Rainfall and sea level drove the expansion of seasonally flooded habitats and associated bird populations across Amazonia
André Oliveira Sawakuchi, Eduardo D. Schultz, Fabiano Nascimento Pupim, Dailson José Bertassoli, Daniela Fonseca Melo de Souza, Diego Fontana Siqueira Cunha, Carlos Eduardo Manjon Mazoca, Manuela Pinheiro Ferreira, Carlos Henrique Grohmann, Ingo Wahnfried, Cristiano Mazur Chiessi, Francisco W. Cruz, Renato Paes de Almeida, Camila C. Ribas
Abstract
Spatial arrangement of distinct Amazonian environments through time and its effect on specialized biota remain poorly known, fueling long-lasting debates about drivers of biotic diversification. We address the late Quaternary sediment deposition that assembled the world's largest seasonally flooded ecosystems. Genome sequencing was used to reconstruct the demographic history of bird species specialized in either early successional vegetation or mature floodplain forests. Sediment deposition that built seasonally flooded habitats accelerated throughout the Holocene (last 11,700 years) under sea level highstand and intensification of the South American Monsoon, at the same time as global increases in atmospheric methane concentration. Bird populations adapted to seasonally flooded habitats expanded due to enlargement of Amazonian river floodplains and archipelagos. Our findings suggest that the diversification of the biota specialized in seasonally flooded habitats is coupled to sedimentary budget changes of large rivers, which rely on combined effects of sea level and rainfall variations.