Carlos Benhur Kasper

Preliminary study by the ecology of Lontra longicaudis (Olfers) (Carnivora, Mustelidae) in Taquari Valley, South Brazil

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.

Estimativa do tamanho de duas espécies de ciclídeos (Osteichthyes, Perciformes) predados por Lontra longicaudis (Olfers) (Carnivora, Mustelidae), através de análise das escamas

The present study was carried out in the Taquari Valley, central region of Rio Grande do Sul State, Southern Brazil. Between December 2001 and December 2002 a study about the predation of Cichlidae by Lontra longicaudis (Olfers, 1818) was performed through scale analysis found in otter scats. Predation was indentified about Gimnogeophagus labiatus (Hensel, 1870) and Crenicichla punctata Hensel, 1870, and the occurence of these fish species in the diet were higher than the relative availability in the environment. A positive correlation between fish and scale sizes was found, allowing to build a regression curve to estimate the size of predated fish, based on scales found in otter scats. In this study ciclids most frequently predated varied in lenght from 100 and 150 mm and in weight from 22 to 37,6 g.

Trophic relationships of sympatric small carnivores in fragmented landscapes of southern Brazil: niche overlap and potential for competition

Abstract Between 2000 and 2010, digestive tracts collected from carnivore carcasses found in southern Brazil were analyzed to determine the frequency and proportion of items constituting the diets of each species. Material was collected and analyzed from 194 animals of 10 species: Cerdocyon thous, Lycalopex gymnocercus (Canidae), Procyon cancrivorus (Procyonidae), Galictis cuja (Mustelidae), Conepatus chinga (Mephitidae), Leopardus colocolo, Leopardus geoffroyi, Leopardus guttulus, Leopardus wiedii, and Puma yagouaroundi (Felidae). Most of these species are sympatric, which makes them potential competitors when sharing, to a greater or lesser degree, the same resources. The food niche breadth was relatively narrow, demonstrating that even generalist species, such as the crab-eating raccoon, used food resources rather unequally. An extensive overlap (>90%) in food niches was found among the cat species, the grison, and the Pampas fox, which had diets based on rodents. Crab-eating raccoons occupied a different food niche, based on aquatic or semiaquatic prey and fruits. Conepatus chinga was unique in exploiting arthropods and insect larvae as basic dietary items.

Trophic ecology of sympatric small cats in the Brazilian Pampa

Information about resource partitioning among small cat species that live in sympatry in South America is fairly incomplete. Knowledge about feeding habits is essential for understanding the role of these predators in the environment, the impact on prey populations, and potential competition among themselves and with other carnivores. This study aimed to describe and compare the diet of four sympatric small cats in the grasslands of southern Brazil. We analysed the stomach contents of 37 Geoffroy’s cats (Leopardus geoffroyi), 27 margays (Leopardus wiedii), 14 pampas cats (Leopardus colocola), and 20 jaguarundis (Herpailurus yagouaroundi) obtained as road kill in the Brazilian Pampa in southern Brazil. Small mammals were the most representative class consumed by all cats, followed by Aves, Reptilia, and Amphibia. Some items, such as rodents Cavia aperea, Akodon sp., Oligoryzomys sp. and Passeriformes were consumed by all cat species. Niche overlap varied widely, from 10% (margay x jaguarundi) to 92% (jaguarundi x pampas cat). Niche breadth indicated that jaguarundi were the most specialized of the cats (Bsta = 0.24) in this region, with a diet closely associated to C. aperea. Margay consumed more items associated with arboreal behaviour than other cat species, but consumed more terrestrial items than arboreal ones. The pampas cat consumed mostly terrestrial species associated with open fields. Geoffroy’s cat consumed mammals found in a diversity of habitats, indicating high ecological flexibility. Species with more similarity in diet such as jaguarundi and pampas cat probably present temporal segregation in activity. In conclusion, despite their habitat and diet similarities, these four species explore distinct microhabitats by foraging different prey groups, what favor them to live in sympatry.