The study was carried out in an area located at "Serra do Mar", belonging to "Mata Atlântica" formation, also known as Atlantic Rain Forest, near the town of Paraibuna, State of São Paulo, Brazil (located at 23º31’S to 23º33’S, 45º39’W to 45º42’W and 944 to 1.136m altitude). Three fragments of natural vegetation (sizes of 47, 26 and 4 hectares) and an adjacent area of eucalypts plantation were utilized for the surveys. In all situations the understorey was quite prominent and the vegetation of the gallery forest fragments was in a medium stage of secondary regeneration. The method used to the register the avifauna specimens was the technique of observations per fixed points. The main objective of the study was to analyze the groups OF birds that were affected by the forest fragmentation and, additionally, to evaluate the impacts caused by the fragmentation and the isolation degree of these areas. Taking into account all studied areas, it was possible to register a total of 113 species of birds, distributed over a range of 27 families and 13 orders. The main species were cHaracterized as insect-eating, omnivorous and grain-eating, all of them occupying the understorey level. The species composition was affected by the fragmentation and also by the reduction of the natural vegetation. The quantity and diversity of birds showed a direct relationship with the size of the fragments, and structure of the vegetation and an inverse relationship with the isolation degree.
bird; fragment; Atlantic Forest; understorey
