Intra-annual dietary variation in the Neotropical otter from southern Brazil

The scats of Lontra longicaudis are easily recognized in the field and provide basic information about its foraging ecology. Two questions were addressed regarding its diet: (I) Does the composition of prey vary temporally? (II) Does the dietary breath vary seasonally? We answered these questions based on scatological analyses. We carried out 12 field trips, once per month for a year, to collect scats along a 13-km stretch of the lower Arroio Grande River in southern Brazil. Scats were collected individually and identified by date and geographic location. Prey items were classified according to food category and to family level. The feeding habits of L. longicaudis were based on fish, with a narrow diet range. Members of the families Cichlidae and Callichthyidae predominated in the diet, and this proportion did not vary during the year. The fish species varied seasonally but the dietary breadth did not. Thus, L. longicaudis hunts, preys, and maintains a degree of feeding flexibility throughout the year.