Microhabitat selection of five sigmodontine rodents in a forest-steppe transition zone in northwestern Patagonia

Abstract

In a transition zone between Andean forests and Patagonian steppe, local populations of five sympatric species of sigmodontine rodents (Abrothrix longipilis, A. xanthorhinus, Eligmodontia morgani, Oligoryzomys longicaudatus, Reithrodon auritus) were examined for their microhabitat use. The study area represents a herbaceous steppe with sparse bushes. Over a four-year period, monthly samples were obtained by baited traps. The vegetation cover at each trapsite was monitored. The capture frequency in a particular microhabitat turned out to be strongly correlated with the local vegetation cover. This result is interpreted as a species-specific selection at a fine spatial scale of those microsites which resemble the characteristic environment in the area of main biogeographic occurrence of each of the rodents. The data on preferential microhabitat use might gather importance considering that two of these sigmodontine species are Hantavirus reservoirs.