LAUSR

The aim of this study was to determine the diet of the neotropical otter in the upper San Diego River. Neotropical otters are predator considered as an indicator of the quality of the aquatic ecosystems, the species is listed as threatened in Mexico; therefore it is essential to conduct studies to understand their biology and ecology. The monitoring was carried out for 2 consecutive years (2012-2013), a longitudinal section of the river of 8 km was surveyed, it was divided into 3 equal sections. A total of 266 scats were collected, food items found in them were identified. Diet was conformed by 7 categories of prey, invertebrates and fish representing the highest percentage (39.45% and 34.86%, respectively), with a smaller presence plants, amphibians, mammals, birds, reptiles and 4.95% of unidentified items. Items in all categories were found in spring. Gila conspersa, Corydalus texanus and Abedus sp., were the most often species found in the diet. There were no significant differences in diet between seasons, or segments of the river (only between dry and rainy season for the year 2012).