The study was carried out in two areas of Taquari Valley, central region of Rio Grande do Sul State, Southern Brazil. Between August 2000 and December 2001 a study about diet and use of shelters and scent marks by Lontra longicaudis (Olfers, 1818) was performed. 275 spraints were colleted, of which 261 were analised for diet determination. The use of scent marks occured by the deposition of feaces mainly under conspicuous sites of the river margin or inside the shelters. The shelters were often formed by parallel excavation of river margin. The shelters were highly reused. Predation occurred on 3 groups of preys: Fish, Mammals and Insects. The fish, formed the diet base, and the families Loricariidae/Callichthyidae, Cichlidae, Pimelodidae/ Auchenipteridae and Erythrinidae were the most frequently identified ones in fecal analysis. The occurrence of these fish groups in the diet was higher then the relative availability in environment.
Diet; otter; Rio Grande do Sul; scent marks; shelters
