Small mammal use of microhabitat reviewed

Small mammal microhabitat research has greatly influenced vertebrate community ecologists. There exists a "microhabitat paradigm" that states that sympatry among small mammal species is enabled by differential use of microhabitat (i.e., microhabitat partitioning). However, several studies have failed to detect microhabitat partitioning, and research has consistently indicated that microhabitat phenomena do not explain larger spatial scale (i.e., macrohabitat) variation. Possible reasons for these difficult to reconcile observations are explored by reviewing and tabulating data from 70 studies. The meaning of the term microhabitat has changed subtly since 1969. This review demonstrates that the existing knowledge of small mammal microhabitat partitioning is highly concentrated among small-scale studies, conducted with modest intensity, that measure microhabitat at inappropriate spatial scales. This concentration of knowledge appears to be an insufficient foundation on which to accept microhabitat partitioning as a widely generalizable phenomenon. The observation that microhabitat phenomena do not explain larger spatial scale variation suggests the importance of underappreciated adaptive mechanisms that relate to the ability of species to coexist, use habitat, and ultimately persist.