Sample records for vizcachas lagidium viscacia

  1. Hábitos alimenticios de Lagidium viscacia y Abrocoma cinerea: roedores sintópicos en ambientes altoandinos del norte de Chile Food-habits of Lagidium viscacia and Abrocoma cinerea: syntopic rodents in high Andean environments of northern Chile




    Lagidium viscacia y Abrocoma cinerea son dos especies de roedores herbívoros de distribución geográfica simpátrida en los ambientes altoandinos del Norte Grande de Chile, donde la disponibilidad de alimento es escasa, fluctuante y poco predecible. Dada su sintopía, y por habitar en ambientes áridos altoandinos (Segunda Región de Chile) con escasez de recursos alimenticios, se espera que ambas especies de roedores seleccionen diferencialmente sus recursos, o segregarse en otros ejes de nicho (...

  2. Hábitos alimenticios de Lagidium viscacia y Abrocoma cinerea: roedores sintópicos en ambientes altoandinos del norte de Chile Food-habits of Lagidium viscacia and Abrocoma cinerea: syntopic rodents in high Andean environments of northern Chile

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    Full Text Available Lagidium viscacia y Abrocoma cinerea son dos especies de roedores herbívoros de distribución geográfica simpátrida en los ambientes altoandinos del Norte Grande de Chile, donde la disponibilidad de alimento es escasa, fluctuante y poco predecible. Dada su sintopía, y por habitar en ambientes áridos altoandinos (Segunda Región de Chile con escasez de recursos alimenticios, se espera que ambas especies de roedores seleccionen diferencialmente sus recursos, o segregarse en otros ejes de nicho (e.g., nicho espacial a fin de evitar la presumible competencia explotativa por los recursos alimenticios. En este estudio evaluamos los hábitos alimenticios de estas dos especies durante dos estaciones contrastantes (invierno, 1996 y verano, 1997. Los resultados indicaron que: (1 L. viscacia consumió 10 ítemes alimenticios en invierno y siete en verano de las 12 únicas especies de plantas presentes en su ambiente. El ítem alimenticio mayormente consumido fue Stipa bomanii, con un 20,9 % (invierno 1996 y un 30,1 % (verano 1997. Otros ítemes alimenticios importantes, pero sólo consumidos en invierno, fueron Nicotiana longibracteata (12,1 % y Parastrephia quadrangularis (9,4 %; mientras que en verano consumió: Festuca ortophylla (19,9 %. En cambio, A. cinerea consumió en invierno Baccharis tola (73,2 %, Lupinus oreophilus (11,9 %, Adesmia horrida (3,6 % y P. quadrangularis (0,4 %, mientras que en verano consumió B. tola (33,7 %, A. horrida (22,5 %, L. oreophilus (24,0 %, P. quadrangularis (2,3 % y Ephedra rupestris (2,9 %. (2 Lagidium viscacia presentó mayor amplitud de nicho trófico que A. cinerea (invierno: H' = 0,67 versus 0,25; verano: H' = 0,53 versus 0,56. (3 En invierno, L. viscacia mostró alta selección por N. longibracteata (Ei = 0,96 y Calceolaria stellarifolia (Ei = 0,80 y, en menor grado, por P. quadrangularis (Ei = 0,62 y S. bomanii (Ei = 0,26, mientras que en verano seleccionó a las gramíneas F. orthophylla (Ei = 0,52 y S

  3. Micromamiferos andinos holocenicos del sitio arqueologico Inca Cueva 5, Ju Juy, Argentina: tafonomia, zoogeografia y reconstruccion paleoambiental

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    Ortiz, P. E.


    Full Text Available A micromammal archaeological sequence (2120 f 120 to 780 f 100 years BP from Inca Cueva 5 site (23" 05' S - 65" 27' W; 3700 m.a.s.l., Jujuy Province, Argentina was studied. The following mammalian taxa were recorded: Order Didelphimorphia, Family Didelphidae, Thylamys cf. T. pallidior; Order Rodentia, Family Muridae, Akodon cf. A. albiventer, Andinomys edax, Auliscomys sublimis, Calomys lepidus, Neotomys ebriosus, Phyllotis sp.; Family Caviidae, Cavia cf. C. tschudii, Galea musteloides; Family Abrocomidae, Abrocoma cinerea; Family Chinchillidae, Lagidium viscacia; Family Octodontidae, Octodontomys gliroides. The taphonomy indicates that the sequence is an owl pellet accumulation inside the cave. The general landscape corresponds to the oriental border of the Puna steppe, with scattered shrub and low brush vegetation. Near the site there are small tree groups of Polylepis australis as well as small streams covered with grass and ciperaceous vegetation known as «vegas». Al1 the recorded taxa at Inca Cueva 5 exist today in Puna and Prepuna environments from Jujuy and Salta Provinces and southem Bolivia, excepting Cavia cf. C. tschudii. The modem records of this species in northem Argentina and southern Bolivia come from localities with high montane bunchgrass prairies and forests of the humid Yungas phytogeographical region. The presence of this species in the sequence suggests wetter climatic conditions on this region when the archaeological site was originated. Later drier conditions, caused probably by anthropic influence in the last 500 years, produced the retraction of Cavia tschudii to the moist eastern side of the Andes and its disappeareance of the Puna areas.El sitio arqueológico Inca Cueva 5 se encuentra en la provincia de Jujuy, Argentina, en el borde oriental de la región de la Puna (23" 05' S - 65" 27' W; 3700 m s n m y está fechado entre 2120 f 120 y 780 f 100 años radiocarbónicos AP. El estudio de una pequeña muestra de

  4. Native herbivore exerts contrasting effects on fire regime and vegetation structure (United States)

    Jose L. Hierro; Kenneth L. Clark; Lyn C. Branch; Diego. Villarreal


    Although native herbivores can alter fire regimes by consuming herbaceous vegetation that serves as fine fuel and, less commonly, accumulating fuel as nest material and other structures, simultaneous considerations of contrasting effects of herbivores on fire have scarcely been addressed. We proposed that a colonial rodent, vizcacha (Lagostomus maximus...

  5. [Further studies on the sinus coronarius cordis, vena cordis media and arcus aortae as well as on the ductus (lig.) Botalli in various mammalian hearts]. (United States)

    Meinertz, T


    This study supplements earlier works on the topography of the mammalian heart. The material comprises the hearts of 25 species, 12 of which have not been examined previously. The general morphology of the hearts is briefly dealt with. V. cava cranialis sinistra is preserved in Phascolomys and Macropus. It is presumably present in all Ruminantia, where it has been reduced to the sinus coronarius cordis in Perissodactyla. A particular emphasis is laid on the fact that the paired A. carotides and Aa. subclaviae originate from a single common stem, truncus brachio-cephalicus, in Rangifer, Ovibos, Cervus axis, Bos banteng, Okapi, the Perissodactyla, and in Dicerorhinus sumatrensis and Viscacia. A common origin of the carotids and the A. subclavia dextra is frequently found in most other groups. The fusion seems occur through wandering of the vessels towards the right - i.e. towards A. subclavia dextra. Separate origins of the 4 beffore-mentioned stems occur rarely and only incompletely. Sinus coronarius is of a typical shape. Most probable V. anonyma is always present.

  6. Rodent middens, a new method for Quaternary research in arid zones of South America (United States)

    Betancourt, J.L.; Saavedra, B.


    In arid and semi-arid regions of South America, historical evidence for climate and vegetation change is scarce despite its importance for determining reference conditions and rates of natural variability in areas susceptible to modern desertification. Normal lines of evidence, such as pollen stratigraphies from lakes, are either rare or unobtainable in deserts; studies of late Quaternary vegetation history are few and generally inconclusive. This gap in knowledge may be corrected with discovery and development of fossil rodent middens in rocky environments throughout arid South America. These middens, mostly the work of Lagidium, Phyllotis, Abrocoma and Octodontomys, are rich in readily identifiable plant macrofossils, cuticles and pollen, as well as vertebrate and insect remains. In the North American deserts, more than 2,500 woodrat (Neotoma) middens analyzed since 1960 have yielded a detailed history of environmental change during the past 40,000 years. Preliminary work in the pre-puna, Monte and Patagonian Deserts of western Argentina, the Atacama Desert of northern Chile/southern Peru, the Mediterranean matorral of central Chile, and the Puna of the Andean altiplano suggest a similar potential for rodent middens in South America. Here we borrow from the North American experience to synthesize methodologies and approaches, summarize preliminary work, and explore the potential of rodent midden research in South America.

  7. Hosts, distribution and genetic divergence (16S rDNA) of Amblyomma dubitatum (Acari: Ixodidae). (United States)

    Nava, Santiago; Venzal, José M; Labruna, Marcelo B; Mastropaolo, Mariano; González, Enrique M; Mangold, Atilio J; Guglielmone, Alberto A


    We supply information about hosts and distribution of Amblyomma dubitatum. In addition, we carry out an analysis of genetic divergence among specimens of A. dubitatum from different localities and with respect to other Neotropical Amblyomma species, using sequences of 16S rDNA gene. Although specimens of A. dubitatum were collected on several mammal species as cattle horse, Tapirus terrestris, Mazama gouazoubira, Tayassu pecari, Sus scrofa, Cerdocyon thous, Myocastor coypus, Allouata caraya, Glossophaga soricina and man, most records of immature and adult stages of A. dubitatum were made on Hydrochoerus hydrochaeris, making this rodent the principal host for all parasitic stages of this ticks. Cricetidae rodents (Lundomys molitor, Scapteromys tumidus), opossums (Didelphis albiventris) and vizcacha (Lagostomus maximus) also were recorded as hosts for immature stages. All findings of A. dubitatum correspond to localities of Argentina, Brazil, Paraguay and Uruguay, and they were concentrated in the Biogeographical provinces of Pampa, Chaco, Cerrado, Brazilian Atlantic Forest, Parana Forest and Araucaria angustifolia Forest. The distribution of A. dubitatum is narrower than that of its principal host, therefore environmental variables rather than hosts determine the distributional ranges of this tick. The intraspecific genetic divergence among 16S rDNA sequences of A. dubitatum ticks collected in different localities from Argentina, Brazil and Uruguay was in all cases lower than 0.8%, whereas the differences with the remaining Amblyomma species included in the analysis were always bigger than 6.8%. Thus, the taxonomic status of A. dubitatum along its distribution appears to be certain at the specific level.

  8. Paleomadrigueras de roedores, un nuevo método para el estudio del Cuaternario en zonas áridas de Sudamérica Rodent middens, a new method for Quaternary research in arid zones of South America

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    Julio L. Betancourt


    Full Text Available Las zonas áridas y semiáridas de Sudamérica carecen de registros históricos exhaustivos de vegetación y clima, a pesar de la utilidad que ellos representan para el establecimiento de condiciones basales y tasas naturales de variabilidad en procesos abióticos y bióticos. Fuentes comúnmente utilizadas en el estudio de paleovegetación como el polen, son escasas en zonas áridas y semiáridas en Sudamérica, lo que se refleja en el limitado número de estudios vegetacionales durante el Cuaternario Tardío. El vacío existente en el conocimiento de la historia vegetacional de esta zona podría ser remediado gracias al descubrimiento y análisis de paleomadrigueras de roedores en ambientes rocosos. Estos depósitos, producidos por roedores de los géneros Lagidium, Phyllotis, Abrocoma y Octodontomys y posiblemente otros, son ricos en restos vegetales como ramas, hojas, polen o cutículas; y restos animales como fecas, huesos o insectos. Las paleomadrigueras de roedores han sido extensamente utilizadas en el estudio de zonas áridas en Norteamérica, donde más de 2.500 registros producidos por roedores del género Neotoma han sido analizadas desde 1960, permitiendo reconstruir una detallada historia de cambios vegetacionales y climáticos de los últimos 40.000 años en el suroeste de Norteamérica. Investigaciones recientes han revelado la presencia de paleomadrigueras en la pre-puna, los desiertos del Monte y Patagonia del oeste argentino, el desierto de Atacama al norte de Chile y sur del Perú, el matorral Mediterráneo de Chile central, y la Puna del Altiplano Andino. Estos hallazgos fortalecen el gran potencial que dichos depósitos tienen para reconstruir la vegetación y el clima en Sudamérica. Con el fin de aportar elementos para la detección, uso y análisis de paleomadrigueras de roedores, entregamos una síntesis de los depósitos registrados hasta la fecha en Sudamérica, así como una descripción de sus probables agentes

  9. "Clouds" above Paranal. (United States)


    ESO, the European Southern Observatory, in reply to questions raised by the media would like to clarify its position with regard to recent events which concern the land on which the Paranal mountain is situated. THE DECISION TO BUILD THE VLT AT PARANAL In December 1987, the Council [1] of the European Southern Observatory decided to build the largest optical telescope in the world, the 16-metre equivalent Very Large Telescope (VLT) [2], before the end of the century and at a total cost that was expected to approach 500 million DEM. Already several years before that, ESO had started a search for the best possible site for this new giant telescope. At the time of Council's decision, intensive investigations at various sites in the Chilean Atacama desert had effectively narrowed down the choice to two possibilities, the Vizcachas mountain near La Silla, and the Paranal mountain, located approx. 130 km south of Antofagasta, the capital of the Chilean Region II. The meteorological data measured by the ESO teams favoured Paranal, especially in terms of number of clear nights and amount of turbulence in the atmosphere. However, while Vizcachas is situated on land that had earlier been acquired by ESO, this was not the case for the Paranal mountain. ESO was therefore very pleased to learn in 1988 that the Chilean government had decided to donate an area of 725 sq. km around Paranal to this Organisation, on the condition that it would be decided within the next five years to construct the VLT at this site. The size of this land is dictated by the need to avoid any activities (e.g., mining) which may adversely influence the exceedingly sensitive astronomical observations with the VLT. The offer was gratefully accepted by the ESO Council and in November 1988 ESO became owner of the land. After further detailed considerations of the scientific and technical implications, the ESO Council during its December 1990 meeting decided to construct the VLT on Paranal [3], thus

  10. The Paranal Metamorphosis (United States)


    Some years ago, the Paranal mountain was still a remote and inhospitable site, some 12 km from the Pacific Coast in the dry Atacama desert in northern Chile. Few aircraft passengers flying along that coast would notice anything particular about this peak, except perhaps that it was one of the tallest in the steep coastal mountain range. Already in the early 1960's, pioneer astronomers crossed this desolate region in search of suitable sites for future observatories. One of them, Jürgen Stock , did notice the Paranal peak as a possible candidate. However, without any water in this extremely dry area, how could any people, even hardy scientists, ever live up there? He then went on to discover La Silla, where ESO decided to build its first observatory in 1964. ESO presence at Paranal from 1983 In the beginning of the 1980's, when the main construction phase at La Silla was over, ESO launched a thorough search for the best possible site for the next-generation telescope, already then known as the "Very Large Telescope", or VLT. During this campaign, the Paranal mountain was visited by a small search troupe from this organisation, including the ESO Director General (1975 - 1987), Lo Woltjer . The first test measurements indicated a great potential for astronomical observations, both in term of clear nights and low humidity, the latter being particularly important for infrared observations. From 1983, ESO maintained a small site testing station at the top of Paranal. The meteorological conditions were registered around the clock and the atmospheric transparency and stability were recorded each night. At that time, the mountain Vizcachas, a site near ESO's first observatory, La Silla, and some 600 km further south, was also considered a possible site for the VLT. The data from the two sites were therefore carefully compared over a period of several years. Paranal becomes the site for the VLT Following the decision in December 1987 by the ESO Council to embark upon the

  11. E-ELT Site Chosen - World's Biggest Eye on the Sky to be Located on Armazones, Chile (United States)


    parameters had to be taken into account as well, such as the costs of construction and operations, and the operational and scientific synergy with other major facilities (VLT/VLTI, VISTA, VST, ALMA and SKA etc). In March 2010, the ESO Council was provided with a preliminary report with the main conclusions from the E-ELT Site Selection Advisory Committee [1]. These conclusions confirmed that all the sites examined in the final shortlist (Armazones, Ventarrones, Tolonchar and Vizcachas in Chile, and La Palma in Spain) have very good conditions for astronomical observing, each one with its particular strengths. The technical report concluded that Cerro Armazones, near Paranal, stands out as the clearly preferred site, because it has the best balance of sky quality for all the factors considered and can be operated in an integrated fashion with ESO's Paranal Observatory. Cerro Armazones and Paranal share the same ideal conditions for astronomical observations. In particular, over 320 nights are clear per year. Taking into account the very clear recommendation of the Site Selection Advisory Committee and all other relevant aspects, especially the scientific quality of the site, Council has now endorsed the choice of Cerro Armazones as the E-ELT baseline site [2]. "Adding the transformational scientific capabilities of the E-ELT to the already tremendously powerful integrated VLT observatory guarantees the long-term future of Paranal as the most advanced optical/infrared observatory in the world and further strengthens ESO's position as the world-leading organisation for ground-based astronomy," says de Zeeuw. In anticipation of the choice of Cerro Armazones as the future site of the E-ELT and to facilitate and support the project, the Chilean Government has agreed to donate to ESO a substantial tract of land contiguous to ESO's Paranal property and containing Armazones in order to ensure the continued protection of the site against all adverse influences, in particular light