Body Size with Relation to Population Density in Mammals

Abstract

The first purpose of this paper is to present certain evidence of a decrease in body size in the Alaska fur seal (Callorhinus ursinus) with relation to a measured increase in population size; second, to review briefly the relationship reported to exist between body size and abundance in the brown rat, house-mouse, vole, muskrat, gray squirrel, raccoon, deer, and man. The body size: abundance relationship in mammals has not, we believe, received the attention it deserves. A third purpose of the paper, then, is to stimulate inquiry into the mechanics of body size regulation by density dependent factors in the environment.