Avifauna del Refugio Nacional de Vida Silvestre Bosque Alegre, Laguna Hule, Río Cuarto de Grecia, Alajuela

Costa Rica, with approximately 850 species of birds, of which 600 are resident, 225 migratory and 150 aquatic species, has the highest density of birds per area in the world (Stiles 1991, Stiles and Skutch 1995, Rappole et al. 1994) . Housing almost 75% of its avifauna in the lower parts of the Caribbean slope. This diversity is seriously threatened by the transformation of forests into areas of agricultural production (mainly banana plantations) and livestock (Blake and Loiselle 1992, Levey and Stiles 1994, Loiselle and Blake 1992). Despite the fact that 12% of its territory is included within the different systems of protected areas, it has one of the highest deforestation rates in Central America, 4.2% (Rappole et al. 1994 and Winograd 1994). In our country, the main habitats for birds are made up of wooded areas of the different altitude levels, subalpine moors, swamps, rivers, lakes and flooded forests, as well as a great variety of artificial habitats or agricultural ecosystems such as coffee plantations, cocoa plantations, grasslands, plantations, secondary growth areas and shrubs (Stiles and Skutch 1992, Jiménez 1999).