Population Dynamics of Rodents and Other Small Mammals

Abstract

Publisher Summary Studies of social behavior and dynamics in natural populations are important, because the behavior of the individual in nature is a basic factor in gene exchange between parts of a species population. This chapter is concerned principally with such population phenomena as: (1) localization of the individual, (2) dispersal, (3) pattern of reproductive behavior, (4) life span in nature, and (5) pattern of distribution. All have a bearing on the gene exchange and geographic differentiation within natural populations. The behavior in natural populations of rodents and other small mammals, as revealed by live-trapping and nest-box studies, theoretically has important effects on the gene exchange in these populations. Attachment of an individual to a limited area of familiar terrain or home range tends to restrict gene dispersal. Estimates of home-range size for 39 species of rodents and for 9 other species of small mammals, although difficult to compare because of the differences in technique, do show the widespread occurrence of the home-range habit. The size of the home range is affected by such attributes as sex, age, mobility, body size, and food habits, and by such ecologic factors as vegetative cover, size of area, and season of the year. Dispersal of the young away from the place of birth at the approach of sexual maturity is the most important means of dispersing genes through the population.