Small mammals and microhabitat selection in forest fragments in the transition zone between Atlantic Forest and Pampa biome

Natural resources are depleted in fragmented landscapes that have their vegetation also altered. As a result, the microhabitat diversity and the composition and distribution of local species are affected. In this study, we evaluated the small mammals' community diversity, composition and microhabitat selection in two Atlantic Forest fragments, in an ecotone area with the Pampa biome, southern Brazil. We recorded five rodents (Akodon montensis, Oligoryzomys nigripes, Sooretamys angouya, Juliomys pictipes and the exotic Rattus rattus) and one marsupial (Didelphis albiventris). Both fragments were dominated by the generalist rodent A. montensis. Akodon montensis and O. nigripes showed similar habitat preferences: ground covered by rocks and higher values of vegetation obstruction. Sooretamys angouya preferred places with higher abundance of trees. Fruit availability was important for A. montensis and D. albiventris, highlighting the importance of this food resource for local wildlife, and the potential role of these species as seed predators and dispersers. Small species richness, the presence of an exotic species and high dominance level suggest that the study area is highly degraded.(AU)

Small mammal diversity in Semi-deciduous Seasonal Forest of the southernmost Brazilian Pampa: the importance of owl pellets for rapid inventories in human-changing ecosystems

Abstract The Pampa biogeographic province covers a mere 2% of the Brazilian territory (176,496 km²). However, it stands out as a complex and diverse ecosystem, although its mammal communities are still scarcely understood. Human activities are transforming the territory into a mosaic of agroecosystems, native and exotic forest fragments, and grasslands. Here we conducted the first investigation to determine the richness of small mammal assemblages in the region based on extensive analyses of owl pellets (Tyto furcata). Craniodental remains were studied from samples collected from 12 Semi-deciduous Seasonal Forest sites in the municipality of São Lourenço do Sul, State of Rio Grande do Sul, Southern Brazil. A total of 2,617 individuals belonging to 18 taxa were recorded, including 2 marsupials (Didelphidae; 0.42%), 2 chiropterans (Molossidae, Phyllostomidae; 0.12%), and 14 rodents (Cricetidae, Muridae, Caviidae; 99.46%). The rodent genera Oligoryzomys, Mus, Calomys, and Akodon were the most common taxa. Large samples also included poorly known taxa, such as the cricetids Bibimys, Juliomys (recording here its southernmost occurrence), Lundomys, and Wilfredomys. From a biogeographical point of view, the recorded assemblage embraces a mixture of Platan, Pampean, and Atlantic Forest elements, highlighting the role of the southernmost Brazilian hills as a wedge favoring the penetration of forest micromammals to higher latitudes. Our findings testify to the great diversity of the Pampa, but also point to a growing homogeneity and dominance of rodent species that are widespread in agroecosystems. Rapid inventories based on owl pellets emerge as a suitable, economic, non-invasive tool to document these community changes.

Small mammal diversity in Semi-deciduous Seasonal Forest of the southernmost Brazilian Pampa: the importance of owl pellets for rapid inventories in human-changing ecosystems

The Pampa biogeographic province covers a mere 2% of the Brazilian territory (176,496 km²). However, it stands out as a complex and diverse ecosystem, although its mammal communities are still scarcely understood. Human activities are transforming the territory into a mosaic of agroecosystems, native and exotic forest fragments, and grasslands. Here we conducted the first investigation to determine the richness of small mammal assemblages in the region based on extensive analyses of owl pellets (Tyto furcata). Craniodental remains were studied from samples collected from 12 Semi-deciduous Seasonal Forest sites in the municipality of São Lourenço do Sul, State of Rio Grande do Sul, Southern Brazil. A total of 2,617 individuals belonging to 18 taxa were recorded, including 2 marsupials (Didelphidae; 0.42%), 2 chiropterans (Molossidae, Phyllostomidae; 0.12%), and 14 rodents (Cricetidae, Muridae, Caviidae; 99.46%). The rodent genera Oligoryzomys, Mus, Calomys, and Akodon were the most common taxa. Large samples also included poorly known taxa, such as the cricetids Bibimys, Juliomys (recording here its southernmost occurrence), Lundomys, and Wilfredomys. From a biogeographical point of view, the recorded assemblage embraces a mixture of Platan, Pampean, and Atlantic Forest elements, highlighting the role of the southernmost Brazilian hills as a wedge favoring the penetration of forest micromammals to higher latitudes. Our findings testify to the great diversity of the Pampa, but also point to a growing homogeneity and dominance of rodent species that are widespread in agroecosystems. Rapid inventories based on owl pellets emerge as a suitable, economic, non-invasive tool to document these community changes.

Small mammal diversity in Semi-deciduous Seasonal Forest of the southernmost Brazilian Pampa: the importance of owl pellets for rapid inventories in human-changing ecosystems

The Pampa biogeographic province covers a mere 2% of the Brazilian territory (176,496 km²). However, it stands out as a complex and diverse ecosystem, although its mammal communities are still scarcely understood. Human activities are transforming the territory into a mosaic of agroecosystems, native and exotic forest fragments, and grasslands. Here we conducted the first investigation to determine the richness of small mammal assemblages in the region based on extensive analyses of owl pellets (Tyto furcata). Craniodental remains were studied from samples collected from 12 Semi-deciduous Seasonal Forest sites in the municipality of São Lourenço do Sul, State of Rio Grande do Sul, Southern Brazil. A total of 2,617 individuals belonging to 18 taxa were recorded, including 2 marsupials (Didelphidae; 0.42%), 2 chiropterans (Molossidae, Phyllostomidae; 0.12%), and 14 rodents (Cricetidae, Muridae, Caviidae; 99.46%). The rodent genera Oligoryzomys, Mus, Calomys, and Akodon were the most common taxa. Large samples also included poorly known taxa, such as the cricetids Bibimys, Juliomys (recording here its southernmost occurrence), Lundomys, and Wilfredomys. From a biogeographical point of view, the recorded assemblage embraces a mixture of Platan, Pampean, and Atlantic Forest elements, highlighting the role of the southernmost Brazilian hills as a wedge favoring the penetration of forest micromammals to higher latitudes. Our findings testify to the great diversity of the Pampa, but also point to a growing homogeneity and dominance of rodent species that are widespread in agroecosystems. Rapid inventories based on owl pellets emerge as a suitable, economic, non-invasive tool to document these community changes.(AU)

Diversidade, biogeografia, caracterização cariotípica e tricológica dos pequenos mamíferos não voadores do parque estadual rio da onça, litoral sul do paraná

ABSTRACT The Atlantic forest possess 1,361 vertebrate species of which 567 are endemic. Rodentia and Didelphimorphia comprise 71% of the endemic mammals observed in this biome. In Brazil, these animals still lack basic information about their biology, distribution, and even total wealth. This study aimed to identify the species of marsupials and rodents present in Rio da Onça State Park and to characterize the morphology of guard hairs and chromosomal set thereof, besides verify the composition of small non-flying mammals in different environments and vegetation strata. Thirteen field campaigns were conducted and as an additional effort, three lines of pitfall traps were installed. The total sampling effort was 6.633 traps and 1.181 buckets spread over 69 nights of sampling, which resulted in 196 captures of 166 individuals of 12 species. Seven species of Rodentia Order were recorded: Akodon montensis, Delomys sublineatus, Euryoryzomys russatus, Juliomys pictipes, Nectomys squamipes, Oligoryzomys nigripes and Thaptomys nigrita and five species of marsupials (Didelphimorphia Order): Didelphis aurita, Gracilinanus microtarsus, Metachirus nudicaudatus, Marmosa paraguayana and Monodelphis iheringi. Trichological and cytogenetic results were consistent with those available in the literature. Regarding the vertical stratification, only seven captures were made in trees. Four of the species Marmosa paraguayana, two Didelphis aurita, and one Akodon montensis. Therefore, in the environment of the lowlands of the study area, sampling carried out on tree and shrub extract of the understory did not contribute to the increase of the species list.

RESUMO Das 1.361 espécies de vertebrados que a Mata Atlântica abriga, 567 são endêmicas. Rodentia e Didelphimorphia somam 71% dos endemismos observados para mamíferos nesse bioma. No Brasil, esses animais ainda carecem de informações básicas a cerca de sua biologia, distribuição, e mesmo riqueza total. Esse trabalho objetivou identificar as espécies de marsupiais e roedores do Parque Estadual Rio da Onça e caracterizar a morfologia dos pelos-guarda e do conjunto cromossômico das mesmas, além de verificar a composição de pequenos mamíferos não voadores em diferentes ambientes e estratos vegetais. Foram realizadas treze campanhas de campo e como esforço adicional, três linhas de armadilhas de queda foram instaladas. O esforço amostral total foi de 6.633 armadilhas e 1.181 baldes distribuídos ao longo de 69 noites de amostragem, que resultaram em 196 capturas de 166 indivíduos de 12 espécies. Foram registradas sete espécies da Ordem Rodentia: Akodon montensis, Delomys sublineatus, Euryoryzomys russatus, Juliomys pictipes, Nectomys squamipes, Oligoryzomys nigripes e Thaptomys nigrita, além de cinco espécies de marsupiais da Ordem Didelphimorphia: Didelphis aurita, Gracilinanus microtarsus, Metachirus nudicaudatus, Marmosa paraguayana e Monodelphis iheringi. Os resultados tricológicos e citogenéticos foram condizentes com os disponíveis na literatura. Quanto à estratificação vertical, somente sete capturas foram feitas em árvore: quatro da espécie Marmosa paraguayana, duas de Didelphis aurita e uma de Akodon montensis. Portanto, para o ambiente de Terras Baixas da área de estudo, a amostragem realizada no extrato arbóreo e arbustivo do sub-bosque não contribuiu para o incremento da lista de espécies.

DIVERSIDADE, BIOGEOGRAFIA, CARACTERIZAÇÃO CARIOTÍPICA E TRICOLÓGICA DOS PEQUENOS MAMÍFEROS NÃO VOADORES DO PARQUE ESTADUAL RIO DA ONÇA, LITORAL SUL DO PARANÁ

ABSTRACT The Atlantic forest possess 1,361 vertebrate species of which 567 are endemic. Rodentia and Didelphimorphia comprise 71% of the endemic mammals observed in this biome. In Brazil, these animals still lack basic information about their biology, distribution, and even total wealth. This study aimed to identify the species of marsupials and rodents present in Rio da Onça State Park and to characterize the morphology of guard hairs and chromosomal set thereof, besides verify the composition of small non-flying mammals in different environments and vegetation strata. Thirteen field campaigns were conducted and as an additional effort, three lines of pitfall traps were installed. The total sampling effort was 6.633 traps and 1.181 buckets spread over 69 nights of sampling, which resulted in 196 captures of 166 individuals of 12 species. Seven species of Rodentia Order were recorded: Akodon montensis, Delomys sublineatus, Euryoryzomys russatus, Juliomys pictipes, Nectomys squamipes, Oligoryzomys nigripes and Thaptomys nigrita and five species of marsupials (Didelphimorphia Order): Didelphis aurita, Gracilinanus microtarsus, Metachirus nudicaudatus, Marmosa paraguayana and Monodelphis iheringi. Trichological and cytogenetic results were consistent with those available in the literature. Regarding the vertical stratification, only seven captures were made in trees. Four of the species Marmosa paraguayana, two Didelphis aurita, and one Akodon montensis. Therefore, in the environment of the lowlands of the study area, sampling carried out on tree and shrub extract of the understory did not contribute to the increase of the species list.

RESUMO Das 1.361 espécies de vertebrados que a Mata Atlântica abriga, 567 são endêmicas. Rodentia e Didelphimorphia somam 71% dos endemismos observados para mamíferos nesse bioma. No Brasil, esses animais ainda carecem de informações básicas a cerca de sua biologia, distribuição, e mesmo riqueza total. Esse trabalho objetivou identificar as espécies de marsupiais e roedores do Parque Estadual Rio da Onça e caracterizar a morfologia dos pelos-guarda e do conjunto cromossômico das mesmas, além de verificar a composição de pequenos mamíferos não voadores em diferentes ambientes e estratos vegetais. Foram realizadas treze campanhas de campo e como esforço adicional, três linhas de armadilhas de queda foram instaladas. O esforço amostral total foi de 6.633 armadilhas e 1.181 baldes distribuídos ao longo de 69 noites de amostragem, que resultaram em 196 capturas de 166 indivíduos de 12 espécies. Foram registradas sete espécies da Ordem Rodentia: Akodon montensis, Delomys sublineatus, Euryoryzomys russatus, Juliomys pictipes, Nectomys squamipes, Oligoryzomys nigripes e Thaptomys nigrita, além de cinco espécies de marsupiais da Ordem Didelphimorphia: Didelphis aurita, Gracilinanus microtarsus, Metachirus nudicaudatus, Marmosa paraguayana e Monodelphis iheringi. Os resultados tricológicos e citogenéticos foram condizentes com os disponíveis na literatura. Quanto à estratificação vertical, somente sete capturas foram feitas em árvore: quatro da espécie Marmosa paraguayana, duas de Didelphis aurita e uma de Akodon montensis. Portanto, para o ambiente de Terras Baixas da área de estudo, a amostragem realizada no extrato arbóreo e arbustivo do sub-bosque não contribuiu para o incremento da lista de espécies.

Diversidade, biogeografia, caracterização cariotípica e tricológica dos pequenos mamíferos não voadores do Parque Estadual Rio da Onça, Litoral Sul do Paraná

The Atlantic forest possess 1,361 vertebrate species of which 567 are endemic. Rodentia and Didelphimorphia comprise 71% of the endemic mammals observed in this biome. In Brazil, these animals still lack basic information about their biology, distribution, and even total wealth. This study aimed to identify the species of marsupials and rodents present in Rio da Onça State Park and to characterize the morphology of guard hairs and chromosomal set thereof, besides verify the composition of small non-flying mammals in different environments and vegetation strata. Thirteen field campaigns were conducted and as an additional effort, three lines of pitfall traps were installed. The total sampling effort was 6.633 traps and 1.181 buckets spread over 69 nights of sampling, which resulted in 196 captures of 166 individuals of 12 species. Seven species of Rodentia Order were recorded: Akodon montensis, Delomys sublineatus, Euryoryzomys russatus, Juliomys pictipes, Nectomys squamipes, Oligoryzomys nigripes and Thaptomys nigrita and five species of marsupials (Didelphimorphia Order): Didelphis aurita, Gracilinanus microtarsus, Metachirus nudicaudatus, Marmosa paraguayana and Monodelphis iheringi. Trichological and cytogenetic results were consistent with those available in the literature. Regarding the vertical stratification, only seven captures were made in trees. Four of the species Marmosa paraguayana, two Didelphis aurita, and one Akodon montensis. Therefore, in the environment of the lowlands of the study area, sampling carried out on tree and shrub extract of the understory did not contribute to the increase of the species list.

Das 1.361 espécies de vertebrados que a Mata Atlântica abriga, 567 são endêmicas. Rodentia e Didelphimorphia somam 71% dos endemismos observados para mamíferos nesse bioma. No Brasil, esses animais ainda carecem de informações básicas a cerca de sua biologia, distribuição, e mesmo riqueza total. Esse trabalho objetivou identificar as espécies de marsupiais e roedores do Parque Estadual Rio da Onça e caracterizar a morfologia dos pelos-guarda e do conjunto cromossômico das mesmas, além de verificar a composição de pequenos mamíferos não voadores em diferentes ambientes e estratos vegetais. Foram realizadas treze campanhas de campo e como esforço adicional, três linhas de armadilhas de queda foram instaladas. O esforço amostral total foi de 6.633 armadilhas e 1.181 baldes distribuídos ao longo de 69 noites de amostragem, que resultaram em 196 capturas de 166 indivíduos de 12 espécies. Foram registradas sete espécies da Ordem Rodentia: Akodon montensis, Delomys sublineatus, Euryoryzomys russatus, Juliomys pictipes, Nectomys squamipes, Oligoryzomys nigripes e Thaptomys nigrita, além de cinco espécies de marsupiais da Ordem Didelphimorphia: Didelphis aurita, Gracilinanus microtarsus, Metachirus nudicaudatus, Marmosa paraguayana e Monodelphis iheringi. Os resultados tricológicos e citogenéticos foram condizentes com os disponíveis na literatura. Quanto à estratificação vertical, somente sete capturas foram feitas em árvore: quatro da espécie Marmosa paraguayana, duas de Didelphis aurita e uma de Akodon montensis. Portanto, para o ambiente de Terras Baixas da área de estudo, a amostragem realizada no extrato arbóreo e arbustivo do sub-bosque não contribuiu para o incremento da lista de espécies.

Diversidade, biogeografia, caracterização cariotípica e tricológica dos pequenos mamíferos não voadores do Parque Estadual Rio da Onça, Litoral Sul do Paraná

The Atlantic forest possess 1,361 vertebrate species of which 567 are endemic. Rodentia and Didelphimorphia comprise 71% of the endemic mammals observed in this biome. In Brazil, these animals still lack basic information about their biology, distribution, and even total wealth. This study aimed to identify the species of marsupials and rodents present in Rio da Onça State Park and to characterize the morphology of guard hairs and chromosomal set thereof, besides verify the composition of small non-flying mammals in different environments and vegetation strata. Thirteen field campaigns were conducted and as an additional effort, three lines of pitfall traps were installed. The total sampling effort was 6.633 traps and 1.181 buckets spread over 69 nights of sampling, which resulted in 196 captures of 166 individuals of 12 species. Seven species of Rodentia Order were recorded: Akodon montensis, Delomys sublineatus, Euryoryzomys russatus, Juliomys pictipes, Nectomys squamipes, Oligoryzomys nigripes and Thaptomys nigrita and five species of marsupials (Didelphimorphia Order): Didelphis aurita, Gracilinanus microtarsus, Metachirus nudicaudatus, Marmosa paraguayana and Monodelphis iheringi. Trichological and cytogenetic results were consistent with those available in the literature. Regarding the vertical stratification, only seven captures were made in trees. Four of the species Marmosa paraguayana, two Didelphis aurita, and one Akodon montensis. Therefore, in the environment of the lowlands of the study area, sampling carried out on tree and shrub extract of the understory did not contribute to the increase of the species list.(AU)

Das 1.361 espécies de vertebrados que a Mata Atlântica abriga, 567 são endêmicas. Rodentia e Didelphimorphia somam 71% dos endemismos observados para mamíferos nesse bioma. No Brasil, esses animais ainda carecem de informações básicas a cerca de sua biologia, distribuição, e mesmo riqueza total. Esse trabalho objetivou identificar as espécies de marsupiais e roedores do Parque Estadual Rio da Onça e caracterizar a morfologia dos pelos-guarda e do conjunto cromossômico das mesmas, além de verificar a composição de pequenos mamíferos não voadores em diferentes ambientes e estratos vegetais. Foram realizadas treze campanhas de campo e como esforço adicional, três linhas de armadilhas de queda foram instaladas. O esforço amostral total foi de 6.633 armadilhas e 1.181 baldes distribuídos ao longo de 69 noites de amostragem, que resultaram em 196 capturas de 166 indivíduos de 12 espécies. Foram registradas sete espécies da Ordem Rodentia: Akodon montensis, Delomys sublineatus, Euryoryzomys russatus, Juliomys pictipes, Nectomys squamipes, Oligoryzomys nigripes e Thaptomys nigrita, além de cinco espécies de marsupiais da Ordem Didelphimorphia: Didelphis aurita, Gracilinanus microtarsus, Metachirus nudicaudatus, Marmosa paraguayana e Monodelphis iheringi. Os resultados tricológicos e citogenéticos foram condizentes com os disponíveis na literatura. Quanto à estratificação vertical, somente sete capturas foram feitas em árvore: quatro da espécie Marmosa paraguayana, duas de Didelphis aurita e uma de Akodon montensis. Portanto, para o ambiente de Terras Baixas da área de estudo, a amostragem realizada no extrato arbóreo e arbustivo do sub-bosque não contribuiu para o incremento da lista de espécies.(AU)

Identidade, riqueza e abundãncia de pequenos mamíferos (Rodentia e Didelphimorphia) de área de Floresta com Araucária no estado do Paraná, Brasil

Rodents and Marsupials are an important component of the fauna in the Neotropical region. Studies about richness and abundance of these animals in the Araucaria Forests are scarce, and here we present an inventory at Piraí do Sul National Forest. This area has approximately 150 ha, surrounded by pastures and Pinus plantations. Pitfall, Shermann and Tomahawk traps were disposed at the main vegetation types found in this National Forest. At least a pair of each species were collected. As a result, during 5.892 traps.night we had a total of 1.049 captures, representing 17 species: Akodon montensis, Bibimys labiosus, Brucepattersonius iheringi, Cryptonanus sp., Didelphis albiventris, D. aurita, Gracilinanus microtarsus, Juliomys ossitenuis, Monodelphis americana, M. scalops, Myocastor coypus, Nectomys squamipes, Oligoryzomys nigripes, Oxymycterus judex, O. nasutus, Sooretamys angouya and Thaptomys nigrita. Pitfall represented 67% of the total, and eight species were recorded only by this method. Akodon montensis, O. nigripes and T. nigrita were the most abundant species.

Roedores e Marsupiais são componentes importantes da fauna na região Neotropical. Estudos sobre a riqueza e abundância destes animais são raros na Floresta Ombrófila Mista (FOM) e aqui apresentamos um inventário conduzido na Floresta Nacional de Piraí do Sul. Esta área possui uma área aproximada de 150 ha, cercada por pastos e plantações de Pinus. A amostragem foi feita através de armadilhas de queda, Sherman e Tomahawk, dispostas nos principais tipos de vegetação encontrados. Pelo menos um casal de cada espécie foi coletado. Como resultado, durante 5.892 armadilhas.noite nós obtivemos um total de 1.049 capturas, representando 17 espécies: Akodon montensis, Bibimys labiosus, Brucepattersonius iheringi, Cryptonanus sp., Didelphis albiventris, D. aurita, Gracilinanus microtarsus, Monodelphis americana, M. scalops, Myocastor coypus, Nectomys squamipes, Oligoryzomys nigripes, Oxymycterus judex, O. nasutus, Sooretamys angouya e Thaptomys nigrita. Capturas por armadilhas de queda representaram 67% do total, e oito espécies foram registradas exclusivamente por este método. Akodon montensis, O. nigripes e T. nigrita foram as espécies mais abundantes.

Identidade, riqueza e abundãncia de pequenos mamíferos (Rodentia e Didelphimorphia) de área de Floresta com Araucária no estado do Paraná, Brasil

Rodents and Marsupials are an important component of the fauna in the Neotropical region. Studies about richness and abundance of these animals in the Araucaria Forests are scarce, and here we present an inventory at Piraí do Sul National Forest. This area has approximately 150 ha, surrounded by pastures and Pinus plantations. Pitfall, Shermann and Tomahawk traps were disposed at the main vegetation types found in this National Forest. At least a pair of each species were collected. As a result, during 5.892 traps.night we had a total of 1.049 captures, representing 17 species: Akodon montensis, Bibimys labiosus, Brucepattersonius iheringi, Cryptonanus sp., Didelphis albiventris, D. aurita, Gracilinanus microtarsus, Juliomys ossitenuis, Monodelphis americana, M. scalops, Myocastor coypus, Nectomys squamipes, Oligoryzomys nigripes, Oxymycterus judex, O. nasutus, Sooretamys angouya and Thaptomys nigrita. Pitfall represented 67% of the total, and eight species were recorded only by this method. Akodon montensis, O. nigripes and T. nigrita were the most abundant species.(AU)

Roedores e Marsupiais são componentes importantes da fauna na região Neotropical. Estudos sobre a riqueza e abundância destes animais são raros na Floresta Ombrófila Mista (FOM) e aqui apresentamos um inventário conduzido na Floresta Nacional de Piraí do Sul. Esta área possui uma área aproximada de 150 ha, cercada por pastos e plantações de Pinus. A amostragem foi feita através de armadilhas de queda, Sherman e Tomahawk, dispostas nos principais tipos de vegetação encontrados. Pelo menos um casal de cada espécie foi coletado. Como resultado, durante 5.892 armadilhas.noite nós obtivemos um total de 1.049 capturas, representando 17 espécies: Akodon montensis, Bibimys labiosus, Brucepattersonius iheringi, Cryptonanus sp., Didelphis albiventris, D. aurita, Gracilinanus microtarsus, Monodelphis americana, M. scalops, Myocastor coypus, Nectomys squamipes, Oligoryzomys nigripes, Oxymycterus judex, O. nasutus, Sooretamys angouya e Thaptomys nigrita. Capturas por armadilhas de queda representaram 67% do total, e oito espécies foram registradas exclusivamente por este método. Akodon montensis, O. nigripes e T. nigrita foram as espécies mais abundantes.(AU)

Morphological diagnosis and geographic distribution of Atlantic Forest red-rumped mice of the genus Juliomys (Rodentia: Sigmodontinae)

Recognition and identification of red-rumped mice of the genus Juliomys González, 2000 has been a problem among many mammalogists, and specimens of this genus are commonly confused with other Atlantic Forest sigmodontine rodents. Herein we provide an expanded diagnosis for the genus based on the analyses of the three living species of Juliomys, and provide morphological comparisons to the small bodied and bright colored rodents Rhagomys rufescens (Thomas, 1886) and Oligoryzomys flavescens (Waterhouse, 1837), which occur in sympatry with Juliomys spp. in forested areas of southeastern Brazil. These taxa are superficially similar, and are therefore commonly misidentified in the field and museum collections. We also provide morphometric data and a key to the living species of Juliomys, and an updated distribution map of the genus and its species.

Morphological diagnosis and geographic distribution of Atlantic Forest red-rumped mice of the genus Juliomys (Rodentia: Sigmodontinae)

Recognition and identification of red-rumped mice of the genus Juliomys González, 2000 has been a problem among many mammalogists, and specimens of this genus are commonly confused with other Atlantic Forest sigmodontine rodents. Herein we provide an expanded diagnosis for the genus based on the analyses of the three living species of Juliomys, and provide morphological comparisons to the small bodied and bright colored rodents Rhagomys rufescens (Thomas, 1886) and Oligoryzomys flavescens (Waterhouse, 1837), which occur in sympatry with Juliomys spp. in forested areas of southeastern Brazil. These taxa are superficially similar, and are therefore commonly misidentified in the field and museum collections. We also provide morphometric data and a key to the living species of Juliomys, and an updated distribution map of the genus and its species.

Morphological diagnosis and geographic distribution of Atlantic Forest red-rumped mice of the genus Juliomys (Rodentia: Sigmodontinae)

Recognition and identification of red-rumped mice of the genus Juliomys González, 2000 has been a problem among many mammalogists, and specimens of this genus are commonly confused with other Atlantic Forest sigmodontine rodents. Herein we provide an expanded diagnosis for the genus based on the analyses of the three living species of Juliomys, and provide morphological comparisons to the small bodied and bright colored rodents Rhagomys rufescens (Thomas, 1886) and Oligoryzomys flavescens (Waterhouse, 1837), which occur in sympatry with Juliomys spp. in forested areas of southeastern Brazil. These taxa are superficially similar, and are therefore commonly misidentified in the field and museum collections. We also provide morphometric data and a key to the living species of Juliomys, and an updated distribution map of the genus and its species.

Small mammal community structure and microhabitat use in the austral boundary of the Atlantic Forest, Brazil

We investigated the richness, composition, and species relative abundance of a terrestrial small mammal community in a Deciduous Forest area in the austral boundary of the Atlantic Forest. The microhabitat use of the most common species was also investigated. Six rodents - Akodon montensis (Thomas, 1913), Oligoryzomys nigripes (Olfers, 1818), Sooretamys angouya (Thomas, 1913), Thaptomys nigrita (Lichtenstein, 1829), Mus musculus (Linnaeus, 1758) and Juliomys sp. - and one marsupial - Didelphis albiventris (Lund, 1840) - were captured. Thaptomys nigrita is recorded in the state of Rio Grande do Sul for the first time. Species richness was poor when compared with communities in the central portions of the Atlantic Forest, but equivalent to that found in the Araucaria and Dense Ombrophilous forests of southern Brazil. The species most often captured in our study, A. montensis and O. nigripes, are also the most common in the majority of faunistic studies carried out in the Atlantic Forest. Akodon montensis and S. angouya used places with high abundance of bamboo, possibly to avoid predators. Oligorizomys nigripes used areas with a high density of scrubs, what could facilitate aboveground movements, and was negatively correlated to mature forest indicators, which reinforce the idea that this species has opportunistic habits.

Small mammal community structure and microhabitat use in the austral boundary of the Atlantic Forest, Brazil

We investigated the richness, composition, and species relative abundance of a terrestrial small mammal community in a Deciduous Forest area in the austral boundary of the Atlantic Forest. The microhabitat use of the most common species was also investigated. Six rodents - Akodon montensis (Thomas, 1913), Oligoryzomys nigripes (Olfers, 1818), Sooretamys angouya (Thomas, 1913), Thaptomys nigrita (Lichtenstein, 1829), Mus musculus (Linnaeus, 1758) and Juliomys sp. - and one marsupial - Didelphis albiventris (Lund, 1840) - were captured. Thaptomys nigrita is recorded in the state of Rio Grande do Sul for the first time. Species richness was poor when compared with communities in the central portions of the Atlantic Forest, but equivalent to that found in the Araucaria and Dense Ombrophilous forests of southern Brazil. The species most often captured in our study, A. montensis and O. nigripes, are also the most common in the majority of faunistic studies carried out in the Atlantic Forest. Akodon montensis and S. angouya used places with high abundance of bamboo, possibly to avoid predators. Oligorizomys nigripes used areas with a high density of scrubs, what could facilitate aboveground movements, and was negatively correlated to mature forest indicators, which reinforce the idea that this species has opportunistic habits.

Small mammal community structure and microhabitat use in the austral boundary of the Atlantic Forest, Brazil

We investigated the richness, composition, and species relative abundance of a terrestrial small mammal community in a Deciduous Forest area in the austral boundary of the Atlantic Forest. The microhabitat use of the most common species was also investigated. Six rodents - Akodon montensis (Thomas, 1913), Oligoryzomys nigripes (Olfers, 1818), Sooretamys angouya (Thomas, 1913), Thaptomys nigrita (Lichtenstein, 1829), Mus musculus (Linnaeus, 1758) and Juliomys sp. - and one marsupial - Didelphis albiventris (Lund, 1840) - were captured. Thaptomys nigrita is recorded in the state of Rio Grande do Sul for the first time. Species richness was poor when compared with communities in the central portions of the Atlantic Forest, but equivalent to that found in the Araucaria and Dense Ombrophilous forests of southern Brazil. The species most often captured in our study, A. montensis and O. nigripes, are also the most common in the majority of faunistic studies carried out in the Atlantic Forest. Akodon montensis and S. angouya used places with high abundance of bamboo, possibly to avoid predators. Oligorizomys nigripes used areas with a high density of scrubs, what could facilitate aboveground movements, and was negatively correlated to mature forest indicators, which reinforce the idea that this species has opportunistic habits.

Estratificação vertical no uso do espaço por pequenos mamíferos (Rodentia, Sigmodontinae) em área de Floresta Ombrófila Mista, RS, Brasil

A estratificação vertical no uso do espaço por pequenos mamíferos foi investigada em área de Floresta Ombrófila Mista no sul do Brasil, de agosto de 2004 a julho de 2005. Sete expedições de três noites consecutivas foram efetuadas no período. Sessenta e três armadilhas do tipo Tomahawk foram dispostas na área de amostragem, ao nível do terreno e em plataformas suspensas, entre 6m e 13m de altura. Empregou-se o Índice Simplificado de Morisita para investigar o grau de similaridade entre os estratos e o Coeficiente de Correlação de Spearman para verificar a influência da cobertura do dossel e da altura do solo sobre a capturabilidade no estrato arbóreo. O esforço total empreendido foi equivalente a 960 armadilhas-noite e o sucesso de captura, a 16,56%. O baixo índice de similaridade registrado (0,102) demonstrou baixa correspondência entre as amostras, sugerindo padrões distintos de associação de espécies em cada estrato. Delomys dorsalis, Akodon montensis e Brucepattersonius iheringi revelaram hábito terrícola, enquanto Oligoryzomys nigripes e Sooretamys angouya (= Oryzomys angouya) utilizaram ambos os estratos. Juliomys sp. apresentou hábito estritamente arbóreo. Constatou-se correlação significativa e positiva apenas entre capturas e cobertura (rs = 0,5530; p = 0,0093). O percentual de cobertura do dossel demonstrou ser um fator de seleção do habitat pelas espécies de hábito a

Estratificação vertical no uso do espaço por pequenos mamíferos (Rodentia, Sigmodontinae) em área de Floresta Ombrófila Mista, RS, Brasil

A estratificação vertical no uso do espaço por pequenos mamíferos foi investigada em área de Floresta Ombrófila Mista no sul do Brasil, de agosto de 2004 a julho de 2005. Sete expedições de três noites consecutivas foram efetuadas no período. Sessenta e três armadilhas do tipo Tomahawk foram dispostas na área de amostragem, ao nível do terreno e em plataformas suspensas, entre 6m e 13m de altura. Empregou-se o Índice Simplificado de Morisita para investigar o grau de similaridade entre os estratos e o Coeficiente de Correlação de Spearman para verificar a influência da cobertura do dossel e da altura do solo sobre a capturabilidade no estrato arbóreo. O esforço total empreendido foi equivalente a 960 armadilhas-noite e o sucesso de captura, a 16,56%. O baixo índice de similaridade registrado (0,102) demonstrou baixa correspondência entre as amostras, sugerindo padrões distintos de associação de espécies em cada estrato. Delomys dorsalis, Akodon montensis e Brucepattersonius iheringi revelaram hábito terrícola, enquanto Oligoryzomys nigripes e Sooretamys angouya (= Oryzomys angouya) utilizaram ambos os estratos. Juliomys sp. apresentou hábito estritamente arbóreo. Constatou-se correlação significativa e positiva apenas entre capturas e cobertura (rs = 0,5530; p = 0,0093). O percentual de cobertura do dossel demonstrou ser um fator de seleção do habitat pelas espécies de hábito a