scholarly journals A framework for the quantification of soundscape diversity using Hill numbers

2022 ◽  
Author(s):  
Thomas Luypaert ◽  
Anderson S. Bueno ◽  
Gabriel S. Masseli ◽  
Igor L. Kaefer ◽  
Marconi Campos-Cerqueira ◽  
...  
Keyword(s):  
Analytical Framework ◽  
Landscape Scale ◽  
Time Of Day ◽  
Functional Ecology ◽  
Taxonomic Richness ◽  
Acoustic Niche ◽  
Acoustic Space ◽  
Hill Numbers ◽  
Sound Unit ◽  
Trait Space

1. Soundscape studies are increasingly common to capture landscape-scale ecological patterns. Yet, several aspects of soundscape diversity quantification remain unexplored. Although some processes influencing acoustic niche usage may operate in the 24h domain, most acoustic indices only capture the diversity of sounds co-occurring in sound files at a specific time of day. Moreover, many indices do not consider the relationship between the spectral and temporal traits of sounds simultaneously. To provide novel insights into landscape-scale patterns of acoustic niche usage at broader temporal scales, we present a workflow to quantify soundscape diversity through the lens of functional ecology. 2. Our workflow quantifies the functional diversity of sound in the 24-hour acoustic trait space. We put forward an entity, the Operational Sound Unit (OSU), which groups sounds by their shared functional properties. Using OSUs as our unit of diversity measurement, and building on the framework of Hill numbers, we propose three metrics that capture different aspects of acoustic trait space usage: (i) soundscape richness; (ii) soundscape diversity; (iii) soundscape evenness. We demonstrate the use of these metrics by (a) simulating soundscapes to assess if the indices possess a set of desirable behaviours; and (b) quantifying the soundscape richness and evenness along a gradient in species richness to illustrate how these metrics can be used to shed unique insights into patterns of acoustic niche usage. 3. We demonstrate that: (a) the indices outlined herein have desirable behaviours; and (b) the soundscape richness and evenness are positively correlated with the richness of soniferous species. This suggests that the acoustic niche space is more filled where taxonomic richness is higher. Moreover, species-poor acoustic communities have a higher proportion of rare sounds and use the acoustic space less effectively. As the correlation between the soundscape and taxonomic richness is strong (>0.8) and holds at low sampling intensities, soundscape richness could serve as a proxy for taxonomic richness. 4. Quantifying the soundscape diversity through the lens of functional ecology using the analytical framework of Hill numbers generates novel insights into acoustic niche usage at a landscape scale and provides a useful proxy for taxonomic richness measurement.

scholarly journals Vocal Communication Within a Forest Bird Community

2021 ◽  
Author(s):  
◽  
Joseph Fawzi Azar
Keyword(s):  
Bird Community ◽  
Song Thrush ◽  
Forest Bird ◽  
Acoustic Adaptation ◽  
Acoustic Niche ◽  
Adaptation Hypothesis ◽  
Acoustic Space ◽  
Acoustic Adaptation Hypothesis ◽  
The Uk ◽  
Study Species

<p><b>This thesis takes a community approach to investigate the acoustics of forest birds in Zealandia sanctuary, Wellington. Initially, the annual changes in vocalisation output of 16 study species and their possible effect on bird conspicuousness were described. Environmental factors that may shape these avian vocalisations were addressed though invoking two key hypotheses, the acoustic adaptation hypothesis, and the acoustic niche hypothesis. In addition, the songs of selected species are investigated: the role of song harmonics in the native North Island saddleback, Philesturnus rufusater, and their role in ranging, change in song dialect through time and space in the introduced song thrush, Turdus philomelos, and temporal change in the song of the native grey warbler, Greygone igata. Vocal activity of the study species varied seasonally, affecting their detectability in bird counts. Some species were mostly first heard rather than seen and viceversa. The results lend support to the acoustic niche hypothesis in that vocalisations within the forest bird community appear to have evolved towards divergence, with native species’ vocalisations being more dispersed within the community acoustic space than those of the introduced species. However, all species concentrated their energy within relatively narrow frequency bands, supporting the predictions of the acoustic adaptation hypothesis. Adaptation to different transmission properties associated with different singing elevations or physiological parameters such as body weight may have an effect on shaping such bird vocalisations.</b></p> <p>Forests provide a complex acoustic space for sound transmission and a “sound window” may not be a constant property of a given forest. The study revealed that a prominent sound window persists in the lower frequency range that is less affected by habitat. Some high frequencies may have similar average attenuation values to those of low frequency, however, with greater fluctuation in attenuation. Ground effect is a further factor in determining how well different frequency ranges transmit and birds may use acoustic characteristics of their habitat to enhance their signal.</p> <p>Harmonics in North Island saddleback chatter song were found to play a potential role in ranging (estimating the distance of signaller), for playback songs with more relative energy within higher harmonics were evidently perceived as coming from a nearby individual.</p> <p>The repertoire size of the song thrush population studied in Zealandia has apparently evolved to become larger and more varied than the source population of song thrushes in the UK, with more syllables delivered with less repetition than the UK song recordings examined.</p> <p>Over a period of 7 years, syllables in grey warbler song have shifted to a higher frequency, but there was no difference in the temporal structure of the song. Habitat effect, competition on the acoustic signal from reintroduced birds and ambient noise level are considered as possible casual factors.</p>

Assessment of Driver Fatigue, Distraction, and Performance in a Naturalistic Setting

2005 ◽  
Vol 1937 (1) ◽  
pp. 51-60 ◽  
Author(s):  
Lawrence C. Barr ◽  
C. Y. David Yang ◽  
Richard J. Hanowski ◽  
Rebecca Olson
Keyword(s):  
Analytical Framework ◽  
Time Of Day ◽  
Video Data ◽  
Driver Fatigue ◽  
Drowsy Driving ◽  
Motor Carrier ◽  
Naturalistic Setting ◽  
And Performance ◽  
The Impact ◽  
The Relationship

The results of a study to characterize episodes of driver fatigue and drowsiness and to assess the impact of driver fatigue on driving performance are documented. This data-mining effort performed additional analyses on data collected in an earlier study by the Federal Motor Carrier Safety Administration of the effects of fatigue on drivers in local and short-haul operations. The primary objectives of the study were to investigate fatigue as a naturally occurring phenomenon by identifying and characterizing episodes of drowsiness during all periods of driving and to determine the operational or driving environment factors associated with drowsy driving. A total of 2,745 drowsy events were identified in approximately 900 total hours of naturalistic driving video data. Higher levels of fatigue were associated with younger and less experienced drivers. In addition, a strong and consistent relationship was found between drowsiness and time of day. Drowsiness was twice as likely to occur between 6:00 a.m. and 9:00 a.m., and approximately 30% of all observed incidences of drowsiness occurred within the first hour of the work shift. Insights about the relationship between driver fatigue and driver distraction and inattention are provided. This study presents an analytical framework for quantitatively assessing driver fatigue and drowsiness as a function of driver characteristics and the driving environment. It is hoped that the results will help to identify effective countermeasures for drowsy driving that will reduce the number of commercial-vehicle-related fatalities and injuries.

scholarly journals Surface-Floating Pupal Exuviae of Chironomidae (Diptera) in Urban Streams: is There a Best Time of Day to Sample Them?

2016 ◽  
Vol 9 (2) ◽  
pp. 101-107
Author(s):  
Herick Soares Santana ◽  
Vanessa Araújo Lima ◽  
Juliana Simião-Ferreira
Keyword(s):  
Local Community ◽  
Adult Emergence ◽  
Time Of Day ◽  
Dry Season ◽  
Urban Streams ◽  
Environmental Condition ◽  
Taxonomic Richness ◽  
Pupal Exuviae ◽  
First Order ◽  
First Time

Abstract. The use of pupal exuviae is a method that allows evaluating the environmental condition using information provided by the diversity of Chironomidae. The exuviae can disperse over distances up to 100 m from where the adults emerged, allowing perform detailed studies on the local community. The aim of this study was verify whether there are differences in the taxonomic richness and abundance in the emergence of pupal exuviae of Chironomidae during different periods of day in three urban Cerrado streams. The samples were taken in the dry season of July 2011, in three first-order streams located nearby Anápolis municipality, Goiás State, Brazil, using drift nets for a period ranging from 8 to 20 h, with removal and replacement of the drift nets every two hours period. 6.129 exuviae were collected in the three streams and the Onconeura and Polypedilum generatotaled 70% of all individuals collected. The time at 16 h was the most representative of the number of exuviae collected, while the first time (8 h) had the lowest amount of exuviae. The genera richness and abundance of exuviae did not show changes according to the time of day on the streams, indicating that there is not a period in which there is a greater frequency of adult emergence of Chironomidae.Exúvias de Pupa de Chironomidae (Diptera) em Riachos Urbanos de Cerrado: existe um Melhor Horário do Dia para Amostrar?Resumo. O uso de exúvias de pupa é um método que permite avaliar condições ambientais utilizando informações da diversidade de Chironomidae. Exúvias de pupas podem se dispersar em distâncias de até 100 m dos locais onde os adultos emergiram, permitindo realizar estudos sobre a comunidade local. O objetivo deste estudo foi verificar se existem diferenças na riqueza taxonômica e abundância em exúvias surgidas de pupa de Chironomidae durante diferentes períodos do dia em córregos urbanos do Bioma Cerrado. As amostras foram coletadas na estação seca de julho de 2011, em três riachos de primeira ordem localizados próximos à cidade de Anápolis, Goiás, Brasil, utilizando redes de deriva por um período que variou de 8-20 h, com remoção e substituição das redes a cada duas horas. Foram coletadas 6129 exúvias nos três córregos e os gêneros Onconeura e Polypedilum totalizaram 70% de todos os indivíduos coletados. O horário de 16 h foi o mais representativo em relação ao número de exuvias coletadas, enquanto que as exúvias coletadas às 8 h foram menos abundantes. A riqueza e a abundância de gêneros de exúvias não apresentaram mudanças de acordo com o horário do dia nos córregos estudados, indicando que não existe um período no qual há uma maior frequência de aparecimento de Chironomidae adulto.

scholarly journals Acoustic niche partitioning in an anuran community from the municipality of Floriano, Piauí, Brazil

2019 ◽  
Vol 79 (4) ◽  
pp. 566-576 ◽  
Author(s):  
M. S. C. S. Lima ◽  
J. Pederassi ◽  
R. B. Pineschi ◽  
D. B. S. Barbosa
Keyword(s):  
Euclidean Distance ◽  
Niche Partitioning ◽  
Sympatric Species ◽  
Dominant Frequency ◽  
Amphibian Species ◽  
Acoustic Interference ◽  
Acoustic Niche ◽  
Important Trait ◽  
Acoustic Space ◽  
Distinct Features

Abstract Vocalizations are an important trait for the identification of cryptic and/or closely related amphibian species. Different vocalizations also contribute to partitioning of the acoustic space by sympatric species. This study aimed to describe the advertisement calls of anurans in a pond of the municipality of Floriano, State of Piauí, Brazil, and infer the acoustic niche partitioning of amphibians. Euclidean distance was used in a cluster analysis approach to infer the acoustic similarities among species. Thirteen species were analysed: Boana raniceps, Dendropsophus nanus, D. rubicundulus , D. minutus, Leptodactylus fuscus, L. troglodytes, L. vastus, Pithecopus nordestinus , Physalaemus cuvieri, P. nattereri, Pleurodema diplolister, Proceratophrys cristiceps and Scinax ruber. From these, six showed more than 90% of acoustic overlap: P. nattereri , P. cuvieri, L. fuscus and L. vastus (Leptodactylidae); and, D. nanus and D. rubicundulus (Hylidae). Despite the acoustic similarities among these six species, the acoustic interference was reduced due to the small number of sympatric species and to distinct features on carrier frequency such as dominant frequency and the degree of modulation in the frequency. Environmental factors limit the periods and sites of reproduction respectively, which may maintain the low anuran diversity and consequently reduce acoustic overlap.

scholarly journals Acoustic niche partitioning in two tropical wet forest bird communities

2020 ◽  
Author(s):  
Patrick J. Hart ◽  
Kristina Paxton ◽  
Thomas Ibanez ◽  
Grace Tredinnick ◽  
Esther Sebastián-González ◽  
...  
Keyword(s):  
Costa Rica ◽  
Strong Support ◽  
Bird Species ◽  
Null Model ◽  
Acoustic Signals ◽  
Bird Communities ◽  
Forest Bird ◽  
Tropical Wet Forest ◽  
Acoustic Niche ◽  
Acoustic Space

AbstractWhen acoustic signals sent from individuals overlap in frequency and time, acoustic interference and signal masking may occur. Under the acoustic niche hypothesis (ANH), signaling behavior has evolved to minimize overlap with other calling individuals through selection on signal structure and the sender’s ability to adjust the timing of signals. In this study, we examine the fine-scale use of acoustic space and the relevance of the acoustic niche hypothesis in two montane tropical wet forest bird communities (Costa Rica and Hawai’i) that vary in bird species richness. We used a null model approach to test the prediction that there are differences between observed and expected signal overlap in both communities. As predicted under ANH, we found much lower overlap of acoustic signals than expected by chance. In addition, spectral and temporal overlap between different signals was far more common in Hawaii than Costa Rica. These findings constitute strong support that there is competition for acoustic space in signaling communities, and this has resulted in temporal and spectral partitioning of the soundscape.

scholarly journals Timing Is Everything: Acoustic Niche Partitioning in Two Tropical Wet Forest Bird Communities

2021 ◽  
Vol 9 ◽  
Author(s):  
Patrick J. Hart ◽  
Thomas Ibanez ◽  
Kristina Paxton ◽  
Grace Tredinnick ◽  
Esther Sebastián-González ◽  
...  
Keyword(s):  
Costa Rica ◽  
Bird Communities ◽  
Frequency Range ◽  
Temporal Partitioning ◽  
Forest Bird ◽  
Tropical Wet Forest ◽  
Acoustic Niche ◽  
Signal Overlap ◽  
Acoustic Space ◽  
Expected Signal

When acoustic signals sent from individuals overlap in frequency and time, acoustic interference and signal masking may occur. Under the acoustic niche hypothesis (ANH), signaling behavior has evolved to partition acoustic space and minimize overlap with other calling individuals through selection on signal structure and/or the sender’s ability to adjust the timing of signals. Alternately, under the acoustic clustering hypothesis, there is potential benefit to convergence and synchronization of the structural or temporal characteristics of signals in the avian community, and organisms produce signals that overlap more than would be expected by chance. Interactive communication networks may also occur, where species living together are more likely to have songs with convergent spectral and or temporal characteristics. In this study, we examine the fine-scale use of acoustic space in montane tropical wet forest bird communities in Costa Rica and Hawai‘i. At multiple recording stations in each community, we identified the species associated with each recorded signal, measured observed signal overlap, and used null models to generate random distributions of expected signal overlap. We then compared observed vs. expected signal overlap to test predictions of the acoustic niche and acoustic clustering hypotheses. We found a high degree of overlap in the signal characteristics (frequency range) of species in both Costa Rica and Hawai‘i, however, as predicted under ANH, species significantly reduced observed overlap relative to the random distribution through temporal partitioning. There was little support for acoustic clustering or the prediction of the network hypothesis that species segregate across the landscape based on the frequency range of their vocalizations. These findings constitute strong support that there is competition for acoustic space in these signaling communities, and this has resulted primarily in temporal partitioning of the soundscape.

scholarly journals Vocal Communication Within a Forest Bird Community

2021 ◽  
Author(s):  
◽  
Joseph Fawzi Azar
Keyword(s):  
Bird Community ◽  
Song Thrush ◽  
Forest Bird ◽  
Acoustic Adaptation ◽  
Acoustic Niche ◽  
Adaptation Hypothesis ◽  
Acoustic Space ◽  
Acoustic Adaptation Hypothesis ◽  
The Uk ◽  
Study Species

<p><b>This thesis takes a community approach to investigate the acoustics of forest birds in Zealandia sanctuary, Wellington. Initially, the annual changes in vocalisation output of 16 study species and their possible effect on bird conspicuousness were described. Environmental factors that may shape these avian vocalisations were addressed though invoking two key hypotheses, the acoustic adaptation hypothesis, and the acoustic niche hypothesis. In addition, the songs of selected species are investigated: the role of song harmonics in the native North Island saddleback, Philesturnus rufusater, and their role in ranging, change in song dialect through time and space in the introduced song thrush, Turdus philomelos, and temporal change in the song of the native grey warbler, Greygone igata. Vocal activity of the study species varied seasonally, affecting their detectability in bird counts. Some species were mostly first heard rather than seen and viceversa. The results lend support to the acoustic niche hypothesis in that vocalisations within the forest bird community appear to have evolved towards divergence, with native species’ vocalisations being more dispersed within the community acoustic space than those of the introduced species. However, all species concentrated their energy within relatively narrow frequency bands, supporting the predictions of the acoustic adaptation hypothesis. Adaptation to different transmission properties associated with different singing elevations or physiological parameters such as body weight may have an effect on shaping such bird vocalisations.</b></p> <p>Forests provide a complex acoustic space for sound transmission and a “sound window” may not be a constant property of a given forest. The study revealed that a prominent sound window persists in the lower frequency range that is less affected by habitat. Some high frequencies may have similar average attenuation values to those of low frequency, however, with greater fluctuation in attenuation. Ground effect is a further factor in determining how well different frequency ranges transmit and birds may use acoustic characteristics of their habitat to enhance their signal.</p> <p>Harmonics in North Island saddleback chatter song were found to play a potential role in ranging (estimating the distance of signaller), for playback songs with more relative energy within higher harmonics were evidently perceived as coming from a nearby individual.</p> <p>The repertoire size of the song thrush population studied in Zealandia has apparently evolved to become larger and more varied than the source population of song thrushes in the UK, with more syllables delivered with less repetition than the UK song recordings examined.</p> <p>Over a period of 7 years, syllables in grey warbler song have shifted to a higher frequency, but there was no difference in the temporal structure of the song. Habitat effect, competition on the acoustic signal from reintroduced birds and ambient noise level are considered as possible casual factors.</p>

scholarly journals Acoustic space partition by four Hylidae in an open habitat in Central Brazil

Heringeriana ◽  
2020 ◽  
Vol 14 (2) ◽  
pp. 65-80
Author(s):  
Andréa Braga de Lira ◽  
Renata Duarte Alquezar ◽  
Aída Pereira Giozza ◽  
Emayre Rebecca Dos Santos Campos ◽  
Antonio Gabriel Torres Cardoso ◽  
...  
Keyword(s):  
Special Interest ◽  
Niche Overlap ◽  
Advertisement Call ◽  
Specific Interactions ◽  
Space Partitioning ◽  
Central Brazil ◽  
Space Partition ◽  
Open Habitat ◽  
Acoustic Niche ◽  
Acoustic Space

The use and partition of the acoustic space by anuran species is of special interest for evaluating inter-specific interactions in acoustic traits. Here we evaluate the acoustic space partitioning by four species of hylidae over the course of eleven months, at the Ecological Station of Águas Emendadas - DF, central Brazil. The acoustic niche overlap among species was smaller than expected by chance, indicating a competition in the use of this resource. If competition affects the use of acoustic resouces by species, low overlap on advertisement call traits are relevant in open habitats anuran assemblies.

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