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Aim Snake faunal dissimilarity within tropical forests is not well characterized, nor are the factors underlying these patterns. Our aim was to disentangle the ecological and historical factors driving biogeographical subregions (BSR) for snakes.Location Brazilian Atlantic Forest (BAF). MethodsWe compiled 274 snake inventories to build a species-by-site matrix and used unconstrained ordination and clustering techniques to identify the number of snake BSR. We applied an interpolation method to map axes of compositional variation over the whole extent of the BAF, and then classified the compositional dissimilarity according to the number of snake BSR identified a priori. We used multinomial logistic regression models and deviance partitioning techniques to investigate the influence of contemporary climatic stability, productivity, topographic complexity, and historical climate shifts in explaining the BSR. ResultsWe identified 198 snake species organized into six BSR, three of them located along the BAF coast and the other three predominantly inland BSR. Climatic stability made the largest contribution to explaining the variability in snake BSR, followed by productivity and historical variation in climate. Topography was important only if historical variation in climate was excluded from the analysis.Main conclusions The highest rates of snake endemism within BAF were in the coastal BSR, as compared to the inland BSR that are mostly composed of open habitat specialists. Our findings suggest that the topographic complexity of the BAF acts on snake distributions not as a physical barrier, but rather as a climatic barrier, providing historical climate refuges for species living along altitudinal gradients. Overall, the predominance of climatic stability and historic variation in climate in explaining snake BSR reinforces the importance of thermoregulatory constraints in shaping the distribution of tropical ectotherm species.Dev. expl (%) = percentage of deviance explained, AICc = Akaike's information criterion corrected for small sample sizes, wAICc = AICc weight. Cstab = contemporary climatic stability, Prod = productivity, Topo = topographic complexity, Cclim = contemporary climate (Cstab + Prod), Hclim = historical variation in climate. See Methods for individual predictor abbreviation.

:The popular knowledge about snakes, including the practices adopted in cases of snakebite, was analysed in this ethnozoological study performed in Araponga region and vicinities of Serra do Brigadeiro (Brigadeiro Mountain Range), Atlantic Forest of Minas Gerais state, southeastern Brazil. Between August and November 2008, interviews were conducted with 50 residents of rural areas of Araponga, and 20 employees of the Serra do Brigadeiro State Park (PESB). In relation to social and cultural profile, these two groups differed only on the level of education (higher among the park staff), with the same distributions for age and religion. There was also a lower level of education among older individuals, a possible reflection of improvements in the social conditions in that region, which would have provided greater access to schools in recent decades. In general, both groups demonstrated adequate knowledge about prevention and procedures in cases of snakebite (78.2% reported seeking medical attention in case of snakebite). The use of folk medicine for treatment of snakebite proved to be a practice falling into disuse, reported by approximately 21% of respondents. Most respondents (57.14%) said they did not know the difference between a poisonous and a non-poisonous snake, and 66.67% showed adequate knowledge of the season when snake encounters are more likely to happen. The "Araponga" group was more hostile concerning to possible encounters with snakes, with 43% of people saying they would kill the animal, against 5% in the "PESB" group. The educational level of the respondents was decisive in determining the kind of attitude taken against snakes, and those with higher levels of education showed to be the less hostile ones. People with lower educational levels were more likely to consider all snakes as dangerous, and they also proved to be more hostile to these animals. More contact with scientific and environmental education activities seems to have been decisive for the higher tolerance to snakes by the "PESB" group. The implementation of activities of environmental education for the population of Araponga can increase the awareness of the importance of snakes, instructing those who still consider them intrinsically harmful. Resumo: O conhecimento popular sobre as serpentes, incluindo as práticas adotadas em casos de acidentes ofídicos, foi abordado neste estudo etnozoológico realizado na região de Araponga e entorno da Serra do Brigadeiro, Mata Atlântica do Estado de Minas Gerais, região Sudeste do Brasil. Entre agosto e novembro de 2008 foram realizadas entrevistas com 50 moradores da zona rural de Araponga e 20 funcionários do Parque Estadual da Serra do Brigadeiro (PESB). Em relação ao perfil cultural e social, os grupos avaliados diferiram entre si somente quanto ao nível de escolaridade (maior entre os funcionários do parque), apresentando as mesmas distribuições em relação a idade e religião. Também se verificou menor nível de escolaridade entre os indivíduos mais velhos. Em geral, ambos os grupos d...

We performed a survey of lizards and amphisbaenians from municipality of Viçosa, in Atlantic Forest from state of Minas Gerais, southeastern Brazil, based on data of the herpetological collections of Museu de Zoologia João Moojen, Universidade Federal de Viçosa, and Museu de Zoologia, Universidade de São Paulo. One hundred and forty six specimens of 14 species were analyzed, belonging to the following families: Amphisbaenidae, Anguidae, Gekkonidae, Gymnophthalmidae, Leiosauridae, Polychrotidae, Scincidae, Teiidae and Tropiduridae. We hope to supply basic that helps to understand species distribution of this group in the Atlantic Forest of Minas Gerais and southeastern Brazil.

Pseudoautotomy (no spontaneous tail breakage without regeneration) occurs in the snakes Drymoluber brazili (Gomes, 1918) and Drymoluber dichrous (Peters, 1863) throughout their geographic range. Examination of 197 specimens of D. dichrous and 60 D. brazili show, respectively, a frequency of tail breakage (FTB) in 26% and 40% of specimens, similar or higher than observed for most species with pseudoautotomy. There is no sexual difference in FTB for D. brazili, and no relationship between tail breakage and snout–vent length (SVL). For D. dicrous, tail breakage is more frequently observed in males when specimens are <710 mm SVL, but for longer specimens, the FTB is higher in females; this strange pattern may not be explained by a single hypothesis. The FTB does not vary significantly between disjunct populations of D. dichrous, suggesting that they are subject to similar predation pressures and escape rates, or minor or no effect of habitat structure on predation risk. The FTB increases with SVL in D. dichrous (but not in D. brazili, probably due to sample size), which is an indication that as the snake grows, the chance of being injured increases and partial tail loss becomes an efficient defense. The multiple tail break hypothesis is not supported for the genus Drymoluber Amaral, 1930, remaining restricted to taxa with specialized pseudoautotomy.

Apresentamos aqui, com base em exemplares depositados em coleções científicas, uma lista das espécies de serpentes do Município de Viçosa, localizado em uma porção da Mata Atlântica do Estado de Minas Gerais, Sudeste do Brasil. Trinta e quatro espécies foram confirmadas em Viçosa. Outras duas possuem registros duvidosos e cinco espécies que foram registradas em municípios vizinhos poderiam também ocorrer em Viçosa. Informações sobre distribuição e história natural das serpentes são apresentadas, baseadas em dados da literatura científica e observações esporádicas na área de estudo. Podemos considerar que de maneira generalizada a fauna de serpentes de Viçosa é constituída por espécies com condições de utilizar ambientes antropizados, mas algumas são dependentes dos fragmentos florestais ainda existentes. Estudos de campo ainda são necessários para aprimorar o conhecimento sobre a riqueza de espécies de serpentes nos fragmentos florestais, para confirmar a presença das espécies com registros incertos e ocorrência potencial em Viçosa, e para investigar a possibilidade de declínio populacional daquelas espécies sem registros há mais de uma década.

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The ongoing biodiversity crisis increases the importance and urgency of studies addressing the role of environmental variation on the composition and evolutionary history of species assemblages, but especially the tropics and ectotherms remain understudied. In regions with rainy summers, coexistence of tropical ectothermic species may be determined by the partitioning of the climatic niche, as ectotherms can rely on water availability and thermoregulatory behaviour to buffer constraints along their climatic niche. Conversely, tropical ectotherms facing dry summers would have fewer opportunities to climatic niche partitioning and other processes rather than environmental filtering would mediate species coexistence. We used 218 snake assemblages to quantify the compositional (CBD) and phylogenetic (PBD) beta-diversity of snakes in the Atlantic Forest (AF) hotspot, South America. We identify two AF regions with distinct climatological regimes: dry summers in the northern-AF and rainy summers in the southern-AF. While accounting for the influence of multiscale spatial processes, we disentangle the relative contribution of thermal, water-related and topographic conditions in structuring the CBD and PBD of snake assemblages, and determine the extent in which snake assemblages under distinct climatological regimes are affected by environmental filtering. Thermal conditions best explain CBD and PBD of snakes for the whole AF, whereas water-related factors best explain the structure of snake assemblages within a same climatological regime. CBD and PBD patterns are similarly explained by spatial factors but snake assemblages facing dry summers are more affected by spatial processes operating at fine to intermediate spatial scale, whereas those assemblages in regions with rainy summers have a stronger signature of coarse-scale processes. As expected, environmental filtering plays a stronger role in southern-AF than northern-AF, and the synergism between thermal and water-related conditions is the key cause behind this difference. Differences in climatological regimes within the tropics affect processes mediating species coexistence. The influence of broad-scale gradients (e.g. temperature and precipitation) in structuring tropical ectothermic assemblages is greater in regions with rainy summers where climatic niche partitioning is more likely. Our findings highlight the potential stronger role of biotic interactions and neutral processes in structuring ectothermic assemblages facing changes towards warmer and dryer climates.