Raridade em morcegos Phyllostomidae (Mammalia: Chiroptera) na Mata Atlântica brasileira

Abstract

Species are considered rare when they have a restricted distribution, low local abundance, high habitat specificity or a combination of these characteristics in comparison to other species analyzed. Thus, considering a species as rare may be an indicator that its vulnerability to extinction is greater than for other ecologically similar common species. As such, assessing species rarity is a way of assessing the conservation importance of both species and their habitats. This type of assessment is particularly important in places such as the Atlantic Forest which has a long history of anthropogenic impact, and where threats are on-going. The environment of the Atlantic Forest biome varies widely, allowing for studies to be carried out focusing on different environmental factors, including those that may influence the presence or absence of rare species. The Phyllostomidae family, which make up of half of the bat species found in the Atlantic Forest, provides a large interspecific variety, are relatively abundant locally and are easy to capture. As such, studying these species in this biome allows for an assessment of which local features and functional traits may be related to species rarity. The main objectives of this study are to: (1) Assess the rarity of species of the family Phyllostomidae in the Atlantic Forest and; (2) Identify which local features may favour the detection or presence of rare species (sampling effort, protected area size, habitat heterogeneity, latitude and altitude) and which functional traits of the species (trophic level, body size and wing morphology) are related to their rarity. The study area comprised of the conservation units of the Brazilian Atlantic Forest. Data were obtained from bibliographical research and from the database of the Bat Diversity Laboratory. Species rarity was evaluated by a rarity index (IR) that takes into account the distribution of the species, their local abundances and habitat specialisation in the Atlantic Forest. The relationship between rarity (IR) and the explanatory variables were analyzed through phylogenetic generalized least squares models. Fifty-five species were recorded (14 rare, 27 uncommon and 14 common). Thus, in terms of conservation, greater attention should be directed to species that were considered rare. However, some uncommon and common species with certain characteristics (endemic or sensitive to disturbances, for example) also need attention. The results show that rare species of Phyllostomidae bats of the Atlantic Forest have smaller body sizes and alar morphology corresponding to larger and wider wings. Thus, greater attention should be directed to species of bats with these characteristics, being probable that the results obtained here will apply to other bats, from other families as well as other places. In addition, according to the results, rare species of Phyllostomidae bats are present in sites with large size protected areas, more heterogeneous and in lower altitudes and latitudes, being necessary a greater effort to detect them. With this, greater attention should be directed to sites with these characteristics, both in terms of conservation and in terms of efforts to better sample them