Does Traffic Noise Affect the Advertisement Call of Dendropsophus nanus (Anura, Hylidae)?

Abstract

Generally, the effect of noise pollution on wildlife is not considered in environmental assessments, although noise scares animals away and, in anuran amphibians that communicate by vocalizations, it can significantly interfere with their reproduction. The alteration of soundscapes is an aspect scarcely explored in the field of conservation. Here, our aim was to assess the impact of noise pollution from vehicular traffic on the advertisement call of the Dwarf Treefrog (Dendropsophus nanus) in northwestern Corrientes Province, Argentina. Specifically, we analyzed whether there were alterations to the acoustic parameters of the advertisement call in D. nanus in environments exposed to traffic noise. We recorded calls using a digital recorder coupled to a directional microphone targeted on individuals vocalizing in environments without traffic noise (control) and others in places close to roads with high vehicular traffic. Permutational Multivariate Analysis of Variance showed significant differences between noisy sites and without-noise sites, and post-hoc analysis indicated significant differences in two temporal parameters (duration of the complex call and note rate) and three spectral parameters (dominant frequency of B note and upper limit of frequency band in A and B type notes). Our study shows that traffic noise affects roadside vocalizing populations of D. nanus. Understanding how anthropogenic noise pollution can affect amphibian populations is a first step in better understanding the effects of expanding urban development on wildlife.