Noise Source and Individual Physiology Mediate Effectiveness of Bird Songs Adjusted to Anthropogenic Noise

Abstract

Anthropogenic noise is a pervasive pollutant altering behaviour of wildlife that communicates acoustically. Some species adjust vocalisations to compensate for noise. However, we know little about whether signal adjustments improve communication in noise, the extent to which effectiveness of adjustments varies with noise source, or how individual variation in physiology varies with response capacity. We played noise-adjusted and unadjusted songs to wild Passerculus sandwichensis (Savannah Sparrows) after measurements of adrenocortical responsiveness of individuals. Playbacks using songs adjusted to noisy environments were effective in restoring appropriate conspecific territorial aggression behaviours in some altered acoustic environments. Surprisingly, however, levels of adrenocortical responsiveness that reduced communication errors at some types of infrastructure were correlated with increased errors at others. Song adjustments that were effective in communicating for individuals with lower adrenocortical responsiveness at pumpjacks were not effective at screwpumps and vice versa. Our results demonstrate that vocal adjustments can sometimes allow birds to compensate for disruptions in communication caused by anthropogenic noise, but that physiological variation among receivers may alter effectiveness of these adjustments. Thus mitigation strategies to minimize anthropogenic noise must account for both acoustic and physiological impacts of infrastructure.

Short-term exposure to unmanned aerial vehicles does not alter stress responses in breeding tree swallows

“…control). Molecular responses to stress were also assessed for a subset of 22 individuals from each treatment group (similar to Curry et al , 2018 , Injaian et al , 2018 , 2019 ). Research activities began at each box after all eggs hatched and ended before young fledged.…”

“…Anthropogenic noise, a side-effect of human development, also alters physiology and behavior in animals ( Wright et al , 2007 ; Injaian et al , 2018 ). Birds are particularly susceptible to noise, which can interfere with vocal communication ( Curry et al , 2018 ), decrease telomere lengths ( Injaian et al , 2019 ), reduce body condition and impact reproductive success ( Wright et al , 2007 ; Francis and Barber, 2013 ; Shannon et al , 2016 ; Injaian et al , 2018 ). Changes in baseline corticosterone levels have also been noted, although the direction of the effect has been variable.…”

“…Repeated stress events can cause a chronic stress response, ultimately changing baseline corticosterone levels, a measure of long-term fitness ( Bonier et al , 2011 ; Flores et al , 2019 ). However, the amount and direction of change of baseline CORT is highly variable depending on individuals, species and circumstances ( Bonier et al , 2011 ; Curry et al , 2018 ; Flores et al , 2019 ; Injaian et al ., 2019 ). Telomeres are repetitive, non-coding DNA sequences found on the ends of eukaryotic chromosomes that help keep the genome stable throughout the DNA replication process ( Dorado-Correa et al , 2018 ).…”

Ecoacoustics: A Quantitative Approach to Investigate the Ecological Role of Environmental Sounds

“…From a human perspective, sound has further characteristics; it is considered a source of pleasure, contributes to creating a sense of place, and maintains and reinforces cultural heritage and wellbeing [35,36]. Sound, when too intense and/or continuous, like urban technophonies, is considered a source of noise and may cause masking effects on other (biological) sounds, producing an interruption of the communication networks with consequences on the physiology of sensitive species [37,38].…”

The Influence of Transport Infrastructure Development on Bird Diversity and Abundance

“…Some birds in proximity to sound, have mechanisms for modulating their effects. But the usefulness of these mechanisms varies, based on physiological differences between different species (Curry et al, 2018b).…”