This web site was completed in partial fulfillment of the requirements for Biology 323, Animal Behavior, at Davidson College in the Spring Semester 2007.

Summary

There are many subspecies of lemmings, members of the family Arvicolidae. Lemmings inhabit northern America and northern Europe, living in boreal forests and tundra. They eat mosses and shrubs and have a number of predators, including martens and birds of prey. Lemmings cannot defend themselves against predators. The popular image of lemmings is that they blindly follow each other, often to commit mass suicide; this is in fact incorrect.

The central element of a lemming social space is the mat, which will contain one or more burrows. This serves as the core area, around which will be a home range. Males and females both have home ranges, although males are more mobile and will move between multiple burrows. Mats may be defended against other lemmings. Lemmings are usually solitary and will become aggressive in the presence of others.

The mating system is overlap promiscuity. Males will attempt to mate with multiple females but do not help with raising offspring or with territorial defense. Females look for the best male, who is usually dominant. Dominance plays a key role in determining mate choice and will affect the ability to claim a mat. Dominance and body mass are related in males and females, and larger individuals tend to be more reproductively successful.

One of the peculiarities of many microtine species is the great effect of population cycles. Within the span of a couple years, population can grow or shrink rapidly. Although the mechanisms of this are not well understood, there are many hypotheses; it is likely that more than one of these play a role. The population cycles affect nutrient availability, core area availability, interactions between individuals, mate access, and interactions with other local microtine species.

Lagurus lagurus - The Steppe Lemming

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