"Soundscapes of the Brazilian Cerrado".
Acoustic index; Acoustic similarity analysis; Bioacoustic; Anthropophony; Anthropogenic noise
Acoustic communication is important in transmitting information about the presence, location, and needs of different species. A successful acoustic communication requires sounds to propagate throughout the environment, from the emitter to the receiver, and one of the factors that can interfere with the transmission of the acoustic signal is anthropogenic noise. In this context, the objective of this research is to explore whether acoustic landscapes vary between urban areas and natural areas in the Brazilian Cerrado. The first specific objective was to verify the acoustic similarity between these areas and whether the communities share similarities in their vocalizations; and the second was to compare and evaluate sound diversity using acoustic indices. Acoustic data from the Planning Laboratory for Biodiversity Conservation at the University of Brasília were used. Recordings were collected at 24 sampling points using a programmable digital recorder; the collection points were in protected natural areas (conservation units) and in urban areas in the Federal District. Next, the acoustic similarity and acoustic indices (ADI, ACI, NDSI, AEI, H and BI) were analyzed. In the acoustic similarity results, it was possible to observe a clear difference between the environments, formed by two distinct groups: one predominantly urban and the other predominantly natural. The results of the acoustic indices showed that ACI, H and ADI were higher for natural environments, while the NDSI, AEI and BI indices were higher for urban environments; All acoustic indices showed a significant difference between natural and urban areas, confirming the hypothesis that predicted the differentiation of acoustic landscapes according to the environment. Contrary to expectations, BI values were higher in urban environments, which may happen because the urban environment is rich in a range of anthropogenic sounds. The results confirm a significant difference in the acoustic landscapes analyzed. However, in urban environments, the amount of anthropogenic sounds can distort the analysis of acoustic indices, which requires caution to avoid hasty conclusions.