Knowledge on the feeding ecology and habitat use of a species is of essential value for effective conservation. We describe the diet and spraints deposition sites for the Neotropical otter (Lontra longicaudis) at Cavernas do Peruaçu National Park, in south eastern Brazil. We collected spraints and recorded characteristics of the deposition sites from 2007-2010. We described otter diet as the number of faeces in which a given taxon was found and the frequency of occurrence of each taxon. We collected 57 spraints and identified 92 food items from nine different taxa, all from animal origin. Fish was the most frequent taxon, found in 98.3% of our samples, followed by arthropods (22.8%) and mammals (10.5%). We recorded 112 spraint deposition sites, most of them located in caves (80%) and < 10 m from the water (93.4%). In our study area the Neotropical otter relies heavily on fish, and we believe that the behaviour of some fish species makes them more vulnerable to predation. Habitat use by otters has important management implications for the national park, as caves are the main tourist attraction and some tourist tracks are located next to the river. Although a well-implemented management action might seem enough to avoid negative impacts of tourism, we believe that monitoring the Neotropical otter population in our study area is of major conservation concern to evaluate the impacts of this activity
