Entity

Time filter

Source Type

San Clemente del Tuyú, Argentina

Masello J.F.,Max Planck Institute for Ornithology (Radolfzell) | Quillfeldt P.,Max Planck Institute for Ornithology (Radolfzell) | Munimanda G.K.,University of Veterinary Medicine Vienna | Klauke N.,Albert Ludwigs University of Freiburg | And 5 more authors.
Frontiers in Zoology | Year: 2011

Background: While the gene flow in some organisms is strongly affected by physical barriers and geographical distance, other highly mobile species are able to overcome such constraints. In southern South America, the Andes (here up to 6,900 m) may constitute a formidable barrier to dispersal. In addition, this region was affected by cycles of intercalating arid/moist periods during the Upper/Late Pleistocene and Holocene. These factors may have been crucial in driving the phylogeographic structure of the vertebrate fauna of the region. Here we test these hypotheses in the burrowing parrot Cyanoliseus patagonus (Aves, Psittaciformes) across its wide distributional range in Chile and Argentina.Results: Our data show a Chilean origin for this species, with a single migration event across the Andes during the Upper/Late Pleistocene, which gave rise to all extant Argentinean mitochondrial lineages. Analyses suggest a complex population structure for burrowing parrots in Argentina, which includes a hybrid zone that has remained stable for several thousand years. Within this zone, introgression by expanding haplotypes has resulted in the evolution of an intermediate phenotype. Multivariate regressions show that present day climatic variables have a strong influence on the distribution of genetic heterogeneity, accounting for almost half of the variation in the data.Conclusions: Here we show how huge barriers like the Andes and the regional environmental conditions imposed constraints on the ability of a parrot species to colonise new habitats, affecting the way in which populations diverged and thus, genetic structure. When contact between divergent populations was re-established, a stable hybrid zone was formed, functioning as a channel for genetic exchange between populations. © 2011 Masello et al; licensee BioMed Central Ltd. Source


Llanos F.A.,Guardafaunas Honorarios de Rio Negro | Failla M.,Proyecto Patagonia Noreste | Garcia G.J.,Guardafaunas Honorarios de Rio Negro | Giovine P.M.,Direccion de Fauna Silvestre de Rio Negro | And 5 more authors.
Check List | Year: 2011

The main ecosystem in northern Patagonia, Argentina, is the Monte, a semi-desert scrubland home to a high biodiversity. Monte is the most endangered ecosystem of southern South America, with an annual rate of clearance of the native vegetation estimated at 3.7%. Here we report the results of bird surveys carried out in the province of Río Negro, northern Patagonia. We surveyed four localities mostly dominated by the Monte ecosystem, between 1986 and 2010. Three localities are Important Bird Areas (IBAs): El Cóndor, San Antonio Oeste and Meseta de Somuncurá. The fourth locality is the Paso Córdoba nature reserve. We recorded a total of 263 bird species. The highest species richness was observed at San Antonio Oeste, followed by El Cóndor. Information regarding the period of occurrence and habitats are provided for all species and localities. Additionally, we indicated the cases in which breeding behavior was observed. This information is urgently needed for the evaluation of the consequences of habitat destruction and deterioration as well as for the success of intended remediation measures. © 2011 Check List and Authors. Source


Failla M.,Fundacion Cethus | Seijas V.A.,Proyecto Patagonia Noreste | Esposito R.,Proyecto Patagonia Noreste | Iniguez M.A.,Fundacion Cethus
Marine Biodiversity Records | Year: 2012

Studies on the biology of the franciscana dolphin (Pontoporia blainvillei) in the Río Negro Estuary (RNE), Patagonia, Argentina, were carried out from 2002 to 2011. Information about group size, group dispersion and behaviour was collected from the coast and by boat, using scanning and focal animal/group sampling methodology. Group size varied from 1 to 5 dolphins ( X = 1.69; standard deviation (SD) = 0.74; N = 121), 2 being the most frequent value (46.28%; N = 56). Group dispersion varied from 0 to 10 dolphin length (DL) ( X = 1.4; SD = 0.75; N = 51), 0 DL (54.9%; N = 28) being the most frequent value. Behaviour of travelling, feeding, milling and resting were recorded, with a higher frequency of animals travelling (36.58%; N = 45). Calves were observed in spring and summer (N = 10). 13 stranded individuals were reported and 3 of them were collected from gillnets. Data presented herein indicate year-round presence of franciscana as well as the RNE being the southernmost breeding and feeding site reported to date. The establishment of the proposed natural reserve by the Governments of Río Negro and Buenos Aires provinces and continued long-term studies are urgently recommended. © 2012 Marine Biological Association of the United Kingdom. Source

Discover hidden collaborations