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Mino C.I.,National University of Misiones | Mino C.I.,Federal University of Sao Carlos | Gardenal C.N.,National University of Cordoba | Bidau C.J.,Laboratorio Of Biologia E Parasitologia Of Mamiferos Silvestres Reservatorios
Journal of Heredity | Year: 2011

Hybrid zones are regions where genetically different populations meet and mate, resulting in offspring of mixed characteristics. In organisms with limited dispersal, such as melanopline grasshoppers, hybrid zones can occur at small spatial scales (i.e., <500 m). We assessed levels of morphological, chromosomal, and molecular variability in adult males of the grasshopper Dichroplus pratensis Bruner (N = 137 males, 188 females) collected at 12 sites within a mosaic hybrid zone in a heterogeneous environment in Sierra de la Ventana, Argentina. In this hybrid zone, 2 Robertsonian chromosomal races, polymorphic for different centric fusions, meet (the "Northern race" at low altitudes and the "Southern race" at higher altitudes), forming hybrids that show monobrachial homologies during meiosis. High morphometric variation in 6 traits was revealed among grasshoppers of both sexes, with male body size positively and significantly correlated with increasing altitude. Frequency of Robertsonian fusions characteristic of the Southern race increased significantly with altitude. Moreover, fusion frequencies covaried between samples. Considerable genetic variation was revealed by random amplification of polymorphic DNA markers, with heterozygosity ranging from 0.3477 to 0.3745. Insects from low-altitude and high-altitude populations showed significant genetic differentiation, as indicated by FST values. The proposed model for D. pratensis, involving the generation and maintenance by chromosomal fusions, of gene complexes adaptive in different environments, could explain the observed clinal patterns within the contact zone. © 2011 The American Genetic Association. 2010. All rights reserved. Source


Teixeira T.S.M.,Federal University of Rio de Janeiro | Teixeira T.S.M.,State University of Rio de Janeiro | Weber M.M.,Federal University of Rio de Janeiro | Dias D.,Laboratorio Of Biologia E Parasitologia Of Mamiferos Silvestres Reservatorios | And 5 more authors.
Journal for Nature Conservation | Year: 2014

The IUCN Red List is a widely accepted system for classifying species' risk of extinction, based on quantitative criteria. Although IUCN discourages the liberal use of the category "Data Deficient" (DD), most assessed groups have a large number of their species assigned to this category, especially in the Tropics. Therefore, DD species can introduce considerable uncertainty into estimates of proportions of threatened species, and research focused on elucidating the true status of those species should be a priority. Here we propose a simple method to gather information on geographic distribution and guide the search for new populations of rare, small-ranged, forest species, using the literature, online data, and standard GIS procedures. The method involves: (i) creating a geographic distribution model; (ii) selecting the environmentally suitable sites from that model; (iii) removing sites that have lost natural vegetation; and (iv) removing habitat networks that are too small and/or isolated, based on thresholds established from known occurrence records and the literature for ecologically similar species. As a case study, we use Lonchophylla peracchii, a recently described forest-dependent bat endemic to southeastern Brazil. We found that environmentally suitable sites for L. peracchii are already heavily deforested, confirming habitat loss as a major threat. Importantly, we identified five priority sites to search for the species outside of its currently known distribution. From that, we discuss its likely status based on IUCN's Criterion B2 (Extent of Occurrence). This method could be useful for other poorly known forest species, especially in the Tropics where most of these species are, and funding for research and fieldwork is scarcest. Currently there are 1910 terrestrial vertebrates in tropical forest worldwide classified as DD that could be evaluated using this method, provided that they have at least 5-10 occurrence records. © 2014 Elsevier GmbH. Source


Martins M.A.,Federal Rural University of Rio de Janeiro | Carvalho W.D.D.,Federal Rural University of Rio de Janeiro | Carvalho W.D.D.,University of Lisbon | Dias D.,Laboratorio Of Biologia E Parasitologia Of Mamiferos Silvestres Reservatorios | And 3 more authors.
Acta Chiropterologica | Year: 2015

The effect of elevational gradients on the richness and composition of communities are reflected by different biotas. The objective of this study was to document changes in the species richness and composition of bats along a tropical elevational gradient between 500 and 2,500 m of elevation in southeastern Brazil. We carried out fieldwork from June 2009 to December 2012 with the use of mist nets. During 32 sampling nights we recorded 270 bats from 22 species. Species richness peaked around low-elevation (500-1,000 m a.s.l.) and there was richness decrease at higher elevations. The analysis of bat assemblage between the elevational range showed a significant difference in species composition along an elevational gradient. Bat richness and abundance were negatively related to altitude. © Museum and Institute of Zoology PAS. Source


Astua D.,Federal University of Pernambuco | Carvalho R.A.,Federal University of Pernambuco | Maia P.F.,Federal University of Pernambuco | Magalhaes A.R.,Federal University of Paraiba | Loretto D.,Laboratorio Of Biologia E Parasitologia Of Mamiferos Silvestres Reservatorios
Biology Letters | Year: 2015

The Didelphidae are considered solitary opossumswith fewsocial interactions, usually limited to mating-related or mother-pouch young interactions. Anecdotal reports suggest that additional interactions occur, including den sharing by a few individuals, usually siblings. Here, we report novel observations that indicate opossums are more social than previously thought. These include nest sharing by males and females of Marmosa paraguayana, Gracilinanusmicrotarsus andMarmosops incanus prior to the onset of the breeding season and without signs of sexual activity; this is taken to indicate early pairbondingmatching and cooperative nest building.We also recorded den sharing among recently weaned siblings of Didelphis aurita and Caluromys philander. In addition, we observed 13 individuals of Didelphis albiventris representing three age classes resting without agonistic interactions in a communal den. These are the first reports of gregarious behaviour involving so many individuals, which are either unrelated or represent siblings from at least two litters, alreadyweaned, sharing the same denwith three adults. Sociality in opossums is probably more complex than previously established, and field experimental designs combining the use of artificial nests with camera traps or telemetry may help to gauge the frequency and extent of these phenomena. © 2015 The Author(s) Published by the Royal Society. All rights reserved. Source


Rocha F.L.,Laboratorio Of Biologia Of Tripanosomatideos | Rocha F.L.,Laboratorio Of Biologia E Parasitologia Of Mamiferos Silvestres Reservatorios | Rocha F.L.,Triade Instituto Brasileiro Para Medicina da Conservac ao Rua Silveira Lobo | Roque A.L.R.,Laboratorio Of Biologia Of Tripanosomatideos | And 7 more authors.
Parasitology | Year: 2013

Aiming to better understand the ecological aspects of Trypanosoma cruzi transmission cycles, wild carnivores, small mammals and dogs were examined for T. cruzi infection in the Serra da Canastra National Park region, Brazil. Isolates were genotyped using mini-exon gene and PCR-RFLP (1f8 and H3) genomic targets. Trypanosoma cruzi transmission was well established in the area and occurred in both wild and peridomestic environments. Dog seroprevalence was 29·4% (63/214) and TcI and TcII genotypes, besides mixed infections were observed. Only TcI was detected in wild mammals. Marsupials displayed lower relative abundance, but a high prevalence of positive haemocultures (4/22), whereas rodents displayed positive haemocultures (9/113) mainly in the abundant Akodon montensis and Cerradomys subflavus species. The felid Leopardus pardalis was the only carnivore to display positive haemoculture and was captured in the same region where the small mammal prevalence of T. cruzi infection was high. Two canid species, Chrysocyon brachyurus and Cerdocyon thous, were serologically positive for T. cruzi infection (4/8 and 8/39, respectively), probably related to their capacity to exploit different ecological niches. Herein, dog infection not only signals T. cruzi transmission but also the genotypes present. Distinct transmission strategies of the T. cruzi genotypes are discussed. © Cambridge University Press 2012. Source

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