Acoustic bird community composition (but not richness) responds to natural coverages in a tropical agro-cultural landscape

Le résumé fourni par la source

The rapid loss of tropical dry forests to agriculture requires effective restoration and monitoring strategies, such as ecological corridors, and robust methods to monitor their success. Birds are excellent bioindicators, yet traditional Conventional Bird Surveys (CBS) can be biased. The emergence of Passive Acoustic Monitoring (PAM) offers a complementary approach. In this study, we evaluated the efficacy of integrating CBS and PAM for assessing avian biodiversity and its relationship with habitat structure in a fragmented tropical dry forest landscape of southwestern Colombia, dominated by sugarcane. We surveyed bird communities along a riverine corridor using both methods and quantified land cover to assess the influence of closed-canopy vegetation. Our results demonstrate that bird community composition was strongly influenced by habitat, with forested sites supporting a significantly higher proportion of closed-habitat species. This relationship was more precisely revealed by PAM, which proved particularly effective at detecting forest-associated birds. While PAM detected a broader range of vocal species, CBS was crucial for identifying silent or less vocal taxa, including certain raptors and waterbirds. The integrated approach recorded 144 species, with each method contributing unique detections, confirming their complementarity. We found that community composition, specifically the proportion of forest-specialist species, was a more sensitive indicator of habitat recovery than species richness alone. We conclude that combining PAM and CBS provides a comprehensive and robust framework for biodiversity assessment in agricultural landscapes. This integrated methodology mitigates detection biases, enhances inventory accuracy, and yields reliable indicators for evaluating the ecological integrity and functional connectivity of riverine corridors.

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