Natural Noise Can Influence Bird Foraging and Vigilance Behavior

2021 ◽  
Author(s):  
Kate Antonia Sweet
Keyword(s):  
Antipredator Behavior ◽  
Bird Species ◽  
Anthropogenic Noise ◽  
Trade Off ◽  
Acoustic Environment ◽  
Vigilance Behavior ◽  
Sound Levels ◽  
Natural Noise ◽  
Acoustic Environments ◽  
High Sound

Natural sounds are an often overlooked, yet important component of an animal's habitat. The acoustic environment may be especially significant during foraging, because a noisy world can limit auditory surveillance. Here, we investigated how natural noise structures the foraging vigilance trade-off to understand how intense acoustic environments may have shaped antipredator behavior across the evolutionary past, and better inform conservation efforts in the present. First, in Chapter 1, I directly compared the foraging and vigilance behaviors of captive song sparrows (Melospiza melodia) in anthropogenic and natural noise. We recorded foraging trials in 4 playback conditions (roadway traffic, whitewater rivers, whitewater rivers shifted upwards in spectrum, and amplitude-modulated rivers), along with an ambient control to assess which acoustic characteristics make a foraging habitat risky. We found that sparrows increased vigilance or decreased foraging in 4 of 6 behaviors when foraging in higher sound levels, regardless of playback type, indicating a broad role for noise in antipredator behavior. Next, in Chapter 2, I sought to understand the ecological relevance of these findings by examining wild bird behavior. To do so, we broadcast the same whitewater river noise as used in our lab experiment across a riparian landscape. To understand if the spectra of the acoustic environment affected bird behavior, we also presented spectrally-shifted whitewater noise to produce a gradient of frequencies. Using 18 bird feeders placed across this landscape, we recorded and analyzed behavior of the three most common bird species. Black-headed grosbeaks (Pheucticus melanocephalus) and lazuli buntings (Passerina amoena) demonstrated an increase in at least one vigilance behavior in high sound levels, while American goldfinches (Spinus tristis) and grosbeaks altered some behaviors according to background frequency. Clearly, adjusting antipredator behavior in noise is conserved across diverse bird species. Taken together, our findings imply that natural soundscapes have likely shaped behavior long before anthropogenic noise, and that high sound levels negatively affect the foraging vigilance trade-off in both anthropogenic and naturally intense acoustic environments. These results are concerning in light of ever-increasing anthropogenic noise pollution.

scholarly journals How Wildlife Respond to Natural Noise

2021 ◽  
Author(s):  
Dylan G.E. Gomes
Keyword(s):  
Sound Level ◽  
Anthropogenic Sources ◽  
Anthropogenic Noise ◽  
Frequency Noise ◽  
Spider Webs ◽  
Predator Prey ◽  
Sound Levels ◽  
Natural Noise ◽  
Acoustic Environments ◽  
High Sound

Animal sensory systems have evolved in a natural din of noise since the evolution of sensory organs. Anthropogenic noise is a recent addition to the environment, which has had demonstrable, largely negative, effects on wildlife. Yet, we know relatively little about how animals respond to natural sources of noise, which can differ substantially in acoustic characteristics from human-caused noise. Here we review the noise literature and suggest an evolutionary approach for framing the study of novel, anthropogenic sources of noise. We also push for a more quantitative approach to acoustic ecology research. To build a better foundation around the effects of natural noise on wildlife, we experimentally and continuously broadcast whitewater river noise across a landscape for three summers. Additionally, we use spectrally-altered river noise to explicitly test the effects of masking as a mechanism driving patterns. We then monitored bird, bat, and arthropod abundance and activity and assessed predator-prey relationships with bird and bat foraging assays and by counting prey in spider webs. Birds and bats largely avoided high sound levels in noisy environments. Bats also avoided acoustic environments dominated by high frequency noise while birds avoided noise that overlapped with their song, the latter trend suggesting that communication is impaired. Yet, when sound levels were high overlapping noise was not any more disruptive than non-overlapping noise, which suggests that intense noise interferes with more than communication. Avoidance of noise that overlapped in frequency with song was stronger for low-frequency singers. Bats that employ higher frequency echolocation were more likely to avoid high sound level noise; we explore potential explanations for this pattern. Most arthropod Orders responded to noise, yet the directions of effects were not consistent across taxa. Some arthropods increased in abundance in high sound level areas - perhaps in response to the absence of bird and bat predators. Reinforcing this possibility, visually foraging birds and passively listening bats decreased foraging effort beyond what was expected based on declines in abundance and activity. Orb-weaving spiders increased dramatically in high sound level areas, which could be due to a release from predation, an increase in prey capture, or direct attraction to high sound level river noise. Overall, we demonstrated significant changes to many vertebrate and invertebrate taxa during playback of whitewater river noise. We were able to parse out the effects of sound pressure level and background frequency on these individual taxa and predator-prey behaviors. Our results reveal that animals have likely long been affected by particular characteristics of noise, which may help explain contemporary responses to anthropogenic noise. As the spatial and temporal footprint of anthropogenic noise is orders of magnitude greater than intense natural acoustic environments, the insights provided by our data increase the importance of mitigating noise pollution impacts on animals and their habitats. It is clear that natural noise has the power to alter animal abundances and behavior in a way that likely reverberates through entire communities and food webs. Future work should focus on strengthening the relationships between these potential predators and prey and highlight how the structure of the system changes under such noise treatments.

scholarly journals Phantom rivers filter birds and bats by acoustic niche

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
D. G. E. Gomes ◽  
C. A. Toth ◽  
H. J. Cole ◽  
C. D. Francis ◽  
J. R. Barber
Keyword(s):  
Insect Wing ◽  
Passive Listening ◽  
Hunting Strategies ◽  
Sound Levels ◽  
Acoustic Niche ◽  
Using Data ◽  
Acoustic Environments ◽  
Breeding Seasons ◽  
And Behavior ◽  
High Sound

AbstractNatural sensory environments, despite strong potential for structuring systems, have been neglected in ecological theory. Here, we test the hypothesis that intense natural acoustic environments shape animal distributions and behavior by broadcasting whitewater river noise in montane riparian zones for two summers. Additionally, we use spectrally-altered river noise to explicitly test the effects of masking as a mechanism driving patterns. Using data from abundance and activity surveys across 60 locations, over two full breeding seasons, we find that both birds and bats avoid areas with high sound levels, while birds avoid frequencies that overlap with birdsong, and bats avoid higher frequencies more generally. We place 720 clay caterpillars in willows, and find that intense sound levels decrease foraging behavior in birds. For bats, we deploy foraging tests across 144 nights, consisting of robotic insect-wing mimics, and speakers broadcasting bat prey sounds, and find that bats appear to switch hunting strategies from passive listening to aerial hawking as sound levels increase. Natural acoustic environments are an underappreciated niche axis, a conclusion that serves to escalate the urgency of mitigating human-created noise.

Hearing Aid Amplification Reduces Communication Effort of People With Hearing Impairment and Their Conversation Partners

2020 ◽  
Vol 63 (4) ◽  
pp. 1299-1311 ◽  
Author(s):  
Timothy Beechey ◽  
Jörg M. Buchholz ◽  
Gitte Keidser
Keyword(s):  
Hearing Impairment ◽  
Hearing Aid ◽  
Normal Hearing ◽  
Referential Communication ◽  
Hearing Impaired ◽  
Directional Hearing ◽  
Acoustic Environment ◽  
Communication Task ◽  
Acoustic Environments ◽  
The Impact

Objectives This study investigates the hypothesis that hearing aid amplification reduces effort within conversation for both hearing aid wearers and their communication partners. Levels of effort, in the form of speech production modifications, required to maintain successful spoken communication in a range of acoustic environments are compared to earlier reported results measured in unaided conversation conditions. Design Fifteen young adult normal-hearing participants and 15 older adult hearing-impaired participants were tested in pairs. Each pair consisted of one young normal-hearing participant and one older hearing-impaired participant. Hearing-impaired participants received directional hearing aid amplification, according to their audiogram, via a master hearing aid with gain provided according to the NAL-NL2 fitting formula. Pairs of participants were required to take part in naturalistic conversations through the use of a referential communication task. Each pair took part in five conversations, each of 5-min duration. During each conversation, participants were exposed to one of five different realistic acoustic environments presented through highly open headphones. The ordering of acoustic environments across experimental blocks was pseudorandomized. Resulting recordings of conversational speech were analyzed to determine the magnitude of speech modifications, in terms of vocal level and spectrum, produced by normal-hearing talkers as a function of both acoustic environment and the degree of high-frequency average hearing impairment of their conversation partner. Results The magnitude of spectral modifications of speech produced by normal-hearing talkers during conversations with aided hearing-impaired interlocutors was smaller than the speech modifications observed during conversations between the same pairs of participants in the absence of hearing aid amplification. Conclusions The provision of hearing aid amplification reduces the effort required to maintain communication in adverse conditions. This reduction in effort provides benefit to hearing-impaired individuals and also to the conversation partners of hearing-impaired individuals. By considering the impact of amplification on both sides of dyadic conversations, this approach contributes to an increased understanding of the likely impact of hearing impairment on everyday communication.

scholarly journals Reciprocity and behavioral heterogeneity govern the stability of social networks

2020 ◽  
Vol 117 (6) ◽  
pp. 2993-2999 ◽  
Author(s):  
Roslyn Dakin ◽  
T. Brandt Ryder
Keyword(s):  
Social Networks ◽  
Social Connectedness ◽  
Social Dynamics ◽  
Social Systems ◽  
Bird Species ◽  
Network Stability ◽  
Apparent Paradox ◽  
Trade Off ◽  
Behavioral Heterogeneity ◽  
The Stability

The dynamics of social networks can determine the transmission of information, the spread of diseases, and the evolution of behavior. Despite this broad importance, a general framework for predicting social network stability has not been proposed. Here we present longitudinal data on the social dynamics of a cooperative bird species, the wire-tailed manakin, to evaluate the potential causes of temporal network stability. We find that when partners interact less frequently and when social connectedness increases, the network is subsequently less stable. Social connectivity was also negatively associated with the temporal persistence of coalition partnerships on an annual timescale. This negative association between connectivity and stability was surprising, especially given that individual manakins who were more connected also had more stable partnerships. This apparent paradox arises from a within-individual behavioral trade-off between partnership quantity and quality. Crucially, this trade-off is easily masked by behavioral variation among individuals. Using a simulation, we show that these results are explained by a simple model that combines among-individual behavioral heterogeneity and reciprocity within the network. As social networks become more connected, individuals face a trade-off between partnership quantity and maintenance. This model also demonstrates how among-individual behavioral heterogeneity, a ubiquitous feature of natural societies, can improve social stability. Together, these findings provide unifying principles that are expected to govern diverse social systems.

scholarly journals Automotive traffic noise and urban public spaces

2021 ◽  
Vol 9 (72) ◽  
Author(s):  
Greicikelly Gaburro Paneto ◽  
Cristina Engel de Alvarez ◽  
Paulo Henrique Trombetta Zannin
Keyword(s):  
Urban Space ◽  
Sound Pressure ◽  
Traffic Noise ◽  
Motor Vehicles ◽  
Open Spaces ◽  
Sound Levels ◽  
Measurement Results ◽  
Sound Pressure Levels ◽  
High Sound

In contemporary cities, and usually without realizing it, the population has been exposed to high sound pressure levels, which besides causing discomfort, can lead to health problems. Considering that a large part of this noise comes from emission from motor vehicles, this research aims to evaluate the sound behavior in sound environments configured by voids in the urban fabric, in order to identify whether open spaces can act as attenuators of sound levels. To obtain the expected results, the methodology used was structured from a review of the state-of-the-art and computer simulations relating the variables that influence the formation of urban space and sound emission and propagation, taking as a case study an urban portion of the municipality of Vitória/ES. In parallel, questionnaires were applied to evaluate the user's perception of their exposure. The measurement results indicated that the sound pressure levels caused by traffic noise are above the limit tolerated limit by the NBR norm 10151:2000 for the daytime period. In turn, the results obtained from the population indicated that there is little perception of noise by the users of the spaces surveyed.

scholarly journals Subjective Experience of Speech Depending on the Acoustic Treatment in an Ordinary Room

2021 ◽  
Vol 18 (23) ◽  
pp. 12274
Author(s):  
Emma Arvidsson ◽  
Erling Nilsson ◽  
Delphine Bard-Hagberg ◽  
Ola J. I. Karlsson
Keyword(s):  
Speech Perception ◽  
Subjective Experience ◽  
Sound Quality ◽  
Reverberation Time ◽  
Acoustic Environment ◽  
Acoustic Environments ◽  
The Right ◽  
Acoustic Treatment ◽  
High Degree ◽  
Speech Clarity

In environments such as classrooms and offices, complex tasks are performed. A satisfactory acoustic environment is critical for the performance of such tasks. To ensure a good acoustic environment, the right acoustic treatment must be used. The relation between different room acoustic treatments and how they affect speech perception in these types of rooms is not yet fully understood. In this study, speech perception was evaluated for three different configurations using absorbers and diffusers. Twenty-nine participants reported on their subjective experience of speech in respect of different configurations in different positions in a room. They judged sound quality and attributes related to speech perception. In addition, the jury members ranked the different acoustic environments. The subjective experience was related to the different room acoustic treatments and the room acoustic parameters of speech clarity, reverberation time and sound strength. It was found that people, on average, rated treatments with a high degree of absorption as best. This configuration had the highest speech clarity value and lowest values for reverberation time and sound strength. The perceived sound quality could be correlated to speech clarity, while attributes related to speech perception had the strongest association with reverberation time.

Exposure to industrial noise: impacts on cognitive performance

2021 ◽  
Vol 263 (4) ◽  
pp. 2590-2600
Author(s):  
Luiz Henrique Mesa Casa Pereira ◽  
Björn Knöfel ◽  
Jan Troge ◽  
Welf-Guntram Drossel ◽  
Marcel Klein ◽  
...  
Keyword(s):  
Cognitive Performance ◽  
Noise Analysis ◽  
Low Frequency ◽  
Cumulative Effect ◽  
Noise Sources ◽  
Industrial Noise ◽  
Sound Levels ◽  
Office Environments ◽  
High Sound ◽  
High Frequency Content

Research on the relation between exposure to noise and cognitive performance inside industrial environments is not as broad as on office environments. For a better understanding of the specific industrial noise problems, participants performed arithmetic tests inside a hemi anechoic room while they were exposed to sounds of five typical industrial noise sources. The subjects also classified how annoying they perceived the noise signals. The effect of noise on the arithmetic test's performance was larger on accuracy than on velocity, which was verified using a Student t-test. Spectral-temporal characteristics - especially high frequency content and strong low frequency modulation - appear to relate better with lower performance on the test than high sound levels. Subjects that evaluated noise as more annoying performed worse in a final arithmetic test (under silence) after being exposed to the noises, indicating a possible cumulative effect of noise on performance. The findings provide a better insight in the cognitive behavior of people who are exposed to industrial noise. Hence, the study will proceed with the specific noise analysis of single industrial workplaces.

Phase locking to complex stimuli at high sound levels and in noise‐damaged ears

1996 ◽  
Vol 100 (4) ◽  
pp. 2626-2626
Author(s):  
Eric D. Young ◽  
Roger L. Miller ◽  
Jeff C. Wong
Keyword(s):  
Phase Locking ◽  
Sound Levels ◽  
Complex Stimuli ◽  
High Sound
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