Trophic position, altitudinal distribution, and water dependence as determining factors for mercury concentrations in tropical montane anurans.

Mercury (Hg) is a widespread and toxic contaminant with potential for long-range atmospheric transport. Previous work has shown that temperate and subtropical montane ecosystems have great potential for deposition of this element. However, little information exists regarding Hg dynamics in tropical mountains. In present study, we evaluated the influence of altitudinal distribution, size, trophic position, and degree of water dependence on Hg concentration in amphibians. For this purpose, we determined the mercury concentration in topsoil and amphibian samples collected at 32 points distributed between 327 and 2181 m above sea level in Serra dos Órgãos, a mountainous complex located in southeastern Brazil. We analyzed the concentration of mercury in whole body samples of 200 individuals of 30 amphibian species. Trophic position of the specimens was estimated by nitrogen stable isotope (δ15N) composition in muscle tissues. We observed a positive relationship between elevation and Hg concentration in topsoil samples from rainforest sites. However, in samples from nebular forest and campos de altitude (highland grasslands) sites, the concentration of Hg was considered lower than expected by the trend in rainforest points, indicating that the vegetation structure plays an important role in the deposition of atmospheric mercury. Mercury concentration in amphibians varies according to the functional characteristics of the species and the environment in which the individual is inserted. Elevation, trophic level and water dependence explained at least some degree of variation in Hg concentration in amphibian tissues. Thus, this community-level analysis suggests that mountainous areas in the tropical region, as recorded for temperate and subtropical mountains, act as regional convergence and deposition sites for atmospheric mercury.

Notes on vocalizations of Brazilian amphibians IV: advertisement calls of 20 Atlantic Forest frog species.

Bioacoustics is a powerful tool used for anuran species diagnoses, given that advertisement calls are signals related to specific recognition and mate attraction. Thus, call descriptions can support species taxonomy. In spite of that, call descriptions are lacking for many species, delaying advances in biodiversity research. Here, we describe the advertisement calls of 20 anuran species from the Brazilian Atlantic Forest. We accessed 50 digital recordings deposited in the Fonoteca Neotropical Jacques Vielliard. Acoustic analyses were carried out in the software Raven pro 1.5. We provide a general comparison of call structure among species inside taxonomic groups and genera. The vocalizations described here belong to poorly known species, which are representatives of six families: Brachycephalidae, Bufonidae, Ceratophryidae, Cycloramphidae, Hylidae, and Phyllomedusidae. Despite this, still there are 163 species of anurans from Atlantic Forest with calls not formally described. Our work represents an important step in providing data for a taxonomic perspective and improving the knowledge of the Atlantic Forest anuran diversity.

Biogeographic links between southern Atlantic Forest and western South America: Rediscovery, re-description, and phylogenetic relationships of two rare montane anole lizards from Brazil.

Data on species ranges and phylogenetic relationships are key in historical biogeographical inference. In South America, our understanding of the evolutionary processes that underlie biodiversity patterns varies greatly across regions. Little is known, for instance, about the drivers of high endemism in the southern montane region of the Atlantic Rainforest. In this region, former biogeographic connections with other South American ecosystems have been invoked to explain the phylogenetic affinities of a number of endemic taxa. This may also be the case of the montane anole lizards Anolis nasofrontalis and A. pseudotigrinus, known from few specimens collected more than 40years ago. We combine new genetic data with published sequences of species in the Dactyloa clade of Anolis to investigate the phylogenetic relationships of A. nasofrontalis and A. pseudotigrinus, as well as estimate divergence times from their closest relatives. Based on newly sampled and previously overlooked specimens, we provide a taxonomic re-description of those two taxa. Our phylogenetic analysis recovered six main clades within Dactyloa, five of which were previously referred to as species series (aequatorialis, heterodermus, latifrons, punctatus, roquet). A sixth clade clustered A. nasofrontalis and A. pseudotigrinus with A. dissimilis from western Amazonia, A. calimae from the Andes, A. neblininus from the Guiana Shield, and two undescribed Andean taxa. We therefore define a sixth species series within Dactyloa: the neblininus series. Close phylogenetic relationships between highly disjunct, narrowly-distributed anoles suggest that patches of suitable habitat connected the southern Atlantic Forest to western South America during the Miocene, in agreement with the age of former connections between the central Andes and the Brazilian Shield as a result of Andean orogeny. The data also support the view of recurrent evolution (or loss) of a twig anole-like phenotype in mainland anoles, in apparent association with the occurrence in montane settings. Our findings stress the value of complementary genetic sampling efforts across South American countries to advance studies of mainland anole taxonomy and evolution.