Reversing landscape amnesia: museum bird collections unearth a lost avifauna in central Brazil

Global environmental change has profoundly altered ecosystems worldwide, yet in many tropical regions the magnitude and timing of biodiversity change remain poorly documented due to limited historical baselines. Here, we reconstruct the historical avifauna and landscape of the Triângulo Mineiro and Alto Paranaíba, central Brazil, a region located at the ecotone between the Cerrado savannas and the Atlantic Forest. Using data from early naturalists' travel reports, museum specimens and historical literature, we compiled records from the early 19th to early 20th centuries and compared them with contemporary records (obtained after 2010) derived from ornithological surveys and citizen science platforms. Historical sources revealed 827 specimens representing 243 bird species recorded between 1819 and 1908. These records document a diverse avifauna composed of species associated with both Cerrado and Atlantic Forest habitats, reflecting the heterogeneous landscape that once characterized the region. Comparison with the contemporary literature and ~80 000 citizen science records indicates that 36 species recorded historically, particularly those specialized in mature evergreen forest, have been locally extirpated. In contrast, disturbance‐tolerant species and farmland birds have colonized or expanded their ranges into the region during the last century. These patterns suggest a pronounced process of biotic homogenization driven by habitat loss, land‐use change and direct human pressures such as hunting and trapping. Our results demonstrate the critical value of museum bird collections for reconstructing ecological baselines and highlight how the loss of historical perspective can contribute to ‘landscape amnesia’, obscuring the magnitude of biodiversity change in human‐modified tropical landscapes.