Microhabitats in a forest-floor small mammal fauna

DUESER, R.D.; SHUGART JR., H.H. 1978. Microhabitats in a forest-floor small mammal fauna. Ecology 59(1):89-98.

Abstract. This study examines microhabitat  configurations for 3 small mammal species occupying second-growth mesic forest on Walker Branch Watershed in eastern Tennessee. Small mammal populations were sampled in oak-hickory, chestnut oak and pine forest types, with three 0.36-ha live-trapping grids per forest type. There were 255 total captures for 4 forest-floor species during 9,696 trap-nights between 1 May and 16 August 1973. These captures included 2% Blarina brevicauda, 66% Peromyscus  leucopus,  5% Ochrotomys  nuttalli  and 27% Tamias striatus.  Blarina was  captured most frequently in the pine forest type, Peromyscus and Tamias most frequently in the oak-hickory, and Ochrotomys exclusively in the pine. Twenty-nine variables describing proximate habitat structure were measured at each small mammal capture site. There were significant overall species differences on  18 of these  variables. A subset of variables was identified for each of the 3 most frequently observed species, consisting of only the variables of particular significance for distinguishing the capture sites of that species from those of the other species collectively. Discriminant analysis of these few variables both described the average microhabitat configuration for a species and indicated the relative importance of each variable for characterizing or describing that configuration, subject to the assumptions of the analysis. The observed differences between species in microhabitat  configuration are consistent with both the composition by  forest type of  each  species  sample and the  literature information for  each species. Microhabitat segregation among these species is discussed with reference to recent theories of habitat selection, ecological specialization and resource partitioning in equilibrium faunas.