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Buenos Aires, Argentina

Schivo F.,National University of San Martin of Argentina | Schivo F.,CONICET | Kandus P.,National University of San Martin of Argentina | Bolkovic M.L.,Direccion de Fauna Silvestre | And 5 more authors.
Tropical Conservation Science | Year: 2015

Habitat loss is one of the main factors reducing wildlife diversity and restricting its conservation. Habitat suitability models are important tools for wildlife management and conservation in order to evaluate the impacts of human activities on wildlife habitats. The capybara (Hydrochoerus hydrochaeris) is a semi-aquatic rodent that lives in South American wetlands that are subject to heavy human use. A spatially explicit model of capybara´s Potential Habitat Suitability (PHS) was developed for the core area of its distribution in the humid subtropical region of Argentina. Predictive variables in this deductive model were related to capybara habitat requirements, and their values were obtained from existing published papers. The PHS model was performed using two data subsets that evaluated both ecological requirements and anthropogenic threats, resulting in two partial indices: Potential Ecological Suitability (PES), and Risk of Human Impact (RHI). The PES assesses vegetation cover and the presence of lentic and lotic freshwater bodies. The RHI estimates habitat fragmentation and accessibility of poachers. Variables for the habitat requirements were spatially expressed through Geographic Information Systems. The model accuracy assessment was performed through field work and achieved 72% of overall accuracy. Results indicate that 13% of the study area had the highest values of PHS index, characterized by the presence of vast wetlands, habitats with low fragmentation and low accessibility for poachers. These results are a useful tool to improve conservation and management programs for protection of capybara habitat. © Facundo Schivo, Patricia Kandus, María Luisa Bolkovic, Priscilla Gail Minotti, Gabriela González Trilla, and Rubén Darío Quintana.


Byrne M.S.,National University of Lujan | Quintana R.D.,Institute Investigacion e Ingenieria Ambiental 3iA | Quintana R.D.,University of Buenos Aires | Quintana R.D.,CONICET | And 5 more authors.
Genetica | Year: 2015

The capybara, Hydrochoerus hydrochaeris, is an herbivorous rodent widely distributed throughout most of South American wetlands that lives closely associated with aquatic environments. In this work, we studied the genetic structure of the capybara throughout part of its geographic range in Argentina using a DNA fragment of the mitochondrial control region. Haplotypes obtained were compared with those available for populations from Paraguay and Venezuela. We found 22 haplotypes in 303 individuals. Hierarchical AMOVAs were performed to evaluate the role of river drainages in shaping the genetic structure of capybara populations at the regional and basin scales. In addition, two landscape genetic models, isolation by distance and isolation by resistance, were used to test whether genetic distance was associated with Euclidean distance (i.e. isolation by distance) or river corridor distance (i.e. isolation by resistance) at the basin scale. At the regional scale, the results of the AMOVA grouping populations by mayor river basins showed significant differences between them. At the basin scale, we also found significant differences between sub-basins in Paraguay, together with a significant correlation between genetic and river corridor distance. For Argentina and Venezuela, results were not significant. These results suggest that in Paraguay, the current genetic structure of capybaras is associated with the lack of dispersion corridors through permanent rivers. In contrast, limited structuring in Argentina and Venezuela is likely the result of periodic flooding facilitating dispersion. © 2015, Springer International Publishing Switzerland.


Courtalon P.,University of Buenos Aires | Bo R.F.,University of Buenos Aires | Spina F.,University of Buenos Aires | Jimenez N.,University of Buenos Aires | And 3 more authors.
Brazilian Journal of Biology | Year: 2015

The objective of this study was to estimate and compare some important reproductive parameters of Myocastor coypus over time (June 2006-May 2008), in wetlands of the Middle Delta of the Paraná River (MD) Entre Ríos province, R. Argentina. Within the original coypu distribution range, the MD is among the areas of highest habitat suitability for the species. Coypus were captured and the following reproductive parameters were estimated on a monthly, seasonal and annual basis: pregnancy rate (PR), litter size (LS), gross productivity (GP) and annual production (AP). Statistical non-parametric tests were used for comparisons. Additionally, the expected birth date of each embryo and fetus was estimated by assigning it to a developmental stage category and considering the gestation period of the species. All the parameters showed high values and PR and LS differed significantly between the dry (2006) and humid years (2007). Two peaks of birth were detected, one in spring and another one in mid-autumn. The implications of these results for ensuring the sustainable management of this rodent are discussed. © 2015 Instituto Internacional de Ecologia. All Right reserved.


Byrne M.S.,National University of Lujan | Quintana R.D.,Institute Investigacion e Ingenieria Ambiental 3iA | Quintana R.D.,CONICET | Bolkovic M.L.,Direccion de Fauna Silvestre | And 4 more authors.
Genetica | Year: 2015

The capybara, Hydrochoerus hydrochaeris, is an herbivorous rodent widely distributed throughout most of South American wetlands that lives closely associated with aquatic environments. In this work, we studied the genetic structure of the capybara throughout part of its geographic range in Argentina using a DNA fragment of the mitochondrial control region. Haplotypes obtained were compared with those available for populations from Paraguay and Venezuela. We found 22 haplotypes in 303 individuals. Hierarchical AMOVAs were performed to evaluate the role of river drainages in shaping the genetic structure of capybara populations at the regional and basin scales. In addition, two landscape genetic models, isolation by distance and isolation by resistance, were used to test whether genetic distance was associated with Euclidean distance (i.e. isolation by distance) or river corridor distance (i.e. isolation by resistance) at the basin scale. At the regional scale, the results of the AMOVA grouping populations by mayor river basins showed significant differences between them. At the basin scale, we also found significant differences between sub-basins in Paraguay, together with a significant correlation between genetic and river corridor distance. For Argentina and Venezuela, results were not significant. These results suggest that in Paraguay, the current genetic structure of capybaras is associated with the lack of dispersion corridors through permanent rivers. In contrast, limited structuring in Argentina and Venezuela is likely the result of periodic flooding facilitating dispersion. © 2015 Springer International Publishing Switzerland

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