Resposta de mamíferos silvestres do Pantanal ao encolhimento-e-expansão sazonal de habitats devido ao regime de enchente

摘要

The pantanal is a large savanna wetland (138,183 km2 in brazil), important for its wildlife, fed by tributaries of the upper paraguay River, center of south america (brazil, touching bolivia and paraguay). uplands are plateaus (250-1,200 m high, 215,000 km2 in brazil) and fatland is the pantanal (80-150 m high, 147,574 km2 in brazil). Rivers are slow moving when they meet the fatland (slope 0.3-0.5 m/km east-west; 0.03-0.15 m/km north-south), periodically overfowing their banks, creating a complex seasonal habitat range. Recurrent shallow fooding occupies 80% of the pantanal; during the dry season fooded areas dry up. fluctuating water levels, nutrients and wildlife form a dynamic ecosystem. a fooding regime forms distinct sub-regions within the pantanal. a mammal survey was carried out in the sub-region of the Rio negro from april, 2003 through March, 2004 to study the diversity and abundance of terrestrial mammals during the dry and fooding seasons. a total of 36 species were observed in the feld. The capybara Hydrochaeris hydrochaeris was the most frequent species, followed by the crab-eating-fox Cerdocyon thous and the marsh deer Blastocerus dichotomus. The highest abundance of species was observed during the dry season (august and september), when there is a considerable expansion of terrestrial habitats, mainly seasonally fooded grassland. animal abundance (in terms of observed individual frequencies) varied during the dry and wet seasons and the seasonally fooded grassland was the most utilized habitat by mammals in the dry season. ________________________________________________________________________________________ RESUMO