Diferencias en el canto de la Ratona Común (<i>Troglodytes musculus</i>) en ambientes con distintos niveles de influencia humana

Abstract

It has been shown that some bird species are able to modify their songs in order to avoid being masked by ambient noise, a particular case of the more general acoustic adaptation hypothesis to the surrounding environment. We analyzed physical and temporal parameters of the song of the Southern House Wren (Troglodytes musculus) in three different acoustic environments (urban, peri-urban and rural zones) in the metropolitan area of Belém (Brazil). To evaluate the acoustic impact on the song, we did not consider the complete spectrum of ambient noise but only included that within the range of vocalization of the species, which is the one that could potentially interfere with the song. Some song parameters as the concentration of energy within the range of frequencies and note duration were correlated with noise levels. Discrepancies between results from noise levels and urban zoning can be a consequence of differences in vegetation or due to the own characteristics of Belém's urban planning. These correlations could be evidence of acoustic adaptation, but other factors could also explain them. Were noise levels the explanation for those changes, more research would be needed to demonstrate that they contribute to an effective improvement of song transmission.