Traffic noise and responses to a simulated approaching avian predator in mixed‐species flocks of chickadees, titmice, and nuthatches

Abstract

Traffic noise likely reaches a wide range of species and populations throughout the world, but we still know relatively little about how it affects anti‐predator behavior of populations. We tested for possible effects of traffic noise on responses to predator acoustic cues in Carolina chickadees (Poecile carolinensis), tufted titmice (Baeolophus bicolor), and white‐breasted nuthatches (Sitta carolinensis) near 14 independent feeding stations in eastern Tennessee. We compared anti‐predator calling and seed‐taking behavior in response to playbacks of predator stimuli (screech owl calls) at sites naturally exposed to traffic noise and at sites that faced relatively little traffic noise. The screech owl call playback was designed to simulate the approach of this dangerous predator to a feeder being used by these small songbirds. We found that chickadees responded consistently to the owl stimuli across different levels of traffic noise. However, titmice, and nuthatches exhibited different behavioral responses to the predator stimulus, suggesting that traffic noise masked these low‐frequency predator calls. Overall, chickadees and nuthatches showed the broadest anti‐predator behavioral responses in comparison to titmice, corroborating earlier published work with an Indiana population. Finally, populations exposed to traffic noise overall seemed less able to detect predator cues potentially masked by that noise, and future work will need to assess likely seasonal variation in these responses as well as species‐level variation in anti‐predator responses in mixed‐species groups.

How Subtle Protocol Choices Can Affect Biological Conclusions: Great Tits' Response to Allopatric Mobbing Calls

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Columbian sharp‐tailed grouse brood success and chick survival in a wind‐energy landscape

“…Grouse chicks use distress calls during dangerous encounters (Connelly et al 2020). Chick survival in our study could have been negatively affected if wind turbine noise interfered with vocal communication between brood females and chicks or affected their ability to detect predator cues (Jung et al 2020).…”

Effective conspecific communication with aberrant calls in the common cuckoo (Cuculus canorus)

“…However, emitted signals may differ from the received signals (Forrest 1994). For example, habitat structure (Morton 1975;Job et al 2016), distance (McGregor and Krebs 1984;Mouterde et al 2014), and anthropogenic traffic noise (Jung et al 2020) may cause degradation in the structure of the vocal signal and, consequently, also in its information content (Wiley and Richards 1982). Both signallers and receivers show adaptations to environmental conditions to preserve the information of acoustic signals during transmission (Brumm and Naguib 2009).…”