Climate Change and American Bullfrog Invasion: What Could We Expect in South America?

BACKGROUND: Biological invasion and climate change pose challenges to biodiversity conservation in the 21(st) century. Invasive species modify ecosystem structure and functioning and climatic changes are likely to produce invasive species' range shifts pushing some populations into protected areas. The American Bullfrog (Lithobates catesbeianus) is one of the hundred worst invasive species in the world. Native from the southeast of USA, it has colonized more than 75% of South America where it has been reported as a highly effective predator, competitor and vector of amphibian diseases. METHODOLOGY/PRINCIPAL FINDINGS: We modeled the potential distribution of the bullfrog in its native range based on different climate models and green-house gases emission scenarios, and projected the results onto South America for the years of 2050 and 2080. We also overlaid projected models onto the South American network of protected areas. Our results indicate a slight decrease in potential suitable area for bullfrog invasion, although protected areas will become more climatically suitable. Therefore, invasion of these sites is forecasted. CONCLUSION/SIGNIFICANCE: We provide new evidence supporting the vulnerability of the Atlantic Forest Biodiversity Hotspot to bullfrog invasion and call attention to optimal future climatic conditions of the Andean-Patagonian forest, eastern Paraguay, and northwestern Bolivia, where invasive populations have not been found yet. We recommend several management and policy strategies to control bullfrog invasion and argue that these would be possible if based on appropriate articulation among government agencies, NGOs, research institutions and civil society

Density, population structure and activity pattern of Hydromedusa tectifera (Testudines-Chelidae) in a mountain stream of Córdoba province

Abstract. The Snake-necked Turtle (Hydromedusa tectifera) is mainly distributed in the northeastern provinces of Argentina; however, some isolated populations occur in central Córdoba. This is the first report on some ecological aspects of one of these populations. Population density and annual activity pattern were characterized at Toro Muerto Stream in the Sierras region of the Córdoba province, central Argentina. Turtles were hand-captured and sex and carapace length were determined for each individual. Mark-recapture data were used to estimate population density, variation in monthly capture rates, and sex ratios throughout the sampling months. A total of 96 turtles were captured and density was estimated at 218 individuals ha −1 . Individuals were captured all year round, but showed activity peaks in spring and summer. This seasonal pattern has also been observed in other freshwater turtles. During the mating season a higher number of males were captured, which suggested a seasonal difference in activity patterns between sexes

Endemic amphibians cornered in headwaters by trout invasion in a mountain range in Argentina

The Sierras Pampeanas Centrales, one of the most important extra-Andean mountain systems of Argentina, harbour endemic and threatened amphibian species. In the past century, two alien predatory fish species (brook trout and rainbow trout) were introduced into rivers and streams of the area where amphibian species breed. We hypothesized that the presence of trout would adversely affect the distribution of native amphibians in streams of the area. To test this hypothesis, the habitat requirements of trout and native amphibians were compared, and the effect of trout presence on amphibian occurrence was evaluated. Transects (n = 126) were surveyed along rivers and streams in high-altitude grasslands of the area, and the occurrences of trout and amphibians and habitat variables were recorded. The habitat requirements of each species were compared using multivariate methods. Generalized linear mixed models were used to evaluate whether the occurrence of amphibians depends on trout, habitat variables or both. The distribution of each species between streams orders was assessed. The results showed that the presence of trout was the main factor conditioning the distribution of two endemic amphibian species (Boana cordobae and Odontophrynus achalensis) in basins of the study area. This threat needs to be incorporated urgently into action plans to guide conservation efforts towards the management of trout populations.Fil: Miloch, Daniela. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Zoología Aplicada; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; ArgentinaFil: Bonino, Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; ArgentinaFil: Leynaud, Gerardo Cristhian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; ArgentinaFil: Lescano, Julián Norberto. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Zoología Aplicada; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; Argentin

Anfibios de las Sierras Pampeanas Centrales de Argentina: diversidad y distribución altitudinal

Amphibians from Sierras Pampeanas Centrales of Argentina: diversity and altitudinal distribution. Sierras Pampeanas Centrales (SPC) mountains are located in Córdoba and San Luis provinces (Argentina) and represent an area of unique biogeographic importance. In this paper we provide a synthesis about the knowledge of diversity and altitudinal distribution of anurans that inhabit SPC mountains. We compiled a species list through different information sources (field data, biological collections and bibliography). Using this information we characterize altitudinal distribution range of each species and analyze associations between species richness and composition and altitude gradient. We recorded 24 amphibians species belonging to five families. These species are heterogeneously distributed over the altitude gradient of SPC. We detect a linear negative relationship between altitude and species richness and defined assemblages associated with different altitude sectors. The results obtained in the paper represent basic information that will be useful to evaluate anthropogenic impact on this particular and fragile mountain system