Avifauna and biogeographical affinities of a carrasco-dominated landscape in north-eastern Brazil: providing baseline data for future monitoring

The carrasco is a dense, shrubby vegetation type that covers the higher parts of table-top mountains in north-eastern Brazil. The vegetation of this phytophysiognomy is often considered to have biogeographical and ecological affinities with the cerrado of Central Brazil, but the biogeographical affinities of its avifauna remain unclear. In recent years, deforestation due to local economic activities has been particularly severe in some carrasco-dominated landscapes. In 2013, we initiated avian surveys at the Fazenda Pau D'Arco, a privately owned property located on top of the Araripe Plateau, to evaluate the effects of a legal forest management program on the avifauna. Here, we present the results of four years of avian inventories to: i) characterize a well-preserved patch of carrasco vegetation; ii) assess avian biogeographical affinities of this vegetation type; iii) identify associations between managed/unmanaged areas and bird species; and iv) provide baseline data for future avian monitoring studies. Using different survey methods, we provide a list of 148 bird species, including several dry-forest specialists and caatinga endemics. Biogeographically, the avifauna of the carrasco represents a subsample of the Caatinga dry forest, lacking cerrado elements. Forest management significantly affected the distribution of several bird species in the study area. We found that 1/5 of the species (24) recorded during our standardized surveys were significantly associated with either unmanaged (14 species) or managed (10 species) areas. Species such as the Ceara Leaftosser Sclerurus cearensis, a globally vulnerable species, have only been detected in non-managed areas and therefore can be negatively affected by the management program. We also present data on 16 avian taxa with ecological and conservation concerns. By presenting a fairly complete and documented list of the avifauna, we characterize the carrasco avifauna and offer the tools to evaluate the effects of forest management on this poorly known vegetation type.