Un inventario de las aves en vegetación de arenas blancas de la cuenca del Guainía / Río Negro, Sur del estado Amazonas, Venezuela.

Resumen

Resumen Español Las regiones de arena blanca cubren inmensas áreas en el sureste de Colombia, el sur de Venezuela y el noroeste de Brasil, especialmente a lo largo de las cuencas del alto Río Negro y Guainía. Los ecosistemas de arena blanca son pobres en especies y tienen baja diversidad; sin embargo, albergan una flora distintiva que exhibe importantes endemismos y diferentes formas de vida. De igual manera, las comunidades de aves de la vegetación de arena blanca se caracterizan por la baja riqueza de especies. No obstante, estudios en la Amazonia brasileña y peruana han demostrado que la vegetación de arena blanca alberga una avifauna única. Durante tres viajes de campo en 2011-2012 se registraron todas las especies detectadas por la vista o por el sonido en varios sitios de arena blanca en el sur del Estado Amazonas, en el sur de Venezuela. Los sitios de estudio se localizaron cerca de los ríos de aguas negras que drenan áreas de arena blanca: Temi, Pimichín, Guainía, Caño San Miguel y Río Negro. Registramos 262 especies agrupadas en 47 familias; de ellas, 38 (14,5%) pertenecientes a 17 familias, están estrechamente asociados con la vegetación arenosa blanca. Además de nuestra lista de aves, completamos el inventario con 51 especies colectadas en la región por la expedición de Phelps en 1954, pero que no fueron registradas por nosotros. Esta adición llevó el número total de especies a 313; 43 (13.8%) de las cuales están estrechamente asociadas a vegetación de arena blanca en nuestra área de estudio. Adicionalmente compilamos una lista preliminar de 46 especies estrechamente asociadas a vegetación de arena blanca al sur del Orinoco. Las comunidades de aves de arena blanca en el sur de Venezuela parecen ricas en especies en comparación con localidades brasileñas y peruanas. Adicionalmente, reportamos extensiones de rangos geográficos y registros notorios para varias especies. Resumen Ingles White-sand regions cover immense areas in southeastern Colombia and southern Venezuela, especially along the upper Rio Negro and Guainía basins. White-sand ecosystems are species poor and have low diversity, yet they host a distinctive flora displaying high endemism. Likewise, bird communities of white-sand vegetation are characterized by low species richness. Nonetheless, studies in Brazilian and Peruvian Amazonia show that white-sand vegetation harbors a unique avifauna. We surveyed the bird fauna of several white-sand sites in southern Amazonas State, southern Venezuela, during three field trips in 2011-2012. Sites were located in the vicinity of blackwater rivers draining white-sand areas: Temi, Pimichín, Guainía, Caño San Miguel and Río Negro. We made rapid surveys of the bird fauna by conducting transects during which we recorded all species detected by sight or sound. We recorded 262 species grouped in 47 families; of these, 38 (14.5%) belonging to 17 families, were closely associated with white sandy vegetation. In addition, we complemented the bird inventory with 51 species collected in the region by the Phelps expedition in 1954, but not recorded by us. This addition brought the totalnumber of species to 313; 43 (13.8 %) of which are closely associated with white-sand vegetation in our study area. We also compiled a preliminary list of 46 species closely associated to white-sand vegetation from Venezuela south of the Orinoco. White-sand bird communities in southern Venezuela seemed species rich when compared to Brazilian and Peruvian sites. In addition, we report range extension and noteworthy records for several species. Abstract White-sand regions cover immense areas in southeastern Colombia and southern Venezuela, especially along the upper Rio Negro and Guainía basins. White-sand ecosystems are species poor and have low diversity, yet they host a distinctive flora displaying high endemism. Likewise, bird communities of white-sand vegetation are characterized by low species richness. Nonetheless, studies in Brazilian and Peruvian Amazonia show that white-sand vegetation harbors a unique avifauna. We surveyed the bird fauna of several white-sand sites in southern Amazonas State, southern Venezuela, during three field trips in 2011-2012. Sites were located in the vicinity of blackwater rivers draining white-sand areas: Temi, Pimichín, Guainía, Caño San Miguel and Río Negro. We made rapid surveys of the bird fauna by conducting transects during which we recorded all species detected by sight or sound. We recorded 262 species grouped in 47 families; of these, 38 (14.5%) belonging to 17 families, were closely associated with white sandy vegetation. In addition, we complemented the bird inventory with 51 species collected in the region by the Phelps expedition in 1954, but not recorded by us. This addition brought the totalnumber of species to 313; 43 (13.8 %) of which are closely associated with white-sand vegetation in our study area. We also compiled a preliminary list of 46 species closely associated to white-sand vegetation from Venezuela south of the Orinoco. White-sand bird communities in southern Venezuela seemed species rich when compared to Brazilian and Peruvian sites. In addition, we report range extension and noteworthy records for several species.