Pristine semi-arid areas in northeastern Brazil remain mainly on slopes of mountain ranges: a case study based on bird community of Serra de Santana

摘要

Pristine areas are becoming rare everywhere, resulting in scattered fragments of natural environments. In the Brazilian steppe savanna, this situation requires attention because habitats with higher economic value are underrepresented by the protected area system. Between 2009 and 2010, we surveyed 60 sites with differing landscapes such as plateaus, slopes, and lowlands in the Serra de Santana. At each site, we applied standardized bird survey methods and compared the observed and projected richness of each landscape. We recorded 189 species, with the highest species richness in the slope habitat, followed by plateaus, and then lowlands. In the slope habitat, there were more forest-dependent species, as well as more species with high and medium sensitivity to disturbance. Endemic species with high and medium sensitivity to disturbances were restricted to slopes and some fragments of the plateaus. Our results show that the region is an important area due to the high bird species richness and presence of endemic and threatened species. The slope areas were the richest due to more recent human occupation. As priority measures for Serra de Santana, we suggest the control of deforestation and the designation of a protected area that encompasses all the altitudinal variation in the region.