stenseth said he expected the next population boom in Norway within 12 months. Lemmings breed under the snow in winter, when a female can produce a new litter of four to seven offspring every three weeks.

He said understanding the lemming phenomenon had repercussions for deeper problems in ecology studies of population density and regulation of populations, but the myths surrounding the lemming had also provided a certain charm.

"It adds to the fun but I think it is a bit depressing that this myth continues to live and spread because it means that we scientists have not been successful in conveying the truth," he said. "This is about science communicating to the general public and we're doing a bad job, especially in ecology."