The ecology and macroecology of mammalian home range area

Although many studies employ allometric relationships to demonstrate possib le dependence of various traits on body mass, the relationship between home range size and body mass has been perhaps the most difficult to understand . Early studies demonstrated that carnivorous species had larger home range s than herbivorous species of similar mass. These studies also argued that scaling relations (e.g., slopes) of the former were steeper than those of t he latter and explained this in terms of the distribution of food resources , which are more uniformly distributed for most herbivores than for carnivo res. In contrast to these studies, we show that scaling relations of home r anges for carnivorous mammals do not differ significantly from those of her bivorous and omnivorous species and that all three exhibit slopes that are significantly steeper than predicted on the basis of energetic requirements . We also demonstrate that home range size is constrained to fit within a p olygonal constraint space bounded by lines representing energetic and/or bi ophysical limitations, which suggests that the log-linear relationship betw een home range area and mass may not be the appropriate function to compare against the energetically predicted slopes of 0.75 or 1.0. It remains uncl ear, however, why the slope of the relationship between home range area and body mass, whether based on raw data or on constraint lines, always exceed s that predicted by the energetic needs hypothesis.