A Chiroptera preliminary survey in the middle Madeira River region of Central Amazonia, Brazil

Western Brazilian Amazonia is considered to be more bat species-rich than areas in other parts of the biome. However, the middle Madeira River region has been pointed out as a lacuna for mammal inventories, and information on its bat diversity is still scarce. I present here a bat fauna survey of the middle Madeira River region and its main tributary, the Aripuana River. Using mist nets [4626 meter net. hours (m.h)], I surveyed ten riverine village sites, four primary forest sites and one secondary forest site distributed along the margins of both rivers. In 22 nights during the dry and rainy seasons, 356 bats of 30 species and five families were recorded. The bat species-richness was similar along both rivers, with 24 species in the Madeira sites and 23 in the Aripuana. Vampyriscus bidens and Mesophylla macconnelli were the most captured bats in the village sites along the Aripuana River, whereas all captures of Artibeus planirostris occurred along Madeira River villages. A new record for Vampyressa thyone in the Amazonas state is reported, approximately 500 km southeast of the nearest record.