140 research outputs found
SITUACIÓN POBLACIONAL DEL PELÍCANO PERUANO (PELECANUS THAGUS) EN CHILE: PROSPECCIÓN INICIAL
Resumen ∙ El Pelícano Peruano (Pelecanus thagus) es un ave marina endémica del Sistema de la Corriente de Humboldt, en América del Sur, habitando la costa Pacífica desde el sur de Ecuador, Perú y hasta el sur de Chile. En Perú está clasificado como una especie En Peligro de Extinción, mientras que globalmente es considerado Casi Amenazado. Si bien más del 50% del hábitat utilizado por el Pelícano Peruano se encuentra en la costa de Chile, en este país se desconoce su estado poblacional y de conservación. Por ello, el objetivo del presente trabajo fue diagnosticar la situación poblacional del Pelícano Peruano en Chile, mediante análisis de bases de datos y percepciones de ornitólogos locales. Entre los años 2010 al 2015 la abundancia del Pelícano Peruano en Chile disminuyó significativamente en la zona central de país. Existe una estacionalidad en su presencia con mayores abundancias durante la temporada invernal. La percepción de los ornitólogos locales indicó un aumento poblacional hacia el sur del país. A lo largo del litoral chileno se han descrito 24 sitios de nidificación del Pelícano Peruano, de los cuales el 29,1% se ubican dentro de un área protegida. Finalmente, identificamos futuras preguntas de investigación y sugerimos la necesidad de aplicar un enfoque meta‐poblacional y establecer marcos de colaboración internacional para el estudio y conservación del Pelícano Peruano. Abstract ∙ Population status of the Peruvian Pelican (Pelecanus thagus) in Chile: initial survey The Peruvian Pelican (Pelecanus thagus) is an endemic seabird of the Humboldt Current System in South America, inhabiting the Pacific coast from the south of Ecuador, Peru to the south of Chile. In Peru it is classified as an Endangered species, while globally it is considered Near Threatened. Although more than 50% of the habitat used by the Peruvian Pelican occurs on the coast of Chile, its population trends and conservation status remain unknown in this country. For this reason, the objective of the present work was to diagnose the population situation of the Peruvian Pelican in Chile, through the analysis of databases and perceptions of local ornithologists. Between the years 2010 and 2015 the abundance of Peruvian Pelican in Chile decreased significantly in the central zone of the country. There is seasonality in its presence, with greater abundances during the winter season. The perception of local ornithologists indicated a population increase towards the south of the country. Along the Chilean coast, 24 nesting sites of the Peruvian Pelican have been described, of which 29.1% are located inside of protected areas. Finally, we identify future research questions, suggest the need to apply a meta‐population approach, and establish international collaboration frameworks for the study and conservation of the Peruvian Pelican
TEMPORAL VARIATION IN THE FEEDING ECOLOGY OF THE BLACK-FACED IBIS (THERISTICUS MELANOPIS) IN PASTURES OF SOUTHERN CHILE
Temporal variation in food availability may generate changes in the feeding strategies and trophic preferences of animals. We studied the temporal variation in feeding behavior, diet composition, and prey availability of the Black-faced Ibis (Theristicus melanopis) in pastures of southern Chile between May 1999 and January 2000. Soil core samples showed that hypogeous invertebrates such as, earthworms (Lumbricus spp.), black cutworm larvae (Agrotis spp.), black pasture caterpillars (Dalaca spp.), and southern green chafers (Hylamorpha elegans) were the most abundant prey in the pastures and that their populations experienced pronounced seasonal variations. Insect larvae were the main prey of the Black-faced Ibis and were consumed in greater proportion than expected by chance. The diet composition (based on feces) and trophic preferences coincided with variations in prey availability. During periods of reduced prey abundance Black-faced Ibises foraged on more different types of prey and their consumption rate diminished. At the same time, the abundance of Black-faced Ibises decreased in the study area. These variations were most evident in late spring and summer, when prey abundance in the pastures was lower than in the other seasons. Our results suggest that the life cycle of the prey is the main causal factor that influences the feeding ecology of the Black-faced Ibis in pastures of southern Chile
Metodi di censimento della Volpe (Vulpes vulpes)
Estimating absolute or relative numbers in red fox populations is not an easy task. Although a range of methods has been described, neither an optimal nor a universally accepted technique has been found. Moreover, none has been tested on populations of known size. We reviewed the efficiency of fourteen indices of fox abundance classified into two groups: (a) methods where individuals are captured and marked, which include ear tagging or similar conspicuous markings, toe clipping, radioactive tagging of faeces, radio-tracking, and statistics from hunting and trapping; (b) methods not requiring capture, which include both direct methods (nocturnal counts, unsystematic observations, and drive censuses), and indirect methods (den counts, transects for track, scat counts, and scent stations). As a rule, statistics are rarely applicable to populations estimates. Methods involving capture are expensive but provide more accurate estimates than the second group of indices, which are not suitable for paired comparisons from one year to another. Management and wildlife specialists should have in mind such restrictions when considering their goals and the required level of accuracy. Finally, we recommend the simultaneous utilization and comparison of several methods (one from each group, as proposed in a double sampling strategy) for optimum evaluations.La valutazione della consistenza di una popolazione di Volpe, mediante censimenti assoluti o relativi, è di difficile soluzione. Tra i diversi metodi di conteggio impiegati, nessuno si è rivelato ottimale e universale. Tuttavia nessuno è stato utilizzato per popolazioni di consistenza nota. Qui esaminiamo la validità di 14 metodi impiegati per il calcolo di indici di abbondanza, ripartendoli in due gruppi: (a) metodi che implicano la cattura e il marcamento degli animali mediante marche auricolari o contrassegni similari, amputazione delle falangi, radioisotopi rilevabili nelle feci, collari radiotelemetrici e metodi che si basano sulle statistiche venatorie e sui trappolaggi; (b) metodi che non richiedono la cattura degli animali e che riguardano sia rilevamenti diretti (conteggio notturno, avvistamenti casuali, censimento in battuta), sia indiretti (conteggio delle tane, conteggio delle impronte e delle feci su percorsi definiti, stazioni odorifere). Raramente l'analisi statistica è applicabile alle stime della consistenza delle popolazioni. I metodi che implicano la cattura degli animali sono molto impegnativi in termini di tempo e costi, ma forniscono stime più accurate rispetto a quelli del secondo gruppo che non sono adatti per la comparazione dei dati da un anno all'altro. Questi limiti vanno attentamente considerati in relazione alle finalità e al grado di precisione che si intende raggiungere. Noi suggeriamo l'impiego simultaneo di più metodi di censimento (almeno uno per ciascun gruppo), per una comparazione incrociata dei dati e per ottenere una stima corretta della consistenza
Scientific productivity of marine science researchers in Latin America
Esta investigación analiza patrones de producción científica, citación y redes de colaboración bajo tres relaciones (investigador/investigador, investigador/centro e investigador/país) de los investigadores más productivos de cuatro centros de investigación marina (CIM) de América Latina durante un período de 20 años (2000-2020) desde una perspectiva bibliométrica. Se utilizó el motor de búsqueda Scopus para los respectivos análisis bibliométricos. En total se identificaron a 57 investigadores que fueron los más productivos entre los cuatro Centros; 5, 7, 14 y 31 para el Centro i~mar, IOUSP, IICYM y CICESE, respectivamente. En dos (i~mar e IICYM) de los cuatro centros, los investigadores (AB) y (OI) registraron el mayor número de publicaciones y fueron también los más citados, sin embargo, este patrón no se cumplió para los investigadores del IOUSP y CICESE. Se encontró que la red de colaboración entre investigadores más productivos está segmentada en ciertos grupos definidos, lo que provoca una falta de cooperación interna entre ellos, especialmente en el Centro i~mar e IOUSP. Además, se evidenció que los investigadores más productivos concentran sus colaboraciones con otros investigadores pertenecientes a universidades, instituciones o centros de su mismo país, y muy escasamente con centros internacionales siendo su cooperación internacional conservadora lo que a su vez demuestra autonomía científica y no requieren en estricto rigor colegas externos para visibilizar sus investigaciones. Esta investigación contribuye con el conocimiento de los centros más productivos y es la base de estudios futuros que sugiere orientar y extender los análisis en la productividad de investigadores con menos publicaciones y citas, así como en el análisis de su red interna de colaboración.This research analyzes patterns of scientific production, citation and collaborative networks under three relationships (researcher/researcher, researcher/center, and researcher/country), of the most productive researchers of four Latin American Marine Research Centers (MICs) over a 20-year period (2000-2020) from a bibliometric perspective. The Scopus search engine was used for the respective bibliometric analyses. In total, 57 most productive researchers were identified among the four centers; 5, 7, 14 and 31 for Centro i~mar, IOUSP, IICYM and CICESE, respectively. In two (i~mar and IICYM) of the four centers, researchers (AB) and (OI) recorded the highest number of publications, and were also the most cited; however, this pattern did not hold true for IOUSP and CICESE researchers. The collaboration network among the most productive researchers is segmented in certain defined groups, which causes a lack of internal cooperation among them, especially in Centro i~mar and IOUSP. In addition, it was evidenced that the most productive researchers concentrate their collaborations with other researchers belonging to Universities, Institutions or Centers of their own country, and very scarcely with international Centers, being their international cooperation conservative which in turn demonstrates scientific autonomy, and does not require external partners to make their research visible. This research contributes with the knowledge of the most productive centers and is the basis for future studies that suggests orienting and extending the analysis of the productivity of researchers with fewer publications and citations, as well as the analysis of their internal collaboration network.Facultad de Humanidades y Ciencias de la Educació
Productividad científica de investigadores en ciencias marinas en América Latina
This research analyzes patterns of scientific production, citation and collaborative networks under three relationships (researcher/researcher, researcher/center, and researcher/country), of the most productive researchers of four Latin American Marine Research Centers (MICs) over a 20-year period (2000-2020) from a bibliometric perspective. The Scopus search engine was used for the respective bibliometric analyses. In total, 57 most productive researchers were identified among the four centers; 5, 7, 14and 31 for Centro i~mar, IOUSP, IICYM and CICESE, respectively. In two (i~mar and IICYM) of the four centers, researchers(AB) and (OI) recorded the highest number of publications, and were also the most cited; however, this pattern did not hold truefor IOUSP and CICESE researchers. e collaboration network among the most productive researchers is segmented in certaindefined groups, which causes a lack of internal cooperation among them, especially in Centro i~mar and IOUSP. In addition, it was evidenced that the most productive researchers concentrate their collaborations with other researchers belonging to Universities, Institutions or Centers of their own country, and very scarcely with international Centers, being their international cooperation conservative which in turn demonstrates scientific autonomy, and does not require external partners to make their research visible. This research contributes with the knowledge of the most productive centers and is the basis for future studies that suggests orienting and extending the analysis of the productivity of researchers with fewer publications and citations, as well as the analysisof their internal collaboration network
Potenciales depredadores de nidos de aves acuáticas de los humedales de Caulín, Chiloé, sur de Chile y evaluación de métodos de detección
Potential predators of ground nesting aquatic birds were identifi ed, through various monitoring techniques, in wetlands of Bahía de Caulín, Chiloé, Chile. As a result, a greater proportion of mammalian predators was found, followed by raptorial birds and the monitoring techniques provided information at different taxonomic levels.Se identifi caron potenciales depredadores de aves acuáticas que nidifi can en el suelo, mediante diversas técnicas de monitoreo, en humedales de la Bahía de Caulín, Chiloé, Chile. Como resultado se encontró una mayor proporción de depredadores mamíferos, seguido de aves rapaces y las técnicas de monitoreo entregaron información a distintos niveles taxonómicos
Ensayo metodológico de cartografía de zonas expuestas a riesgos de caídas de materiales: Las Trancas-Termas de Chillán (VIII Región) - Chile
El problema de los riesgos ligados a los movimientos del suelo en Chile, tiene una importancia particular dada las condiciones geomorfológicas desfavorables que existen en diferentes zonas del territorio nacional, especialmente en aquellas que presentan un re lieve montañoso y por la importancia de la creciente presión urbanística que dichas zonas soportan.Se presenta en este artículo una proposición de metodología cartográfica de riesgos de caídas de materiales, a lo largo de vías de comunicación, con aplicación a la ruta 55 en 11 kms. del tramo Las Trancas-Termas de Chillán, en un ambiente de media montaña, en la Provincia de Ñuble, VIII Región del país. Se trata de un avance en la metodología, pues ésta requiere de mayor profundidad en los elementos que se han considerado y de otros no tomados en cuenta aquí y que dicen relación en forma más específica a los aspectos de protección.Estudios sobre este riesgo y sobre otros relativos a movimientos del suelo, han comenzado recientemente en Chile. Estos, diferentes entre ellos pero todos presentando un interés metodológico, permanecen heterogéneos a nivel nacional y aislados a nivel regional, lo que no permite concebir aún aplicaciones prácticas en distintos niveles de gestión, a lo que se agrega una información d esigual de un territorio a otro, así como de sus especificidades
EVIDENCE OF HIGH CONSUMPTION OF WASTE BY THE ANDEAN CONDOR (VULTUR GRYPHUS) IN AN ANTHROPIZED ENVIRONMENT OF CHILE
Abstract · Anthropogenic food subsidies and waste disposals have become a new food resource for wildlife, including the Andean Condor (Vultur gryphus), a situation that implies benefits and health risks. To increase understanding of Andean Condor feeding habits in the most anthropized area in Chile, we analyzed 280 pellets collected during 2016 from one roost in the Metropolitan Region, central Chile. We identified the main diagnostic elements microscopically and expressed them as percentage of occurrence (percentage of each item in relation to all pellets). We found 12 prey categories (including mammals, birds, and plant material) and 9 waste categories. Condors fed mainly on mammals (99%); livestock was their main feeding source (52%), followed by native (22%) and exotic wild species (19%). Birds were detected less frequently (8%). We found a high occurrence of waste (31%), of which plastic remains were the main item (27%). According to our results, landfills serve as a complementary food source for condors, probably a low-quality but easily accessible, and which exposes them to a variety of health and mortality risks. Despite the fact that Andean Condors can reach distant places in foraging flights to find food resources, a high proportion of the population is attracted to rubbish dumps and landfills. Despite the spatio-temporal limitations of our results, this is the first record that describes and quantifies a high presence of waste as a component of the Andean Condor diet. We recommend a more comprehensive study to assess their feeding habits and habitat preferences in a broader spatio-temporal context, and to determine the possible impact of the use of waste disposals on Andean Condor populations.Resumen · Evidencia de alto consumo de basura por el Cóndor Andino (Vultur gryphus) en un ambiente antropizado de Chile Los subsidios antropogénicos y sitios de disposición de basura se han convertido en una nueva fuente de alimentación para la fauna, incluido el Cóndor Andino (Vultur gryphus), lo que implica beneficios y riesgos. Con el fin de estudiar los hábitos alimenticios del cóndor andino en un área altamente antropizada, analizamos 280 egagrópilas colectadas durante 2016 en un dormidero de la Región Metropolitana, en Chile central. Identificamos microscópicamente los principales elementos diagnósticos y los expresamos como porcentaje de ocurrencia (porcentaje de cada ítem respecto del total de pellet). Encontramos 12 ítems dietarios (incluyendo mamíferos, aves y materia vegetal) y 9 ítems de basura. Los cóndores se alimentaron principalmente de mamíferos (99%); el ganado fue la principal fuente de alimento (52%), seguido por especies silvestres nativas (22%) y exóticas (19%), mientras que las aves estuvieron escasamente representadas (8%). Encontramos una alta ocurrencia de basura (31%), de la cual los restos de plástico fueron el principal ítem (27%). De acuerdo a nuestros resultados, los basurales sirven como una fuente complementaria de alimentación para los cóndores, probablemente de baja calidad, pero de fácil acceso, y que los expone a una variedad de riesgos de mortalidad y para su salud. Aunque el Cóndor Andino puede alcanzar lugares distantes en sus vuelos de forrajeo, una alta proporción de su población es atraída a vertederos y rellenos sanitarios. A pesar de las limitaciones espaciotemporales de nuestros resultados, este es el primer registro que describe y cuantifica la alta presencia de basura como componente de la dieta del Cóndor Andino. Recomendamos ampliar el estudio para evaluar sus hábitos alimentarios y preferencias de hábitat en un contexto espacial y temporal amplio y poder determinar el posible impacto del uso de basurales en poblaciones de Cóndor Andino
Dieta invernal del cormorán imperial Phalacrocorax atriceps (Aves: Suliformes) en Bahía Caulín, Chiloé, sur de Chile
The imperial cormorant (Phalacrocorax atriceps) is one of the most abundant cormorant species in the Chilean channels and fjords. Although its reproductive and non-reproductive distributions have been studied, works on its diet are inexistent. This paper describes the diet and determines the dominance and diversity of the prey consumed during the winter periods of 2011 and 2014 in Caulín Bay, Chiloé, southern Chile. A total of 73 pellets were collected (30 in 2011 and 43 in 2014). Prey were identified and classified into three categories: fishes (53.57%), cephalopods (39.29%) and crustaceans (7.14%). When prey consumption was analyzed according to their distribution in the water column, we observed statistically significant differences in a preference of benthic demersal over pelagic prey
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