Inter- vs intra- specific variations in home range size of sciurid rodents: influence of ecological constraints [Variations inter et intraspécifique de la taille du domaine vital chez les rongeurs sciuridés : effet des contraintes écologiques].

Résumé

Studies of the influence of biological and environmental factors on social-spatial strategies of sciurid rodents are based on an interspecific approach. However, data on different populations of the same squirrel species show that, intraspecific variations in socio-spatial strategy can be substantial and can yield important information on ecological correlates of social organization. To illustrate the relative contribution of intra- and inter-specific comparisons, we address the question of how ecological constraints affect the use of space of sciurid rodents. Data collected on different populations of woodchucks (Marmota monax) and red squirrels (Tamiasciurus hudsonicus) are used for intraspecific comparisons. It appears that population density and food availability can induce differences in home range size from one population to the other. Others factors, such as habitat used, type of hoarding utilized, and reproduction strategy, can also cause variations of home range size between populations. At the interspecific level, within the squirrel family, home range size is influenced by body weight. When granivorous and herbivorous species are considered separately, it turns out that the former tend to have larger home range size, relative to their body weight, than the latter. Thus, conclusions reached with these two levels of comparison yield different but complementary information on ecological constraints of home range size in sciurid rodents. Recommendations are proposed for future research.