14 research outputs found

    Maned wolves retain moderate levels of genetic diversity and gene flow despite drastic habitat fragmentation

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    The maned wolf Chrysocyon brachyurus is the largest South American canid and categorized as Near Threatened on the IUCN Red List. The major threat to conservation efforts is the drastic reduction of suitable habitat for the species. A large portion of its range has been converted into farm and ranch lands as well as urban areas. To better understand the impact that these anthropogenic activities are having over the remaining populations across their current distribution range, we evaluated patterns of genetic variability and differentiation between them. We also compared these results with those obtained from captive maned wolves in order to make proper ex situ recommendations. We cross-amplified 12 microsatellite loci in maned wolf samples collected throughout their range (from Argentina, Brazil, Uruguay and Bolivia) and from captive stocks (from captive breeding centers and zoos in Brazil, Argentina and the USA). We found that wild populations retain moderate levels of genetic variability compared with other microsatellite studies on wild canids, and our structure analysis revealed 2 genetic clusters in wild samples, one of which included samples exclusively from Bolivia. This cluster could represent a different management unit with conservation priority. The captive stock population showed higher levels of genetic variability, with the ones from Brazil being the most genetically diverse stock. The USA stock showed strong genetic differences with all other groups. This is the first study to examine the patterns of genetic diversity of both wild and captive populations of maned wolves. These results should be incorporated into further population viability assessments and in the Maned Wolf Species Survival Plan.Agencia Nacional de Investigación e Innovació

    Population structure and gene flow of Geoffroy's cat (Leopardus geoffroyi) in the Uruguayan Savanna ecoregion

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    Felids are among the species most threatened by habitat fragmentation resulting from land-use change. In the Uruguayan Savanna ecoregion, about 30% of natural habitats have been lost, large felids have been eradicated from most of the region, and the impact of anthropogenic threats over the smaller species that remain is unknown. To develop management strategies, it is important to enhance knowledge about species population structure and landscape connectivity, particularly when land-use change will continue and intensify in the next years. In this study, we evaluate the population structure and gene flow of Geoffroy's cat in the Uruguayan Savanna ecoregion. We generated a matrix of 11 microsatellite loci for 70 individuals. Based on Bayesian approaches we found that within the Uruguayan Savanna, Geoffroy's cat shows high levels of genetic variability and no population structure. However, we observed genetic differences between individuals from the Uruguayan Savanna and those from the contiguous ecoregion, the Argentinian Humid Pampa. Four first-generation migrants from Humid Pampa were identified in the Uruguayan Savanna, suggesting a stronger gene flow in the west-east direction. We detected a past bottleneck followed by a subsequent recovery in Geoffroy's cat populations in both ecoregions. These results lay the groundwork to understand the population dynamics and conservation status of Geoffroy's cat in the Uruguayan Savanna ecoregion, and provide baseline data to establish population monitoring.Fil: Bou, Nadia. Ministerio de Educacion y Cultura.; UruguayFil: Soutullo, Álvaro. Universidad de la Republica; UruguayFil: Hernández, Daniel. Laboratorio de Control Ambiental; UruguayFil: Mannise, Natalia. Ministerio de Educacion y Cultura.; UruguayFil: González, Susana. Ministerio de Educacion y Cultura.; UruguayFil: Bartesaghi, Lucía. Ministerio de Educacion y Cultura.; UruguayFil: Pereira, Javier Adolfo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Merino, Mariano Lisandro. Universidad Nacional del Noroeste de la Provincia de Buenos Aires. Centro de Bioinvestigaciones (Sede Junín); ArgentinaFil: Espinosa, Caroline. Universidade Federal do Rio Grande do Sul; BrasilFil: Trigo, Tatiane C.. Museu de Ciencias Naturais; ArgentinaFil: Cosse, Mariana. Ministerio de Educacion y Cultura.; Urugua

    The role of the environment in the spatial dynamics of an extensive hybrid zone between two neotropical cats

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    Identifying factors that create and maintain a hybrid zone is of great interest to ecology, evolution and, more recently, conservation biology. Here, we investigated the role of environmental features in shaping the spatial dynamics of a hybrid zone between the southern tigrina, Leopardus guttulus, and Geoffroy's cat, L. geoffroyi, testing for exogenous selection as the main force acting on its maintenance. These Neotropical felid species are mainly allopatric, with a restricted area of sympatry in the ecotone between the Atlantic Forest and Pampa biomes. As both biomes have experienced high rates of anthropogenic habitat alteration, we also analysed the influence of habitat conversion on the hybrid zone structure. To do this, we used 13 microsatellite loci to identify potential hybrids and generated ecological niche models for them and their parental species. We compared the influence of variables on parental species and hybrid occurrence and calculated the amount of niche overlap among them. Parental species showed different habitat requirements and predicted co-occurrence was restricted to the forest-grassland mosaic of the ecotone. However, hybrids were found beyond this area, mainly in the range of L. geoffroyi. Hybrids demonstrated higher tolerance to habitat alteration than parental types, with a probability of occurrence that was positively related with mosaics of cropland areas and remnants of natural vegetation. These results indicate that exogenous selection alone does not drive the dynamics of the hybrid zone, and that habitat conversion influences its structure, potentially favouring hybrids over parental species.Fil: Sartor, Caroline Charão. Universidade Federal do Rio Grande do Sul; BrasilFil: Cushman, Samuel Alan. United States Department of Agriculture; Estados UnidosFil: Wan, Ho Yi. Humboldt State University; Estados UnidosFil: Kretschmer, Rafael. Universidade Federal do Rio Grande do Sul; BrasilFil: Pereira, Javier Adolfo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Bou, Nadia. Ministerio de Educacion y Cultura.; UruguayFil: Cosse, Mariana. Ministerio de Educacion y Cultura.; UruguayFil: González, Susana. Ministerio de Educacion y Cultura.; UruguayFil: Eizirik, Eduardo. Pontificia Universidade Católica do Rio Grande do Sul; BrasilFil: de Freitas, Thales Renato O.. Universidade Federal do Rio Grande do Sul; BrasilFil: Campos Trigo, Tatiane. Universidade Federal do Rio Grande do Sul; Brasi

    Maned wolves retain moderate levels of genetic diversity and gene flow despite drastic habitat fragmentation

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    The maned wolf Chrysocyon brachyurus is the largest South American canid and categorized as Near Threatened on the IUCN Red List. The major threat to conservation efforts is the drastic reduction of suitable habitat for the species. A large portion of its range has been converted into farm and ranch lands as well as urban areas. To better understand the impact that these anthropogenic activities are having over the remaining populations across their current distribution range, we evaluated patterns of genetic variability and differentiation between them. We also compared these results with those obtained from captive maned wolves in order to make proper ex situ recommendations. We cross-amplified 12 microsatellite loci in maned wolf samples collected throughout their range (from Argentina, Brazil, Uruguay and Bolivia) and from captive stocks (from captive breeding centers and zoos in Brazil, Argentina and the USA). We found that wild populations retain moderate levels of genetic variability compared with other microsatellite studies on wild canids, and our structure analysis revealed 2 genetic clusters in wild samples, one of which included samples exclusively from Bolivia. This cluster could represent a different management unit with conservation priority. The captive stock population showed higher levels of genetic variability, with the ones from Brazil being the most genetically diverse stock. The USA stock showed strong genetic differences with all other groups. This is the first study to examine the patterns of genetic diversity of both wild and captive populations of maned wolves. These results should be incorporated into further population viability assessments and in the Maned Wolf Species Survival Plan

    Feeding ecology of Ozotoceros bezoarticus: conservation implicationsin Uruguay

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    The pampas deer (Ozotoceros bezoarticus Linnaeus, 1758) was in the recent past one of the most characteristic species in the Uruguayan grasslands. However, today the species is very rare, with small relict populations inhabiting in few ranches. To improve our understanding of pampas deer habitat use in modified ecosystems and propose management guidelines we analyzed the pampas deer feeding ecology at Los Ajos ranch. We performed an annual vegetation survey with the purpose to identify the main components of pampas's deer diet and the spatial overlap with livestock. Vegetation offer was characterized by predominance of monocotyledon plants; in three of the four sample periods. The preference values for the crops were positive for ryegrass in winter (0.24) and spring (0.54), the moments of greatest productivity of this pasture; while the rice crops values were negative all year round. The spatial overlap indexes with sheep show a complete exclusion, whereas with cattle the indexes gave values of 0.95 in spring to 0.14 in summer. The niche amplitude was significantly correlated with the spatial overlap levels with cattle. Pampas deer foraging behaviour is opportunistic, typical of mixed feeders. Conservation efforts should focus on implementation of management guidelines of agriculture and cattle breeding activities

    KM406516- KM406517 and KM406502- KM406515

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    Maned wolves mtDNA haplotypes. Two haplotypes of Cytochrome b fragment and 14 haplotypes of hypervariable Dloop fragmen

    Data from: Population structure of mtDNA variation due to Pleistocene fluctuations in the South American maned wolf (Chrysocyon brachyurus, Illiger, 1815): management units for conservation

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    The maned wolf (Chrysocyon brachyurus) is one of the largest South American canids, and conservation across this charismatic carnivore’s large range is presently hampered by a lack of knowledge about possible natural subdivisions which could influence the population’s viability. To elucidate the phylogeographic patterns and demographic history of the species, we used 2 mtDNA markers (D-loop and cytochrome b) from 87 individuals collected throughout their range, in Argentina, Bolivia, Brazil, and Uruguay. We found moderate levels of haplotype and nucleotide diversity, and the 14 D-loop haplotypes were closely related. Genetic structure results revealed 4 groups, and when coupled with model inferences from a coalescent analysis, suggested that maned wolves have undergone demographic fluctuations due to changes in climate and habitat during the Pleistocene glaciation period approximately 24000 years before present (YBP). This genetic signature points to an event that occurred within the timing estimated for the start of the contraction of the Cerrado around 50000 YBP. Our results reveal a genetic signature of population size expansion followed by contraction during Pleistocene interglaciations, which had similar impacts on other South American mammals. The 4 groups should for now be considered management units, within which future monitoring efforts should be conducted independently
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