Invertebrate dispersal by waterbird species in neotropical wetlands

Endozoochory by waterbirds is particularly relevant to the dispersal of non-flying aquatic invertebrates. This ecological function exercised by birds has been demonstrated in different biogeographical regions, but there are no studies for the neotropical region. In this work, we identified propagules of invertebrates in faeces of 14 syntopic South American waterbird species representing six families, and hatched additional invertebrates from cultured faeces. We tested whether propagule abundance, species richness and composition varied among bird species, and between the cold and warm seasons. We found 164 invertebrate propagules in faecal samples from seven different waterbirds species, including eggs of the Temnocephalida and Notonectidae, statoblasts of bryozoans (Plumatella sp.) and ephippia of Cladocera. Ciliates (including Paramecium sp. and Litostomatea), nematodes and rotifers (Adineta sp. and Nottomatidae) hatched from cultured samples. Potential for endozoochory was confirmed for 12 of 14 waterbird species. Our statistical models suggest that richness and abundance of propagules are associated with bird species and not affected by seasonality. Dispersal by endozoochory is potentially important to a broad variety of invertebrates, being promoted by waterbirds with different ecological and morphological traits, which are likely to drive the dispersal of invertebrates in neotropical wetlands.

Effects of Increased Renewable Energy Consumption on Electricity Prices: Evidence for Six South American Countries

This research examines the relationship between renewable energy consumption and electricity prices in six South American countries (Argentina, Bolivia, Colombia, Chile, Ecuador and Peru). The methodology used is a panel econometric model with annual data for the period 1990–2015. The results show that the consumption of renewable energies influences the price of electricity paid by households, although its influence is very moderate. On the other hand, it was observed that the consumption of renewable energies has no relationship with the energy prices of the industrial sector and the commercial and services sector. In the countries analyzed, an increase in GDP causes an increase in the price of energy in the industrial sector. With more CO2 emissions and a rise in the international price of oil, the annual average price of the industrial sector decreases.

A new catfish of the genus Trichomycterus from the Rio Paraíba do Sul Basin, south-eastern Brazil, a supposedly migrating species (Siluriformes, Trichomycteridae)

A new species of the catfish genus Trichomycterus is described from the Rio Paraíba do Sul, south-eastern Brazil. This species exhibits some morphological character states that are unique amongst congeners, including a robust opercle and a long interopercle with numerous odontodes (50–60 opercular and 90–100 interopercular), a black bar on the basal portion of the caudal fin and a dark brown flank with a well delimited dorsal yellow stripe. It also exhibits some morphological traits that are uncommon amongst congeners, such as the presence of nine pectoral-fin rays. The presence of a shallow hyomandibular outgrowth and a ventrally expanded pre-opercular ventral flap suggests that this species is closely related to T. melanopygius, T. pradensis and T. tete. The new species also differs from T. melanopygius, T. pradensis and T. tete by having an emarginate caudal fin and a single median supra-orbital pore S6. Anecdotal evidence suggests that T. largoperculatus and T. pradensis have migratory habits, a condition not previously reported for eastern South American trichomycterines.

Action of Varespladib (LY-315920), a Phospholipase A2 Inhibitor, on the Enzymatic, Coagulant and Haemorrhagic Activities of Lachesis muta rhombeata (South-American Bushmaster) Venom

Varespladib (VPL) was primarily developed to treat inflammatory disturbances associated with high levels of serum phospholipase A2 (PLA2). VPL has also demonstrated to be a potential antivenom support agent to prevent PLA2-dependent effects produced by snake venoms. In this study, we examined the action of VPL on the coagulant, haemorrhagic and enzymatic activities of Lachesis muta rhombeata (South-American bushmaster) venom. Conventional colorimetric enzymatic assays were performed for PLA2, caseinolytic and esterasic activities; in vitro coagulant activities for prothrombin time (PT) and activated partial thromboplastin time (aPTT) were performed in rat citrated plasma through a quick timer coagulometer, whereas the dimensions of haemorrhagic haloes obtained after i.d. injections of venom in Wistar rats were determined using ImageJ software. Venom (1 mg/ml) exhibited accentuated enzymatic activities for proteases and PLA2in vitro, with VPL abolishing the PLA2 activity from 0.01 mM; VPL did not affect caseinolytic and esterasic activities at any tested concentrations (0.001–1 mM). In rat citrated plasma in vitro, VPL (1 mM) alone efficiently prevented the venom (1 mg/ml)-induced procoagulant disorder associated to extrinsic (PT) pathway, whereas its association with a commercial antivenom successfully prevented changes in both intrinsic (aPTT) and extrinsic (PT) pathways; commercial antivenom by itself failed to avoid the procoagulant disorders by this venom. Venom (0.5 mg/kg)-induced hemorrhagic activity was slightly reduced by VPL (1 mM) alone or combined with antivenom (antivenom:venom ratio 1:3 ‘v/w’) in rats, with antivenom alone producing no protective action on this parameter. In conclusion, VPL does not inhibit other major enzymatic groups of L. m. rhombeata venom, with its high PLA2 antagonize activity efficaciously preventing the venom-induced coagulation disturbances.

WRF Sensitivity for Seasonal Climate Simulations of Precipitation Fields on the CORDEX South America Domain

Dynamic numerical models of the atmosphere are the main tools used for weather and climate forecasting as well as climate projections. Thus, this work evaluated the systematic errors and areas with large uncertainties in precipitation over the South American continent (SAC) based on regional climate simulations with the weather research and forecasting (WRF) model. Ten simulations using different convective, radiation, and microphysical schemes, and an ensemble mean among them, were performed with a resolution of 50 km, covering the CORDEX-South America domain. First, the seasonal precipitation variability and its differences were discussed. Then, its annual cycle was investigated through nine sub-domains on the SAC (AMZN, AMZS, NEBN, NEBS, SE, SURU, CHAC, PEQU, and TOTL). The Taylor Diagrams were used to assess the sensitivity of the model to different parameterizations and its ability to reproduce the simulated precipitation patterns. The results showed that the WRF simulations were better than the ERA-interim (ERAI) reanalysis when compared to the TRMM, showing the added value of dynamic downscaling. For all sub-domains the best result was obtained with the ensemble compared to the satellite TRMM. The largest errors were observed in the SURU and CHAC regions, and with the greatest dispersion of members during the rainy season. On the other hand, the best results were found in the AMZS, NEBS, and TOTL regions.

The distribution and conservation status of Tapirus terrestris in the South American Atlantic Forest

Tapirus terrestris is the largest South American land mammal, with an extensive historical distribution and capable of occupying diverse habitats, and yet its populations have declined across its range. In order to provide baseline data on the conservation status of tapirs in the Atlantic Forest, we conducted a long-term study in one landscape, visited 93 forests, and received 217 expert reports over the 15-year study. We estimate that 2,665–15,992 tapirs remain in 48 confirmed populations, occupying 26,654 km2 of forest or 1.78% of its original range in the biome. Historically, hunting and deforestation were the main causes of decline, but today population isolation is the principal long-term threat. Vortex models indicate that 31.3–68.8% and 70.8–93.8% of the populations are demographically and genetically non-viable over the next 100 years, respectively, and that only 3–14 populations are viable when considering both variables. Habitat use data indicate that tapirs are adaptable to disturbed and secondary forests and will use diverse tree plantations and agricultural lands but hunting and highways keep populations isolated. Reserve staff report tapirs as common/abundant at 62.2% of the sites, and populations as stable and growing in 60% and 36% of the sites, respectively, and there is ample habitat in the biome for a population expansion, but overcoming the causes of isolation will be necessary for this to occur. Lack of adequate funding for protecting reserves is a chronic threat throughout the biome, especially in federal and state/provincial reserves, and increased funding will be necessary to implement effective conservation plans.