Spatial distribution and daily activity patterns of three carnivore species in temperate grasslands of southern Brazil and northern Uruguay

Distribuição espacial e padrões de atividade diária de três espécies de carnívoros em pastagens temperadas do sul do Brasil e norte do Uruguai

Resumo

In the temperate grasslands of southern Brazil and northern Uruguay, three species of mesopredators have similar size, are in the same guild, and they seem to tolerate anthropogenic modifications. Sympatric species from the same trophic guild tend to divide resources both spatially and temporally to facilitate coexistence.  The aim of this study was to determine the patterns of the periods of daily activity and habitat use through different detection and occupancy models, of Cerdocyon thous (crab-eating fox), Lycalopex gymnocercus (pampas fox) and Leopardus geoffroyi (geoffroy's cat) in the mosaic of landscapes of anthropic domain in the Uruguayan Savanna ecoregion, through camera trap records. A total of 66 cameras were installed, divided into the 3 main environments, with a distance of 2 km between each camera to maintain the independence of the records, achieving a real sampling effort of 4,756 trap nights. The three mesocarnivores considered in this study were predominantly nocturnal. Cerdocyon thous presented a vesperal-nocturnal  activity pattern, being sunset the moment of highest activity, in contrast, L. gymnocercus presented highest activity at sunrise, being crepuscular-nocturnal. These opposite daily activity patterns among foxes species have not been recorded in other regions. With respect to L. geoffroyi, these specie presented a mostly nocturnal activity pattern. Regarding the use of habitats by the species after applying different models, the highest probability of detection and occupation of C. thous and L. geoffroyi was in the native forest environment and for L. gymnocercus was the natural grassland. Even the preference of L. geoffroyi for the native forest environment, these species presented a certain degree of adaptability for habitats with alterations produced by agricultural activities. The results obtained represent a very important contribution to the region in which this study was carried out, as well as allowing us to compare the results with other studies with these species in other regions.