181 resultados para Didelphis marsupialis
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Faunal impoverishment and distorted species compositions are common phenomena in oceanic islands; however, many land-bridge islands are poorly inventoried, especially in the Neotropics. We sampled a small mammal community on a land-bridge island (Anchieta Island) along the Brazilian coast. We found only one marsupial Didelphis aurita (Wied-Neuwied, 1826) and two rodent species Oligoryzomys nigripes (Olfers, 1818) and Trinomys iheringi (Thomas, 1911) during 12 months of live trapping and 9195 trap-nights. The diversity of rodents and marsupials was not explained by species-area relations, indicating possible past extinctions. The abundance of D. aurita and O. nigripes was approximately three times higher, while the abundance of T. iheringi was approximately four times lower than abundances reported from other Brazilian Atlantic Forest sites. The population of D. aurita exhibited many phenotypic changes; males were on average 8 % smaller and females produced 30 % less litters than those from the mainland and other land-bridge islands. The long history of forest disturbance, habitat loss, reduction in forest productivity, and the recent introduction of mesopredators may be the major drivers that explain the small mammal community composition on this island. © 2013 Walter de Gruyter GmbH, Berlin/Boston.
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Pós-graduação em Ciências Biológicas (Botânica) - IBB
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Atlantic Forest and Cerrado are between the biological richest areas in the world, for that are considered top conservation priorities. Those ecosystems are found at Botucatu region, where it´s extremely fragmented by routes, agricultural areas and urban centres. This fragmentation causes restrictions on animals populations, in particular to medium and large mammals, that needs larger areas to live and also are often hunted. Even isolated and suffering anthropic influences the fragments are fundamental for local biodiversity conservation. We realized a mammal survey on two forest fragments of Atlantic forest transition to Cerrado of Rubião Júnior – Botucatu – SP – Brazil: Santo Antônio Church and Parque das Cascatas forests. The Santo Antônio church munt is considered a turistic point and its forest receive many visitants, Parque das Cascatas forest is inside of a residential condominium. Both areas are classify as semidecidual stational forest and are disconected by Domingos Sartori route, that connect Botucatu centre to Rubião Júnior district. Around both fragments can be found residences, plantations and pastures. The utilized method included: recognition of tracks on the forests, interviews with next residents and sand plots mounting. The interviews indicated 29 mammals species, and 19 was validated for animal traces, overruns or visualization. Other 3 species found were not mentioned on interviews. Totally, was found 22 small and medium mammals presence evidences on both forest fragments. Parque das Cascatas forest showed more diversity (19) then Santo Antônio Church forest (11), and species like Eira barbara, Procyon cancrivorus, Mazama americana, Shiggurus villosus, Dasypus novemcinctus, Didelphis albiventris, Lutreolina crassicaudata and Lepus europaeus looked for other areas once that was verifyed overruns of individuals... (Complete abstract click electronic access below)
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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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Pós-graduação em Doenças Tropicais - FMB
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Bovine tuberculosis (bovine TB), caused by Mycobacterium bovis, has reemerged in northern Michigan, USA, with detections in white-tailed deer (Odocoileus virginianus) in 1994 and in cattle in 1998. Since then, significant efforts have been directed toward reducing deer densities in the area in the hopes of reducing the bovine TB prevalence rate in deer and eliminating spillover of the disease into cattle. Despite the success of the efforts to reduce deer densities, additional cattle herds have become infected. Other mammals can be infected with M. bovis, and some carnivores and omnivores had been found to be infected with the disease in northern Michigan, USA. We conducted a multiyear surveillance effort to detect bovine TB in wild species of mammals in the Michigan, USA, outbreak area. From 2002 to 2004, tissue samples from 1,031 individual animals of 32 species were collected, processed, and cultured for M. bovis. Only 10 (1.0%) were culture-positive for M. bovis (five raccoons [Procyon lotor], four opossums [Didelphis virginiana], and one grey fox [Urocyon cinereoargenteus]). We also found two raccoons and four opossums to be positive for Mycobacterium avium. We collected 503 environmental samples from cattle farms recently identified as bovine TB positive; none yielded positive M. bovis culture results. Finally, we used infrared cameras to document wildlife use of four barns in the area. Many avian and mammalian species of wildlife were observed, with raccoons being the most commonly observed species. This surveillance study identified no new wildlife species that should be considered significant reservoirs of bovine TB in the outbreak area in northern Michigan, USA. However, the relatively high, apparent bovine TB prevalence rates in some carnivorous and omnivorous species, their relatively long life spans, and their frequent use of barns, suggests that removal of raccoons, opossums, foxes, and coyotes (Canis latrans) should be considered when a newly infected farm is depopulated of cattle.
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This study evaluated for the first time the life cycle of Amblyomma ovale in the laboratory. For this purpose, larvae and nymphs were exposed to Gallus gallus (chickens), Cavia porcellus (guinea pigs), Rattus norvegicus (wistar rats), Oryctolagus cuniculus (domestic rabbits), Calomys callosus (vesper mouse), and Didelphis albiventris (white-eared opossum). Nymphs were also exposed to Nectomys squamipes (South American water rat). Adult ticks were fed on dogs. The life-cycle of A. ovale in laboratory could be completed in an average period of ca. 190 days, considering prefeeding periods of 30 days for each of the parasitic stages. Vesper mice were the most suitable host for A. ovale larvae, whereas water rats were the most suitable host for A. ovale nymphs. Our results, coupled with literature data, strongly indicate that small rodents have an important role in the life history of A. ovale. Chickens (the only avian host used in the present study) showed to be moderately suitable hosts for subadult A. ovale ticks, indicating that wild birds might have a secondary role in the life history of A. ovale. Domestic dogs showed to be highly suitable for the adult stage of A. ovale, in agreement with literature data that indicate that the domestic dog is currently one of the most important hosts of A. ovale adult ticks in Latin America.
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Between December 2007 and March 2009, small mammals were captured in 6 Atlantic Forest patches in Brazil. We assessed tick-host associations and whether they differ among forest strata, sites, seasons, and host age classes or between sexes. Moreover, we assessed the exposure of animals to Rickettsia spp. In total, 432 animals were captured and 808 ticks were found on 32-9% of them. Significant differences were found among host species, collection sites, and forest strata; microhabitat preference was a strong risk factor for tick infestation. The highest tick density rates were recorded in forest fragments settled in rural areas; 91.3% of the ticks were collected from animals trapped in these forest fragments. A high prevalence (68.8%) of antibodies to Rickettsia spp. was detected among animals. This study suggests that disturbed Atlantic Forest fragments provide an environment for ticks and small mammals, which are highly exposed to rickettsiae. It also indicates that forest patches settled in rural areas are usually associated with higher small mammal diversity as well as with higher tick density rates.
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Background The significant biodiversity found in Brazil is a potential for the emergence of new zoonoses. Study in some places of the world suggest of the presence to hantavirus in tissues of bats. Researches of hantavirus in wildlife, out rodents, are very scarce in Brazil. Therefore we decided to investigate in tissues of different species of wild animals captured in the same region where rodents were detected positive for this virus. The present work analyzed ninety-one animals (64 rodents, 19 opossums, and 8 bats) from a region of the Atlantic forest in Biritiba Mirin City, São Paulo State, Brazil. Lungs and kidneys were used for RNA extraction. Findings The samples were screened for evidence of hantavirus infection by SYBR-Green-based real-time RT-PCR. Sixteen samples positive were encountered among the wild rodents, bats, and opossums. The detection of hantavirus in the lungs and kidneys of three marsupial species (Micoureus paraguayanus, Monodelphis ihering, and Didelphis aurita) as well in two species of bats (Diphylla ecaudata and Anoura caudifer) is of significance because these new hosts could represent an important virus reservoirs.
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The bat tick Ornithodoros mimon Kohls, Clifford & Jones is currently known by only few reports in Bolivia, Uruguay, Argentina, and the state of São Paulo in southeastern Brazil. Here, we expand the distribution of O. mimon in Brazil to the states of Minas Gerais (southeastern region), Goiás (central-western), Pernambuco, and Rio Grande do Norte (northeastern). Ticks were collected on human dwellings, where there had been repeated complains of tick bites on persons during the night. Tick bites were generally followed by intense inflammatory reactions that lasted for several weeks at the bite site. Bats and opossums were reported to inhabit the attic of the infested houses. In addition, a free-ranging opossum (Didelphis albiventris Lund) trapped in Rio Grande do Norte was found infested by argasid larvae. Based on morphological and/or molecular analysis, all ticks were identified as O. mimon. From one of the sites (Tiradentes, state of Minas Gerais), 20 field-collected nymphs were tested by a battery of polymerase chain reaction protocols targeting tick-borne microorganisms of the genera Babesia, Hepatozoon, Rickettsia, Borrelia, Anaplasma, Ehrlichia, and Coxiella; no tick specimen was found infected by any of these microorganism genera. The current study expands northwards the distribution of O. mimon, which has been shown to be very harmful to humans because of the intense inflammatory response that usually occurs after tick bites.
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Leishmaniasis are endemic diseases wild spread in the New and Old World, caused by the flagelated protozoan Leishmania. In the New World, the distribution of different forms of leishmaniasis is mostly in tropical regions. In the State of Rio Grande do Norte, Northeast Brazil, 85% of the captured sand flies fauna is Lutzomyia longipalpis. The distribution of the sand fly vector in the state overlaps with the disease distribution, where the presence of sand flies is associated with presence of animals shelters. The aim of this study was to analyse the blood meal preference of sand flies vector from the genus Lutzomyia spp. in laboratory conditions, to verify the vector life cicle at different temperatures sets and to identify the main blood meal source in endemic areas for visceral leishmaniasis (VL) at peri-urban regions of Natal. Sand flies samples were collected from the municipalities of São Gonçalo do Amarante and Nísia Floresta where female sand flies were grouped for the colony maintenance in the laboratory and for the analysis of the preferred source of sand fly blood meal in natural environment. The prevalence of blood meal preference and oviposition for the females sand flies was 97% for Cavia porcellus with oviposition of 19 eggs/female; 97% for Eqqus caballus with 19 eggs/female; 98% for human blood with 14 eggs/female; 71.3% for Didelphis albiventris with 8.4 eggs/female; 73% for Gallus gallus with 14 eggs/female; 86% for Canis familiaris with 10.3 eggs/female; 81.4% for Galea spixii with 26 eggs/female; 36% for Callithrix jachus with 15 eggs/female; 42.8% for Monodelphis domestica with 0% of oviposition. Female sand flies did not take a blood meal from Felis catus. Sand flies life cycle ranged from 32-40 days, with 21-50 oviposition rates approximately. This study also showed that at 32°C the life cycle had 31 days, at 28° C it had 50 days and at 22°C it increased to 79 days. Adjusting the temperature to 35°C the eggs did not hatch, thus blocking the life cycle. A total of 1540 sand flies were captured, among them, 1.310 were male and 230 were female. Whereas 86% of the sand flies captured were Lu. longipalpis as compared to 10.5% for Lu. evandroi and, 3.2% for L. lenti and 0.3% for Lu whitmani. The ratio between female and male sandfly was approximately 6 males to 1 female. In Nísia Floresta, 50.7% of the collected females took their blood meal from armadillo, 12.8% from human. Among the female sand flies captured in São Gonçalo do Amarante, 80 of them were tested for the Leishmania KDNA infectivity where 5% of them were infected with Leishmania chagasi. Female Lutzomyia spp. showed to have an opportunistic blood meal characteristic. The behavioral parameters seem to have a higher influence in the oviposition when compared to the level of total proteins detected in the host s bloodstream. A higher Lu. longipalpis life cycle viability was observed at 28°C. The increase of temperature dropped the life cycle time, which means that the life cycle is modified by temperature range, source of blood meal and humidity. Lu longipalpis was the most specie found in the inner and peridomiciliar environment. In Nísia Floresta, armadillos were the main source of blood meal for Lutzomyia spp. At São Gonçalo do Amarante, humans were the main source of blood meal due to CDC nets placed inside their houses
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El Cerro El Potosí es un área prioritaria para la Comisión Nacional para la Biodiversidad (CONABIO) y un Área Natural Protegida por el estado (Anónimo, 2000), debido a la existencia de una gran diversidad de tipos de vegetación y de especies de importancia fitogeografica o su orografía y altitud (3715 msnm) se considera un área promotora de procesos de especiación, registrándose especies endémicas y relictuales como el caso del Pinus culminicola y Nucifraga columbiana , es una de las montañas más altas del noroeste del país, está enclavada en la Sierra Madre Oriental. Con base en la información previa disponible, se presume que esta área ostente una mayor diversidad de flora y fauna. El objetivo principal fue el análisis de la diversidad y distribución de los mamíferos en los diferentes estratos vegetativos y altitudes dentro de los límites del Cerro El Potosí. Con el propósito de realizar las comparaciones de las diversidades de las especies en forma altitudinal, por vegetación, estacional; Se seleccionó la prueba de Chi-cuadrada para determinar dependencia entre especies y la altitud, tipo de muestreo o tipo de vegetación. Se efectuaron 24 salidas (mensuales) de campo, de noviembre del 2006 a octubre del 2008, de 3 a 4 días por salida. Se registraron 27 especies (14 Familias, 24 géneros, 27 especies, y 14 especies no reportadas previamente). De acuerdo al tipo de vegetación la riqueza se concentro en el bosque de pino seguido por el bosque de encino, las especies se distribuyeron en uno, en dos o más estratos de vegetación (patrones), para los diferentes tipos de vegetación se distribuyeron las especies de Silvilagus floridanus, Thomomys bottae, Peromyscus melanotis, Peromyscus levipes ambiguus, Canis latrans y Lynx rufus. Las especies que sólo se encontraron en un solo tipo de vegetación fueron Bassariscus astutus, Conepatus mesoleucus, Corynorhinus townsendii, Didelphis virginiana, Eptesicus fuscus, Puma yagouaroundi, Lasiurus cinereus, Lasiurus ega, Leptonycteris nivalis, Mustela frenata y Sorex milleri, por lo que se aprecia la diversidad encontrada en el sitio, esto en gran medida por la asociación de la vegetación y la altura marcado por la temperatura reportada para el sitio. Las especies que se localizaron en dos o más estratos o patrones de vegetación fueron Myotis thysanodes, Sciurus alleni, Otospermophilus variegatus, Microtus mexicanus, Urocyon cinereoargenteus, Procyon lotor, Puma concolor, Pecari tajacu y Odocoileus virginianus.