Traffic noise drives an immediate increase in call pitch in an urban frog

Abstract

Noise pollution is an underappreciated component of global environmental change and can impact species that have a strong reliance on acoustic communication. In urban areas, traffic noise can interfere with the ability of animals to communicate and complete essential aspects of their daily lives. We investigated the impact of traffic noise on the calling behaviour of the brown tree frog (Litoria ewingii) in south‐eastern Melbourne, the fastest‐growing human population centre in Australia. We placed six acoustic recorders at increasing distances from a busy suburban road and recorded the calling behaviour (call pitch and call rate) of brown tree frogs immediately before and after loud traffic noises, and in response to different chorus sizes. Traffic noise resulted in a significant, but short‐term, increase in call pitch in the brown tree frog. Both call pitch and call rate decreased with increasing distance from the road, yet traffic noise still resulted in increased call pitch even 200–300 m from the road. Conversely, although traffic noise increased call pitch across all chorus sizes of the brown tree frog, larger chorus sizes were associated with decreased call pitch. Our study highlights the pervasive, and sustained, impact that anthropogenic noise can have on urban frog populations.

Environmental Correlates of Sexual Signaling in the Heteroptera: A Prospective Study

“…And changes in signals due to changes in habitat, for instance, through urbanization, are becoming more widely researched and provide more examples of how selection pressures can result in sexual signaling that compensates for the surrounding environment. Anurans, in particular, have demonstrated a change in call rate or call complexity in response to novel selection pressures introduced by an urban environment [157][158][159][160][161].…”

Advertisement Call Variation of Two Frog Species along an Urban–Rural Gradient in Shanghai, China

“…Many insects, anurans, birds, and mammals use acoustic signals to attract mates and protect their territory [8,9]. However, anthropogenic noise, anthropogenic substrate-borne vibrations, light pollution, and habitat change resulting from urbanization affect the production, transmission, and reception of acoustic signals [10][11][12][13]. For example, studies reported that birds vocalized at higher dominant frequencies and sound levels in urban areas than in forests because of background noise [14][15][16].…”

“…Many studies found that anthropogenic noise had a significant effect on frog-calling parameters and behaviors in the urban environment. For example, Higham et al [10] found that traffic noise increased the call pitch of brown tree frogs (Litoria ewingii) in urban areas. Similarly, anthropogenic noise in urban areas also altered the call rate or call duration of frog species [29][30][31][32].…”