All these characteristics make them an ideal species for analyzing the effect of noise on the repertoire of elements and on the variation of proportion of low and high frequency elements.įigure 2 Roselvy recording birds in an urban environment © John van Dort In Costa Rica, House Wrens sing throughout the year, but more frequently during the prolonged breeding season (March to October Skutch 1953) and inhabit open or semi-open habitats in rural and urban areas where anthropogenic noise levels vary considerably (Redondo et al. Additionally, House Wrens develop songs by hearing other individuals of the same species and expand their repertoire after the first breeding season by including new elements in their songs from tutors (Sosa-López & Mennill 2014a). Most of House Wren song elements are produced at frequencies between 0.80–5 kHz, partially overlapping with anthropogenic noise (Redondo et al.

We studied the House Wren because male songs play an important role in mate choice, pair communication, and in male-male competitions (dos Santos et al. elements with frequencies above 3 kHz, which is the highest frequency of noise in cities) were more common in sites with high noise levels.įigure 1 House Wren advertising its urban territory © John van Dort Also, we investigated whether the proportion of elements that do not overlap with noise (i.e. A song element is a continuous sound, the equivalent of the sound that we produced when saying any letter of our alphabet. We investigated if high noise levels reduce the number of song elements in the repertoire of House Wren, Troglodytes aedon, a common species in American cities.

Thus, in noisy places like cities, birds may have difficulty learning their song when they produce songs at frequencies that overlap with anthropogenic noise. Noise produced in cities by traffic, factories, and other human activities affects the vocal communication of birds living in those cities because it masks their vocalizations (i.e., prevents them from hearing certain sounds) and affects the learning capacities of individuals because they need to hear themselves and other individuals of their own species to learn correctly their song. Juárez, R., Araya-Ajoy, Y., Barrantes, G. House Wrens Troglodytes aedon reduce repertoire size and change song element frequencies in response to anthropogenic noise.

House wren song