Acceleration hotspots of North American birds' decline are associated with agriculture

Human activities might have accelerated declines of population abundance, but this acceleration remains underexplored. Using 1033 North American Breeding Bird Survey routes, we analyze abundance change and its acceleration for 261 bird species, 54 avian families, and 10 habitats from 1987 to 2021. We show an average continent-wide decline of abundance of all birds per local route, with hotspots of decline in southern and warm parts of North America and hotspots of accelerating decline in the Mid-Atlantic, Midwest, and California, matching patterns of agricultural intensity. Overall, 122 species (47%) exhibit significant declines, of which 63 also show acceleration of this decline, and 67 show declining per-capita growth rate, raising concerns for a large part of North American bird populations. These findings suggest that bird abundance decline is mostly accelerating, with spatial patterns of this acceleration indicating that agricultural intensity may be a driver of this trend.