931 resultados para Grand Canyon National Park


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Coexistence of sympatric species is mediated by resource partitioning. Pumas occur sympatrically with jaguars throughout most of the jaguar's range but few studies have investigated space partitioning between both species. Here, camera trapping and occupancy models accounting for imperfect detection were employed in a Bayesian framework to investigate space partitioning between the jaguar and puma in Emas National Park (ENP), central Brazil. Jaguars were estimated to occupy 54.1% and pumas 39.3% of the sample sites. Jaguar occupancy was negatively correlated with distance to water and positively correlated with the amount of dense habitat surrounding the camera trap. Puma occupancy only showed a weak negative correlation with distance to water and with jaguar presence. Both species were less often present at the same site than expected under independent distributions. Jaguars had a significantly higher detection probability at cameras on roads than at off-road locations. For pumas, detection was similar on and off-road. Results indicate that both differences in habitat use and active avoidance shape space partitioning between jaguars and pumas in ENP. Considering its size, the jaguar is likely the competitively dominant of the two species. Owing to its habitat preferences, suitable jaguar habitat outside the park is probably sparse. Consequently, the jaguar population is likely largely confined to the park, while the puma population is known to extend into ENP's surroundings. (C) 2011 Deutsche Gesellschaft fur Saugetierkunde. Published by Elsevier GmbH. All rights reserved.

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A taxonomic and annotated functional description of microbial life was deduced from 53 Mb of metagenomic sequence retrieved from a planktonic fraction of the Neotropical high Andean (3,973 meters above sea level) acidic hot spring El Coquito (EC). A classification of unassembled metagenomic reads using different databases showed a high proportion of Gammaproteobacteria and Alphaproteobacteria (in total read affiliation), and through taxonomic affiliation of 16S rRNA gene fragments we observed the presence of Proteobacteria, micro-algae chloroplast and Firmicutes. Reads mapped against the genomes Acidiphilium cryptum JF-5, Legionella pneumophila str. Corby and Acidithiobacillus caldus revealed the presence of transposase-like sequences, potentially involved in horizontal gene transfer. Functional annotation and hierarchical comparison with different datasets obtained by pyrosequencing in different ecosystems showed that the microbial community also contained extensive DNA repair systems, possibly to cope with ultraviolet radiation at such high altitudes. Analysis of genes involved in the nitrogen cycle indicated the presence of dissimilatory nitrate reduction to N2 (narGHI, nirS, norBCDQ and nosZ), associated with Proteobacteria-like sequences. Genes involved in the sulfur cycle (cysDN, cysNC and aprA) indicated adenylsulfate and sulfite production that were affiliated to several bacterial species. In summary, metagenomic sequence data provided insight regarding the structure and possible functions of this hot spring microbial community, describing some groups potentially involved in the nitrogen and sulfur cycling in this environment. Citation: Jimenez DJ, Andreote FD, Chaves D, Montana JS, Osorio-Forero C, et al. (2012) Structural and Functional Insights from the Metagenome of an Acidic Hot Spring Microbial Planktonic Community in the Colombian Andes. PLoS ONE 7(12): e52069. doi:10.1371/journal.pone.0052069

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Adriano E.A., Ceccarelli P.S., Silva M.R.M. & Maia A.A. M. 2012. [Prevalence, geographic and seasonal distribution of protozoan and myxozoan parasites of jau (Zungaro jahu) in the Pantanal of Mato Grosso, Brazil.] Prevalencia, distribuicao geografica e sazonal de protozoarios e mixozoarios parasitos de jau (Zungaro jahu) no Pantanal Matogrossense. Pesquisa Veterinaria Brasileira 32(12):1341-1344. Departamento de Ciencias Basicas, Faculdade de Zootecnia e Engenharia de Alimentos, Universidade de Sao Paulo, Av. Duque de Caxias Norte 225, Pirassununga, SP 13635-900, Brazil. E-mail: antomaia@usp.br In a study carried out in the Pantanal of Mato Grosso, Brazil, the prevalence, geographic and seasonal distribution of protozoan and myxozoan parasites of Zungaro jahu was evaluated. The fish were captured in the southern region of Pantanal Mato-grossense (Aquidauana, Miranda and Paraguay rivers) in 2001, 2002 and 2003, in the central region (Pantanal National Park - PARNA Pantanal) in 2003, 2004, 2005 and 2008, and in the northern region (Cuiaba and Manso rivers, in the municipality of Nobres) in 2003, 2004 and 2005. Trichodina sp. was identified parasitized skin and gills of jau in the three regions studied. Epistylis sp. parasitized skin and Cryptobia sp. the gills and were restricted to the Central region, whilst Ichthyophthirius multifiliis parasitized skin in the three regions studied. The occurrence of myxozoans was also observed: Myxobolus cordeiroi parasitized several organs and Henneguya sp. parasitized the gills of jau in the three regions studied.

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Mach number and thermal effects on the mechanisms of sound generation and propagation are investigated in spatially evolving two-dimensional isothermal and non-isothermal mixing layers at Mach number ranging from 0.2 to 0.4 and Reynolds number of 400. A characteristic-based formulation is used to solve by direct numerical simulation the compressible Navier-Stokes equations using high-order schemes. The radiated sound is directly computed in a domain that includes both the near-field aerodynamic source region and the far-field sound propagation. In the isothermal mixing layer, Mach number effects may be identified in the acoustic field through an increase of the directivity associated with the non-compactness of the acoustic sources. Baroclinic instability effects may be recognized in the non-isothermal mixing layer, as the presence of counter-rotating vorticity layers, the resulting acoustic sources being found less efficient. An analysis based on the acoustic analogy shows that the directivity increase with the Mach number can be associated with the emergence of density fluctuations of weak amplitude but very efficient in terms of noise generation at shallow angle. This influence, combined with convection and refraction effects, is found to shape the acoustic wavefront pattern depending on the Mach number.

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We use a recently developed computerized modeling technique to explore the long-term impacts of indigenous Amazonian hunting in the past, present, and future. The model redefines sustainability in spatial and temporal terms, a major advance over the static "sustainability indices" currently used to study hunting in tropical forests. We validate the model's projections against actual field data from two sites in contemporary Amazonia and use the model to assess various management scenarios for the future of Manu National Park in Peru. We then apply the model to two archaeological contexts, show how its results may resolve long-standing enigmas regarding native food taboos and primate biogeography, and reflect on the ancient history and future of indigenous people in the Amazon.

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Precambrian rocks comprise nearly one-quarter of the surface of Brazil and range from Paleoarchean (ca. 3.6 Ga) to the latest Ediacaran (0.542 Ga) in age. Except for controversial phosphatized 'embryo-like' microfossils like those from the lower Ediacaran Doushantuo Formation, China and complex rangeomorphs, Brazilian research has revealed all major categories of Precambrian life forms described elsewhere - microbialites, biomarkers, silicified microfossils, palynomorphs, vase-shaped microfossils, macroalgae, metazoans, vendobionts and ichnofossils - but the paleobiological significance of this record has been little explored. At least four occurrences of these fossils offer promise for increased understanding of the following aspects of Precambrian biospheric evolution: (i) the relationship of microbialites in 2.1-2.4 Ga old carbonates of the Minas Supergroup in the Quadrilatero Ferrifero, Minas Gerais (the oldest Brazilian fossils) to the development of the early oxygenic atmosphere and penecontemporaneous global tectonic and climatic events; (ii) the evolutionary and biostratigraphic significance of Mesoproterozoic to Ediacaran organic-walled microfossils in central-western Brazil; (iii) diversity and paleoecological significance of vase-shaped heterotrophic protistan microfossils in the Urucum Formation (Jacadigo Group) and possibly the Bocaina Formation (Corumba Group), of Mato Grosso do Sul; and (iv) insights into the record of skeletogenesis and paleoecology of latest Ediacaran metazoans as represented by the abundant organic carapaces of Corumbella and calcareous shells of the index fossil Cloudina, of the Corumba Group, Mato Grosso do Sul. Analysis of the Brazilian Precambrian fossil record thus holds great potential for augmenting paleobiological knowledge of this crucial period on Earth and for developing more robust hypotheses regarding possible origins and evolutionary pathways of biospheres on other planets. Received 26 February 2012, accepted 17 May 2012, first published online 18 June 2012

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A new species of Oreobates is described from Cavernas do Peruacu National Park, Januaria, Minas Gerais state, in the Atlantic Dry Forests of Brazil. The new species is distinguished from all other Oreobates by having the following combination of characters: large tympanum, discs broadly enlarged and truncate on Fingers III and IV, smooth dorsal skin, nuptial pads absent, snout subacuminate, and a very short pulsatile (2-3 pulses) single-noted advertisement call with dominant frequency of about 3150 Hz, and no harmonic structure. Molecular phylogenetic analyses using partial sequences of the mitochondrial genes cytochrome b (cyt b) and 16S using multiple outgroups recovered the new species within Oreobates and sister to O. heterodactylus. The latter species inhabits the Dry Forests of Mato Grosso (Cerrado) and Bolivia (Chiquitano forests), and is strictly associated to these habitats, which suggests a preterit connection between Chiquitano and Atlantic Dry Forests. The discovery of a new Oreobates in the Atlantic Dry Forest is of great importance for the conservation of these dry forests, as it is known only from this type of habitat.

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Line transect distance sampling (LTDS) can be applied to either trails or roads. However, it is likely that sampling along roads might result in biased density estimates. In this paper, we compared the results obtained with LTDS applied on trails and roads for two primate species (Callithrix penicillata and Callicebus nigrifrons) to clarify whether roads are appropriate transects to estimate densities. We performed standard LTDS surveys in two nature reserves in south-eastern Brazil. Effective strip width and population density were different between trails and roads for C. penicillata, but not for C. nigrifrons. The results suggest that roads are not appropriate for use as transects in primate surveys, at least for some species. Further work is required to fully understand this issue, but in the meantime we recommend that researchers avoid using roads as transects or treat roads and trails as covariates when sampling on roads is unavoidable. Copyright (C) 2012 S. Karger AG, Basel

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During 2008D2010, ticks were collected from road-killed wild animals within the Serra dos Orgaos National Park area in the state of Rio de Janeiro, Brazil. In total, 193 tick specimens were collected, including Amblyomma dubitatum Neumann and Amblyomma cajennense (F.) from four Hydrochoerus hydrochaeris (L.), Amblyomma calcaratum Neumann and A. cajennense from four Tamandua tetradactyla (L.), Amblyomma aureolatum (Pallas) and A. cajennense from five Cerdocyon thous L., Amblyomma longirostre (Koch) from one Sphiggurus villosus (Cuvier), Amblyomma varium Koch from three Bradypus variegatus Schinz, and A. cajennense from one Buteogallus meridionalis (Latham). Molecular analyses based on polymerase chain reaction targeting two rickettsial genes (gltA and ompA) on tick DNA extracts showed that 70.6% (12/17) of the A. dubitatum adult ticks, and all Amblyomma sp. nymphal pools collected from capybaras were shown to contain rickettsial DNA, which after DNA sequencing, revealed to be 100% identical to the recently identified Rickettsia sp. strain Pampulha from A. dubitatum ticks collected in the state of Minas Gerais, Brazil. Phylogenetic analysis with concatenated sequences (gltA-ompA) showed that our sequence from A. dubitatum ticks, referred to Rickettsia sp. strain Serra dos Orgaos, segregated under 99% bootstrap support in a same cluster with Old World rickettsiae, namely R. tamurae, R. monacensis, and Rickettsia sp. strain 774e. Because A. dubitatum is known to bite humans, the potential role of Rickettsia sp. strain Serra dos Orgaos as human pathogen must be taken into account, because both R. tamurae and R. monacencis have been reported infecting human beings.

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Socioecological models assume that primates adapt their social behavior to ecological conditions, and predict that food availability and distribution, predation risk and risk of infanticide by males affect patterns of social organization, social structure and mating system of primates. However, adaptability and variation of social behavior may be constrained by conservative adaptations and by phylogenetic inertia. The comparative study of closely related species can help to identify the relative contribution of ecological and of genetic determinants to primate social systems. We compared ecological features and social behavior of two species of the genus Sapajus, S. nigritus in Carlos Botelho State Park, an area of Atlantic Forest in Sao Paulo state, and S. libidinosus in Fazenda Boa Vista, a semi-arid habitat in Piaui state, Brazil. S. libidinosus perceived higher predation risk and fed on clumped, high quality, and usurpable resources (fruits) all year round, whereas S. nigritus perceived lower predation risk and relied on evenly distributed, low-quality food sources (leaves) during periods of fruit shortage. As predicted by socioecology models, S. libidinosus females were philopatric and established linear and stable dominance hierarchies, coalitions, and grooming relationships. S. nigritus females competed less often, and could transfer between groups, which might explain the lack of coalitions and grooming bonds among them. Both populations presented similar group size and composition and the same polygynous mating system. The species differed from each other in accordance with differences in the characteristics of their main food sources, as predicted by socioecological models, suggesting that phylogenetic inertia does not constrain social relationships established among female Sapajus. The similarity in mating systems indicates that this element of the social system is not affected by ecological variables and thus, is a more conservative behavioral feature of the genus Sapajus. Am. J. Primatol. 74:315331, 2012. (c) 2011 Wiley Periodicals, Inc.

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The maned wolf, Chrysocyon brachyurus, is an endangered Neotropical canid that survives at low population densities. Diseases are a potential threat for its conservation but to date have been poorly studied. We performed clinical evaluations and investigated the presence of infectious diseases through serology and coprologic tests on maned wolves from Galheiro Natural Private Reserve, Perdizes City, Minas Gerais State, southeastern Brazil. Fifteen wolves were captured between 2003 and 2008. We found high prevalences of antibody to canine distemper virus (CDV; 13/14), canine parvovirus (CPV; 4/14), canine adenovirus type 2 (13/14), canine coronavirus (5/11), canine parainfluenza virus (5/5), and Toxoplasma gondii (6/8), along with Ancylostomidae eggs in all feces samples. Antibodies against Leishmania sp. were found in one of 10 maned wolves, and all samples were negative for Neospora caniman. Evidence of high exposure to these viral agents was also observed in unvaccinated domestic clogs from neighboring farms. High prevalence of viral agents and parasites such as CDV, CPV, and Ancylostomidae indicates that this population faces considerable risk of outbreaks and chronic debilitating parasites. This is the first report of exposure to canine parainfluenza virus in Neotropical free-ranging wild canids. Our findings highlight that canine pathogens pose a serious hazard to the viability of maned wolves and other wild carnivore populations in the area and emphasize the need for monitoring and protecting wildlife health in remaining fragments of the Cerrado biome.

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Analyses of spatial relationships and social interactions provide insights into the social structure of animal societies and the ways in which social preferences among and between dyads affect higher order social relationships. In this paper we describe the patterns of spatial associations and social interactions among adult male northern muriquis in order to evaluate the dynamics of their social networks above the dyadic levels. Systematic observations were made on the 17 adult males present in a multi-male/multi-female group from April 2004 through February 2005, and in July 2005. Analyses of their spatial relationships identified two distinct male cliques; some adult males (called "N" males) were more connected to the females and immatures than other adult males ("MU" males), which were more connected to one another. Affiliative interactions were significantly higher among dyads belonging to the same clique than to different cliques. Although frequencies of dyadic agonistic interactions were similarly low among individuals within and between cliques, MU males appeared to be subordinate to N males. Nonetheless, there were no significant differences in the copulation rates estimated for MU males and N males. Mutual benefits of cooperation between MU and N cliques in intergroup encounters might explain their ongoing associations in the same mixed-sex group [Current Zoology 58 (2): 342-352, 2012].

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Neste trabalho, objetivou-se estabelecer o perfil dos incêndios florestais ocorridos no Parque Nacional da serra da Canastra, utilizando dados contidos nos Relatórios de Ocorrências de Incêndios de 1988 até 2008, cedidos pela unidade de conservação. Foram registradas 219 ocorrências, totalizando 415572,50 ha de área queimada, com média de 10,43 incêndios e 19789,17 ha queimados por ano. Em relação à área queimada, os incêndios causados por incendiários apresentaram o maior valor, seguido por queimas para limpeza de pastagens, raios e causa desconhecida. Considerando-se número de ocorrências, os incêndios decorrentes de raios apresentaram a maior frequência. Nos meses de setembro e agosto predominaram os incêndios causados por incendiários e de causa desconhecida, enquanto os incêndios naturais ocorreram principalmente nos meses de outubro e fevereiro e os decorrentes da queima para limpeza de pastagens se concentraram em julho. Os incêndios que atingiram maiores áreas foram observados em locais com maior declividade, enquanto os de menores proporções ocorreram em áreas planas e ou de relevos suaves. Quanto à localização, registrou-se o maior número de focos na área regularizada do parque, provavelmente por ser esta área a mais fiscalizada.

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Faeces provide relevant biological information which includes, with the application of genetic techniques, the sex and identity of individuals that defecated, thus providing potentially useful data on the behaviour and ecology of individuals, as well as the dynamics and structure of populations. This paper presents estimates of the sex ratio of different felid species (jaguar, Panthera onca; puma, Puma concolor; and ocelot/margay, Leopardus pardalis/Leopardus wiedi) as observed in field collected faeces, and proposes several hypotheses that could explain the strikingly high proportion of faeces from male jaguars. The proportion of male and female faeces was estimated using a non-invasive faecal sampling method in 14 study areas in Mexico and Brazil. Faecal samples were genetically analysed to identify the species, the sex and the individual (the latter only for samples identified as belonging to jaguars). Considering the three species, 72.6% of faeces (n = 493) were from males; however, there were significant differences among them, with the proportion from males being higher for jaguars than for pumas and ocelots/margays. A male-bias was consistently observed in all study areas for jaguar faeces, but not for the other species. For jaguars the trend was the same when considering the number of individuals identified (n = 68), with an average of 4.2 +/- 0.56 faeces per male and 2.0 +/- 0.36 per female. The observed faecal marking patterns might be related to the behaviour of female jaguars directed toward protecting litters from males, and in both male and female pumas, to prevent interspecific aggressions from male jaguars. The hypothesis that there are effectively more males than females in jaguar populations cannot be discarded, which could be due to the fact that females are territorial and males are not, or a tendency for males to disperse into suboptimal areas for the species.

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Abstract Background Bat trypanosomes have been implicated in the evolutionary history of the T. cruzi clade, which comprises species from a wide geographic and host range in South America, Africa and Europe, including bat-restricted species and the generalist agents of human American trypanosomosis T. cruzi and T. rangeli. Methods Trypanosomes from bats (Rhinolophus landeri and Hipposideros caffer) captured in Mozambique, southeast Africa, were isolated by hemoculture. Barcoding was carried out through the V7V8 region of Small Subunit (SSU) rRNA and Fluorescent Fragment Length barcoding (FFLB). Phylogenetic inferences were based on SSU rRNA, glyceraldehyde phosphate dehydrogenase (gGAPDH) and Spliced Leader (SL) genes. Morphological characterization included light, scanning and transmission electron microscopy. Results New trypanosomes from bats clustered together forming a clade basal to a larger assemblage called the T. cruzi clade. Barcoding, phylogenetic analyses and genetic distances based on SSU rRNA and gGAPDH supported these trypanosomes as a new species, which we named Trypanosoma livingstonei n. sp. The large and highly polymorphic SL gene repeats of this species showed a copy of the 5S ribosomal RNA into the intergenic region. Unique morphological (large and broad blood trypomastigotes compatible to species of the subgenus Megatrypanum and cultures showing highly pleomorphic epimastigotes and long and slender trypomastigotes) and ultrastructural (cytostome and reservosomes) features and growth behaviour (when co-cultivated with HeLa cells at 37°C differentiated into trypomastigotes resembling the blood forms and do not invaded the cells) complemented the description of this species. Conclusion Phylogenetic inferences supported the hypothesis that Trypanosoma livingstonei n. sp. diverged from a common ancestral bat trypanosome that evolved exclusively in Chiroptera or switched at independent opportunities to mammals of several orders forming the clade T. cruzi, hence, providing further support for the bat seeding hypothesis to explain the origin of T. cruzi and T. rangeli.