The Ecology and Macroecology of Mammalian Home Range Area

Abstract

Although many studies employ allometric relationships to demonstrate possible 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 ranges than herbivorous species of similar mass. These studies also argued that scaling relations (e.g., slopes) of the former were steeper than those of the latter and explained this in terms of the distribution of food resources, which are more uniformly distributed for most herbivores than for carnivores. In contrast to these studies, we show that scaling relations of home ranges for carnivorous mammals do not differ significantly from those of herbivorous 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 polygonal constraint space bounded by lines representing energetic and/or biophysical limitations, which suggests that the log-linear relationship between 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 unclear, however, why the slope of the relationship between home range area and body mass, whether based on raw data or on constraint lines, always exceeds that predicted by the energetic needs hypothesis.

New macroecological insights into functional constraints on mammalian geographical range size

“…Conversely, small mammals require less absolute energy, but minimum GRS may be restricted because individuals must forage relatively widely (for their body size) to meet their high mass-specific energy demand, again in the face of spatio-temporal variation in resource availability ('relative (mass-specific) energy demand constraint' in figure 1b). The break point in the relationship between home range size and body size around 100 g is consistent with this argument: for species smaller than 100 g there is a lower bound on minimum home range size that increases with decreasing body size [23,24]. Thus, the smallest species tend to have larger individual home ranges than predicted by mass alone, which points to the high mass-specific energy demand of small body size as a constraint on space use.…”

“…Presumably, this range of body sizes-at which absolute and mass-specific energy demands are jointly minimized compared with larger or smaller body sizes-relaxes constraints on minimum space needs of individuals and therefore species. If true, the break point in body size-GRS space thus may reflect a transition in the energetics of body size (and see Kelt & Van Vuren's [23,24] discussions on the body size-home range size relationship).…”

“…The mechanism proposed by Brown & Maurer [20] to explain the lower bound in figure 1a is that as animals get larger they require more energy [22], larger home ranges [23,24], lower densities [25], and therefore larger distributions to maintain minimum viable populations to avoid extinction. We term this the 'energetic constraint on minimum range size' or ECMS hypothesis.…”

Energy Costs of Catfish Space Use as Determined by Biotelemetry

“…Animals search for dispersed resources throughout the HR [2], the size of which can be larger than predicted by energy needs [3], [4] reflecting, for example, low habitat productivity, in which the energy needs of the resident animals are poorly satisfied [5], [6], and/or competition with neighbors for resources within the HR [7]–[9]. An unbalanced distribution of resources within the HR results in a disproportional use of the HR [10].…”

Home range areas of koalas in an urban area of north-east New South Wales

“…Overcoming the challenges posed by these factors will be more difficult for large vertebrates than for small ones due to their greater vulnerability when crossing roads (e.g. Rytwinski and Fahrig 2012) and their needs for larger areas (Kelt and Van Vuren 2001).…”