Cliff, First Mate Foxy reads an interesting fact: Lemmings dont jump. I think that, if I were a lemming, I would prefer more steady, balanced arrangements. Read the Book, Lemmings A book by Ame Dyckman. It all seems rather dramatic and stressful. Then, when the feasting has wiped out vast numbers of lemmings, many predators run out of food, and their numbers drop. Their abundance leads to more predators, who feast on the poor little rodents. In short, the reason for the lemmings' dramatic population swings is that - under the right conditions - the lemmings multiply rapidly. The 'generalist' predators are still affected by a fall in lemming numbers but their population decline takes longer to kick in because they can immediately find other food when the crash takes effect." The statistical clue to understanding the cycle is stoat numbers, which take a delay of about a year before falling in response to a lemming crash. The three other predators are 'generalists' - they like to tuck into lemmings but also have alternative nutrition. It is a four-year 'boom and bust' cycle whose key is the stoat, a specialist predator whose only source of food is the lemming. what is interesting in this case is that, with the lemmings, the pattern is almost like clockwork. The next phase is that the lack of lemming drives down the predator numbers. That, in turn, boosts the predator numbers, which become so numerous and gorge so much on the lemmings that the rodent numbers plummet dramatically. The researchers found that the population of lemmings and their cousins, the vole, can explode by 100 or even 1,000 times their original size. Lemming populations, say, surge spectacularly and fall just as quickly, thanks to the combined feasting of four predators: the stoat, arctic fox, snowy owl and a seabird called the long-tailed skua. Olivier Gilg of the University of Helsinki in Finland and colleagues publish their research in today's issue of the journal Science. "One of the oddest phenomena in the natural world - the sudden mass death of lemmings - has been resolved, according to a trio of European biologists. Now for the article (written October 31, 2003). and, for no particular reason, a picture of a much cuter baby squirrel (from this site): In any case, this article discusses an alternate, more plausible, explanation for the dramatic population swings that really do occur.įirst, the obligatory picture of a lemming (from the article): (I've heard that this myth originated with a Disney film, but that could be a myth too.) Lemmings are most famous for their alleged tendency to commit mass suicide by jumping off cliffs when their numbers become too great. We are also partial to the name, World War IV.I don't consider lemmings particularly cute as rodents go, but they can be comparatively interesting. In fact, the word "lemming" comes from the Norwegian "lemmus" which means destruction.Īre there any up-and-coming death metal bands in our reader-base? Feel free to use the name. Lemmings can be fierce little buggers, bearing their teeth when approached and decimating entire sections of countryside of vegetation. They might look cute, but they do not have a reputation for cuddliness. They are often be so focused on moving forward in a frenzied rate, that they can plunge straight off of embankments, as seen in this video. Instead, overpopulation and density triggers a migration reaction in the little rodents, causing a frantic and single-minded migration across long distances in search of greener pastures. While they sometimes do fall to their deaths, they are not consciously committing suicide. One popular myth about lemmings is that they react to overpopulation by leaping off of cliffs to their death. Though the little rodents (Norway lemmings, Lemus lemus) have not yet begun swarming in a locust-like frenzy, they have been turning up all over Lapland, including drowned in the nets of salmon fishermen, clinging to the oar of a rower and attached to a woman's ankle as it bit her. Northern Finland is experiencing its largest lemming migration in 20 years, according to t his article in Helsingin Sanomat's "International Edition" (we never miss an issue!).
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