It's time to listen: there is much to be learned from the sounds of tropical ecosystems

Knowledge that can be gained from acoustic data collection in tropical ecosystems is low-hanging fruit. There is every reason to recordand with every day, there are fewer excuses not to do it. In recent years, the cost of acoustic recorders has decreased substantially(some can be purchased for under US$50, e.g., Hillet  al.2018) and the technology needed to store and analyze acoustic data is contin-uously improving (e.g., Corrada Bravoet  al.2017, Xieet  al.2017). Soundscape recordings provide a permanent record of a site at agiven time and contain a wealth of invaluable and irreplaceable information. Although challenges remain, failure to collect acoustic datanow in tropical ecosystems would represent a failure to future generations of tropical researchers and the citizens that benefit fromecological research. In this commentary, we (1) argue for the need to increase acoustic monitoring in tropical systems; (2) describe thetypes of research questions and conservation issues that can be addressed with passive acoustic monitoring (PAM) using both short-and long-term data in terrestrial and freshwater habitats; and (3) present an initial plan for establishing a global repository of tropical recordings.