Resumo
Gastrointestinal parasites are well-documented in small mammals from north-central Chile, but little is known about endoparasites of rodents in southern Chile. A survey was conducted between January and February 2018 to evaluate gastrointestinal parasites and risk factors of wild rodents that live in rural areas in Northern Chiloé Island, Chile. A total of 174 fecal samples from rodents of six native and one introduced species were collected and examined using the Mini-FLOTAC method. Also, 41 individuals of four native wild rodent species were examined furtherly to determinate adult parasites from gastrointestinal tracts. The overall prevalence of endoparasites was 89.65% (156). Helminth egg types included: Rodentolepis spp., Capillariidae, Trichuris sp., Syphacia sp., oxyurid-type eggs, Strongyloides sp., Spirurid-type eggs, Strongilid-type eggs, Moniliformis sp., and an unidentified nematode egg and larvae. Protozoa comprised coccidia, amoeba, and unidentified cysts. From necropsies, adult parasites involved Syphacia sp. Trichuris sp., Protospirura sp. and Physaloptera sp. In Abrothrix olivacea, individuals with low-body-mass index exhibited reduced infection probability for Spirurid-type and Strongilid-type eggs. Some parasites in this study may affect human health. In rural settings where environmental conditions are changing, more research should be undertaken to understand parasitic infections in wildlife and implications for public health and conservation.(AU)
Parasitos gastrointestinais são bem documentados em pequenos mamíferos do centro-norte do Chile, mas pouco conhecido sobre endoparasitos de roedores no sul do Chile. Uma pesquisa foi realizada entre janeiro e fevereiro de 2018, avaliando parasitas gastrointestinais e fatores de risco de roedores selvagens vivendo em áreas rurais no norte da Ilha de Chiloé, Chile. Um total de 174 amostras fecais de roedores de seis espécies nativas e uma introduzida foi coletado e examinado pelo método Mini-FLOTAC. Ademais, 41 indivíduos de quatro espécies nativas de roedores selvagens foram examinados para determinar parasitas adultos do trato gastrointestinal. A prevalência geral de endoparasitos foi de 89,65% (156). Os tipos de ovos de helmintos incluíram: Rodentolepis spp., Capillariidae, Trichuris sp., Syphacia sp.; dos tipos Oxyurideos, Strongyloides sp., dos tipos Spirurideos e Estrongilideos, Moniliformis sp.; e um ovo e larvas de nematoides não identificados. Os protozoários compreendiam coccídios, amebas e cistos não identificados. Nas necropsias, os parasitos adultos envolveram Syphacia sp. Trichuris sp., Protospirura sp. e Physaloptera sp. Em Abrothrix olivacea, indivíduos com baixo índice de massa corporal apresentaram probabilidade de infecção reduzida para ovos Spirurideos e Estrongilideos. Alguns parasitos, neste estudo, podem afetar a saúde humana. Em ambientes rurais, onde as condições ambientais mudam, mais pesquisas são necessárias para entender as infecções parasitárias na vida selvagem e as implicações para a saúde pública e conservação.(AU)
Assuntos
Animais , Doenças Parasitárias em Animais/diagnóstico , Doenças dos Roedores/parasitologia , Roedores/parasitologia , Gastroenteropatias/veterinária , ChileResumo
Background: The term rabbit gastrointestinal syndrome (RGIS) refers to a decrease in peristaltic movements, which insome cases can progress to absolute inactivity of the digestive apparatus. This condition is mostly secondary to others thatpromote changes in gastrointestinal motility, such as dehydration, fiber deficiency, excess carbohydrates in diets, stress,and acute or chronic painful processes. Clinical manifestations are mostly nonspecific. Thus, a case of RGIS resultingfrom environmental change in a domestic rabbit (Oryctolagus cuniculus) is reported.Case: A 4-month-old male domestic rabbit weighing 0.962 kg was referred to a university veterinary hospital. The patient had a history of absence of defecation and anorexia for the past two days. The owner reported that the patient wasapathetic but became aggressive when manipulated. The changes started after a move of residence. On physical evaluation, an increase in abdominal volume and a painful response to touch on the abdomen were observed. Complementaryexaminations were performed, such as a blood count and an ultrasound study. The blood tests showed no alterations,but the ultrasound evaluation showed the presence of free abdominal fluid, dilated intestinal loops due to fluid content,reduced gastrointestinal motility, and a hyperechoic structure associated with acoustic shading in the small intestine, allfindings suggestive of obstruction. Given the failure of clinical management, the patient was referred for an exploratorylaparotomy procedure followed by enterotomy. The obstruction point was located near the ileocecal junction. After surgery,analgesics, antibiotics, fluid therapy, anti-inflammatory drugs, intestinal motility inducers, and probiotics were prescribed.One week after the surgical procedure, the patient showed improvement in the clinical condition, with normal appetite,defecation, and docility...
Assuntos
Masculino , Animais , Coelhos , Coelhos , Obstrução Intestinal/veterinária , Ceco/cirurgia , Íleo/cirurgiaResumo
Background: The term rabbit gastrointestinal syndrome (RGIS) refers to a decrease in peristaltic movements, which insome cases can progress to absolute inactivity of the digestive apparatus. This condition is mostly secondary to others thatpromote changes in gastrointestinal motility, such as dehydration, fiber deficiency, excess carbohydrates in diets, stress,and acute or chronic painful processes. Clinical manifestations are mostly nonspecific. Thus, a case of RGIS resultingfrom environmental change in a domestic rabbit (Oryctolagus cuniculus) is reported.Case: A 4-month-old male domestic rabbit weighing 0.962 kg was referred to a university veterinary hospital. The patient had a history of absence of defecation and anorexia for the past two days. The owner reported that the patient wasapathetic but became aggressive when manipulated. The changes started after a move of residence. On physical evaluation, an increase in abdominal volume and a painful response to touch on the abdomen were observed. Complementaryexaminations were performed, such as a blood count and an ultrasound study. The blood tests showed no alterations,but the ultrasound evaluation showed the presence of free abdominal fluid, dilated intestinal loops due to fluid content,reduced gastrointestinal motility, and a hyperechoic structure associated with acoustic shading in the small intestine, allfindings suggestive of obstruction. Given the failure of clinical management, the patient was referred for an exploratorylaparotomy procedure followed by enterotomy. The obstruction point was located near the ileocecal junction. After surgery,analgesics, antibiotics, fluid therapy, anti-inflammatory drugs, intestinal motility inducers, and probiotics were prescribed.One week after the surgical procedure, the patient showed improvement in the clinical condition, with normal appetite,defecation, and docility...(AU)
Assuntos
Animais , Masculino , Coelhos , Coelhos , Obstrução Intestinal/veterinária , Íleo/cirurgia , Ceco/cirurgiaResumo
Less than 10% of the original Atlantic Forest cover now remains standing in the Brazilian state of Sergipe, although few scientific studies have focused on its mammalian diversity. The present study describes the diversity of non-volant mammals found in the Ibura National Forest (INF), based on live trapping, and direct and indirect observations. We sampled the IBF on six days per month between June 2012 and August 2013, using live-traps (Sherman-type) positioned in pairs (ground and understory). We equally sampled semideciduous forest and an abandoned Eucalyptusplantation with dense understory (over 30 years). We also used non-systematics methods (direct observations, vestiges, camera-trap, and opportunistic captures). We recorded 18 species, from 12 families and 7 orders considering all the applied methods. Among recorded species, Bradypus torquatusand Lontra longicaudisare considered threatened of extinction. Considering only the live-trapping (totaling 3,240 trapping nights), we captured 125 individuals (3.85% success) from four species, Marmosa demerarae(52%), Didelphis albiventris(19.2%), Cerradomys vivoi(15.2%), and M. murina(13.6%). Estimated and observed richness was the same, suggesting a satisfactory effort. Didelphis albiventrisand M. demeraraeshowed significantly higher captures in the dry seasons. Didelphis albiventrisand C.vivoishowed significantly higher captures in the substratum, and M. demeraraehigher in the understory. Cerradomysvivoishowed significantly higher captures in the Eucalyptusphytophysiognomy. Non-Metric Multidimensional Scaling and the ANOSIM showed a significant difference in the captured species among semidecidual forest and Eucalyptus. Despite the small area (144 ha), the INF still houses a relatively high mammalian diversity. Further investigations may help to understand the role of habitat reduction in the diversity and habitat partitioning among mammal species in the Atlantic Forest of Northeastern Brazil.
Assuntos
Animais , Biodiversidade , Ecossistema , Mamíferos/anatomia & histologia , Áreas Protegidas/análiseResumo
Small mammals play an essential role in the transmission and maintenance cycles of Borrelia spirochetes. In Chile, recent studies have characterized novel Borrelia genotypes in ticks collected from small mammals, a fact that suggests these vertebrates are hosts for spirochetes from this genus. Considering this evidence, the goal of this study was to determine the presence of Borrelia DNA in small mammals inhabiting northern Chile. In winter of 2018, 58 small mammals were captured in five localities. Blood samples were collected from rodents and DNA was extracted to determine the presence of Borrelia DNA by PCR targeting the flaB gene and rrsrrlA intergenic spacer (IGS). From three individuals (5%), belonging to two rodent species of Cricetidae family (Phyllotis xanthopygus and Oligoryzomys longicaudatus), we retrieved three flaB and two IGS Borrelia genotypes. Phylogenetic analyses performed with both Maximum Likelihood and Bayesian inferences showed that our sequences grouped with homologous genotypes from the relapsing fever and Lyme borreliosis groups. Our findings suggest that P. xanthopygus and O. longicaudatus rodents may play a role as reservoirs for borrelial spirochetes in Chile.(AU)
Pequenos mamíferos possuem um papel essencial na transmissão e manutenção de espiroquetas do gênero Borrelia. No Chile, estudos recentes têm descrito novos genótipos de Borrelia em carrapatos, parasitando pequenos mamíferos. Isso sugere que esses vertebrados podem atuar como possíveis reservatórios dessas espiroquetas. Considerando-se essa evidência, o objetivo deste estudo foi determinar a presença de DNA de Borrelia em pequenos mamíferos da região norte do Chile. Durante o inverno de 2018, 58 pequenos mamíferos foram capturados em cinco localidades. Amostras de sangue obtidas a partir dos indivíduos capturados foram submetidas à extração de DNA e ensaios de PCR, para a detecção de Borrelia spp. baseados no gene flaB e espaçador intergênico rrsrrlA (IGS). A partir de três espécimes (5%) pertencentes a duas espécies de roedores da família Cricetidae (Phyllotis xanthopygus e Oligoryzomys longicaudatus) obtiveram-se três genótipos de Borrelia para o gene flaB e dois para IGS. Análises filogenéticas inferidas, usando-se os métodos Bayesiano e de Máxima Verossimilhança, indicaram que as sequências geradas neste estudo agrupam-se com borrelias do grupo da Febre Recorrente e Borreliose de Lyme. Os achados deste estudo sugerem que roedores P. xanthopygus e O. longicaudatus poderiam atuar como possíveis reservatórios para Borrelia spp. no Chile.(AU)
Assuntos
Animais , Borrelia/patogenicidade , Roedores/parasitologia , Reservatórios de Água , NoxasResumo
The helminth fauna and metacommunity structure of eight sympatric sigmodontine rodents were investigated at the Serra dos Órgãos National Park, an Atlantic Forest reserve located in the State of Rio de Janeiro, southeast Brazil. Rodents of the species Abrawayaomys ruschii, Akodon montensis, Blarinomys breviceps , Delomys dorsalis, Oligoryzomys flavescens, Oligoryzomys nigripes, Oxymycterus quaestor and Thaptomys nigrita were found infected with helminths. Akodon montensis presented the highest total helminth species richness, with six different species of helminths. The nematode Stilestrongylus lanfrediae was the most abundant and prevalent helminth species observed. The host-parasite network analysis showed little interactions among host species. Akodon montensis seems to act as a keystone-species in the rodent community. This species shared the nematodes Stilestrongylus aculeata with A. ruschii and Protospirura numidica criceticola with T. nigrita, and the cestode Rodentolepis akodontis with D. dorsalis. The congeners host species O. flavescens and O. nigripes shared the nematodes Guerrerostrongylus zetta and S. lanfrediae. The rodents B. breviceps and O. quaestor did not share any helminths with other hosts. The helminth metacommunity showed a random pattern on both infracommunity and component community levels, indicating different responses by each helminth species to the environmental gradient.(AU)
Foram investigadas a helmintofauna e suas estruturas da metacomunidade em oito roedores sigmodontíneos simpátricos ao longo do Parque Nacional da Serra dos Órgãos, uma reserva de Mata Atlântica no estado do Rio de Janeiro, Brasil. Roedores das espécies Abrawayaomys ruschii, Akodon montensis, Blarinomys breviceps, Delomys dorsalis, Oligoryzomys flavescens, Oligoryzomys nigripes, Oxymycterus quaestor e Thaptomys nigrita foram infectados por helmintos. Akodon montensis apresentou a maior riqueza total de espécies de helmintos, com seis espécies. O nematoide Stilestrongylus lanfrediae foi a espécie de helminto com maior abundância e prevalência. A análise de rede parasito-hospedeiro mostrou poucas interações entre as espécies hospedeiras e A. montensis atuou como uma espécie-chave na comunidade de roedores. Esta espécie compartilhou os nematoides Stilestrongylus aculeata com A. ruschii e Protospirura numidica criceticola com T. nigrita, e o cestoide Rodentolepis akodontis com D. dorsalis. As espécies congêneres O. flavescens e O. nigripes compartilharam os nematoides Guerrerostrongylus zetta e S. lanfrediae. Os roedores B. breviceps e O. quaestor não compartilharam helmintos com outros hospedeiros. A metacomunidade de helmintos mostrou um padrão aleatório em ambos os níveis, comunidade componente e infracomunidade, indicando diferentes respostas de cada espécie de helminto ao gradiente ambiental.(AU)
Assuntos
Animais , Helmintos , Roedores/parasitologia , Sigmodontinae/parasitologia , Biota , Animais Selvagens/parasitologia , BrasilResumo
A assimetria flutuante é um exemplo de modificação que se dá através da diferença existente entre os planos simétricos, podendo ser ocasionada por distúrbios ambientais e/ou genético. Uma das causas mais comuns de distúrbios ambientais é a fragmentação de hábitats que ocasiona estresse durante o desenvolvimento dos organismos, originando em alterações em suas estruturas corporais. Este trabalho foi desenvolvido no bioma Caatinga e avaliou a diferença do plano simétrico de três caracteres corporais de duas espécies de marsupiais, Monodelphis domestica e Gracilinanus agilis em um fragmento de mata que atualmente está conservado, mas, no passado foi muito explorado. Entre Agosto de 2014 e Junho de 2016, um total de 111 indivíduos de diferentes idades e sexo foram amostrados. O resultado obtido a partir das análises estatísticas indicaram que existe dimorfismo sexual em tamanho para ambas as espécies sendo os machos maiores. As orelhas dos G. agilis apresentaram uma diminuição ao longo do tempo, com indivíduos jovens possuindo orelhas maiores, evidenciando um possível desgaste deste caractere ao longo da vida e que poderia vir a ocasionar falsa assimetria. Apesar da área de estudo ser um fragmento florestal, o baixo valor de assimetria deste estudo pode estar relacionado ao fato que esta área esteja em recuperação e bem conectada com outros fragmentos. Os resultados indicam uma maior AF em indivíduos menores de M. domestica que podem estar sofrendo pressão sobre o seu fitness e reduzindo o tamanho dos caracteres. Indivíduos maiores dessa espécie podem ser novos na população como indicativos da recuperação deste fragmento. Foi possível observar que um único caractere não pode representar a assimetria de todo o organismo e os índices de assimetria também não indicaram resultados significativos, mostrando que não foi encontrada assimetria ao avaliar os caracteres em relação à população. Ao comparar o índice de assimetria entre as espécies, foi possível observar que a espécie G. agilis apresentou maior assimetria que o M. domestica e isso pode estar relacionado com os hábitos, tamanho corporal e área de vida destes indivíduos. No entanto, a comparação com outros trabalhos é limitada por falta de informações e pelo uso de diferentes índices e formas de cálculo.
Fluctuating asymmetry is an example of differences between sides of a symmetry plane, which can be caused by environmental disturbances and/or genetic disorders. One of the most common causes of environmental disturbances is the fragmentation of habitats, which generates stress during the development stage of the organisms and causing changes in morphological traits. This study assessed the differences between sides of three bilateral morphological traits of two species of marsupials, Monodelphis domestica and Gracilinanus agilis, from a forest fragment in the Caatinga biome, Rio Grande do Norte (Brazil). Between August 2014 and June 2016, 111 individuals from the two species (46 Monodelphis domestica and 65 Gracilinanus agilis), comprising different sexes and ages, were sampled. Results indicate that there is sexual dimorphism in both species, with males being bigger than females. Juveniles of G. agilis presented larger ears than adults, which could indicate some degree of wear through time of this trait and hinder fluctuating asymmetry values. Although this study was conducted in a forest fragment, low levels of FA may indicate that this area is recovering from previous impacts and well connected to other fragments. Smaller M. domestica individuals presented greater FA values than larger individuals, which indicates they may be under stress. In addition, M. domestica larger individuals may have come from surrounding areas with less environmental pressure, which would also indicate that the studied fragment is in recovery. Further results show that asymmetry in both species cannot be represented by a single trait. When comparing the composite fluctuating asymmetry indexes between species, G. agilis presented greater FA than M. domestica, which could be related to different habits and body size. Finally, comparison with previous works is hindered by missing information and the use of different indexes and future research should ameliorate this issues.
Resumo
A fauna de pequenos mamíferos e de carrapatos da Reserva Florestal do Morro Grande, Cotia, SP, foi investigada assim como microrganismos associados a eles. Coletas foram realizadas bimestralmente, e resultaram na captura de 158 pequenos mamíferos silvestres e cães, distribuídos em 126 roedores de 10 espécies, 26 marsupiais de 3 espécies, um tapiti, além de 6 cães domésticos inspecionados. Destes hospedeiros foram recolhidos 327 carrapatos de 9 espécies de 4 gêneros, e larvas de Amblyomma sp. Novos registros de hospedeiros foram acrescentados para as espécies I. aragaoi, I. loricatus, I. schulzei e de espécie morfologicamente semelhante a I. fuscipes. Simultaneamente, fizemos a pesquisa de exemplares em vida livre na vegetação por arraste e busca visual. Um total de 597 exemplares foram recolhidos e identificados, representando 9 espécies de 3 gêneros, além de larvas do gênero Amblyomma. Na sorologia por RIFI, com exceção dos cães domésticos que foram todos negativos, a soro reatividade apresentada para pequenos mamíferos silvestres sugere a circulação de cepas de Rickettsia naquela região. Dos 102 animais testados, 39 foram soro positivos e em 6 amostras nós sugerimos provável antígeno homólogo para R. bellii (3), R. rickettsii (2) e R. rhipicephali (1). Encontramos na quase totalidade dos espécimes adultos de I. aragaoi uma Rickettsia próxima à cepa endosiombionte de I. scapularis, e em uma fêmea de A. sculptum, sequências parciais do gene ompA foram similares a R. parkeri isoladas de A. triste no Brasil e na Argentina. Sequências geradas a partir de um fragmento do gene 18S rRNA de Hepatozoon sp. foram obtidas de amostras dos carrapatos I.c.f. fuscipes e I. schulzei, coletados sobre o roedor A. montensis. Outro hemoprotozoário encontrado foi um genótipo de Babesia sp. proveniente de pools de larvas e de ninfas de A. incisum, coletados em vida livre. Na investigação da presença de bactérias do gênero Coxiella, 14 amostras de diferentes espécies do gênero Amblyomma (A. aureolatum, A. brasiliense, A. incisum, A. naponense e A. sculptum) foram positivas, e as análises de homologia utilizando o marcador molecular 16S rDNA foram compatíveis com Coxiella endosimbiontes de carrapatos.
The fauna of small mammals and ticks of the reserved forest of Morro Grande (RFMG) was assessed and investigated, as well as associated infectious microorganisms. Sample collections were performed bimonthly, and resulted in 158 wild small mammals and dogs inspected, distributed in 126 rodents of 10 different species, 26 marsupials of 3 different species, a Tapiti, and also 6 domestic dogs. 327 ticks were collected from the mentioned hosts; these ticks were representatives of 9 species of 4 different genera, and Amblyomma sp. larvae. New hosts records were appended for 4 species of the genus Ixodes; I. aragaoi, I. loricatus, I. schulzei and a I. fuscipes simile species. Simultaneously, free roaming ticks were collected from the vegetation by dragging a flannel through the forest and visual search. A total of 597 ticks were collected and identified belonging to 9 species of 3 genera, as well as Amblyomma genus larvae. Serology arrays using RIFI technique were performed, and with exception of the domestic dogs that all were negative, the serum reactivity showed in the wild small mammals demonstrated the circulation of Rickettsia strains in the studied region. 39 animals of the 102 tested were positive and 6 samples had strong evidences of being homologous antigens for R. bellii (3), R. rickettsii (2), and R. rhipicephali (1). Molecular research of microorganisms in ticks showed that almost all the adult individuals of I. aragaoi were positive for a Rickettsia similar to an endosymbiont strain of I. scapularis, and in a female of A. sculptum partial sequences the gene of ompA were similar to R. parkeri isolated from A. triste in Brasil and Argentina. Sequences obtained from a fragment of the gene 18S rRNA of Hepatozoon sp. amplified from samples of the tick species I.c.f. fuscipes and I. schulzei, collected from a rodent A. montensis. Another Hemo-protozoon found was a genotype of Babesia sp. from pools of A. incisum larvae and nymphs, collected in the vegetation. For the bacteria of the genus Coxiella, 14 samples of different species of the genus Amblyomma (A. aureolatum, A. brasiliense, A. incisum, A. naponense and A. sculptum) were positive, and the similarity analyses using the 16S rDNA molecular marker were compatible with Coxiella endosymbiont of ticks.
Resumo
One of the most commonly used sampling techniques to capture leaf litter amphibians, lizards and small mammals is a set of pitfall traps with drift fences. However, there are still many speculations concerning the effectiveness of different designs of pitfall traps and the most adequate size of each trap. To address this problem, we conducted the first standardized comparison of patterns of species richness, rank-abundance, and community structure of leaf litter amphibians, lizards and small mammals for two trap designs (I and Y format) and three bucket sizes (35, 62, and 100 L) in a Neotropical forest. Results are very similar for the herpetofauna, regardless of the pitfall trap design or size used, while for small mammals values of species richness were higher for 100 L pitfall traps, as compared to the smaller traps. Therefore, the use of 100 L pitfall traps is recommended to sample the terrestrial vertebrate fauna, in multidisciplinary studies. For surveys aiming only the herpetofauna the use of smaller (35 L) traps is acceptable, taking into consideration the cost-benefits obtained by the smaller traps, in comparison to the larger ones.
Resumo
One of the most commonly used sampling techniques to capture leaf litter amphibians, lizards and small mammals is a set of pitfall traps with drift fences. However, there are still many speculations concerning the effectiveness of different designs of pitfall traps and the most adequate size of each trap. To address this problem, we conducted the first standardized comparison of patterns of species richness, rank-abundance, and community structure of leaf litter amphibians, lizards and small mammals for two trap designs (I and Y format) and three bucket sizes (35, 62, and 100 L) in a Neotropical forest. Results are very similar for the herpetofauna, regardless of the pitfall trap design or size used, while for small mammals values of species richness were higher for 100 L pitfall traps, as compared to the smaller traps. Therefore, the use of 100 L pitfall traps is recommended to sample the terrestrial vertebrate fauna, in multidisciplinary studies. For surveys aiming only the herpetofauna the use of smaller (35 L) traps is acceptable, taking into consideration the cost-benefits obtained by the smaller traps, in comparison to the larger ones.
Resumo
One of the most commonly used sampling techniques to capture leaf litter amphibians, lizards and small mammals is a set of pitfall traps with drift fences. However, there are still many speculations concerning the effectiveness of different designs of pitfall traps and the most adequate size of each trap. To address this problem, we conducted the first standardized comparison of patterns of species richness, rank-abundance, and community structure of leaf litter amphibians, lizards and small mammals for two trap designs (I and Y format) and three bucket sizes (35, 62, and 100 L) in a Neotropical forest. Results are very similar for the herpetofauna, regardless of the pitfall trap design or size used, while for small mammals values of species richness were higher for 100 L pitfall traps, as compared to the smaller traps. Therefore, the use of 100 L pitfall traps is recommended to sample the terrestrial vertebrate fauna, in multidisciplinary studies. For surveys aiming only the herpetofauna the use of smaller (35 L) traps is acceptable, taking into consideration the cost-benefits obtained by the smaller traps, in comparison to the larger ones.
Resumo
A community of small mammals was studied in seasonal semideciduous submontane forest in the state of Mato Grosso, Brazil. This study evaluated the use of edge and matrix pasture, by different small mammal species. Overall, 31 areas were studied, with a total sampling effort of 33,800 trap x nights. Only seven of the 25 species captured in the study sites were able to use the pasture matrix; we classified these species as generalists. Fourteen species were found to be intermediate in habits, being able to use forest edges. We found only four species habitat specialists, occurring only on transect lines in the interior of the fragment, at least 150 m from the edge. Transects located in the pasture matrix and 50 m from the edge had significantly lower species richness and abundance than transects located in the fragment edge or in the interior of the fragment. All transects located within the fragment had similar species richness and abundance, but transects located 50 m from the edge had slightly lower, but non-significant, species richness than transects located 100 m apart from edges. Rarefaction curves demonstrated that only medium-sized fragments (100 300 ha) reached an asymptote of species accumulation. The other areas require further sampling, or more sampling transect, before species accumulation curves stabilize, due to a continued increase in species number.
Uma comunidade de pequenos mamíferos foi estudada em fragmentos de floresta estacional semidecidual submontana no Estado de Mato Grosso, Brasil. Nesse estudo, buscou-se avaliar o uso da borda e da matriz de pastagem pelas diferentes espécies. No total, 31 áreas foram estudadas, com um esforço total de 33.800 armadilhas x noite. Apenas sete das 25 espécies capturadas foram capazes de utilizar a matriz de pastagem, sendo estas consideradas generalistas. Quatorze foram consideradas intermediárias no uso do habitat, sendo capazes de utilizar habitats de borda. Encontramos apenas quatro especialistas, ocorrendo somente nas transecções do interior do fragmento, a aproximadamente 150 m da borda. Dentre todas as transecções utilizadas para amostragem, a disposta na matriz de pastagem, a 50 m da borda, demonstrou ser significativamente menos rica e abundante que as dispostas na borda e no interior dos fragmentos. Todas as transecções localizadas dentro do fragmento tiveram riqueza e abundância de espécies similares, porém a transecção localizada a 50 m da borda teve uma tendência a ser menos rica que a transecção a 100 m. Através de ajustes das curvas de rarefação, somente uma das áreas considerada de médio porte, entre 100 a 300 ha., atingiu uma assíntota. As outras áreas necessitam de um maior número de transecções, a fim de se obter uma estabilização das curvas, pois continuaram a acrescentar espécies.
Resumo
We collected small mammals in two hydrographic basins in central Brazil, namely the Paraná and Araguaia basins, with the aim of examining the composition of forest dwelling small mammal species and to compare their geographic distributions. Fourteen sites were sampled, eight in the Paraná basin and six in the Araguaia basin. A total of 20 species of small mammals was registered (8 marsupials and 12 rodents), 16 of them in live traps (5,253 trap-nights) and eight in pitfalls (224 trap-nights), adding to a total of 161 captures of 139 individuals. The Paraná basin showed 16 species (trap-nights: 3,115 and 104 respectively) and the Araguaia basin 11 species (trap-nights: 2,138 and 120 respectively), being both richness similar when the rarefaction method was applied. Seven (35%) out of the 20 species recorded occurred in both basins. The marsupial Didelphis albiventris Lund, 1840 was the most abundant species. The marsupials species recorded were D. albiventris, Caluromys philander (Linnaeus, 1758), Cryptonanus cf. agricolai Voss, Lunde & Jansa, 2005, Gracilinanus agilis (Burmeister, 1854), G. microtarsus (Wagner, 1842), Lutreolina crassicaudata (Desmarest, 1804), Marmosa murina (Linnaeus, 1758), and Philander opossum (Linnaeus, 1758). The rodent species recorded were Akodon gr. cursor, Calomys tener (Winge, 1887), Nectomys rattus (Pelzen, 1883), N. squamipes (Brants, 1827), Oecomys bicolor (Tomes, 1860), Oryzomys maracajuensis Langguth & Bonvicino, 2002, Oryzomys cf. marinhus, O. megacephalus (Fischer, 1814), Oligoryzomys fornesi (Massoia, 1973), Oligoryzomys sp., Proechimys longicaudatus (Rengger, 1830) and P. roberti (Thomas, 1901). The range extension of some species is discussed, in addition to biogeographic considerations. The Caiapós Mountains may have been a geographic barrier for some small mammal species in the face of the retraction and expansion of forests in the past.
Realizaram-se amostragens de pequenos mamíferos em duas bacias hidrográficas do Brasil central pertencentes aos rios Araguaia e Paraná com intuito de descrever a composição de espécies de pequenos mamíferos de hábito florestal e comparar suas distribuições geográficas. Quatorze pontos de coleta foram amostrados, subdivididos em oito na bacia do Rio Paraná e seis na bacia do Rio Araguaia. Foram registradas 20 espécies de pequenos mamíferos na região (oito de marsupiais e 12 de roedores), sendo 16 delas por meio de armadilhas metálicas (5.253 armadilhas-noite) e oito delas por meio de armadilhas de queda (224 baldes-noite), totalizando 161 capturas de 139 indivíduos. A bacia do Rio Paraná apresentou 16 espécies (armadilhas-noite: 3.115; baldes-noite: 104) e a bacia do Araguaia apresentou 11 espécies (armadilhas-noite: 2.138; baldes-noite: 120), sendo que as riquezas foram similares quando aplicado o método da rarefação. Das 20 espécies registradas, sete (35%) ocorreram em ambas as bacias. Apesar da elevada riqueza de espécies amostrada, destacou-se a elevada abundância do marsupial Didelphis albiventris Lund, 1840. As espécies de marsupiais amostradas foram D. albiventris, Caluromys philander (Linnaeus, 1758), Cryptonanus cf. agricolai Voss, Lunde & Jansa, 2005, Gracilinanus agilis (Burmeister, 1854), G. microtarsus (Wagner, 1842), Lutreolina crassicaudata (Desmarest, 1804), Marmosa murina (Linnaeus, 1758), e Philander opossum (Linnaeus, 1758). As espécies de roedores amostradas foram Akodon gr. cursor, Calomys tener (Winge, 1887), Nectomys rattus (Pelzen, 1883), N. squamipes (Brants, 1827), Oecomys bicolor (Tomes, 1860), Oryzomys maracajuensis Langguth & Bonvicino, 2002, Oryzomys cf. marinhus, O. megacephalus (Fischer, 1814), Oligoryzomys fornesi (Massoia, 1973), Oligoryzomys sp., Proechimys longicaudatus (Rengger, 1830) e P. roberti (Thomas, 1901). A ampliação da distribuição de algumas espécies é discutida, assim como aspectos biogeográficos. A Serra dos Caiapós pode ter sido uma barreira geográfica para algumas espécies de pequenos mamíferos em face da retração e expansão das florestas ocorridas no passado.
Resumo
We collected small mammals in two hydrographic basins in central Brazil, namely the Paraná and Araguaia basins, with the aim of examining the composition of forest dwelling small mammal species and to compare their geographic distributions. Fourteen sites were sampled, eight in the Paraná basin and six in the Araguaia basin. A total of 20 species of small mammals was registered (8 marsupials and 12 rodents), 16 of them in live traps (5,253 trap-nights) and eight in pitfalls (224 trap-nights), adding to a total of 161 captures of 139 individuals. The Paraná basin showed 16 species (trap-nights: 3,115 and 104 respectively) and the Araguaia basin 11 species (trap-nights: 2,138 and 120 respectively), being both richness similar when the rarefaction method was applied. Seven (35%) out of the 20 species recorded occurred in both basins. The marsupial Didelphis albiventris Lund, 1840 was the most abundant species. The marsupials species recorded were D. albiventris, Caluromys philander (Linnaeus, 1758), Cryptonanus cf. agricolai Voss, Lunde & Jansa, 2005, Gracilinanus agilis (Burmeister, 1854), G. microtarsus (Wagner, 1842), Lutreolina crassicaudata (Desmarest, 1804), Marmosa murina (Linnaeus, 1758), and Philander opossum (Linnaeus, 1758). The rodent species recorded were Akodon gr. cursor, Calomys tener (Winge, 1887), Nectomys rattus (Pelzen, 1883), N. squamipes (Brants, 1827), Oecomys bicolor (Tomes, 1860), Oryzomys maracajuensis Langguth & Bonvicino, 2002, Oryzomys cf. marinhus, O. megacephalus (Fischer, 1814), Oligoryzomys fornesi (Massoia, 1973), Oligoryzomys sp., Proechimys longicaudatus (Rengger, 1830) and P. roberti (Thomas, 1901). The range extension of some species is discussed, in addition to biogeographic considerations. The Caiapós Mountains may have been a geographic barrier for some small mammal species in the face of the retraction and expansion of forests in the past.
Realizaram-se amostragens de pequenos mamíferos em duas bacias hidrográficas do Brasil central pertencentes aos rios Araguaia e Paraná com intuito de descrever a composição de espécies de pequenos mamíferos de hábito florestal e comparar suas distribuições geográficas. Quatorze pontos de coleta foram amostrados, subdivididos em oito na bacia do Rio Paraná e seis na bacia do Rio Araguaia. Foram registradas 20 espécies de pequenos mamíferos na região (oito de marsupiais e 12 de roedores), sendo 16 delas por meio de armadilhas metálicas (5.253 armadilhas-noite) e oito delas por meio de armadilhas de queda (224 baldes-noite), totalizando 161 capturas de 139 indivíduos. A bacia do Rio Paraná apresentou 16 espécies (armadilhas-noite: 3.115; baldes-noite: 104) e a bacia do Araguaia apresentou 11 espécies (armadilhas-noite: 2.138; baldes-noite: 120), sendo que as riquezas foram similares quando aplicado o método da rarefação. Das 20 espécies registradas, sete (35%) ocorreram em ambas as bacias. Apesar da elevada riqueza de espécies amostrada, destacou-se a elevada abundância do marsupial Didelphis albiventris Lund, 1840. As espécies de marsupiais amostradas foram D. albiventris, Caluromys philander (Linnaeus, 1758), Cryptonanus cf. agricolai Voss, Lunde & Jansa, 2005, Gracilinanus agilis (Burmeister, 1854), G. microtarsus (Wagner, 1842), Lutreolina crassicaudata (Desmarest, 1804), Marmosa murina (Linnaeus, 1758), e Philander opossum (Linnaeus, 1758). As espécies de roedores amostradas foram Akodon gr. cursor, Calomys tener (Winge, 1887), Nectomys rattus (Pelzen, 1883), N. squamipes (Brants, 1827), Oecomys bicolor (Tomes, 1860), Oryzomys maracajuensis Langguth & Bonvicino, 2002, Oryzomys cf. marinhus, O. megacephalus (Fischer, 1814), Oligoryzomys fornesi (Massoia, 1973), Oligoryzomys sp., Proechimys longicaudatus (Rengger, 1830) e P. roberti (Thomas, 1901). A ampliação da distribuição de algumas espécies é discutida, assim como aspectos biogeográficos. A Serra dos Caiapós pode ter sido uma barreira geográfica para algumas espécies de pequenos mamíferos em face da retração e expansão das florestas ocorridas no passado.
Resumo
We inventoried terrestrial small mammals in an agricultural area in southern Brazil by using trapping and prey consumed by Barn Owls (Tyto alba) and White-tailed Kites (Elanus leucurus). Small mammals were trapped in three habitat types: corn fields, uncultivated fields ("capoeiras"), and native forest fragments. A total of 1,975 small mammal specimens were trapped, another 2,062 identified from the diet of Barn Owls, and 2,066 from the diet of White-tailed Kites. Both trapping and prey in the predators' diet yielded 18 small mammal species: three marsupials (Didelphis albiventris, Gracilinanus agilis, and Monodelphis dimidiata) and 15 rodents (Akodon paranaensis, Bruceppatersonius iheringi, Calomys sp., Cavia aperea, Euryzygomatomys spinosus, Holochilus brasiliensis, Mus musculus, Necromys lasiurus, Nectomys squamipes, Oligoryzomys nigripes, Oryzomys angouya, Oxymycterus sp.1, Oxymycterus sp.2, Rattus norvegicus, and Rattus rattus (Linnaeus, 1758)). The greatest richness was found in the uncultivated habitat. We concluded that the three methods studied for inventorying small mammals (prey in the diet of Barn Owls, White-tailed Kites, and trapping) were complementary, since together, rather than separately, they produced a better picture of local richness.
Nós inventariamos a fauna de pequenos mamíferos terrestres numa área agrícola no sul do Brasil utilizando armadilhas e presas consumidas pela coruja suindara (Tyto alba) e pelo gavião-peneira (Elanus leucurus). Os pequenos mamíferos foram amostrados em três tipos de habitat: cultivos de milho, capoeiras e fragmentos de floresta nativa. Ao todo, 1975 espécimes de pequenos mamíferos foram capturados com armadilhas, 2062 identificados a partir da dieta da suindara e 2066 da dieta do gavião-peneira. Juntas, as capturas com armadilhas e presas identificadas na dieta de ambos os predadores revelaram 18 espécies de pequenos mamíferos: três marsupiais (Didelphis albiventris, Gracilinanus -agilis e Monodelphis dimidiata) e 15 roedores (Akodon paranaensis, Bruceppatersonius iheringi, Calomys sp., Cavia -aperea, Euryzygomatomys spinosus, Holochilus brasiliensis, Mus musculus, Necromys lasiurus, Nectomys squamipes, Oligoryzomys nigripes, Oryzomys angouya, Oxymycterus sp.1, Oxymycterus sp.2, Rattus norvegicus e Rattus rattus). A maior riqueza de espécies foi encontrada nas capoeiras. Nós concluímos que os três métodos estudados para inventariar a fauna de pequenos mamíferos (presas na dieta da suindara, do gavião-peneira e capturas com armadilhas) foram complementares, pois juntos forneceram uma idéia melhor da riqueza local do que individualmente.
Resumo
Anthropic activities are frequently related in many ways to forest fragmentation and alteration of natural communities. In this study, we correlate the presence of hunting, tourism activity, agriculture/pasturing, and the distance of the study sites to the nearest human residences with the species composition of small Atlantic forest mammals. To do this, we utilize a multiple regression analysis of similarity matrices. The presence of both agriculture/pasturing and human residences near the study sites proved to be determinant factors in species composition of small mammals of the studied areas. Working with socioeconomic variables related directly with the study site could be a reliable and a direct way to predict the influence of human presence and entailed activity on small mammal communities.
Atividades antrópicas estão freqüentemente associadas à fragmentação da paisagem e alteram as comunidades naturais de diversas maneiras. Neste estudo, a presença de caça, turismo, agricultura/pastagens e a distância até as residências mais próximas foram relacionadas à composição de espécies de pequenos mamíferos na Mata Atlântica por meio de uma análise de regressão múltipla de matrizes de similaridade. Verificamos que a presença de agricultura/pastagens, bem como de residências próximas aos locais de estudo, foram determinantes para a composição das espécies de pequenos mamíferos das áreas estudadas. Trabalhar com variáveis socioeconômicas diretamente relacionadas à área de estudo pode ser uma forma direta e confiável de predizer a influência da presença humana e de suas atividades relacionadas às comunidades de pequenos mamíferos.
Resumo
Studies quantifying habitat structure generally use several instruments. This paper aims to propose a new and efficient device to characterize microhabitat structure of small mammals. Seven measurements were taken: plant cover, litter cover, rock cover, canopy cover, and vegetative obstruction at three heights. The device is a 0.25 m² square wooden frame (0.50 m x 0.50 m) divided in to 100 open squares by wire mesh. Average time spent to measure each trapping station was six minutes. This new device is efficient, i.e., quick, practical, simple, and reliable. It can be used in any kind of forest. We propose this method as a standard method to describe habitat structure.
Os estudos que quantificam a estrutura do habitat geralmente usam vários instrumentos. Este artigo objetiva propor um novo e eficiente instrumento para caracterizar a estrutura do microhabitat de pequenos mamíferos. Sete medidas foram tomadas: cobertura vegetal (herbáceos e lenhosos), cobertura de folhiço, cobertura de pedras, cobertura de dossel e obstrução foliar vertical em três alturas. O instrumento é uma tela quadrada de 0,25 m² (0,50 m x 0,50 m) de madeira, dividida por arame em 100 quadrados abertos. O tempo médio para medir cada estação de captura foi de 6 minutos. Este novo instrumento é eficiente, isto é, rápido, prático, simples e confiável. Ele pode ser usado em qualquer tipo de floresta. Propomos este método como padrão para descrever a estrutura do habitat.
Resumo
Studies quantifying habitat structure generally use several instruments. This paper aims to propose a new and efficient device to characterize microhabitat structure of small mammals. Seven measurements were taken: plant cover, litter cover, rock cover, canopy cover, and vegetative obstruction at three heights. The device is a 0.25 m² square wooden frame (0.50 m x 0.50 m) divided in to 100 open squares by wire mesh. Average time spent to measure each trapping station was six minutes. This new device is efficient, i.e., quick, practical, simple, and reliable. It can be used in any kind of forest. We propose this method as a standard method to describe habitat structure.
Os estudos que quantificam a estrutura do habitat geralmente usam vários instrumentos. Este artigo objetiva propor um novo e eficiente instrumento para caracterizar a estrutura do microhabitat de pequenos mamíferos. Sete medidas foram tomadas: cobertura vegetal (herbáceos e lenhosos), cobertura de folhiço, cobertura de pedras, cobertura de dossel e obstrução foliar vertical em três alturas. O instrumento é uma tela quadrada de 0,25 m² (0,50 m x 0,50 m) de madeira, dividida por arame em 100 quadrados abertos. O tempo médio para medir cada estação de captura foi de 6 minutos. Este novo instrumento é eficiente, isto é, rápido, prático, simples e confiável. Ele pode ser usado em qualquer tipo de floresta. Propomos este método como padrão para descrever a estrutura do habitat.