Abstract:We report a new record for the bushy-tailed opossum Glironia venusta Thomas, 1912 and the water opossum Chironectes minimus (Zimmermann, 1780) in the Floresta Nacional de Carajás, municipality of Parauapebas, state of Pará, Brazil (06°03'00" S, 50°15'00" W). This study represents the second record of Glironia venusta, but the first voucher specimen for eastern Brazilian Amazon. For Chironectes minimus, this record extends the range of the species 558 km southeastwards from the closest known locality in Pará.
The Atlantic Forest is considered a hotspot due to its current state of vast degradation and high indexes of biodiversity. This biome has been degraded through the years by processes resulting from the Brazilian socioeconomic model of development. The seasonal semi-deciduous Atlantic Forest is a poorly studied phytophysiognomy specially degraded by human activities in the state of Rio de Janeiro. In the present study we report the results of a rapid mammalian inventory conducted in the municipality of Cambuci, in a fragment of seasonal semi-deciduous forest. We used live traps and pitfall traps to capture non-volant small mammals, and mist-nets of different lengths to collect bats. To sample medium and large-sized mammals we used camera traps. We recorded 27 mammal species in the region, of which 16 are volant mammals. We emphasize the distribution extension of Trinomys setosus in 150 km (that enabled its insertion in the species list of Rio de Janeiro) and the capture of Lonchophylla peracchii, a recently described species apparently restricted to Atlantic Forest. Both facts show the importance of the fragment for the region biodiversity.
The Carajás National Forest contains some of the largest iron ore deposits in the world. The majority of the minerals are found below a plant community known as Savana Metalófila, or “Canga”, which represents only 3% of the landscape within the Carajás National Forest (CNF). The aim of our study was to understand the diversity of community of non-volant small mammals in the two predominant vegetation types: Ombrophilous Forest and Canga, and to examine how mining impacts these communities. Sampling was conducted from January 2010 to August 2011 in 11 sampling sites divided by the total area of Canga and 12 sampling sites in the forest, totalizing 23 sites. Of these, 12 sites (Canga and Forest) were considered impacted areas located close to the mine (<< 900 meters) and 11 sites (Canga and Forest), serving as controls, which were at least 7,000 meters from the mine. We recorded 28 species, 11 from the Order Didelphimorphia and 17 from the Order Rodentia. The two forest types shared 68.42% of the species found in the CNF. A gradient analysis (Non-metric multidimensional scaling) revealed that the first axis clearly separated the non-flying small mammal communities by vegetation type. Occupancy models showed that the detectability of species was affected by the distance from the mining activities. Of all the small mammals analyzed, 10 species were positively affected by the distance from mining in areas impacted (e.g. more likely to be detected farther from mining areas) and detectability was lower in impacted areas. However, three species were negatively affected by the distance from mining, with higher detectability in the impacted areas, and seven species showed no effect of their proximity to mining operations. To date, there are no studies in Brazil about the impact of mining on mammals or other vertebrates. This study reveals that the effect of mining may go beyond the forest destruction caused by the opening of the mining pits, but also may negatively affect sensitive wildlife species.
This study was the first to evaluate the efficiency of trapping methods in the study of small mammals in the Carajás National Forest, southeastern Brazilian Amazon. It is an area with a unique vegetation type (metalofilic savannah or Canga). The aims of this study were to compare the efficiency of two trapping methods (i.e. live-traps and pitfalls), the bait types used, and evaluate if trapping success varied seasonally. We used four sampling grids, each with six parallel transects. The trap effort for live-traps and pitfalls was 51,840 trap*nights and 10,800 bucket*nights, respectively. We used three types of bait: a paste of peanut butter and sardines, bacon, and bananas. We placed one type of bait in each trap, alternating between points. We recorded 26 species of small mammals, 11 from the order Didelphimorphia and 15 from the order Rodentia. Pitfalls captured a higher number of species compared with live-traps. The capture rate, the mortality rate and the quantity of juveniles and adults did not differ significantly between methods. Capture rate for pitfalls differed significantly between seasons. The majority of species were captured by a single method. Species were equally attracted to the traps regardless of the type of bait used. Some of our results differed significantly from other studies in Amazonia and such variation should be taken into account when designing survey methods for Amazonian small mammals. KEYWORDS: Live-traps; pitfall-traps; Didelphimorphia; Rodentia; capture rate Diferenças na eficiência entre dois métodos de amostragem para capturar pequenos mamíferos não-voadores em uma área na Amazônia oriental RESUMO Este estudo foi o primeiro a avaliar a eficiência de métodos de captura de pequenos mamíferos não-voadores na Floresta Nacional de Carajás, sudeste da Amazônia brasileira. É uma área que apresenta características fitofisionômicas exclusivas (savana metalófila ou Canga) e sofre pressão da atividade mineradora. Os objetivos desse estudo foram comparar a eficiência de dois métodos de captura e de três tipos de iscas, bem como se a eficiência dos métodos variou sazonalmente. Nós usamos quatro grades de amostragem, cada uma com seis trilhas paralelas. Capturas com armadilhas de gaiola (live-traps) e armadilhas de caída (pitfall traps) foram realizadas durante três estações secas e três úmidas. O esforço total de captura foi de 51.840 armadilhas*noite e 10.800 baldes*noite para live-traps e pitfalls, respectivamente. Três tipos de isca (pasta de amendoim com sardinha, bacon e banana) foram usadas de forma alternada em todas as armadilhas. Nós registramos 26 espécies de pequenos mamíferos, 11 da ordem Didelphimorphia e 15 da ordem Rodentia. Pitfalls capturaram mais espécies que live-traps. As taxas de captura e de mortalidade e a proporção de jovens e adultos não diferiram entre os métodos. O sucesso de captura diferiu sazonalmente apenas para pitfalls. A maioria das espécies foi capturada preferencialmente ou exclusivamente por um dos dois métodos. As espécies foram igualmente atra...
We report 22 records of giant armadillo roadkill on Brazilian highways in the Cerrado, Pantanal and Amazon biomes illustrating that highways are a threat to this species.However, we also documented the species using underpasses, demonstrating that these structures could help to reduce the risk of roadkill for giant armadillos. Abstract in Portuguese is available with online material K E Y W O R D S
We present new records for the disk-winged bats Thyroptera tricolor and T. devivoi in central and northern Brazil. Records of T. tricolor are from Aripuanã, Usina Hidrelétrica (UHE) Colíder (both in the northern Mato Grosso state) and Santana do Araguaia (southern Pará state). New records of T. devivoi are from a Cerrado area in the Rio Manso, Rio Quilombo (both in Mato Grosso state) and from an Amazon rainforest area at Juruti (Pará state). The records of Thyroptera devivoi for Pará and Mato Grosso are the first ones for these states and the records from the latter are based on two specimens previously identified as T. discifera. Based on the new identifications, we argue that T. discifera does not occur in the Cerrado.
The brown or pouchless four-eyed opossums or jupatis represent the genus Metachirus with a wide geographical range in the Neotropics. Recent studies show distinct monophyletic clades with high genetic divergence and recognized two species, Metachirus nudicaudatus and Metachirus myosuros. Nevertheless, there is a need for systematic revision with multiple sources of evidence on the taxonomy of Metachirus, which has never been fully revised. Here we describe a new species of Metachirus for the Brazilian Amazon from the Xingu/Tocantins interfluve using the unification of concepts and evolutionary significant units, morphological, genetic, and geographic data. Our analysis reveals a new species within Metachirus as a differentiated Amazonian clade from the Serra dos Carajás region and the Caxiuanã National Forest, both in the Xingu endemism centre. This new species can be distinguished from the type species, M. nudicaudatus and from M. myosuros through discrete external morphological characters, including cranium and dentition, and molecular data with an average degree of divergence, but ancient divergence time for the mitochondrial cytochrome b gene. The Amazon River delimits the distribution of the new species, which also occurs in areas under strong anthropogenic pressure, reinforcing the importance to guide conservation strategies for the region.
Two short-tailed opossum species, Monodelphis glirina and M. touan, occur in sympatry in an area of eastern Amazonia. Habitat structure and resource availability may influence habitat use and, consequently, species distribution, detectability, occupancy, and abundance. We evaluated occupancy and detectability of the species M. glirina and M. touan in the Carajás National Forest to answer the following questions: (1) Do both species occur in canga and forest habitats? (2) Do detectability and occupancy of M. touan and M. glirina differ in areas of canga and forest? (3) Does the presence of one species affect the detection of the other? We undertook surveys at 50 sampling sites (26 in canga and 24 in forest habitat). In addition, we developed co-occurrence models to test the relationships between occupancy and detection of M. touan in the presence or absence of M. glirina. We captured 693 individuals of M. glirina (587 in canga and 106 in forest) and 112 of M. touan (only one individual captured in canga). Occupancy by M. glirina was positively influenced by superficial rock cover and litter depth, while detectability was negatively influenced by canopy cover. Occupancy by M. touan was influenced positively by canopy cover, number of fallen trunks on the ground, and litter depth (Ψ = 0.315). Data from forest sites where M. touan and M. glirina occurred more often corroborated our third hypothesis, that detectability of M. touan is low when M. glirina is present. Our results highlight the existence of habitat preference by the two species of Monodelphis.
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