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Mercury is a global contaminant found in the Amazon; it can be biomagnified in the aquatic trophic chain. The use of piscivorous birds for biomonitoring of mercury contamination is increasing, mainly due to the non-mobility of mercury in bird feathers. We examined the concentrations of total mercury and methylmercury in different tissues of the green kingfisher, Chloroceryle americana collected from the Teles Pires and Juruena Rivers in the southern Brazilian Amazon. We also evaluated total mercury in small Characidae fish (potential C. americana food) in the same areas. The results indicate contamination of the birds with high concentrations, on average two-times higher in the green kingfishers from the Teles Pires River compared to the Juruena River; the same results were found for the fish specimens. Fifty-eight per cent of the feather samples from the Juruena River and 90% from the Teles Pires River had total mercury concentrations above 5 µg/g, a level previously associated with adverse effects related to bird breeding. The methylmercury concentration was lowest in the liver, followed by feathers and highest in muscle. Although Juruena River bird feathers had a lower total mercury concentration, > 96% of the total mercury was methylmercury, the highest amount for specimens from both rivers. Although the concentration of Hg in the muscle of the green kingfisher is higher when compared to the feather and liver, the non-invasive monitoring through analysis of samples of feathers is an efficient biomonitoring tool for evaluation of mercury contamination in tropical birds.

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Faunal inventories contribute to our understanding of regional diversity, and are fundamental for policy and de-cision-making regarding the management and conservation of large natural areas. This study aimed to inventory and com-pile information on amphibian species occurring in the North Pantanal region, in the municipal limits of Cáceres, Mato Grosso, Brazil. We used three methods to inventory amphibian species: (1) fieldwork, (2) analysis of specimens deposited in scientif-ic collections, and (3) literature reviews. We registered 49 amphibian species in Cáceres. Of them, 48 species belonged to the Anura order and were distributed across eight families and 20 genera, and one species belonged to the Gymnophiona order (Siphonops paulensis). The families Leptodactylidae (20 spp.) and Hylidae (17 spp.) were dominant in terms of richness, ac-counting for 75.5% of all species found in Cáceres. The remaining families had between four and one species each. The mu-nicipality is strongly influenced by non-forested formations (e.g., the Cerrado and Pantanal) and presents a high species rich-ness for a non-forested location in Brazil. Our findings highlight Cáceres as one of the richest areas in amphibian species in the North Pantanal region, expanding our knowledge regarding frog diversity. This study provides a foundation for future conser-vation strategies and additional assessments of amphibian species in light of potential population declines and other emerg-ing threats.(AU)

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Energetic subsidies between terrestrial and aquatic ecosystems can strongly influence food webs and population dynamics. Our objective was to study how aquatic subsidies affected jaguar (Panthera onca) diet, sociality, and population density in a seasonally flooded protected area in the Brazilian Pantanal. The diet (n = 138 scats) was dominated by fish (46%) and aquatic reptiles (55%), representing the first jaguar population known to feed extensively on fish and to minimally consume mammals (11%). These aquatic subsidies supported the highest jaguar population density estimate to date (12.4 jaguars/100 km²) derived from camera traps (8,065 trap nights) and GPS collars (n = 13). Contrary to their mostly solitary behavior elsewhere, we documented social interactions previously unobserved between same-sex adults including cooperative fishing, co-traveling, and play. Our study demonstrates that aquatic subsidies, frequently described in omnivores, can also transform the ecology and behavior of obligate carnivores.

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This study aims to evaluate the dynamics of fish trophic guilds according to the longitudinal gradient of the Paraguay River, northern Pantanal, Brazil. Three river segments were sampled: plateau, confluence and plain. These segments have different physical and biological characteristics, with high water flow in forest areas in plateau and slow flow in meanders, with Pantanal typical vegetation. In total, 26,542 individuals distributed in 130 fish species were collected. The sampled species were characterized in seven trophic guilds. From the seven trophic guilds identified, only three were statistically related to the type of the environment; herbivores were more abundant in the plateau, piscivores in the confluence, and invertivores in the plain. According to values of corrected Akaike Information Criteria, the environmental variable that best explains the abundance of piscivorous fishes in the segments sampled in the Paraguay River was water transparency. For herbivores, the model that explained the variation in abundance was composed by temperature, altitude and dense forest proportion. The variable altitude best represented the abundance of invertivores. Water transparency, temperature, altitude, river width and dense forest proportion were determining factors for the distribution of piscivorous, herbivorous and invertivorous fishes as a response to an environmental gradient that meets its ecological requirements. Understanding the trophic relationships is fundamental for management actions, contributing to the maintenance of ecosystem services of different species. Therefore, future research must be taken into account regarding management and ecological relationships.(AU)

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Abstract The process of exotic species introduction is recognized as one of the greatest threats to the ecology and economy of the planet, due to changes in interactions in native biological communities. In this sense, reporting bioinvasions is the first step to understanding its introduction process and creating strategies to mitigate possible socio-environmental damages. Here we report the first records of Podocnemis unifilis introduced in the Northern Pantanal, Mato Grosso, Brazil. We obtained the species' first records occasionally during 2014 and 2015. In the following years from 2016 to 2019, we carried out systematic observations through nautical incursions on the Paraguay River, between the Sepotuba River mouth and the Taiamã Ecological Station (TES). We also included third part records, when it was possible to prove the species identification and registration sites. Podocnemis unifilis adults, hatchling and nests were recorded at different points along the Paraguay River. Our results indicate that P. unifilis was introduced close to the urban nucleus of Cáceres about 30 years ago. Currently, it has an established population, recording nests and hatchling for years in a row. A particular one is its occurrence at the TES, an important natural fish nursery and refuge for the wetland fauna. Thus, continuous monitoring is suggested from P.unifilis, since the Pantanal's environment with several different aquatic environments, offers favorable conditions for the species population increase in the Northern Pantanal.

Resumo O processo de introdução de espécies exóticas é reconhecido como uma das maiores ameaças à ecologia e economia do planeta, devido às mudanças nas interações em comunidades biológicas nativas. Nesse sentido, relatar as bioinvasões é o primeiro passo para entender seu processo de implantação e criar estratégias para mitigar possíveis danos socioambientais. Aqui relatamos os primeiros registros de P. unifilis introduzidos no Pantanal Norte, Mato Grosso, Brasil. Obtivemos os primeiros registros das espécies ocasionalmente durante 2014 e 2015. Nos anos seguintes, de 2016 a 2019, realizamos observações sistemáticas por meio de incursões náuticas no rio Paraguai, entre a foz do rio Sepotuba e a Estação Ecológica Taiamã (TES). Incluímos também registros de terceiros, quando foi possível comprovar os locais de identificação e registro das espécies. Adultos de Podcnemis unifilis, filhotes e ninhos foram registrados em diferentes pontos ao longo do rio Paraguai. Nossos resultados indicam que P. unifilis foi introduzido próximo ao núcleo urbano de Cáceres há cerca de 30 anos. Atualmente, ela tem uma população estabelecida, registrando ninhos e filhotes por anos consecutivos. Uma em particular é a sua ocorrência no TES, importante viveiro natural de peixes e refúgio da fauna pantaneira. Assim, sugere-se o monitoramento contínuo de P.unifilis, uma vez que o ambiente do Pantanal com diversos ambientes aquáticos distintos, oferece condições favoráveis para o aumento da população da espécie no Pantanal Norte.

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The evaluation of mercury (Hg) toxicity in wildlife species has prompted a search for sensitive indicators to accurately measure the body burden of Hg. Despite the extensive use of feathers as an indicator of Hg in birds, they do not appear to be an entirely suitable indicator of the extent of contamination in certain conditions and bird species since Hg levels are influenced by the growth period, timing of the last moult and migration. This research aimed to evaluate rhamphotheca as a potential indicator of environmental Hg concentrations in seabirds. We used culled yellow-legged gulls (Larus michahellis) (n = 20) and determined THg in rhamphotheca and feathers. We distinguished between upper and lower rhamphotheca, and divided each one into 16 equal portions along the culmen to analyse their THg content spatially. In each bird, THg was also determined in primary (P1) and secondary (S8) feathers and compared with rhamphotheca. The median (25th, 75th percentile) rhamphotheca Hg concentration was 13.44 (9.63, 17.46) µg/g, which was twofold higher than in the feathers 7.56 (4.88, 12.89) µg/g. Median THg in rhamphotheca was significantly higher (p < 0.05) in females 15.05 (10.35, 23.04) µg/g than in males 12.34 (8.57, 15.19) µg/g, whereas no differences (p > 0.05) were found in the feathers. No significant differences in Hg levels were found between upper and lower beak mandibles or along either. In contrast, significant differences in Hg concentrations were found between the P1 and S8 feathers (mean, 12.04 vs. 6.04 µg/g). No correlation was found between Hg content in rhamphotheca and feathers. Mercury levels in rhamphotheca exhibited stronger significant relationships with weight (R2 = 0.568), length (R2 = 0.524) and culmen (R2 = 0.347) than the levels in the feathers, which showed no correlation. Overall, our results suggest that rhamphotheca is a suitable tissue indicator for Hg monitoring in gulls; however, further studies are needed to extend our research to other bird species.

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Agricultural frontier expansion into the Amazon over the last four decades has created million hectares of fragmented forests. While many species undergo local extinctions within remaining forest patches, this may be compensated by native species from neighbouring open-habitat areas potentially invading these patches, particularly as forest habitats become increasingly degraded. Here, we examine the effects of habitat loss, fragmentation and degradation on small mammal assemblages in a southern Amazonian deforestation frontier, while accounting for species-specific degree of forest-dependency. We surveyed small mammals at three continuous forest sites and 19 forest patches of different sizes and degrees of isolation. We further sampled matrix habitats adjacent to forest patches, which allowed us to classify each species according to forest-dependency and generate a community-averaged forest-dependency index for each site. Based on 21,568 trap-nights, we recorded 970 small mammals representing 20 species: 12 forest-dependents, 5 matrix-tolerants and 3 open-habitat specialists. Across the gradient of forest patch size, small mammal assemblages failed to show the typical species-area relationship, but this relationship held true when either species abundance or composition was considered. Species composition was further mediated by community-averaged forest-dependency, so that smaller forest patches were occupied by a lower proportion of forest-dependent rodents and marsupials. Both species richness and abundance increased in less isolated fragments surrounded by structurally simplified matrix habitats (e.g. active or abandoned cattle pastures). While shorter distances between forest patches may favour small mammal abundances, forest area and matrix complexity dictated which species could persist within forest fragments according to their degree of forest-dependency. Small mammal local extinctions in small forest patches within Amazonian deforestation frontiers are therefore likely offset by the incursion of open-habitat species. To preclude the dominance of those species, and consequent losses of native species and associated ecosystem functions, management actions should limit or reduce areas dedicated to pasture, additionally maintaining more structurally complex matrix habitats across fragmented landscapes.

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In order to determine whether southern Amazonian bats could harbour hantaviruses we, serologically and molecularly, screened blood, saliva, excreta and organ tissues of 47 bats captured from September to December 2015. We found that only phyllostomid bats presented antibodies against hantavirus. The seropositive bats belonged to two species of Phyllostomid bats: the greater spear-nosed bat Phyllostomus hastatus (omnivorous) and the gnome fruit-eating bat Dermanura gnoma. The overall seroprevalence was of 4.2%. Therefore, we show here that hantaviruses are circulating among phyllostomid bats in the Amazonian arc of deforestation.

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As comunicações oroantrais são complicações comuns, geralmente relacionadas a exodontias de dentes superiores posteriores devido ao íntimo contato dos ápices radiculares destes com o assoalho do seio maxilar. Seu diagnóstico é baseado na história clínica e em achados imaginológicos. O presente trabalho objetiva revisar a literatura para demonstrar as facilidades, além de vantagens e desvantagens da utilização da bola de Bichat no fechamento de comunicações bucossinusais, apresentando um caso clínico utilizando essa técnica (AU).

The oroantral communication is a common complication, often related to extractions of posterior maxillary teeth due to close contact with the shoot tips root of the floor of the maxillary sinus. Its diagnosis is based on clinical history and imaging findings. This study aims to review the literature to demonstrate the facilities, as well as advantages and disadvantages of the use of the Bichat ball at close of oroantral communication, presenting one clinical case using this technique (AU).

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O fibroma odontogênico central é definido como uma neoplasia benigna dos maxilares caracterizada por apresentar uma quantidade variável de epitélio odontogênico inativo em meio a um estroma de tecido conjuntivo fibroso. É considerada uma neoplasia rara que representa de 0% a 5,5% de todos os tumores odontogênicos na maioria dos estudos retrospectivos encontrados na literatura. Acomete pacientes em uma ampla faixa etária com certa predominância em indivíduos do sexo feminino. Apresenta-se, na grande maioria dos casos, como uma lesão de crescimento lento e assintomático que pode promover abaulamento das corticais ósseas adjacentes. Do ponto de vista radiográfico, aparece, tipicamente, sob a forma de uma imagem radiolúcida uni ou multilocular com margens bem definidas, podendo apresentar focos de calcificação em seu interior. O fibroma odontogênico central é subdividido histologicamente em tipo simples (pobre em epitélio) e tipo OMS (rico em epitélio). A lesão responde bem ao tratamento cirúrgico conservador por enucleação associada à curetagem, sendo as recidivas muito incomuns. Esse trabalho tem o objetivo de fazer uma breve revisão de literatura a respeito das características epidemiológicas, clínico-imaginológicas e histopatológicas desta lesão e relatar um caso diagnosticado num paciente do sexo masculino, 13 anos, com queixa de aumento de volume em mento. Os exames de imagem evidenciaram a presença de defeito osteolítico bem delimitado em região de sínfise mandibular associado aos elementos dentários 33 e 43 que se apresentavam inclusos. A lesão foi submetida à enucleação e curetagem. O paciente encontra-se em proservação há dois anos sem sinais de recidiva da lesão.

The central odontogenic fibroma is defined as a benign neoplasm of the jaws characterized by having a variable amount of inactive odontogenic epithelium in the midst of a fibrous connective tissue stroma. It is considered a rare neoplasm that is from 0% to 5.5% of all odontogenic tumors in most retrospective studies found in the literature. Affects patients in a wide age range with a certain predominance in females. , Is shown in most cases, as a slow-growing lesions and asymptomatic which can promote the bulging adjacent cortical bone. The radiographic point of view, appears typically in the form of an image radiolucent uni or multilocular with well-defined margins and may have foci of calcification inside. The central odontogenic fibroma is subdivided histologically in simple type (poor epithelium) and WHO type (rich in epithelium). The injury responds well to conservative treatment by surgical enucleation associated with curettage, and the very unusual relapses. This work aims to make a brief review of literature on the epidemiological, clinical and histopathological imaginological this injury and to report a case diagnosed in a male patient, 13, with volume up complaint ment. Imaging tests showed the presence of well-defined osteolytic defect in mandibular symphysis region associated with dental elements 33 and 43 who performed included. The lesion was submitted to enucleation and curettage. The patient is under observation for two years without signs of recurrence.

RESUMO

Although the impacts of large dams on freshwater biota are relatively well known, the effects of small hydropower plants (SHP) are not well investigated. In this work, we studied if mercury (Hg) concentrations in fish rise in two tropical SHP reservoirs, and whether similar effects take place during impoundment. Total Hg concentrations in several fish species were determined at two SHP in the Upper Guaporé River basin floodplain, Brazil. In total, 185 specimens were analysed for Hg content in dorsal muscle and none of them reported levels above the safety limit (500 µg kg-1) for fish consumption recommended by the World Health Organisation (WHO). The highest levels of Hg (231 and 447 µg kg-1) were found in carnivorous species in both reservoirs. Mercury increased as a function of standard length in most of the fish populations in the reservoirs, and higher Hg concentrations were found in fish at the reservoir compared with fish downstream. The high dissolved oxygen concentrations and high transparency of the water column (i.e. oligotrophic reservoir) together with the absence of thermal stratification may explain low Hg methylation and low MeHg levels found in fish after flooding. Overall, according to limnological characteristics of water, we may hypothesise that reservoir conditions are not favourable to high net Hg methylation.

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Historical records of Ateles chamek (black-faced black spider monkey) suggest that the species range extends further south of the known species distribution, within an ecotonal region between the Amazonia, Cerrado and Pantanal biomes in Brazil. Ecotones are zones of habitat transition with high species richness that remain undersampled as conservationists often prioritize biodiversity hotspots. Thus, distribution ranges may be inaccurately measured when species occur in ecotonal zones. We report the first precise records of A. chamek in 24 new localities surveyed in the ecotonal zone of the Upper Paraguay River Basin, and we present subgroup encounter rates in the 11 largest patches (>70 ha) along 207 km of the line transects surveyed. The new records represent an expansion of the distribution of A. chamek approximately 200 km to the south, increasing the known extent of its occurrence by 10.8%. Local tributaries may not be barriers for spider monkeys, which are able to swim and cross slow-moving rivers. However, the dry forests of the Cerrado and the flooded areas of the Pantanal, formed by grassland and scarce trees, may be habitat barriers for A. chamek. The populations living in this ecotonal zone are relatively abundant (1.1-6.67 subgroup sightings/10 km) compared to the heavily hunted continuous forests of northern Amazonia. Furthermore, these values are similar to those for other Ateles spp. inhabiting forests with low or no hunting pressure. We highlight the need for specific conservation action to protect the spider monkeys living in these landscapes, which are threatened by agriculture expansion.

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The importance of estimating the biological diversity and understanding how ecological specialization of species changes with spatially-organized habitats in undeniable. High beta diversity between neighboring places means an elevated number of species living within small distances, which usually are adapted to local conditions and highly vulnerable to anthropogenic actions as deforestation and burning. We investigated beta diversity of birds from the order Passeriformes in Southern Amazon, within landscapes with a large heterogeneous vegetation cover (habitats with flooded forest, dry forest, and marsh palm) through sound, observational, and photographic censuses. We marked 126 points in equidistant transects. A total of 148 species of birds were identified, distributed in 27 families. We found that 97% of the species foraged in flooded forest, 77% in dry forest and 19% in marsh palms, and only 18% foraged in the three habitats. An ordination analyses revealed which species showed the strongest preference to each habitat. The analysis for the Global beta diversity showed that this value is high (Whittaker: 7.7405), and the same pattern was obtained with the measure of pairwise dissimilarity. An influence of spatial distance was clearly observed in the cluster analysis and confirmed with a partial Mantel analysis; however, this was not observed at points that coincided with the transition and substitution of species. The influence of spatial distance in the dissimilarity index (beta diversity) was significant (r: 0.0608, p: 0.0049). The assemblage of species in small local populations with high beta diversity may be at risk if deforestation, selective logging, and poaching continue. In summary, this study provides important information on specific habitats with high beta diversity that may be at risk of destabilization of its populations due to continuing environmental changes imposed by humans.(AU)

Estimar a diversidade biológica e entender as mudanças acerca da especialização ecológica das espécies entre habitats em uma organização espacial é importante. A alta diversidade beta reflete numa pequena distância entre locais, mas que contêm alta incorporação de espécies, que geralmente possuem grande sensibilidade e não estão adaptadas ao estreitamento causado pelo desmatamento ou a presença de queimadas por ações antrópicas. Investigou-se a diversidade beta de pássaros (Passeriformes) na Amazônia Meridional em paisagens com coberturas vegetais mais heterogêneas: habitats de floresta alagada (iguapó), floresta de terra firme e buritis através de censo de audições, observações e fotografias. Marcaram-se pontos em equidistantes transectos. Em todo o estudo foram amostrados 126 pontos. Identificaram-se 148 espécies de pássaros da ordem Passeriformes, distribuídas em 27 famílias. A classificação sobre os habitats de forrageamento resultou em 97% das espécies que forrageiam em iguapó, 77% em floresta de terra firme e 18,1% em buritis, apenas 18% forragem nos três habitats. A análise de ordenação mostrou quais espécies estão mais relacionadas com cada habitat, a análise para a Beta diversidade Global certificou que a diversidade beta é alta (Whittaker: 7,7405). Como era esperado encontrou-se o mesmo padrão quando foi utilizada a medida de dissimilaridade por pares. Na análise de agrupamento, pode-se ver claramente a influência da distância espacial, mas em alguns pontos isto não ocorre. Estes pontos indicam o momento de transição e substituição de espécies. Na maioria dos casos, a influência da distância espacial é predominante e confirmou-se na análise de Mantel parcial. A influência da distância espacial entre o índice de dissimilaridade (diversidade beta) foi significante (r:0,0608, p:0,0049). Esta composição de espécies organizadas em pequenas populacões locais mas com alta diversidade beta não pode ser [...](AU)

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Abstract The importance of estimating the biological diversity and understanding how ecological specialization of species changes with spatially-organized habitats in undeniable. High beta diversity between neighboring places means an elevated number of species living within small distances, which usually are adapted to local conditions and highly vulnerable to anthropogenic actions as deforestation and burning. We investigated beta diversity of birds from the order Passeriformes in Southern Amazon, within landscapes with a large heterogeneous vegetation cover (habitats with flooded forest, dry forest, and marsh palm) through sound, observational, and photographic censuses. We marked 126 points in equidistant transects. A total of 148 species of birds were identified, distributed in 27 families. We found that 97% of the species foraged in flooded forest, 77% in dry forest and 19% in marsh palms, and only 18% foraged in the three habitats. An ordination analyses revealed which species showed the strongest preference to each habitat. The analysis for the Global beta diversity showed that this value is high (Whittaker: 7.7405), and the same pattern was obtained with the measure of pairwise dissimilarity. An influence of spatial distance was clearly observed in the cluster analysis and confirmed with a partial Mantel analysis; however, this was not observed at points that coincided with the transition and substitution of species. The influence of spatial distance in the dissimilarity index (beta diversity) was significant (r: 0.0608, p: 0.0049). The assemblage of species in small local populations with high beta diversity may be at risk if deforestation, selective logging, and poaching continue. In summary, this study provides important information on specific habitats with high beta diversity that may be at risk of destabilization of its populations due to continuing environmental changes imposed by humans.

Resumo Estimar a diversidade biológica e entender as mudanças acerca da especialização ecológica das espécies entre habitats em uma organização espacial é importante. A alta diversidade beta reflete numa pequena distância entre locais, mas que contêm alta incorporação de espécies, que geralmente possuem grande sensibilidade e não estão adaptadas ao estreitamento causado pelo desmatamento ou a presença de queimadas por ações antrópicas. Investigou-se a diversidade beta de pássaros (Passeriformes) na Amazônia Meridional em paisagens com coberturas vegetais mais heterogêneas: habitats de floresta alagada (iguapó), floresta de terra firme e buritis através de censo de audições, observações e fotografias. Marcaram-se pontos em equidistantes transectos. Em todo o estudo foram amostrados 126 pontos. Identificaram-se 148 espécies de pássaros da ordem Passeriformes, distribuídas em 27 famílias. A classificação sobre os habitats de forrageamento resultou em 97% das espécies que forrageiam em iguapó, 77% em floresta de terra firme e 18,1% em buritis, apenas 18% forragem nos três habitats. A análise de ordenação mostrou quais espécies estão mais relacionadas com cada habitat, a análise para a Beta diversidade Global certificou que a diversidade beta é alta (Whittaker: 7,7405). Como era esperado encontrou-se o mesmo padrão quando foi utilizada a medida de dissimilaridade por pares. Na análise de agrupamento, pode-se ver claramente a influência da distância espacial, mas em alguns pontos isto não ocorre. Estes pontos indicam o momento de transição e substituição de espécies. Na maioria dos casos, a influência da distância espacial é predominante e confirmou-se na análise de Mantel parcial. A influência da distância espacial entre o índice de dissimilaridade (diversidade beta) foi significante (r:0,0608, p:0,0049). Esta composição de espécies organizadas em pequenas populacões locais mas com alta diversidade beta não pode ser exposta ao desmatamento, corte seletivo de madeira e a caça furtiva como tem acontecido. Este estudo provê informações de habitats específicos de alta diversidade beta que estão correndo risco na estabilidade de suas populacões em face às mudanças ambientais contínuas nesta área de estudo.

RESUMO

The importance of estimating the biological diversity and understanding how ecological specialization of species changes with spatially-organized habitats in undeniable. High beta diversity between neighboring places means an elevated number of species living within small distances, which usually are adapted to local conditions and highly vulnerable to anthropogenic actions as deforestation and burning. We investigated beta diversity of birds from the order Passeriformes in Southern Amazon, within landscapes with a large heterogeneous vegetation cover (habitats with flooded forest, dry forest, and marsh palm) through sound, observational, and photographic censuses. We marked 126 points in equidistant transects. A total of 148 species of birds were identified, distributed in 27 families. We found that 97% of the species foraged in flooded forest, 77% in dry forest and 19% in marsh palms, and only 18% foraged in the three habitats. An ordination analyses revealed which species showed the strongest preference to each habitat. The analysis for the Global beta diversity showed that this value is high (Whittaker: 7.7405), and the same pattern was obtained with the measure of pairwise dissimilarity. An influence of spatial distance was clearly observed in the cluster analysis and confirmed with a partial Mantel analysis; however, this was not observed at points that coincided with the transition and substitution of species. The influence of spatial distance in the dissimilarity index (beta diversity) was significant (r: 0.0608, p: 0.0049). The assemblage of species in small local populations with high beta diversity may be at risk if deforestation, selective logging, and poaching continue. In summary, this study provides important information on specific habitats with high beta diversity that may be at risk of destabilization of its populations due to continuing environmental changes imposed by humans.

Estimar a diversidade biológica e entender as mudanças acerca da especialização ecológica das espécies entre habitats em uma organização espacial é importante. A alta diversidade beta reflete numa pequena distância entre locais, mas que contêm alta incorporação de espécies, que geralmente possuem grande sensibilidade e não estão adaptadas ao estreitamento causado pelo desmatamento ou a presença de queimadas por ações antrópicas. Investigou-se a diversidade beta de pássaros (Passeriformes) na Amazônia Meridional em paisagens com coberturas vegetais mais heterogêneas: habitats de floresta alagada (iguapó), floresta de terra firme e buritis através de censo de audições, observações e fotografias. Marcaram-se pontos em equidistantes transectos. Em todo o estudo foram amostrados 126 pontos. Identificaram-se 148 espécies de pássaros da ordem Passeriformes, distribuídas em 27 famílias. A classificação sobre os habitats de forrageamento resultou em 97% das espécies que forrageiam em iguapó, 77% em floresta de terra firme e 18,1% em buritis, apenas 18% forragem nos três habitats. A análise de ordenação mostrou quais espécies estão mais relacionadas com cada habitat, a análise para a Beta diversidade Global certificou que a diversidade beta é alta (Whittaker: 7,7405). Como era esperado encontrou-se o mesmo padrão quando foi utilizada a medida de dissimilaridade por pares. Na análise de agrupamento, pode-se ver claramente a influência da distância espacial, mas em alguns pontos isto não ocorre. Estes pontos indicam o momento de transição e substituição de espécies. Na maioria dos casos, a influência da distância espacial é predominante e confirmou-se na análise de Mantel parcial. A influência da distância espacial entre o índice de dissimilaridade (diversidade beta) foi significante (r:0,0608, p:0,0049). Esta composição de espécies organizadas em pequenas populacões locais mas com alta diversidade beta não pode ser [...]

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This study evaluated the risk to human health from mercury (Hg) exposure through fish consumption in the Pantanal, Brazil. In order to address these risks, Hg concentrations and accumulation patterns were determined in target organs of predatory fish (Crenicichla lepidota and Pygocentrus nattereri). Levels of Hg were analysed during the two phases of the flood pulse (flood and drought) in fish from different local ecosystems, such as the Bento Gomes and Paraguay rivers. Although the former study area is directly affected by gold mining, a higher, but not significantly different, Hg concentration in fish was found compared with fish at the Paraguay River, which is regarded as pristine area. Moreover, no seasonal variability was found in either river. Although total mercury levels in fish did not exceed the maximum FAO/WHO threshold (0.5 µg g(-1)), according to dietary habits in riverine communities of the Pantanal (up to 6 oz of fish per day), there is reason for concern over the potential for deleterious health effects that could be caused by high Hg intake. In fact, the estimated daily intake in the present study ranged from 0.49 to 1.08 µg Hg kg(-1) day(-1), for adults (including women of childbearing age) and children, respectively. Because of high Hg intakes in riverine groups, which exceed the recommended reference dose value, these communities could be considered at risk. Therefore, it is necessary to consider regulatory measures and public education regarding fish consumption, particularly in vulnerable groups (i.e. children, pregnant women and women of childbearing age).

Assuntos

RESUMO

Mercury (Hg) is a ubiquitous environmental contaminant that poses potential threats to ecosystems due to its toxicity to humans and wildlife. The development of non-lethal sampling techniques is a critical step for evaluation of Hg in threatened species in tropical floodplain environments, where most of Hg found is the result of land use and gold mining activities, and more methylation sites are available. We evaluated the spatial and seasonal effectiveness of caudal scutes and claws to estimate Hg bioaccumulation in crocodilians (Caiman yacare), in the scarcely documented Pantanal. Hence, we investigated the potential for Hg bioaccumulation in top predators according to its proximity to mining sites, and in water bodies with different hydrological characteristics and connectivity with the main river during two phases of the flood pulse (dry and flood). The highest Hg concentrations were detected in caimans captured close to mining activities, in claws (2176 ng g(-1) ww) and caudal scutes (388 ng g(-1) ww). THg concentration in claws was related to the flood season and its mean concentration was thirteen fold higher than Hg concentration in scutes during whole year. Both tissues were found to be effective as non-lethal sampling techniques for measuring Hg bioaccumulation in reptiles over time. Nevertheless, claw tissue seems to have a more consistent result, since its constitutional chemical characteristics makes it a better indicator of spatial patterns that influence on Hg exposure.

Assuntos

RESUMO

The effectiveness of ecological researches on small mammals strongly depends on trapping techniques to survey communities and populations accurately. The main goal of this study was to assess the efficiency of three types of traps (Sherman, Tomahawk and Pitfall) to capture non-volant small mammals. We installed traps in 22 forest fragments in the southern Brazilian Amazonia. We captured 873 individuals belonging to 21 species; most of the individuals (N = 369) and species (N = 19) were trapped using Pitfalls, followed by Shermans (N = 271 individuals; N = 15 species) and Tomahawks (N = 233 individuals; N = 15 species). Pitfalls trapped a richer community subset of small mammals than the two other types of traps, and a more abundant community subset than Tomahawks. Proechimys sp. was the most abundant species trapped (N = 125) and Tomahawk was the most efficient type of trap to capture this species (N = 97 individuals). Neacomys spinosus and Marmosops bishopi were more trapped in Pitfalls (N = 92 and 100 individuals, respectively) than Shermans and Tomahawks. Monodelphis glirina was more trapped in Shermans and Pitfalls than Tomahawks. Species composition trapped using the three types of traps were distinct. Pitfalls captured a more distinct subset of the small mammal community than the two other live traps. We recommend the association of the three types of traps to reach a more comprehensive sampling of the community of small mammals. Thus, as stated by previous studies, we also recommend the complementary use of Shermans, Tomahawks and Pitfalls to account for a thorough sampling of the whole small mammal community in researches conducted in the tropical forests of Amazonia.(AU)

A eficácia das pesquisas ecológicas de comunidade de pequenos mamíferos depende fortemente do uso de técnicas adequadas nas capturas durante as amostragens. O principal objetivos deste estudo foi avaliar a eficiências de três tipos de armadilhas (Sherman, Tomahawk e Pitfall) para capturas de pequenos mamíferos não-voadores. Nós instalamos armadilhas em 22 fragmentos de floresta no sul da Amazonia Brasileira. Nós capturamos 873 indivíduos de 21 espécies, a maior parte dos indivíduos (N=369) e espécies (N=19) foram capturados usando pitfalls, seguidos de Shermans (N=271 indivíduos, N=15 espécies) e Tomahawks (N=233 indivíduos, N= 15 espécies). Pitfalls capturou a maior riqueza da comunidade de pequenos mamíferos quando comparada aos outros dois tipos de armadilhas, e uma maior abundancia que Tomahawk. Proechimys sp. foi a espécies mais abundante capturada (N=125) e Tomahawk foi o tipo de armadilha mais eficiente para a captura desta espécie (N=97 indivíduos). Neacomys spinosus e Marmosops bishopi foram mais capturados em Pitfalls (N = 92 e 100 indivíduos, respectivamente) que Shermans e Tomahawks. Monodelphis glirina foram mais capturados em Shermans e Pitfalls que Tomahawks. A composição de espécies capturada usando os três tipos de armadilhas foi distinta. Pitfalls capturou um diferente subgrupo da comunidade de pequenos mamíferos quando comparado aos outros dois tipos de live traps. Assim, como sugerido em estudos anteriores, nós também recomendamos o uso conjugado de Sherman, Tomahawks e Pitfalls para uma amostragem mais completa da comunidade de pequenos mamíferos em pesquisas realizadas nas florestas tropicais da Amazônia.(AU)

Assuntos

RESUMO

The effectiveness of ecological researches on small mammals strongly depends on trapping techniques to survey communities and populations accurately. The main goal of this study was to assess the efficiency of three types of traps (Sherman, Tomahawk and Pitfall) to capture non-volant small mammals. We installed traps in 22 forest fragments in the southern Brazilian Amazonia. We captured 873 individuals belonging to 21 species; most of the individuals (N = 369) and species (N = 19) were trapped using Pitfalls, followed by Shermans (N = 271 individuals; N = 15 species) and Tomahawks (N = 233 individuals; N = 15 species). Pitfalls trapped a richer community subset of small mammals than the two other types of traps, and a more abundant community subset than Tomahawks. Proechimys sp. was the most abundant species trapped (N = 125) and Tomahawk was the most efficient type of trap to capture this species (N = 97 individuals). Neacomys spinosus and Marmosops bishopi were more trapped in Pitfalls (N = 92 and 100 individuals, respectively) than Shermans and Tomahawks. Monodelphis glirina was more trapped in Shermans and Pitfalls than Tomahawks. Species composition trapped using the three types of traps were distinct. Pitfalls captured a more distinct subset of the small mammal community than the two other live traps. We recommend the association of the three types of traps to reach a more comprehensive sampling of the community of small mammals. Thus, as stated by previous studies, we also recommend the complementary use of Shermans, Tomahawks and Pitfalls to account for a thorough sampling of the whole small mammal community in researches conducted in the tropical forests of Amazonia.

A eficácia das pesquisas ecológicas de comunidade de pequenos mamíferos depende fortemente do uso de técnicas adequadas nas capturas durante as amostragens. O principal objetivos deste estudo foi avaliar a eficiências de três tipos de armadilhas (Sherman, Tomahawk e Pitfall) para capturas de pequenos mamíferos não-voadores. Nós instalamos armadilhas em 22 fragmentos de floresta no sul da Amazonia Brasileira. Nós capturamos 873 indivíduos de 21 espécies, a maior parte dos indivíduos (N=369) e espécies (N=19) foram capturados usando pitfalls, seguidos de Shermans (N=271 indivíduos, N=15 espécies) e Tomahawks (N=233 indivíduos, N= 15 espécies). Pitfalls capturou a maior riqueza da comunidade de pequenos mamíferos quando comparada aos outros dois tipos de armadilhas, e uma maior abundancia que Tomahawk. Proechimys sp. foi a espécies mais abundante capturada (N=125) e Tomahawk foi o tipo de armadilha mais eficiente para a captura desta espécie (N=97 indivíduos). Neacomys spinosus e Marmosops bishopi foram mais capturados em Pitfalls (N = 92 e 100 indivíduos, respectivamente) que Shermans e Tomahawks. Monodelphis glirina foram mais capturados em Shermans e Pitfalls que Tomahawks. A composição de espécies capturada usando os três tipos de armadilhas foi distinta. Pitfalls capturou um diferente subgrupo da comunidade de pequenos mamíferos quando comparado aos outros dois tipos de live traps. Assim, como sugerido em estudos anteriores, nós também recomendamos o uso conjugado de Sherman, Tomahawks e Pitfalls para uma amostragem mais completa da comunidade de pequenos mamíferos em pesquisas realizadas nas florestas tropicais da Amazônia.

Assuntos

RESUMO

The current study aimed to evaluate the diet of Monodelphis glirina (Wagner, 1842) in forest fragments of Alta Floresta, located in the south of the Amazon, state of Mato Grosso. The diet was determined by the analysis of the stomach contents from 57 subjects sampled between May and September 2009. Nine food categories were present: Coleoptera, Orthoptera, Hymenoptera, Diplopoda, Nematoda, seeds, miscellaneous, hair and bait leftovers (banana and peanut butter). Coleoptera was the category eaten most frequently, rating 50% of abundance and 91.22% of occurrence. "Seeds" were the least abundant (0.11%) and rated 1.75% in occurrence, probably because seeds are easy to digest. The size of the fragments negatively and significantly influenced the amount of Coleoptera in the diet. The rainy season seemed to have significant influence over the abundance of arthropods in the diet. The items in the diet suggest that M. glirina is opportunistic and has a generalist diet, tending to be insectivore when living in the forest and exploring the food resources according to their availability.