Terrestrial amphibians may dehydrate when exposed to low humidity, representing an important factor affecting spatial distribution and community composition. In this study we investigated whether rates of dehydration and rehydration are able to explain the spatial distribution of an anuran community in a Restinga environment at the northern coast of the State of Bahia, Brazil, represented by 11 species distributed in 27 sample units. The environmental data set containing 20 variables was reduced to a few synthetic axes by principal component analysis (PCA). Physiological variables measured were rates of dehydration, rehydration from water, and rehydration from a neutral substrate. Multiple regression analyses were used to test the null hypothesis of no association between the environmental data set (synthetic axes of PCA) and each axis representative of a physiological variable, which was rejected (P , 0.001). Of 15 possible partial regressions only rehydration rate from neutral substrate vs. PC1 and PC2, rehydration rate from water vs. PC1, and dehydration rate vs. PC2 were significant. Our analysis was influenced by a gradient between two different groups of sample units: a beach area with high density of bromeliads and an environment without bodies of water with low density of bromeliads. Species of very specific natural history and morphological characters occur in these environments: Phyllodytes melanomystax and Scinax auratus, species frequently occurring in terrestrial bromeliads, and Ischnocnema paulodutrai, common along the northern coast of Bahia and usually found in forest remnants within environments with low number of bodies of water. In dry environments species with lower rates of dehydration were dominant, whereas species showing greater rates of dehydration were found predominantly in microhabitats with greater moisture or abundance of bodies of water.

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The study of the ixodofauna in fragments of woods in an urban area is important to the knowledge of species of tick and the dynamic among wild and domestic hosts, allowing to subsidize proposals for the conservation of the fauna and the control of zoonoses such as Brazilian spotted fever. To accomplish the survey, CO2 traps were built up in six different sites of the forest, during a oneyear period, totalizing 12 collections. The ixodids were collected by monitoring the traps and the adjacent vegetation during two hours and put in ethanol 70° GL. At the laboratory they were identified under the stereoscopic optics. At the end of a one-year period of study 2.122 ixodids were colleted, being 793 larvae (37,3%) and 1.277 nymphs (57,8%) of the genus Amblyomma and 102 were adults (4,9%) of the Amblyomma species. The most constant species was Amblyomma cajennense, present in 83,33% of the collections (71 specimen) followed by Amblyomma dubitatum, present in 50% (30 specimen), and Amblyomma calcaratum, 8,33% (one specimen). The observations showed that in the observed environment the populations of Ixodidae have an aggregate distribution, possibly because of the aggregate distribution of the resource, in the case wild hosts.