Distribución, ecología y conservación de la avifauna de la cuenca del río Savegre, Costa Rica

We present here information on richness, distribution, and endemism patterns on the avifauna from the watershed of the rio Savegre. Additionally, we include general information on diet, migratory and resident status, and threaten species. The study was conducted on an area of 540 km_, over an altitudinal range from sea level to 3 400 masl in elevation, from September 2001 to december 2002. Along the altitudinal range five monitoring stations were established at different elevations and forest types: basal, premontane, low montane, high montane, and subalpine-alpine. Each monitoring station was visited at least four times during the study period, and birds were surveyed, using point counts and mist-nets. We recorded 508 species along the elevational gradient, 429 resident and 79 migratory. The species richness (353 species at the basal forest) decreased as elevation increased (82 species at subalpine-alpine forest). The whole watershed included 53 of the 75 Costa Rican endemic species, most of which (about 30 species) inhabit exclusively the high montane and subalpine-alpine forests. The vast majority of birds ingest insects as part of their diet, followed by fruits, vertebrates, seeds, and nectar. Other items, e.g., leaves, are rarely used by birds. Finally, 40 out of the 114 bird species with some potential risk of extinction that occurred in Costa Rica are present on the study region.