Lemmings And The Myths Essay, Research Paper
Adam Rodney ? Lemmings-
This paper explores the truth and fiction surrounding one of the natural kingdom?s strangest citizens; the lemming. The subject of countless studies, stories and legend, this paper will attempt to separate fact from fiction, truth from legend, and give an in depth view of lemmings in general and in particular the Norwegian lemming.
First off, what is a lemming? To those who are not naturalist, field biologist, or zoologist, the animal seems indistinguishable from the pet store guinea pig, a chubby hamster, a small tailless nutria or some other common southern rodent.
?It’s a plump little rodent that looks like a mouse. But it’s not. It’s more closely related to voles and muskrats. It has thick fur, short legs, tiny ears, a stubby tail and black button eyes. It’s four to five inches long and grayish brown or reddish brown.? (Phil Myers, associate professor of zoology and associate curator of mammals, Email, University of Michigan)
?Some lemmings like the Collared lemming Dicrostonyx, have a rather obscure grayish brown coat, but other species are more colorful. The Norway lemming, for example is boldly pattered with a black head and a large black patch on the back on a yellowish-brown background, while the smaller Wood lemming is slate gray with a streak of rust- red on the back.? (Macdonald, D. W. 1984. The encyclopedia of mammals. Facts on File Inc. New York. Pp. 650-657. )
?All lemmings have strong claws by which they dig tunnels amongst the roots of the tundra heaths and grasses. Lemmings have very angular skulls to accommodate especially powerful muscles of mastication and like their relatives the voles, their teeth keep growing keep growing throughout life to compensate for the heavy wear resulting from the staple diet of tough vegetation.?
?Lemmings can be found through out the arctic tundra, although a few species extend south in to the coniferous forest zone in both America and Eurasia.? (Macdonald, D. W. 1984. The encyclopedia of mammals. Facts on File Inc. New York. Pp. 650-657. )
According to the Canadian wildlife service 11 different species of lemming are found throughout North America, North Asia and Northern Europe. Of the eleven species the Norwegian lemming is clearly the best known for its striking natural behavior.
The misunderstanding of its odd migratory behavior has given the Norwegian Lemming a false reputation for being an angry, suicidal creature who shows no respect for its own life. This is a rodent linked in our minds with mass suicides and one of the main aims here is to put the Norwegian lemming?s story into perspective.
The Norwegian lemming can be found in ranges across Sweden, Finland, Scandinavia, and northwest Russia.
?The Norwegian lemming lives at 2,500-3,000 ft above sea level. In the summer the Norway lemming will occupy moist stony ground partly covered by sedges, willow shrubs and dwarf birch.?(Dr. Maurice Burton: Lemmings. Wildlife Encyclopedia, volume (10): 1301-1302)
Besides the strange migrations the norwiegen lemming possesses a number of unique adaptations to survive in the harsh atmosphere of the Arctic Circle.
? Most mammals have to increase heat production to maintain their body heat when temperatures fall below freezing but the Norwegian lemmings do not do so until the temperature reaches ?12°C?. (Robin Dunbar: Mammals. Remarkable Animals, Volume (1): p40)
During the endless winter months lemmings must physically change in order to survive.
? To reduce heat loss as much as possible, the Norwegian lemming grows a long winter coat that traps a layer of air in the under fur.? (The Biology of Lemmings, edited by N.C. Stenseth and R.A. Ims, Academic Press, London, 1993)
?It also develops two paculiar, enlarged, forked claws on the front feet, well adapted for digging in frozen snow.? (Macdonald, D. W. 1984. The encyclopedia of mammals. Facts on File Inc. New York. Pp. 650-657. )
They use these claws to build homes under the snow in the winter.
?In winter they usually live under snow, protected from cold and from enemies, building rounded nests of grass that keep the moisture out of the dens. They make extensive tunnels under the snow.? (Marsden, W. 1964. The lemming year. Chatto and Windus. London, U.K.)
Like all lemmings the Norwegian lemming is a herbivore. It survives off the small plants that grow in the Arctic.
“Because their food is lichens, mosses, and grasses the brutal wintry conditions do not interrupt their feeding and therefore continue to breed.? (Dr. Maurice Burton: Lemmings. Wildlife Encyclopedia, volume (10): 1301-1302)
Because of that yearly supply of food the lemming has almost unlimited breeding capabilities.
?Breeding can occur at all seasons, lemmings sometimes breed in the winter, but there is always a pause in spring and fall separating summer and winter breeding. How such a small mammal, already under a severe thermal stress, can muster enough energy to breed in an arctic winter, and what factors determine when winter breeding will occur, are still mysteries.? (Elton, C. 1942. Voles, mice and lemmings. Oxford. London. )
The lemming is one of the fastest breeders in the animal kingdom.
During the practically year round breeding season, family after family is born into the lemming colony.
?Each mother lemming has several litters. There may be three babies in a litter or four, or five, or even eleven. Just a few weeks later these young lemmings start having babies of their own.? (Smithsonian Institute. Internet WWW- page, URL: http://www.mnh.si.edu/arctic/html/lemming.html)
Even though lemmings can reproduce trough out the year, they are still prone to fluctuations in the population.
?The lemming populations build up over a period of y
What causes these population explosions and what happens when the population gets to high? In the last ten years these questions have been particularly studied and several accounts have been published, including one by Kai Curry-Lindahl, in Natural history for August-September 1963.
Curry-Lindahl gives three main reasons for the population explosions.
?First an early spring and a late autumn produce favorable climate conditions that not only yield an abundance of food but give the lemmings a longer period in which to take advantage of it. Secondly, mild winters with thaws and also severe winters are damaging to winter breeding. In winters that are between these extremes there is a high rate of breeding and of survival among the young. The third is that because of the lack of enemies (Arctic Fox, Snowy owl, and Ermine) during winter there is no brake on the mounting increases in numbers resulting from the first two.?
When the population density gets to large the food sources are quickly diminished and the lemmings must embark on a journey in search of new food in a new land.
?Lemmings migrate periodically from their home area when their population begins to exceed the food supply?. (J. Tast, Lemmus lemmus ? Berglemming, pp. 87 – 105, by Jochen Niethammer, 1982)
The lemmings don?t really seem to show any pattern in their migrations, they do not follow a set direction and they do not follow any leaders.
?Mass movements of lemmings are very aimless, although they may travel several miles each day?. (Macdonald, D. W. 1984. The encyclopedia of mammals. Facts on File Inc. New York. Pp. 650-657. )
?When there is a population explosion panic follows and the lemmings move haphazardly in all directions.? (Dr. Maurice Burton: Lemmings.Wildlife Encyclopedia, volume (10): 1301-1302)
?They may go up mountains as well as down into trenches. They may go to any point of the compass. They may go over glaciers or swim across rivers or lakes or as in Norway where mountains run down strait to the sea, into the sea.? (Macdonald, D. W. 1984. The encyclopedia of mammals. Facts on File Inc. New York. Pp. 650-657. )
Many lemmings die by throwing themselves off cliffs, crossing dangerous city streets, or trying to swim across the ocean.
?Their determination is such that they will cross busy roads, down steep cliffs and swim through rivers and lakes without stopping.? (Robin Dunbar: Mammals. Remarkable Animals, Volume (1): p40)
This behavior is why people have come to view the lemming as a suicidal maniac mouse. Ultimately they are trying to find food to support the abnormally high population.
But why would they kill themselves in the process of trying to find food? No one knows for sure why the lemmings put their own lives at risk, some say it is bad judgement, ?The drowning of lemmings was once thought to be a mass suicide by crazed, overcrowded lemmings. More likely it is just bad judgment on their part.
?Lemmings are small and have no way of estimating the size of the ocean? (GrantHummer and Daniel Babai: Lemmings. Internet WWW- page, URL: http://www.ucls.uchicago.edu/projects/1996-97/Hillocks96/lemmings.html)
Other naturalists say that it is stress among the lemming groups.
?Lemmings live secluded lives on mountain tops and are probably intolerant of each others company, when they move down into the valleys they become gregarious. For a while, therefore they crowd together, feed amicably side by side and share burrows. As the numbers rise, so the stress mounts, with a high death rate and many try to leave the area even if the result is death.? (Macdonald, D. W. 1984. The encyclopedia of mammals. Facts on File Inc. New York. Pp. 650-657. )
Naturalist like WB Quay believe that lemmings do not consider their death a loss, maybe they consider it a contribution to the survival of the species, these strange migrations are bedded so deep into the mind of the creature that it is more of unstoppable instinct than a conscientious thought. (An article from the German magazine ?Neue Welt?, number 48/1998)
Because no one really knows why lemmings put them selves to rest, many stories and legends have arisen as a result of lack of knowledge. Zeigler, a geographer in Norway wrote the first published account of the suicidal tendencies of the Norwegian lemming, in 1532. He stated that in stormy weather lemming?s fell from the sky, that there bite was poisonous and that they died when the spring grass began to sprout. In 1718, Jovan Norberg said
?People maintain that clouds leave behind vermin called mountain mice or lemmings?. (Macdonald, D. W. 1984. The encyclopedia of mammals. Facts on File Inc. New York. Pp. 650-657.)
Even the Inuit Eskimos have similar beliefs about lemmings falling from the sky. A 19th Century naturalist, Edward Nelson recounts:
“The Norton Sound Eskimo have an odd superstition that the White Lemming lives in the land beyond the stars and that it sometimes comes down to the earth, descending in a spiral course during snow-storms. I have known old men to insist that they had seen them coming down.? (Smithsonian Institute. Internet WWW- page, URL: http://www.mnh.si.edu/arctic/html/lemming.html)
The lemming is an animal shrouded in fiction and misinterpretation. Eleven different types of lemming are found throughout the Arctic Circle. The lemming is well adapted for life in the in the tundra. Of the entire species the Norwegian is the most famous and is the subject of countless studies. The Norway lemming embarks on a kamikaze migration in search of food that has bewildered scientist for centuries. No matter how strange the lemming may seem it has lived virtually unchanged for millions of years.