45 research outputs found

    Conserving predators across agricultural landscapes in Colombia: habitat use and space partitioning by jaguars, pumas, ocelots, and jaguarundis

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    Habitat loss and degradation continue to increase across the tropics. Consequently there is an urgent need to understand their effects, as well as species’ habitat requirements and distribution within human-modified landscapes, in order to reconcile agricultural expansion with the conservation of endangered and keystone species, like the felids. We combined camera trapping and remote sensing-generated data into occupancy modelling to study the habitat use and space partitioning by four sympatric felids across an agricultural landscape in Colombia. The area includes cattle ranching and oil palm cultivation, an emerging land use in the Neotropics. Strong determinants of species occupancy were wetlands for jaguars (positive effect); water proximity (positive effect) for pumas; and pasture (negative effect) for ocelots and jaguarundis. Felid species except ocelots were never recorded in oil palm areas. Our results suggest that to align development with the conservation of top predators it is key to maintain areas of forest and wetland across agricultural landscapes and targeting agricultural and oil palm expansion to already-modified areas like pastures, which showed limited conservation value in the region. Lastly, as there was no spatial segregation between the studied felid species, conservation strategies to simultaneously benefit this guild seem possible even in modified landscape

    INSIGHTS INTO THE HABITS OF THE ELUSIVE NOCTURNAL CURASSOW (NOTHOCRAX URUMUTUM)

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    Nocturnal curassows (Nothocrax urumutum) are one of the most enigmatic birds from South American rainforests. Their elusive habits and their nocturnal vocal behavior have led to the generalized assumption that they differ from other curassows in their presumable nocturnal habits. Here, we compiled camera trap data from long term projects in the Amazon rainforest and the Andes Cordillera piedmont to describe the temporal activity of Nocturnal Curassows. Based on an overall sampling effort of 68838 camera nights we obtained 274 independent records of their activity. The results of this study evidence that Nothocrax has diurnal habits and resembles in activity patterns to all other cracids more than previously expected. This study highlights the use of novel technologies and collaborative research towards the understanding of the natural history, ecology and behavior of animals with cryptic behaviors such as the Nocturnal Curassows

    Richness, diversity, and factors influencing occupancy of mammal communities across human-modified landscapes in Colombia

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    As human-modified landscapes are increasing in the tropics, it becomes critical to understand how they affect mammal communities to reconcile conservation and development. We combined land cover information and camera-trapping data to explore the effects of agricultural expansion on mammals in the Magdalena river valley of Colombia. We estimated species diversity, evenness, and dominance across two agricultural landscapes, modified by cattle ranching and oil palm cultivation. We further assessed which variables influence species- and community-level occupancy using multi-species occupancy models. Results highlight that modified landscapes display lower species richness, diversity and evenness, and higher dominance than more pristine sites. Residual forest cover and distance to water had significant effect on community occupancy (positive and negative respectively). Forests were particularly important for pumas, ocelots, lowland pacas, Central American agoutis, and crab-eating raccoons while wetlands had a positive effect on jaguars, the apex predator in the region. The influence of anthropogenic pressure was not clearly evident, though pastures were not valuable habitats for any mammal species, as they had a negative, yet not significant, effect on species and community occupancy. In light of rapidly expanding agriculture across the tropics, our findings highlight species-specific responses to disturbance that can inform land use planning and conservation policies. We stress the conservation value of forest and wetland habitat to mammal occupancy in heterogeneous ecosystems. Moreover, our results demonstrate that oil palm and crop expansion should target existing pastures, which displayed limited conservation value for Neotropical mammals but occupy vast swathes of land across Latin America

    Jaguar Densities across Human-Dominated Landscapes in Colombia: The Contribution of Unprotected Areas to Long Term Conservation

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    Large carnivores such as jaguars (Panthera onca) are species of conservation concern because they are suffering population declines and are keystone species in their ecosystems. Their large area requirements imply that unprotected and ever-increasing agricultural regions can be important habitats as they allow connectivity and dispersal among core protected areas. Yet information on jaguar densities across unprotected landscapes it is still scarce and crucially needed to assist management and range-wide conservation strategies. Our study provides the first jaguar density estimates of Colombia in agricultural regions which included cattle ranching, the main land use in the country, and oil palm cultivation, an increasing land use across the Neotropics. We used camera trapping across two agricultural landscapes located in the Magdalena River valley and in the Colombian llanos (47–53 stations respectively; >2000 trap nights at both sites) and classic and spatially explicit capture-recapture models with the sex of individuals as a covariate. Density estimates were 2.52±0.46–3.15±1.08 adults/100 km2 in the Magdalena valley, whereas 1.12±0.13–2.19±0.99 adults/100 km2 in the Colombian llanos, depending on analysis used. We suggest that jaguars are able to live across unprotected human-use areas and co-exist with agricultural landscapes including oil-palm plantations if natural areas and riparian habitats persist in the landscape and hunting of both jaguar and prey is limited. In the face of an expanding agriculture across the tropics we recommend land-use planning, adequate incentives, regulations, and good agricultural practices for range-wide jaguar connectivity and survival

    Management of hepatitis C virus genotype 4: recommendations of an international expert panel.

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    HCV has been classified into no fewer than six major genotypes and a series of subtypes. Each HCV genotype is unique with respect to its nucleotide sequence, geographic distribution, and response to therapy. Genotypes 1, 2, and 3 are common throughout North America and Europe. HCV genotype 4 (HCV-4) is common in the Middle East and in Africa, where it is responsible for more than 80% of HCV infections. It has recently spread to several European countries. HCV-4 is considered a major cause of chronic hepatitis, cirrhosis, hepatocellular carcinoma, and liver transplantation in these regions. Although HCV-4 is the cause of approximately 20% of the 170 million cases of chronic hepatitis C in the world, it has not been the subject of widespread research. Therefore, this document, drafted by a panel of international experts, aimed to review current knowledge on the epidemiology, natural history, clinical, histological features, and treatment of HCV-4 infections
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