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| Registros recuperados: 845 | |
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| SARNO,RONALD J.; FRANKLIN,WILLIAM L.; PREXL,WALTER S.. |
| Data were collected on general activity patterns and population characteristics of free-ranging Andean Condors Vultur gryphus in Torres del Paine National Park, Chile from July 1992 to June 1994 during 3,680 h of observation. Seasonal differences were evident in relative abundance and activity patterns. The mean number of condors sighted/ observation significantly higher in fall-winter than in spring-summer. There was a significant decrease from spring-summer to fall-winter in the percentage of observations during which we sighted solitary condors and a significant increase in the number of groups of condors. In addition, mean monthly maximum group size was significantly larger in fall-winter than spring-summer. The sex ratio (males:females ) of juveniles... |
| Tipo: Journal article |
Palavras-chave: Andean Condor; Activity; Patagonia; Sex ratio. |
| Ano: 2000 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2000000100001 |
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| YOUNG,JULIE K.; FRANKLIN,WILLIAM L.. |
| We observed behavioral patterns of territorial male guanacos (Lama guanicoe) in Torres del Paine National Park, Chile. Both solo territorial males and family-group territorial males were observed to compare the activity time budgets of males (n = 23) in different social groups and habitats. We found no difference in the activity time budgets of males based on social group type, total number of females or all guanacos present, or age of territorial males. Males, in all categories, spent most of their time foraging (65 % of overall time budget). There was a significant difference in time spent in aggressive and in miscellaneous (defecation, alertness to observer, scratching) activities based on habitat type; most aggressive encounters and miscellaneous... |
| Tipo: Journal article |
Palavras-chave: Guanaco; Activity budget; Territorial behavior; Resource-defense. |
| Ano: 2004 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2004000400005 |
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| Muñoz-Sáez,Andrés; Perez-Quezada,Jorge F.; Estades,Cristián F.. |
| Abstract Background: Understanding the role of agroecosystems as habitat for wildlife is crucial for long-term conservation planning, as different crop stratification and landscape elements can influence bird communities, which are also affected by seasonality. The goal of our study was to determine how agricultural landscapes varying in land cover characteristics affect bird richness and abundance. Bird surveys were conducted at 110 locations within agricultural landscapes in central Chile. The surveyed areas were characterized by land cover at two scales (50 and 500 m radii) through direct observation and photo-interpretation, during winter and spring seasons. Generalized Linear Mixed Models were used to evaluate the effects of different agricultural... |
| Tipo: Journal article |
Palavras-chave: Hedgerows; Season; Orchards; Low crops; Avian communities. |
| Ano: 2017 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2017000100202 |
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| GALLARDO,MILTON H. |
| Este año se conmemoran 100 años del fallecimiento de Alfred Russel Wallace, codescubridor de la teoría de la evolución por selección natural. Nació en Gales, y a los 13 años dejó la escuela por los escasos recursos de su familia. Era un libre pensador, de mente abierta e inquisitiva. Su interés y conocimiento por la evolución se desarrolló en sus viajes al Amazonas y al archipiélago Malayo, donde recolectaba especies que vendía a los museos de Inglaterra para subsistir. Su trabajo en mariposas es un ejemplo paradigmático de darwinismo que incluye el rol del aislamiento reproductivo. Sus estudios en el suroeste de Asia lo llevaron a descubrir la Línea de Wallace. Otro gran éxito fue su trabajo de 1855, "On the law which regulated the introduction of new... |
| Tipo: Journal article |
Palavras-chave: Darwinismo; Evolución; Selección natural; Wallace. |
| Ano: 2013 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2013000300002 |
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| GALLARDO,M.H; GONZÁLEZ,C; MENA,C; LOMOVASKY,B; MORRICONI,E; CLASING,E. |
| The correspondence between allozymic variation and specific differentiation was studied in four populations corresponding to the three nominal, allopatric species of clam genus Eurhomalea (E. rufa, E. lenticularis, E. exalbida) described for southern South America. Allozyme variation scored in 12 loci was high as indicated by heterozygosity levels (15.8-20.7 %) and by the presence of only three monomorphic loci (Hk-2, Icd-2, and Xdh-1). These high estimates of allelic variability were influenced by the low levels of interspecific genetic similarity (I = 0.64) and for the high conspecific values of genetic identity observed. The high estimates of substructuring found at the species level (F ST = 0.39) contrasted with the low differentiation (F ST = 0.027)... |
| Tipo: Journal article |
Palavras-chave: Allozymic variation; Genetic structure; Taxonomic status. |
| Ano: 2003 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2003000300013 |
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| TOGNELLI,MARCELO F; ROIG-JUÑENT,SERGIO A; MARVALDI,ADRIANA E; FLORES,GUSTAVO E; LOBO,JORGE M. |
| Various studies have shown that model performance may vary depending on the species being modelled, the study área, or the number of sampled localities, and suggest that it is necessary to assess which model is better for a particular situation. Thus, in this study we evalúate the performance of different techniques for modelling the distribution of Patagonian insects. We applied eight of the most widely used modelling methods (artificial neural networks, BIOCLIM, classification and regression trees, DOMAIN, generalized additive models, GARP, generalized linear models, and Maxent) to the distribution of ten Patagonian insect species. We compared model performance with five accuracy measures. To overeóme the problem of not having reliable absence data with... |
| Tipo: Journal article |
Palavras-chave: Expert opinión; Model evaluation; Patagonia; Pseudo-absence data; Species distribution modelling. |
| Ano: 2009 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2009000300003 |
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| REZENDE,ENRICO L.; GOMES,FERNANDO R.; GHALAMBOR,CAMERON K.; RUSSELL,GREGORY A.; CHAPPELLl,MARK A.. |
| How complex physiological systems evolve is one of the major questions in evolutionary physiology. For example, how traits interact at the physiological and genetic level, what are the roles of development and plasticity in Darwinian evolution, and eventually how physiological traits will evolve, remains poorly understood. In this article we summarize the current frame of work evolutionary physiologists are employing to study the evolution of physiological adaptations, as well as the role of developmental and reversible phenotypic plasticity in this context. We also highlight representative examples of how the integration of evolutionary and developmental physiology, concomitantly with the mechanistic understanding of physiological systems, can provide a... |
| Tipo: Journal article |
Palavras-chave: Adaptation; Evolutionary processes; Natural selection; Life-history; Oxygen availability; Phenotypic plasticity. |
| Ano: 2005 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2005000200016 |
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| HALPIN,PATRICIA M.; STRUB,P. TED; PETERSON,WILLIAM T.; BAUMGARTNER,TIM R.. |
| Physical processes, biotic processes and human activities all act to shape marine ecosystems. Future management of these valuable ecosystems requires an integrative approach that takes into account complicated organismal interactions, oceanographic processes that span large scales of time and space, and how anthropogenic effects interact with the natural environment. The temperate west coasts of North and South America represent a unique opportunity for comparison, as many of the same oceanographic processes, particularly upwelling, occur off both coasts. Additionally, a number of marine ecosystems in both areas have surprising parallels. Here we present an overview of the oceanographic processes that dominate the coastlines, and give examples of... |
| Tipo: Journal article |
Palavras-chave: Eastern boundary currents; Anthropogenic effects; Marine community ecology; Fisheries; Interdecadal variability. |
| Ano: 2004 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2004000300002 |
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| PONCE,MÓNICA; MEHLTRETER,KLAUS; DE LA SOTA,ELÍAS R.. |
| Las Pteridófitas de Chile continental están representadas por 116 especies nativas (43 géneros, 20 familias), y en Argentina continental por 346 (86 géneros, 27 familias). Ambos países comparten 89 especies (41 géneros, 20 familias). La menor diversidad pteridofítica y el mayor endemismo en Chile (11,2 %) que en Argentina (3,5 %) están relacionados probablemente con extinciones históricas y su actual aislamiento geoclimático. Sin embargo, se destaca que el endemismo en los helechos es cinco a seis veces menor que en Angiospermas. Los géneros con más especies en Argentina son Thelypteris (34), Asplenium (32), Cheilanthes (21), Blechnum (19) e Hymenophyllum (16). Los dos últimos también son los más diversificados en Chile (Hymenophyllum, 18 y Blechnum, 10).... |
| Tipo: Journal article |
Palavras-chave: Pteridófitas; Biogeografía; Diversidad; Argentina. |
| Ano: 2002 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2002000400006 |
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| FIGUEROA,RICARDO; PALMA,ALEJANDRO; RUIZ,VICTOR; NIELL,XAVIER. |
| El uso de macroinvertebrados bentónicos como indicadores biológicos es de larga tradición en los países desarrollados y son incorporados en todas las evaluaciones de calidad ecológica de sistemas fluviales. En América Latina estos estudios son menos frecuentes y las normativas para la protección de los recursos acuáticos recién comienzan a elaborarse, como es el caso de Chile, dejando abierta la posibilidad al uso de criterios biológicos. El presente estudio realiza una adaptación de índices bióticos (IBE, BMWP, IBF y SIGNAL) los que son aplicados y comparados en una cuenca mediterránea de Chile, el río Chillan. Los resultados muestran el mismo patrón de comportamiento para todos los índices, definiendo áreas en buen estado y otras fuertemente impactadas... |
| Tipo: Journal article |
Palavras-chave: Índices bióticos; Macroinvertebrados bentónicos; Chile mediterráneo. |
| Ano: 2007 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2007000200008 |
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| COPETE,MIGUEL A; HERRANZ,JOSÉ M; FERRANDIS,PABLO. |
| Se evalúa la variación del parámetro área foliar y un índice de morfología foliar (índice de forma) en plantas de 1, 2 y 3 meses de edad pertenecientes a cuatro taxones del género Coincya (Cruciferae) relacionados filogenéticamente. Para todas las edades el área foliar alcanzó sus valores más altos en las formas que tienen frutos con rostros gruesos (C. rupestris), aumentando progresivamente según el siguiente orden: C. monensis subsp. orophila, C. longirostra, C. rupestris subsp. leptocarpa y C. rupestris subsp. rupestris. Se plantea que el aumento del área foliar en los taxones cuyos frutos poseen rostros gruesos puede constituir otra ventaja adaptativa adicional a las ya mencionadas para estos en trabajos anteriores a la vez que refuerza el esquema... |
| Tipo: Journal article |
Palavras-chave: Área foliar; Morfología foliar; Rostro engrosado; Ventaja adaptativa. |
| Ano: 2010 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2010000300004 |
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| Registros recuperados: 845 | |
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