Efeitos da poluição sonora em comunidades de aves do Cerrado: o impacto das rodovias

Abstract

Acoustic signals are employed by various animal taxa in the exchange of information. Currently this communication channel suffers from noise pollution, with vehicle traffic being one of its main sources. This study aimed to verify if traffic noise pollution affects the communication and local diversity of birds. Automated digital recordings were conducted in two ecological reserves in the municipality of Uberlândia, MG, Brazil. Recordings were made at different distances from the MGC-455 highway. The Acoustic Complexity Index (ACI) was used to analyze the vocal activity of birds. Thirty-four species were identified through acoustic signals. Their composition varied according to the studied environments. The ACI presented higher values near the highway, indicating that near the source of noise pollution local birds increased the rate of vocalization, employing the redundancy principle, thereby increasing the probability of being heard by conspecifics. Nystalus maculatus has not been recorded near the highway, indicating that this species avoids places with intense noise pollution. Bird communities studied compete directly for acoustic space with traffic noise. Thus, some species exhibit behavioral adaptations so that their signals are received by other individuals in the community.