Nest Boxes in Pinus Radiata Woodlands in Southern Chile: a Too! to Mitigate Negative Environmental Impacts?

27 Mar Nest Boxes in Pinus Radiata Woodlands in Southern Chile: a Too! to Mitigate Negative Environmental Impacts?

View Original

Abstract

La biodiversidad de los ecosistemas naturales es afectada por el monocultivo silvicola de especies exoticas, siendo la perdida de habitats silvestres una de las principales causas de los problemas de conservacion que afectan a la ornitofauna chilena, mucha de la cual no habita los rodales de Pinus radiata por su homogeneidad espacial y carencia de refugios. Para evaluar la aceptacion (habitabilidad y nidificacion) de casas anideras en rodales de P. radiata del sur de Chile se instalaron 116 nidos artificiales apropiados para aves insectivoras. Los nidales artificiales tuvieron una alta aceptacion en las dos areas de estudio (98,4% en Temuco y 66,6% en Valdivia). Se observo un aumento de la aceptacion a partir de octubre (1992) llegando a practicamente un 100% de ocupacion en febrero ( 1993). El porcentaje de casas operables se mantuvo alto durante todo el estudio. Las casas anideras fueron habitadas casi en su totalidad por Troglodytes aedon (chercan) y solo una por Passer domesticus (gorrion). T. aedon construyo nidos en forma de taza, con base de ramas de U/ex europaeus, P. radiata, Rubus ulmifolius, hojas de Eucaliptus globulus, y, en la parte superior plumas de contorno y filoplumas. Las aciculas de P. radiata fueron el material de construccion preferido. El uso de nidos artificiales para atraer aves resulto exitoso, y si se mejora el habitat para la ornitofauna, es posible atraerlas a los bosques exoticos de P. radiata. Las casas anideras que construimos fueron de bajo costo y, unidas a tecnicas de manejo como perchas-posaderas, senderos y agroforesteria, podrian tener beneficiosas repercusiones en la conservacion de la biodiversidad y el control biologico de plagas forestales, lo que implicaria una mitigacion de los impactos ambientales negativos de las plantaciones monoespecificas y coetaneas de P. radiata.

English Abstract

Biodiversity is affected by forest monoculturing of exotic species, along with wild habita! loss, appear as the principal causes of the conservation problems affecting wild Chilean bird species. Many of these species do not inhabit Pinus radiata dueto its homogeneity and the scarcity of habitable havens. To assess the acceptance (habitableness and nesting) of nest boxes in stands of P. radiata in southern Chile, 116 artificial nests, with Jures designed to attract insectivores, were installed. Bird houses were highly accepted in the two study areas (98.4% in Temuco and 66.6% in Valdivia). An increase in acceptance was noted, starting in October (1992), reaching practically 100% occupation by February ( 1993). The percentage of operable houses was maintained high throughout the study. Troglodyres aedon (house wren) occupied almost all of the houses, with only one house occupied by Passer domesticus (house sparrow). T. aedon constructed cup-shaped nests with a base of branches of U/ex europaeus, P. radiara, Rubus ulmifolius, leaves of Eucaliptus globulus and, in the upper part, animal material such as feathers. The needles of P. radiata were the preferred construction material. The use of bird house to attract birds is successful, and if we improve the habita! for the bird, it is possible to attract them to the exotic forests of P. radiata. The nests we built are of low cost, and, combined with management techniques such as perches, footpaths and agroforestry. could have benefits on the preservation of biodiversity and the biological control of forest plagues, which in turn could imply a mitigation of negative environmental impacts of the monoculture plantations and similar stands of P. radiata.