Integrating life-history traits and amphibian upland habitat use in a Neotropical hotspot

Abstract

Effective management of semi-aquatic animals requires detailed information on upland habitat use around aquatic habitats. Quantifying the amount of habitats needed to sustain local animals’ populations is a crucial criterion when setting protective buffers to water bodies, especially for amphibians, which depend on these upland habitats for breeding and development. Differences in upland habitat use can emerge among amphibian species with distinct life-history traits, including reproductive-strategy (pond-breeding vs. non-pond breeding anurans), life-stage (adults vs. juveniles), and sex (males vs. females). To date there has been no quantitative study of upland habitat use in the Neotropics, which can provide a baseline for quantifying the amount of upland forested habitats needed to sustain local amphibian populations. We monitored three ponds for over two sampling year using drift fences with pitfall traps to investigate how reproductive-strategy, life-stage, and sex affect anuran upland habitat use in a forest remnant in the Atlantic Forest hotspot. We found no differences in upland habitat use between adult and juvenile anurans. However, we found that although the species richness of pond-breeding and non-pond breeding anurans was similar near wetlands, there was greater abundance of pond-breeding compared to non-pond breeding anurans. We also found a strong difference between the sexes in pond-breeding anurans, with males remaining closer to wetlands than females. Thus, the sex ratio of amphibian populations can be strongly skewed toward males if only small protective terrestrial buffers (50-m) are enforced during land development. Our findings also point to the inadequacy of current Brazilian policies to protect small wetlands and the fauna that depend on them. We recommend that policymakers adjust regulatory criteria to set hierarchical protective buffers around wetlands allowing different levels of land-use intervention.