Abstract:

Calomys musculinus (Muridae, Sigmodontinae) is a small rodent species found in most central and northern Argentina. It is the reservoir of the Junin virus, ethiological agent of the Argentine Hemorrhagic Fever (FHA). In the present work we studied habitat selection by C. musculinus at different spatial scales in rural habitats where the landscape is mainly formed by cropfields, surrounded by weedy margins (borders). We found that C. musculinus selects borders over cropfields, but there were not differences between types of fields or types of borders. The structure of the spatial heterogeneity, which is mainly grouped between macrohabitats due to agrarian labors, did not allow to detect habitat selection, within cropfields and borders, for habitat patches larger than individual trap sites. Distribution between fields and borders was related to the green plant cover in early autumn, probably because of specific requirements of reproductive individuals. Within these habitats, we found differences in captures according to the presence of some plant species, which varied according to the season and the habitat.