Microhabitat partitioning by small mammals in cedar glade and deciduous forest habitats

The Peromyscus sexes occupy different microhabitats in the deciduous forest and the same microhabitat in the cedar glade. Since the cedar glade is more heterogeneous than the deciduous forest, it is hypothesized that interspecific competition with Ochrotomys limits Peromyscus to more homogeneous portions of the cedar glade and thus allows neither Peromyscus sex the opportunity to gain a more favorable microhabitat through intraspecific competitive exclusion.

Differential microhabitat use by male and female Peromyscus in the deciduous forest probably increases the reproductive capacity of the individuals of this population, as females appear to occupy more favorable microhabitats. This resource partitioning on the part of Peromyscus may explain the low diversity of rodent species in eastern deciduous forests and indicates the importance of considering intraspecific competitive regimes in the theory of species packing. It is postulated that intraspecific competition in heterogeneous habitats may serve as one basis for the evolution of kin and interdemic selection by selection for pseudo-altruistic males.