Patterns of interspecific and intraspecific microhabitat segregation of two rodents Praomys jacksoni (De Winton 1897) and Hylomyscus stella (Thomas 1911) (Rodentia) in an African rainforest subjected to various levels of anthropogenic di

A. Mortelliti, L. Boitani

Abstract


The aim of this study was to evaluate whether anthropogenic disturbance in tropical rainforests, in the form of alteration of lower vegetation structure, affects the patterns of interspecific and intraspecific microhabitat segregation in small mammals. We chose two areas of a Kenyan tropical rainforest: one disturbed and the other relatively undisturbed. Rodents were live-trapped with Sherman traps and 30 microhabitat variables were measured around each trapping site. Due to small sample sizes we concentrated our analysis on the two most abundant species: Praomys jacksoni (De Winton 1897) and Hylomyscus stella (Thomas 1911). We structured trapping patterns and data analysis to examine patterns of microhabitat segregation on various spatio-temporal scales. First, all available data (696 captures — all sessions of all grids in both areas) were pooled. Step by step this large sample was divided into comparisons concerning single areas, single grids (merging all sessions) and finally single sessions of single grids. The species segregate in structurally different microhabitats and are vertically stratified. In the disturbed forest there is a higher overlap between microhabitats, and patterns of microhabitat segregation are different, suggesting a response to the reduction of microhabitat variability occurring in the disturbed forest. Intraspecific differential microhabitat use was also found for Praomys jacksoni. We discuss whether juveniles, subadults and males are segregated in poorer quality microhabitats, and we hypothesize that anthropogenic disturbance affects this dynamic.

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