Species richness, composition and abundance of fruit-feeding butterflies in the Brazilian Atlantic Forest: comparison between a fragmented and a continuous landscape

Aim To evaluate frugivorous butterflies as indicators of forest disturbance in the Brazilian Atlantic Forest. Location The study area is located in the municipality of Cotia, Sao Paulo State, south-eastern Brazil (23 degrees 35'-23 degrees 50' S, 46 degrees 45'-47 degrees 15' W). Methods Sampling was done at four sites inside a large forest block, the Morro Grande State Reserve, and in five forest fragments in an adjacent fragmented landscape. Butterflies were sampled with portable traps, baited with a fermented mixture of banana and sugar cane juice. Sampling was carried out during the period most favourable for the capture of frugivorous butterflies in south-eastern Brazil. Results All richness-related results indicated no effect of forest fragmentation on the frugivorous butterfly guild, concurring with the suggestion of appreciable resistance of Atlantic Forest butterflies to habitat modification. However, species composition discriminated between the two landscapes, indicating that fragmentation may have effects beyond simple species richness. When species were analysed individually, clear patterns of distribution emerged, with some species that were very abundant in the fragmented landscape being practically absent in the continuous landscape, and vice versa. This pattern seems consistent even for some subfamilies. Main Conclusion Our findings support the usefulness of the frugivorous butterfly guild as a biological indicator of forest disturbance effects in one of the world's most threatened ecosystems.