IUCN / SSC Cat Specialist Group - Digital Cat Library |
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| Alves, M.Z. | |
| Influence of environmental conditions and predator-prey relationship in a community of medium and large sized terrestrial mammal in dense rain forest | |
| 2016 Full Book | |
The destruction of tropical forests is alarming and may lead to the extinction of species susceptible to fragmentation. In the Atlantic Forest, mammals with important functions in the ecosystem balance, such as _Panthera onca _(jaguar), are already absent in part of the biome. Therefore, it is urgent to understand the processes that influence the permanence of these species in an area, in order to prevent future local extinctions. Thus, this study aimed to analyze the influence of environmental characteristics on the richness and occurrence of terrestrial mammals of medium and large size; as well as the spatio-temporal relationship between the top predator, mesopredator and preys, in the Atlantic foreste area continuos continuous with Serra do Mar State Park, with recent degradation history (Neblinas Park, Bertioga, State of SÆo Paulo). Sample data was collected by camera trapping for 90 days in 2013 and 2014, 27 sampling points 1km distant from each other. The environmental characteristics were altitude, drainage density, average rainfall, average temperature, number of palm hearts (_Euterpe edulis_) and the presence of nature trails. Generalized Linear Models were used to analyze the environmental influences on the richness and occurrence of species (with more than 3 records per year). For the other analyses, species were grouped into predator, mesopredators, preys of large, medium and small size. The period and overlap activity of these groups were estimated by the Kernel density. Abundance was estimated for mesopredators and prey through N-mixture models. Single-season occupancy models were used to analyze the probability of occupancy and detection of top predators. A total of 18 terrestrial mammals of medium and large size were sampled, with nine of them being threatened with extinction: _Cabassous unicinctus _(naked-tailed armadillo), _Cuniculus paca _(paca), _Leopardus guttulus _(oncilla), _Leopardus pardalis _(ocelot), _Leopardus wiedii _(margay), _Pecari tajacu _(collared peccary), _Puma concolor _(cougar), _Puma yagouaroundi _(jaguarundi) and _Tapirus terrestris _(tapir). In the 2013, the species richness was positively influenced by the largest volume of precipitation and the species occurrence (_C. unicinctus_, _Dasypus novemcinctus _(tatu-galinha), _P. concolor_, _Sylvilagus brasiliensis _(tapiti) e _T. terrestris_) was interfered by the drainage density. In 2014, richness was not explained by any of the environmental characteristics mentioned and only four species have suffered influence of them. The top predator recorded was catemeral, the mesopredator and large prey were mainly nocturnal and prey of medium and small size were mainly daylight. Smaller prey had the highest total overlap with the predator (D1=0.72). The influence on the probability of occupancy of the area by the predator varied between the years: in 2013 it was the abundance of large and small preys, and in 2014, the influence was the abundance of medium preys. The detection was negatively influenced by the occasion only in 2014. Our findings showed the environmental characteristics that should be maintained in the area, such as water resources and abundance of prey, for conservation of Atlantic Forest and its fauna community. |
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