Effects of cereal harvest on abundance and spatial distribution of the rodent Akodon azarae in central Argentina

The effects of corn and wheat harvest on abundance, movement, disappearance, sex ratio and age structure of Akodon azarae were studied in cropfield-border systems. Sampling occurred both before and after harvest, in crops, in their weedy margins (borders) and in surrounding areas. The abundance of A. azarae decreased in fields between before and after harvest and increased along borders. Rodents moved among habitat patches, movement being higher as a consequence of harvest. There was no difference among habitats in terms of disappearance and sex ratio but changes occurred in age structure because of harvest. In response to harvest A. azarae was able to move from crops to borders, decreasing the mortality effects. The ability to respond to habitat changes allows A. azarae to maximize fitness in periodically disturbed habitats.