In the flooded forests of Peru's Upper Amazon, water levels affect everything. Rivers rise and fall with the seasons, reshaping habitat and determining animal movements and behavior. In the face of climate change, water patterns are changing, and typical seasonal variations are shifting. Join one of Earthwatch Expeditions’ longest-running studies to track that impact, noting how more extreme floods and droughts are altering habitats and populations of mammals, birds and fish. Aboard a riverboat near the headwaters of the Amazon River system, you are immersed in a dynamic ecosystem where dolphins ply narrow channels, monkeys swing through the canopy, and scarlet macaws flush from the dense forest. Your work in recording the presence of these and other species helps grow our understanding of how changing water levels impact their populations, offering critical insight for conservation.