Navegando por Palavras-chave "Habitat selection"

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    Uso de hábitat e período de atividade do sapinho botão de ouro Brachycephalus ephippium
    (Universidade Federal de São Paulo, 2015-07-31) Santos, Juliana Correia [UNIFESP]; Brasileiro, Cinthia Aguirre [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    Anurans are ectothermics and have permeable skin; therefore, they respond to changes in humidity and temperature conditions of the microhabitat. Thus, these environmental factors, as well as prey availability, must influence habitat use and daily activity. For diurnal species these environmental factors must be even more important. Brachycephalus ephippium is a diurnal small sized species exhibiting direct development, which inhabits the leaf-litter of Atlantic Forest of southeastern Brazil, so, this species is highly exposed to dehydration. Our goal was to investigate the influence of abiotic and biotic factors in the habitat use of B. ephippium and also to describe the species daily activity evaluating physiological costs of diurnal habits. We described habitat use with 60 plots (2x2m) that were randomly distributed at Reserva Biológica Municipal da Serra do Japi. We related the density and occurrence of B. ephippium with six abiotic factors and with prey abundance and richness. We determined the daily activity through evaluating the phisiological costs, that were determined by the water loss in agar models and we also checked whether sheltering under the leaf-litter reduced dehydration. Brachycephalus ephippium density was inversely correlated with the temperature and positively correlated with prey richness. We also found that the occurrence of B. ephippium was positively associated with the humidity of leaf-litter. The lowest number of individuals was recorded in the hottest and drier period of the day, when we observed the dehydration in agar models. During this period the majority of individuals was sheltered under the leaf-litter, where the dehydration is lowest. As a diurnal species, B. ephippium seemed to respond more strongly to shifts in temperature than humidity. Besides the behavior of choosing colder sites, B. ephippium also reduces their activity during hot and dry periods of the day, when they shelter under the leaf-litter to avoid dehydration. Besides the behavioral control, B. ephippium is also capable of regulating water absorption physiologically at different temperatures.