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Invasive species are known to affect native species in a variety of ways, but the effect of acoustic invaders has not been examined previously. We simulated an invasion of the acoustic niche by exposing calling native male white-banded tree frogs ( Hypsiboas albomarginatus ) to recorded invasive American bullfrog ( Lithobates catesbeianus ) calls. In response, tree frogs immediately shifted calls to significantly higher frequencies. In the post-stimulus period, they continued to use higher frequencies while also decreasing signal duration. Acoustic signals are the primary basis of mate selection in many anurans, suggesting that such changes could negatively affect the reproductive success of native species. The effects of bullfrog vocalizations on acoustic communities are expected to be especially severe due to their broad frequency band, which masks the calls of multiple species simultaneously.

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We evaluated tadpole communities of temporary and permanent ponds, in order to understand how community richness varies monthly in a subtropical humid climate, to interpret the community structure in relation to biotic and abiotic environmental variables related to the temporary and permanent ponds. The study site was the Pró-Mata Research and Nature Conservation Center, a private reserve in southern Brazil. The climate is classified as Temperate Superhumid, with no dry season. We sampled three temporary and three permanent ponds. We compared the richness of tadpole assemblages of permanent and temporary ponds through individual-based rarefaction curves, and tested for possible differences using a MANOVA test. Tadpole richness was related to temporal environmental descriptors through General Regression Model. Relationships between the tadpole assemblages and possible predictors of their spatial variation were measured using a partial Canonical Correspondence Analysis. Analysis of rarefaction curves indicated higher expected richness for the temporary ponds. The mean values of richness were significantly different between the two hydroperiods across all months. Monthly richness showed the same tendency of variation for both pond types. Only temperature was related to tadpole richness. The pCCA analysis was significant. The most important predictors on the first pCCA axis were vegetation cover, conductivity, depth, and predator diversity. In this study, vegetation cover, conductivity, predator diversity, and water depth explained the spatial variation of tadpoles between ponds, with tadpole richness and diversity being higher in temporary than in permanent ponds. Our results suggest that different spatial-seasonal patterns operating in temporary and permanent ponds are related to maintaining the species diversity of pond-breeding anurans.

Anurans are important prey for the American buUfrog Lithobates catesbeianus, but field assessments of its diet in the context of a local prey assemblage are lacking. We aimed to identify the frog species consumed by an invasive bullfrog population in subtropical South America, and to assess their relative importance among other types of prey. Characterization of the frog assemblage in the study area also allowed us to calculate the degree of electivity of the recorded anuran prey, in order to gain insight regarding bullfrog feeding preferences and to test if the bullfrog prey composition differed from a random sample of the assemblage. A total of 32.6% of the bullfrogs had at least one anuran in the stomach contents, and post-metamorphic anurans represented 49.1% of the relative prey importance for adult bullfrogs. Anurans were preyed on by all size classes, and constituted the volumetrically most important prey category in the diet of individuals heavier than 100 g. Cycloramphidae, HyMdae and Leiuperidae were positively selected, and Hypsiboas pulchellus and Physalaemus cuvieri were the species most often taken. We found a low occurrence of cannibalism, despite the high density of bullfrogs at the study site. Our results showed that the degree of electivity differed among bullfrog prey types, suggesting that some frog species may be preyed on in a higher proportion than their relative abundance in the assemblage. Testing the clues provided by this assemblage-level approach may lead to a better assessment of the interactions between buUfrogs and the native frog fauna.

Aim Disentangling the effects of climate and historical factors on biodiversity distribution remains a challenge for biogeographers. Here, we provide an analytical framework to discriminate the contributions of contemporary climate and the biogeographical history of taxa to the geographical distributions of phylogenetic lineages. Furthermore, we evaluate the constraint that the biogeographical history of clades exerts on the association between climate and clade distribution, i.e. the historical legacy of climatic effects. As a case study, we analysed the distributions of amphibian lineages across the Americas. Location The Americas. Methods We tallied the number of amphibian species per genus in each of 262 ecoregions. Each ecoregion was described by the composition of phylogenetic lineages using phylogenetic fuzzy weighting. The composition of amphibian genera and phylogenetic clades represented the distributions of shallow and deep phylogenetic nodes, respectively. We characterized each ecoregion by the biogeographical history of amphibian taxa and its current climate, whose influences on shallow and deep phylogenetic nodes were analysed using variation partitioning analysis. Results The association between climate and the distributions of deep phylogenetic nodes showed a strong historical legacy, although the distribution of amphibian genera was mostly associated with climate. Hyloidea were associated with a Gondwanan origin and higher annual mean temperatures, whereas other clades (e.g. Caudata) were related to a Laurasian origin and higher temperature seasonality. Microhylidae were related to occurrence in the Early Jurassic in Gondwana and recent occurrence in the Neotropics. Main conclusions Biogeographical patterns can be thought of as the net outcome of evolutionary, historical and ecological processes. Although temperature is likely to affect the ecology of amphibians, the effects of climate on the distributions of deep phylogenetic nodes were strongly constrained by the biogeographical history of clades. Nevertheless, local, climatically driven processes are likely to influence the distributions of shallow phylogenetic nodes. The historical biogeography of clades might help to explain the interplay between evolutionary and environmental processes in determining assembly patterns found elsewhere.

Anthropogenic disturbance has been pointed to as one of the major causes of the world´s biodiversity crisis. Among them, noise pollution is a potential underestimated threat, projected to increase in the next decades accompanying urban expansion. Rising levels of noise pollution may result in negative impacts on species highly dependent on acoustic communication. Amphibians have long served as model organisms for investigating animal acoustic communication because their reproduction depends on transmitting and receiving acoustic signals. A few studies have investigated the effects of anthropogenic noise on anurans, but there is still limited knowledge on how it affects them. In this study, we test the effect of two intensities of traffic noise on calling males of two Neotropical treefrogs species. We expect to record more changes in call parameters, to avoid masking effect, at higher intensity noise treatments, and in the species with higher call/noise frequency overlap. We performed a set of field playback experiments exposing male frogs to road noise at two different intensities (65dB and 75dB). Focal species are Boana bischoffi (high call/noise frequency overlap) and B. leptolineata (low call/noise frequency overlap). Both species changed acoustic parameters during or after the exposure to traffic noise. Advertisement call rate of B. bischoffi decreased during road noise, and dominant frequency decreased over time. Call length of B. leptolineata increased or decreased, depending on the order of noise intensity. We also observed spatial displacement in both species, which moved away from the noise source. Our results provide evidence that traffic noise affects anuran calling behavior, and noise intensity is an important factor affecting how species respond.

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