Vocal constraints on song amplitude in star finches Bathilda ruficauda 1Graduate School of Life Science, Hokkaido University, Sapporo, Hokkaido, Japan 2Faculty of Science, Hokkaido University, Sapporo, Hokkaido, Japan 3Faculty of Science, University of Alberta, Edmonton, Alberta, Canada 4Faculty of Science, University of New South Wales, Sydney, New South Wales, Australia 5Animal Communication & Urban Ecology Group, Max Planck Institute for Biological Intelligence, Seewiesen, Germany DOI...