Indigenous Peoples and locals report a drastic decline in bird size across three continents

Birds currently inhabiting many territories across Africa, Latin America and Asia are, on average, considerably smaller than those that predominated in 1940. This is the conclusion of an international study led by the Institute of Environmental Science and Technology at the Universitat Autònoma de Barcelona (ICTA-UAB), which documents—drawing on the collective ecological memory of 10 Indigenous Peoples and local communities—a reduction of up to 72% in the mean body mass of the bird species present in their territories between 1940 and 2020.