Overview

• A groundbreaking study published in *Science* shows that North American bird populations are shrinking most rapidly in areas where they remain most abundant, affecting 83% of species studied.
• Grassland and dryland birds are experiencing the steepest declines, while pockets of stability in regions like the Appalachians and western mountains suggest opportunities for targeted conservation.
• The study analyzed 36 million bird observations from the eBird program (2007–2021), using advanced machine learning to map trends at an unprecedented 27 km resolution.
• Nearly all species (97%) show both gains and losses depending on location, highlighting the importance of fine-scale data for understanding population dynamics.
• This research provides actionable insights for conservation efforts, enabling scientists and policymakers to prioritize areas of decline and leverage regions of recovery.