Castor canadensis specimens were imported from Canada and released in the wilderness on the Argentinean part of Tierra del Fuego (TDF) in the year 1946. First studies on the development of the beaver population and subsequent environmental changes were conducted four decades later and indicated a strong expansion of these animals, with negative effects on the forest, especially the dominant Nothofagus sp. Between 1999 and 2001, we investigated the density of the beaver population in the Chilean part of TDF and the southern adjacent island Navarino (NAV). Data were mapped into a geographical information system. The mean colony density was 1.03 (range: 0.15-1.91) and 1.1 per km watercourse for 75% of the area of TDF (mainly south and central region) and the total NAV island, respectively. The average number of individuals estimated per colony was five. Based on these findings, the number of beavers in the Chilean part of TDF and on NAV was estimated at 61,300 individuals. The population is increasing and expanding in the Northern region, with a linear rate of 2.6-6.3 km/year.
Documentamos la dieta del jabalí silvestre en el centro-sur de Chile basados en el examen de 20 estómagos colectados en los faldeos de volcán Mocho-Choshuenco (39°54' S, 72°02' O) y en el Parque Nacional Vicente Pérez Rosales (41°03' S, 71°54' O). La dieta está representada por animales, vegetales y hongos. Entre los vegetales y hongos son consumidas tanto las partes epígeas como hipógeas, lo mismo que frutos y semillas. Hongos y rizomas de Gunnera tinctoria constituyen ítemes vegetales cuantitativamente importantes en la alimentación. El jabalí forrajea en general en ambiente boscoso, pero las especies vegetales más frecuentes en la dieta se encuentran en espacios abiertos o fuera del bosque. El ambiente dominado por Chusquea spp. constituye un importante sitio de alimentación. Los roedores de la familia Muridae dominan entre los animales determinados en la dieta del jabalí. Esta situación, sin embargo, parece obedecer a la ocurrencia de una ratada producto de la semillación masiva de Chusquea spp. durante la época de muestreo. Las aves de la familia Rhinocryptidae e invertebrados (en especial larvas del coleóptero Chiasognathus grantii) constituyen parte frecuente de los ítemes animales de la dieta del jabalí. En comparación a estudios en otras partes del mundo, el jabalí silvestre en Chile consume hongos en porcentaje de ocurrencia similar (65 %) a su dieta en Estados Unidos de América pero bastante más alta que su dieta en Europa (5-32 %). En relación al volumen del componente animal, el jabalí en Chile consume más (16,1 %) que en Estados Unidos de América (6 %) y que en Europa (7-13 %).
We evaluated the possibility of deriving primary cell cultures from tissue biopsies taken in field conditions from six threaten endemic Chilean species of free-ranging mammals. Biopsies were taken either by ear punching or darts fired to animals and hold in hypothermic conditions (4 degrees C) in defined salt solution for time periods ranging from 0 to 7 d before biopsy samples reached the cell culture laboratory. Previously, holding times were evaluated in experimental cows in controlled conditions. Two enzymatic treatments, collagenase alone or collagenase followed by tripsin, were used to disaggregate tissues for cell culture. We found that ear notches and dart-derived biopsies can be storaged at 4 degrees C for 1 wk and still yield primary cultures. For dart-derived biopsies, there was an invert correlation between length of cold storage and cellular viability in culture. Healthy fibroblast cell lines were obtained in 92% of the biopsies taken despite the origin (punch or biopsy). We are not aware of similar study for free-ranging animals, especially for the use of darting system to biopsy wild terrestrial mammals, we believe that our results could help for a more widespread implementation of these procedures in the practice of ex situ conservation.
RESUMENSe estudió la dieta del puma (Puma concolor) en los años 1988 y 2004 en los faldeos de los volcanes Mocho y Choshuenco, pluviselva valdiviana, sur de Chile, a través de la identifi cación de ítemes-presas en sus heces y la búsqueda en terreno de carcasas de jabalí europeo (Sus scrofa). Se registra por primera vez al jabalí europeo entre los ítemes-presas del puma en Chile. El puma depredó predominantemente sobre juveniles y los porcentajes de consumo variaron entre un 17-37 % dependiendo del método empleado para analizar el contenido de presas presentes en sus heces.Palabras clave: depredadores nativos, invasiones biológicas, presas exóticas.
ABSTRACTThe diet of the American puma (Puma concolor) was studied in 1988 and 2004 in the foothills of the volcanoes Mocho and Choshuenco, Valdivian rainforest, southern Chile, through the identifi cation of prey-items in their feces and fi eld surveys of European wild boar (Sus scrofa) carcasses. We reported for the fi rst time the invader European wild boar as a puma's prey in Chile. The puma preys mainly on juveniles and its percentage of consumed prey ranges between 17 and 37 % according to the method employed to assess the analyses of their feces prey contents.
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