Seasonal variations and changes in the diet of southern river otter in different freshwater habitats in Chile

Abstract

The diet of southern river otter Lutra prouocax Thomas, 1908 was determined from 605 scats collected from four sites in Southern Chile between 1990-1991. Crustacean remains were the most common item found in scats. Crustacean species that were the most common in scats collected from lakes, became less important in the river outlets. Fish remains were all from fish less than 100 mm in length and were found more frequently in scats collected at the river sites than at the lake sites. Differences in the diet between otter's scats collected in lakes and their river outlets may be related to prey availability and vulnerability. Diet was more diverse in river habitats than in the lakes. The diet of southern river otter appears to be closer to that described for Aonyx capensis and Lutra maculicollis in South Africa. The southern river otter is heavily dependent on the abundance of three crustacean species. Differences in the diets observed between lake and their river outlets suggest important differences in habitat conditions. This may have future implications for prioritising habitat protection in the conservation of southern river otter.