Mesostigmatic mites of the Laelapinae Berlese, 1892 (Acari: Laelapidae) are nidicolous arthropods that commonly occur in the fur of Neotropical small mammmals. In this 2-yr study, the laelapine acarofauna associated with the small mammal community in an area of Atlantic forest on Ilha Grande, Rio de Janeiro State, was examined, including observations on patterns of host specificity, mite dispersal, ecology, and food habits. A total of 1,347 laelapines was sampled from the pelage of 6 species of small mammals (Marmosops incanus, Nectomys squamipes, Oryzomys russatus, Rhipidomys n. sp., Oxymycterus dasytrichus, and Trinomys dimidiatus), all of which occurred exclusively in monoxenous associations with their hosts. No evidence of a blood meal was observed in the gut of the mites. With the exception of the 2 species of Tur, mite populations on hosts were entirely or nearly restricted to adult females. These results, together with some morphological characteristics of laelapines, reinforce the hypotheses that Neotropical laelapine mites are not ectoparasitic, and that females disperse by phoresy.
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 Carajás National Forest is located in the Amazonian region, Pará State, Brazil and is part of a mosaic of conservation units comprising over one million hectares. This region has been explored for its mineral reserves, but knowledge of the distribution of animals and plants is lacking. The objective of this paper is to provide a list of the medium and large-sized mammals recorded from the Carajás NF. We used four methods to record mammals: linear transects, camera traps, records of road-killed animals, and opportunistic observations. We recorded 45 species distributed in nine taxonomic orders, eight of them currently on the Brazilian list of threatened species and seven in the IUCN red list. The area has high mammalian diversity and holds 56% of the threatened species known for the State, confirming that the study area is correctly categorized as Extremely High Priority for the conservation of Brazilian 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.
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