Determining temporal sampling schemes for passiveacoustic studies in different tropical ecosystems

Among different approaches to exploring and describing the ecological complexity of natural environments, soundscape analyses have recentlyprovided useful proxies for understanding and interpreting dynamic patterns and processes in a landscape. Nevertheless, the study ofsoundscapes remains a new field with no internationally accepted protocols. This work provides the first guidelines for monitoring soundscapesin three different tropical areas, specifically located in the Atlantic Forest, Rupestrian fields, and the Cerrado (Brazil). Each area was investigatedusing three autonomous devices recording for six entire days during a period of 15 days in both the wet and dry seasons. The recordings wereprocessed via a specific acoustic index and successively subsampled in different ways to determine the degree of information loss whenreducing the number of minutes of recording used in the analyses. We describe for the first time the temporal and spectral soundscape featuresof three tropical environments. We test diverse programming routines to describe the costs and the benefits of different sampling designs,considering the pressing issue of storing and analyzing extensive data sets generated by passive acoustic monitoring. Schedule 5 (recording oneminute of every five) appeared to retain most of the information contained in the continuous recordings from all the study areas. Less denserecording schedules produced a similar level of information only in specific portions of the day. Substantial sampling protocols such as thosepresented here will be useful to researchers and wildlife managers, as they will reduce time- and resource-consuming analyses, whilst stillachieving reliable results