Of mice, mastodons and men: human-mediated extinctions on four continents

Abstract

Numerous anthropological and ecological hypotheses have been proposed to explain the extinction of many large-bodied mammals at the terminal Pleistocene. We find that body size distributions of all mammals in North America, South America, Africa and Australia before and after the late Pleistocene show a similar large-size selectivity of extinctions across con-tinents, despite differences in timing. All extinctions coincide with the colonization of the continent by aboriginal man, but only two coincide with periods of climate change. Further, historical (within the last 300 years) extinctions in Australia demonstrate a higher susceptibility of small and medium-sized mammals. On all four continents, large-bodied Recent mammals are threatened by human hunting practices, whereas small-bodied species are not. We conclude that the late Pleistocene extinctions were caused primarily by anthropogenic factors such as human hunting, whereas historical extinctions were due mostly to habitat alteration and exotic species introductions.