El jilguero dorado (Sicalis flaveola) modifica la estructura de sus vocalizaciones para adaptarse a hábitats urbanos

Abstract

Urban and suburban ecosystems are areas that, despite of being modified by human activities, can sustain a large amount of biodiversity. Acoustic field alterations affect communication among animals, threatening the populations' stability dynamics. In birds, where acoustic communication take place at a certain distance, signals that reach the receptor may differ from those emitted, due to song degradation and acoustic pollution. In order to secure communication, species have to modify their vocalizations in different ways. We studied songs of the Saffron finch (Sicalis flaveola) at 2 sites with different levels of acoustic pollution. At the most polluted site, songs showed shorter trills with higher frequencies (max and min), and preludes with lower maximum frequencies. This is the first contribution on the vocalization's structure of the Saffron Finch at the study area, and provides new evidence on the effects that acoustic pollution produces on it. None of known song hypothesis was able to explain by itself the changes in song structure found in this study. Thus, this species adjusts its vocalizations to acoustic pollution in different ways simultaneously, depending on the species' inner capacities.