Abstract
Anthropogenic activities are among the primary drivers of global biodiversity decline. In conservation practice, monitoring population parameters and clarifying habitat requirements constitute fundamental prerequisites for developing effective strategies. Long-term research addresses these needs through systematic population monitoring and comprehensive data analysis, establishing critical foundations for biodiversity preservation. This study presents a 15-year dataset on Merops viridis-a nationally protected avian species in China-documenting spatial shifts in nest-site selection driven by anthropogenic habitat modification and revealing a consistent annual population decline. Our results demonstrate that alterations in nesting habitat critically influence population dynamics, providing theoretical support for evidence-based conservation strategies. We further discuss potential drivers of observed changes in nest-site selection and population decline, advocating for the urgent establishment of large-scale protected areas targeting sandy floodplands to safeguard this species.