In Chapter 1, I posed the question as to whether the geomorphic role and effects of animals are significant and fundamental, or merely interesting but minor curiosities. Thereafter, I examined the geomorphic role of invertebrates, ectothermic vertebrates, birds, and mammals. In each and every case, despite human interference in the natural life cycles and distributions of animals around the globe, the answer has been resoundingly in favor of significance, whether it be as a result of the work of termites in the tropics, or of whales and walrus on the Arctic seafloor.

Although an individual species or genus may not have geographically widespread geomorphic influence, it may have profound effects locally. Examples include the setts of European badgers, mounds constructed by crayfish, salmonid redds, or food and den excavations by grizzly bears at alpine tree line. One must keep in mind, however, how many species of animals produce geomorphic effects on at least a local scale. Individual studies that denigrate the geomorphic contributions of animals in comparison to the work of running water, wind, or mass movements invariably acknowledge the local importance of one or a few species of animals as geomorphic agents; but what those studies fail to recognize is the quantity, significance, and geographical ubiquity of geomorphic accomplishments by animals collectively as a group. Although the amount of sediment displaced annually by rabbits or badgers, for example, may be impressive but spatially restricted, what about all the other animals also working that same area, as well as areas beyond the influence of the rabbits or badgers?