Protecting biodiversity in urbanizing regions: The role of urban reserves for the conservation of Brazilian Atlantic Forest birds

Abstract

Although the Brazilian Atlantic Forest and other global biodiversity hotspots are rapidly urbanizing, there is little information on the potential of metropolitan regions to safeguard biodiversity within their reserves. We sampled bird assemblages in nine protected areas (14.8–1058ha) of the metropolitan region of João Pessoa, Northeast Brazil, to test the hypothesis that larger urban reserves are more effective than smaller ones in protecting the regional species richness, as more habitat and environmental heterogeneity are available for birds. We recorded 126 species belonging to 41 families, including seven endemics and two introduced species. Thraupidae and Tyrannidae were the most representative families with 16 species each. Larger areas clearly protected greater proportion of the regional species richness, but the smaller areas accounted for at least 35.7% of the regional richness. Differences in size and isolation significantly influenced species similarity, but hunting, catching for illegal trade, presence of exotic predators and noise pollution were likely to affect composition as well. The remarkable bird diversity suggests good potential for legal-based, well-planned birdwatching activities in the studied region. The results highlight that urban reserves of any size are valuable for bird conservation in metropolitan regions, though larger ones should be prioritized.