961 resultados para CAMERA TRAPS


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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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A região do rio Urucu, localizada na porção oeste da Amazônia brasileira, está entre as áreas consideradas prioritárias para conservação devido a sua grande riqueza de espécies e importância biogeográfica. Nesta região são desenvolvidas atividades de exploração de petróleo e gás natural, as quais geram a abertura de clareiras em meio a floresta contínua. Os objetivos deste estudo foram: 1) estimar a riqueza, composição e abundância da comunidade de mamíferos de médio e grande porte em Urucu a qual foi amostrada através dos métodos de transecção linear, busca por vestígios e armadilhas fotográficas; e 2) registrar a presença de mamíferos nas clareiras e verificar a participação destes animais no processo de regeneração através do onitoramento das clareiras artificiais por meio de armadilhas fotográficas e por observações in loco (clareira-focal). Adicionalmente, também foram instaladas armadilhas fotográficas no interior da floresta (amostras-controle). No total foram registradas 40 espécies de mamíferos de médio e grande porte, sendo 25 através da transecção linear, 16 pela busca por vestígios e 15 por armadilhas fotográficas. A espécie Lagothrix cana foi a mais abundante através do método de transecção linear, enquanto Tapirus terrestris foi a mais abundante para os métodos de busca por vestígios e armadilhas fotográficas. O monitoramento através das armadilhas fotográficas resultou no registro de sete espécies em clareiras e 14 espécies em floresta. Nas clareiras registrouse maior freqüência de espécies herbívoras-frugívoras. Já na floresta, espécies de diferentes hábitos alimentares foram registradas em proporção equilibrada. O monitoramento visual (clareira-focal) nas clareiras totalizou 144 horas de observação, sendo registradas três espécies. A espécie D. fuliginosa exibiu com maior freqüência as categorias comportamentais deslocamento e parado, enquanto que as espécies T. terrestris e S. pileatus despenderam maior tempo na categoria alimentação. Os dados obtidos através do monitoramento das clareiras sugerem que estes animais podem atuar ativamente na regeneração destas áreas através dos processos de herbivoria e dispersão de frutos e sementes.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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The Brazilian Atlantic forest has been reduced to a small fraction of its original area, with most remaining fragments being small and surrounded by anthropogenic matrices. This degree of disturbance, together with the increasing sprawl of cities towards the rural zone, greatly facilitates the entrance of domestic animals into these remnants. We used camera traps to compare the abundances of the domestic dog with a similarly sized native carnivore, the ocelot, in a 957-ha reserve of the Brazilian Atlantic forest in a landscape largely composed by pastures and agriculture. The dog was the most recorded species among all 17 mammal species "captured" by the cameras. Dog abundance (32-38 dogs) and density (0.812-1.813 dogs/km(2)) were significantly higher than that of the ocelot (n=2 ocelots; density=0.158-0.347 ocelots/km(2)). Although our result is restricted to a single study site, it is supported by an increasing number of recent studies, which have detected dogs inside other Atlantic forest reserves. Our study suggests, therefore, that this invasion might be more widespread than generally thought. The presence of the domestic dog is a threat to native fauna and constitutes an important edge effect of human presence at the rural zone.

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We studied the Red-billed Currasow (Cray blumenbachii) in Vale Natural Reserve, Linhares, Espirito Santo State, Brazil, using camera traps. We found the Red-billed Curassow present in the entire area of the reserve (similar to 22,000 ha) during 40 months of camera trapping (2005-2008). Most records were of single individuals, especially males, but pairs and even groups of individuals were also recorded. Males were paired with one and two females, suggesting polygyny in the species. The species was recorded throughout the day with one peak from 0500 to 0600 hrs and another after 1600 hrs. The daily activity pattern was similar for males and females. The number and widespread nature of the records suggests the local population of this species may be higher than previously thought. Received 10 March 2011. Accepted 5 December 2011.

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The forest-like characteristics of agroforestry systems create a unique opportunity to combine agricultural production with biodiversity conservation in human-modified tropical landscapes. The cacao-growing region in southern Bahia, Brazil, encompasses Atlantic forest remnants and large extensions of agroforests, locally known as cabrucas, and harbors several endemic large mammals. Based on the differences between cabrucas and forests, we hypothesized that: (1) non-native and non-arboreal mammals are more frequent, whereas exclusively arboreal and hunted mammals are less frequent in cabrucas than forests; (2) the two systems differ in mammal assemblage structure, but not in species richness; and (3) mammal assemblage structure is more variable among cabrucas than forests. We used camera-traps to sample mammals in nine pairs of cabruca-forest sites. The high conservation value of agroforests was supported by the presence of species of conservation concern in cabrucas, and similar species richness and composition between forests and cabrucas. Arboreal species were less frequently recorded, however, and a non-native and a terrestrial species adapted to open environments (Cerdocyon thous) were more frequently recorded in cabrucas. Factors that may overestimate the conservation value of cabrucas are: the high proportion of total forest cover in the study landscape, the impoverishment of large mammal fauna in forest, and uncertainty about the long-term maintenance of agroforestry systems. Our results highlight the importance of agroforests and forest remnants for providing connectivity in human-modified tropical forest landscapes, and the importance of controlling hunting and dogs to increase the value of agroforestry mosaics.

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Scent-marking is widespread among mammals and has been observed in many felid species. Although the behaviour is well-described, little is known about its function in wild felid populations. We investigated patterns of scent-marking and its role in intra- and intersexual communication among resident and non-resident Eurasian lynx Lynx lynx by observing interactions among wild lynx at natural marking sites by means of infrared camera traps. Marking activity of resident animals showed a peak during the mating season and was lowest during the time when females gave birth and lactated. Both sexes scent-marked, but male lynx visited marking sites much more often than females and marked relatively more often when visiting a site. Most visits to marking sites were by residents but we also observed scent-marking by non-residents. Juveniles were never observed marking. We found no evidence of lynx regularly renewing scent-marks after a certain 'expiry date' but the presence of a strange scent-mark triggered over-marking. Males responded similarly to the presence of another individual's scent-mark, irrespective of whether it was the top- or the underlying scent-mark in a mixture of scent-marks they encountered. Our results suggest that marking sites could serve as 'chemical bulletin boards', where male lynx advertise their presence and gain information on ownership relationships in a given area. Females placed their urine marks on top of the ones left by resident males, but further studies are needed to explain the functions of over-marking in females.

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During November 2010–February 2011, we used camera traps to estimate the population density of Eurasian lynx Lynx lynx in Ciglikara Nature Reserve, Turkey, an isolated population in southwest Asia. Lynx density was calculated through spatial capture—recapture models. In a sampling eff ort of 1093 camera trap days, we identifi ed 15 independent individuals and estimated a density of 4.20 independent lynx per 100 km2, an unreported high density for this species. Camera trap results also indicated that the lynx is likely to be preying on brown hare Lepus europaeus, which accounted for 63% of the non-target species pictured. As lagomorph populations tend to fl uctuate, the high lynx density recorded in Ciglikara may be temporary and may decline with prey fl uctuation. Therefore we recommend to survey other protected areas in southwestern Turkey where lynx is known or assumed to exist, and continuously monitor the lynx populations with reliable methods in order to understand the populations structure and dynamics, defi ne sensible measures and management plans to conserve this important species.

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Este trabajo de investigación es pionero y original ya que nunca antes se ha realizado un estudio de la gineta (Genetta genetta) dentro del ámbito valenciano y más concretamente sobre la relación de su distribución con los factores geográficos que la condicionan en el PN Sierra de Mariola. Un mejor conocimiento de su ocupación en el espacio será de interés para la definición de medidas de gestión de fauna del Parque. Utilizando técnicas de fototrampeo se han recopilado 95.372 imágenes con algún contacto animal. De estas imágenes, el 0,10% de las fotografías registradas son de gineta y se ha detectado su presencia en 8 de las 63 cuadrículas (4 Km2) del PN Sierra de Mariola (12,70%). Este estudio ha permitido integrar la información recopilada en campo con las bases de datos existentes para concluir que la situación de la gineta en Sierra de Mariola no es preocupante.

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El principal objetivo de esta investigación es conocer aspectos ecológicos y distribución del arruí — Ammotragus lervia (Pallas, 1777)— dentro de la sierra de Mariola. El área de estudio es un parque natural de 17.500 hectáreas situado en el sur de la Comunidad Valenciana. Un mejor conocimiento de su distribución será de interés para la definición de medidas de gestión de fauna del parque. En 2009, utilizando técnicas de fototrampeo, se recopilaron 29.941 imágenes con algún contacto animal. De estas imágenes, el 0,09% de las fotografías registradas son de arruí y se ha detectado su presencia en 7 de las 63 cuadrículas (2 × 2 km) del Parque Natural de la Sierra de Mariola (el 11,11%). El periodo de muestreo se prolongó desde agosto de 2008 hasta mayo de 2010. Este estudio ha permitido integrar la información recopilada en campo con las bases de datos existentes para confirmar la colonización y la expansión del arruí en la sierra de Mariola.

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Este trabajo de investigación es pionero y original ya que nunca antes se ha realizado un estudio del tejón (Melesmeles) dentro del ámbito valenciano y más concretamente sobre la relación de su distribución con los factores geográficos que la condicionan en el Parque Natural Sierra de Mariola. Un mejor conocimiento de su ocupación en el espacio será de interés para la definición de medidas de gestión de fauna del Parque. En 2009, utilizando técnicas de fototrampeo se recopilaron 29.941 imágenes con algún contacto animal. De estas imágenes, el 0,16% de las fotografías registradas son de tejón y se ha detectado su presencia en 6 de las 63 cuadrículas (4 Km2) del Parque Natural Sierra de Mariola (9,38%). Este estudio ha permitido integrar la información recopilada en campo con las bases de datos existentes para concluir que la situación del tejón en Sierra de Mariola no es preocupante.

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Although the value of primary forests for biodiversity conservation is well known, the potential biodiversity and conservation value of regenerating forests remains controversial. Many factors likely contribute to this, including: 1. the variable ages of regenerating forests being studied (often dominated by relatively young regenerating forests); 2. the potential for confounding on-going human disturbance (such as logging and hunting); 3. the relatively low number of multi-taxa studies; 4. the lack of studies that directly compare different historic disturbances within the same location; 5. contrasting patterns from different survey methodologies and the paucity of knowledge on the impacts across different vertical levels of rainforest biodiversity (often due to a lack of suitable methodologies available to assess them). We also know relatively little as to how biodiversity is affected by major current impacts, such as unmarked rainforest roads, which contribute to this degradation of habitat and fragmentation. This thesis explores the potential biodiversity value of regenerating rainforests under the best of scenarios and seeks to understand more about the impact of current human disturbance to biodiversity; data comes from case studies from the Manu and Sumaco Biosphere Reserves in the Western Amazon. Specifically, I compare overall biodiversity and conservation value of a best case regenerating rainforest site with a selection of well-studied primary forest sites and with predicted species lists for the region; including a focus on species of key conservation concern. I then investigate the biodiversity of the same study site in reference to different types of historic anthropogenic disturbance. Following this I investigate the impacts to biodiversity from an unmarked rainforest road. In order to understand more about the differential effects of habitat disturbance on arboreal diversity I directly assess how patterns of butterfly biodiversity vary between three vertical strata. Although assessments within the canopy have been made for birds, invertebrates and bats, very few studies have successfully targeted arboreal mammals. I therefore investigate the potential of camera traps for inventorying arboreal mammal species in comparison with traditional methodologies. Finally, in order to investigate the possibility that different survey methodologies might identify different biodiversity patterns in habitat disturbance assessments, I investigate whether two different but commonly used survey methodologies used to assess amphibians, indicate the same or different responses of amphibian biodiversity to historic habitat change by people. The regenerating rainforest study site contained high levels of species richness; both in terms of alpha diversity found in nearby primary forest areas (87% ±3.5) and in terms of predicted primary forest diversity from the region (83% ±6.7). This included 89% (39 out of 44) of the species of high conservation concern predicted for the Manu region. Faunal species richness in once completely cleared regenerating forest was on average 13% (±9.8) lower than historically selectively logged forest. The presence of the small unmarked road significantly altered levels of faunal biodiversity for three taxa, up to and potentially beyond 350m into the forest interior. Most notably, the impact on biodiversity extended to at least 32% of the whole reserve area. The assessment of butterflies across strata showed that different vertical zones within the same rainforest responded differently in areas with different historic human disturbance. A comparison between forest regenerating after selective logging and forest regenerating after complete clearance, showed that there was a 17% greater reduction in canopy species richness in the historically cleared forest compared with the terrestrial community. Comparing arboreal camera traps with traditional ground-based techniques suggests that camera traps are an effective tool for inventorying secretive arboreal rainforest mammal communities and detect a higher number of cryptic species. Finally, the two survey methodologies used to assess amphibian communities identified contrasting biodiversity patterns in a human modified rainforest; one indicated biodiversity differences between forests with different human disturbance histories, whereas the other suggested no differences between forest disturbance types. Overall, in this thesis I find that the conservation and biodiversity value of regenerating and human disturbed tropical forest can potentially contribute to rainforest biodiversity conservation, particularly in the best of circumstances. I also highlight the importance of utilising appropriate study methodologies that to investigate these three-dimensional habitats, and contribute to the development of methodologies to do so. However, care should be taken when using different survey methodologies, which can provide contrasting biodiversity patterns in response to human disturbance.

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Context Seed dispersal is recognized as having profound effects on the distribution, dynamics and structure of plant populations and communities. However, knowledge of how landscape structure shapes carnivore-mediated seed dispersal patterns is still scarce, thereby limiting our understanding of large-scale plant population processes. Objectives We aim to determine how the amount and spatial configuration of forest cover impacted the relative abundance of carnivorous mammals, and how these effects cascaded through the seed dispersal kernels they generated. Methods Camera traps activated by animal movement were used for carnivore sampling. Colour-coded seed mimics embedded in common figs were used to know the exact origin of the dispersed seed mimics later found in carnivore scats. We applied this procedure in two sites differing in landscape structure. Results We did not find between-site differences in the relative abundance of the principal carnivore species contributing to seed dispersal patterns, Martes foina. Mean dispersal distance and the probability of long dispersal events were higher in the site with spatially continuous and abundant forest cover, compared to the site with spatially aggregated and scarcer forest cover. Seed deposition closely matched the spatial patterning of forest cover in both study sites, suggesting behaviour-based mechanisms underpinning seed dispersal patterns generated by individual frugivore species. Conclusions Our results provide the first empirical evidence of the impact of landscape structure on carnivore-mediated seed dispersal kernels. They also indicate that seed dispersal kernels generated strongly depend on the effect that landscape structure exerts on carnivore populations, particularly on habitat-use preferences.

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We compared particle data from a moored video camera system with sediment trap derived fluxes at ~1100 m depth in the highly dynamic coastal upwelling system off Cape Blanc, Mauritania. Between spring 2008 and winter 2010 the trap collected settling particles in 9-day intervals, while the camera recorded in-situ particle abundance and size-distribution every third day. Particle fluxes were highly variable (40-1200 mg m**-2 d**-1) and followed distinct seasonal patterns with peaks during spring, summer and fall. The particle flux patterns from the sediment traps correlated to the total particle volume captured by the video camera, which ranged from1 to 22 mm**3 l**-1. The measured increase in total particle volume during periods of high mass flux appeared to be better related to increases in the particle concentrations, rather than to increased average particle size. We observed events that had similar particle fluxes, but showed clear differences in particle abundance and size-distribution, and vice versa. Such observations can only be explained by shifts in the composition of the settling material, with changes both in particle density and chemical composition. For example, the input of wind-blown dust from the Sahara during September 2009 led to the formation of high numbers of comparably small particles in the water column. This suggests that, besides seasonal changes, the composition of marine particles in one region underlies episodical changes. The time between the appearance of high dust concentrations in the atmosphere and the increase lithogenic flux in the 1100 m deep trap suggested an average settling rate of 200 m d**-1, indicating a close and fast coupling between dust input and sedimentation of the material.