US bird losses accelerating due to farming

Bird populations across the contiguous United States are experiencing accelerating declines, with a new study revealing that losses are speeding up, especially in regions dominated by intensive agriculture. Between 1987 and 2021, bird numbers decreased by approximately 15%, meaning for every six birds in 1987, only five remained three decades later. Areas such as the Midwest, California, and parts of the Mid-Atlantic are identified as hotspots where bird declines are rapidly worsening.

The transformation of landscapes by modern agriculture, including the replacement of diverse habitats with large croplands and the extensive use of herbicides and pesticides, is a primary driver. These practices reduce food sources like insects and limit nesting opportunities for many bird species. The study suggests that the interaction of multiple agricultural pressures, potentially including chemicals and temperature changes, amplifies these population declines.

This acceleration in bird loss serves as a critical early warning for broader ecological health. Birds are sensitive indicators of environmental change and play vital roles in ecosystems. Management of agricultural landscapes, which cover nearly 40% of US land, is therefore crucial for addressing the biodiversity crisis and ensuring the well-being of both wildlife and human populations exposed to agricultural chemicals.