EN
We employed a live-trapping grid encompassing several discrete vegetation patches to analyze spatial differences in the demographic structure of an Oxymycterus rufus (Fischer, 1814) population living on the delta of the Parana River, Argentina. Abundance, residence and reproduction of both females and males have been associated with microhabitats where food (measured through the availability of arthropods) was more abundant, and were not associated with the plant cover of those microhabitats. Our results emphasize the importance of food availability in the spatial distribution of resident and reproductive individuals, and hence in the survival and breeding success of their populations in the Parana delta area.