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BiologicalMyths: The LemmingLegend

* HenryE. Childs,Jr., CerritosCollege, Norwalk, California

The Chairmanof the Divisionof Life Sciencesat Cerritospoints out the necessityof checking the validityof informationbefore it is presentedand reportedto a class.

Everybody 'knows" that lemmings mi- miles, and there, for reasons known only grate to the sea and commit suicide and to lemmings,they throw themselves (or are that the swallows always return to Capis- thrown as in a recent movie depicting this trano on Saint Joseph's Day. Or do they? event!) into the sea to destroy themselves. These interesting and instructive biological For a particularlypsychodelic descriptionof myths are commonly used in teaching to this remarkable event, read Sally Carrig- illustrate population phenomena that are har's "IceboundSummer," pages 95-118. In- actually untrue or at best misunderstoodby credibly large numbers of people, including those using them. This paper proposes to some otherwisewell-informed mammalogists, expose the first of these myths and to put actually believe that this story is true. Lets the story in its proper perspective. The examine it. swallowswill arriveat a later date. 1. Lemmings migrate. Any serious stu- dent of population behavior who uses the The LemmingStory term "migration"means that individualsborn This classic story states that at times lem- in one place move to another and return to mings migrate to the sea, a trip of many breed somewhere near the point of origin

660 The AmericanBiology Teacher, October, 1968 e.g., bird and salmon migration. No one small rodents closely related to the meadow describes the return of lemmings who have, mice (Microtus) of North America and after all according to the story, committed the voles of Europe. This group, which in- suicide. We should at least use the right cludes the muskrat,is noted for its violent term for it. Dispersal would be best. Cari- and irregular population fluctuations or bou, for example, are nomads, not migrants. plagues. Two species are significantin North 2. There is a directed movement to thte America,the Brown Lemming (Lemmus tri- sea. The lemming myth originated in Scan- mucronatus), a close relative of the Scan- dinavia where the lemming (Lemmus lem- dinavianform and thought to be conspecific mus) is a subalpine species living in the by some, and the collared or varying Lem- highlands between Norway and Sweden ming (Dicrostonyx groenlandicus). The lat- (see Elton, C. Mice, Voles and Lemmings ter is relatively unimportantin the lemming 1942: 209-223). When the population be- story as it has not been observed to be came abundant, individuals move downhill particularly irruptive in its populations. It (it's easier!). Soon the movement is fun- was, however, the actor used in the cast of Downloaded from http://online.ucpress.edu/abt/article-pdf/30/8/660/24763/4442226.pdf by guest on 02 October 2021 neled by the upper topography of a fiord Disney's film, "WhiteWilderness." In winter into a directed movement to the sea. In the collared lemming changes to a white the arctic people live primarilyat the edge pelage and develops enlarged front claws, of the sea and at the heads of the fiords apparently an adaptation for digging in and thus "see"the migration. snow. The directed movementto the sea is mere- The Brown Lemming and its close rela- ly a result of the passive action of the topog- tives in Russia and Scandinaviahave been raphy, not an inherited migratorypathway. extensively studied since World War II, and In arctic Alaska,where we have worked because of their cyclic population fluctua- across northern Canada the tundra is low tions, that is, predictably, every three or and flat for hundreds of miles south to the four years tremendous increases in their mountains and movements of the kind de- populationsare observed with a consequent scribed above have not been observed. That dramaticreduction in numbers.Research in these movements are a vestigal remnant of this country has been led by Frank A. a desire to return to the lost continent of Pitelka of the Museum of VertebrateZool- Atlantis is so patently absurd that further ogy, University of California, and his stu- comment is unnecessary. dents (see Pitelka, F. A., Some Character- 3. Lemmings commit mass suicide. That istics of MicrotineCycles in the Arctic. 18th any population has an inherent desire to Biology Colloquium pp. 73-88, 1957.) The destroy itself must be ridiculousto any biol- problem of basic biological concern is an ogist. Perhaps the fact that individual hu- understandingof the factors regulatingsuch mans kill themselveslends a fatal fascination cyclic populations. to this myth. In Scandinaviathe semi-aquatic lemmings move through the towns into the It was not the purpose of this paper to sea (a big tundra pond to them?). Death discuss in detail the ecology of Lemmings. occurs by drowning in about two minutes That has been done elsewhere. My purpose from wet fur that no longer insulates these is to warn against the teaching of inaccurate endothermswho then can no longer thermo- information about a significant population regulate. phenomenon, generally inaccurately ob- 4. What are lemmings? Lemmings are servedand reported.

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