Seasonal variation in rodent consumption by the barn owl (Tyto furcata) in a relict of Espinal in southern Santa Fe, Argentina

Abstract

There are few antecedents on the trophic habits of Tyto furcata in the south of Santa Fe province, Argentina. Based from the analysis of pellets, we characterized the diet of this raptor in a relict of Espinal in the south of Santa Fe province, Argentina. A total of 1789 items and 18 prey categories were determined in the 638 pellets collected during the research. According to the Shannon-Wiener index (H'), the dietary diversity was (H'= 1.47). Mammals, represented by 16 taxa, constituted 98% of the total of prey consumed, being Akodon azarae the most consumed prey. No statistically significant differences were found between the seasons and the species consumed, but significant differences were found when analyzing relative abundance. As it happens with other Strigiformes, the seasonal variation in the Tyto furcata’s diet in a relict of Espinal in southern Santa Fe, could be explained by the temporal cycles of abundance of rodent prey and its opportunistic hunting behavior according to the fluctuations of its prey, thus incorporating a greater number of alternative taxa in seasons with lower abundance of rodents.