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Anthropogenic noise impairs owl hunting behavior
Abstract
Emerging evidence indicates that anthropogenic noise has highly detrimental impacts on natural communities; however, the effects of noise on acoustically specialized predators has received less attention. We demonstrate experimentally that natural gas compressor station noise impairs the hunting behavior of northern saw-whet owls (Aegolius acadius). We presented 31 wild-caught owls with prey inside a field-placed flight tent under acoustic conditions found 50–800 m (46–73 dBA) from a compressor station. To assess how noise affected hunting, we postulated two hypotheses. First, hunting deficits might increase with increasing noise—the dose–response hypothesis. Secondly, the noise levels used in this experiment might equally impair hunting, or produce no impact—the threshold hypothesis. Using a model selection framework, we tested these hypotheses for multiple dependent variables—including overall hunting success and each step in the attack sequence (prey detection, strike, and capture). The dose–response hypothesis was supported for overall hunting success, prey detection, and strike behavior. For each decibel increase in noise, the odds of hunting success decreased by 8% (CI 4.5%–11.0%). The odds of prey detection and strike behavior also decreased with increasing noise, falling 11% (CI 7%–16%) and 5% (CI 5%–6%), respectively. These results suggest that unmitigated noise has the potential to decrease habitat suitability for acoustically specialized predators, impacts that can reverberate through ecosystems.
... Additionally, noise has been shown to have a number of adverse effects on acoustically-mediated behaviors. For instance, noise can lead to decreased anti-predator responses (Jung et al., 2020), lower foraging success (Mason et al., 2016;Halfwerk and van Oers, 2020), and increased time spent on vigilance (Meillère et al., 2015), presumably to compensate for diminished acoustic detection of threats. Perhaps the best studied effects of noise on acoustically-mediated behaviors are the impacts of noise on songbird communication. ...
... This again, is likely a reflection of the behavior and ecology of the animals. Barn owls and Northern saw-whet owls can hunt in total darkness, localizing prey by sound, which requires enhanced auditory sensitivity relative to other species (Payne, 1971;Mason et al., 2016). Barn owls and Northern saw-whet owls both have asymmetric ears and complete facial ruffs that likely enhance sound detection and localization (Norberg, 1977;Knudsen and Konishi, 1979;Moiseff, 1989). ...
... Although thresholds have not been determined psychophysically for Northern saw-whet owls, they have been shown behaviorally to have excellent sound localization abilities (Frost et al., 1989). The extremely low thresholds suggest that even very low amplitude masking noises may have an effect on the detection abilities of owls (Mason et al., 2016). ...
Anthropogenic noise and its impact on wildlife has recently received considerable attention. Research interest began to increase at the turn of the century and the number of publications investigating the effects of anthropogenic noise has been growing steadily ever since. Songbirds have been a major focus in the study of anthropogenic noise effects, with a significant portion of the literature focusing on the changes in singing behavior in noise. Many of these studies have found increases in the amplitude or frequency of song, or changes in the temporal patterning of song production, putatively due to the masking effects of noise. Implicit in the masking hypothesis is the assumption that all species process sounds in noise similarly and will therefore be subject to similar masking effects. However, the emerging comparative literature on auditory processing in birds suggests that there may be significant differences in how different species process sound, both in quiet and in noise. In this paper we will (1) briefly review the literature on anthropogenic noise and birds, (2) provide a mechanistic overview of how noise impacts auditory processing, (3) review what is known about the comparative avian auditory processing in noise, and (4) discuss the implications of species level differences in auditory processing for behavioral and physiological responses to anthropogenic noise.
... Hearing sensitivities among predators of rodents are likely reflected by this general range (~1-8 kHz). Many predators target rodents using acoustic cues for prey detection (reviewed in Barber et al., 2010) and interference from the soundscape is known to result in declines in prey detection and hunting success (Mason et al., 2016;Senzaki et al., 2016). Lower prey capture success could lead to predators avoiding louder areas, which could then have direct effects on rodent populations and/or decrease rodents' perceived predation risk, changing their behavior. ...
... For instance, moonlight can increase perceived predation risk by small rodents (Fanson, 2010;Johnson & De León, 2015) likely due to improved hunting success by predators (Clarke, 1983;Penteriani et al., 2013). Just as moonlight can influence behavior relevant to predator-prey interactions through relative changes in visibility, variation in natural sounds that can influence an animal's abilities to detect threats or find prey through audition is also highly relevant to animal behavior and distributions (Mason et al., 2016;Römer & Holderied, 2020;Siemers & Schaub, 2011). ...
... The five groups we defined were mesocarnivores, Cricetid rodents, kangaroo rats, ground foraging birds, and insectivorous birds. Because there is evidence of decreased hunting success for predators in noise (Mason et al., 2016;Senzaki et al., 2016;Siemers & Schaub, 2011;Tuttle et al., 1982) we expected that impaired hunting success would cause mesocarnivores to avoid natural sound treated areas. Thus, we predicted that both detection (p) and occupancy (Ψ) probabilities of mesocarnivores would be lower in phantom, shifted, and real ocean conditions relative to control, with the lowest probabilities in shifted conditions due to the shifted treatment's higher frequency overlapping more strongly with mesocarnivores' hearing range and the rustling sounds these predators use to locate prey (Goerlitz & Siemers, 2007;Goerlitz et al., 2008;Heffner, 1983;Neff & Hind, 1955). ...
A growing body of research focuses on how background sounds shape and alter critical elements of animals’ lives, such as foraging behavior, habitat use, and ecological interactions (Bradbury & Vehrencamp, 2011; Barber et al., 2010; Kight & Swaddle, 2011; Shannon et al., 2016). Much of this research has centered on the effects of anthropogenic noise (Dominoni et al., 2020; Francis & Barber, 2013; Ortega, 2012; Swaddle et al., 2015), but recent studies have also revealed that natural sound sources can influence animal behavior (Davidson et al., 2017; Le et al., 2019). Natural sounds, such as crashing surf, can create conditions where signaling and listening are difficult, but how this influences different species’ ecological interactions are unknown. To study the effects of crashing surf sound we experimentally introduced landscape-level acoustic playbacks where surf sound was not naturally present to create a “phantom ocean”. Phantom ocean treatment sites were employed alongside higher frequency “shifted” treatment sites to test for frequency-dependent effects, “real ocean” sites where surf sound was endemic, and ambient control sites. The phantom and shifted treatments were played continuously during the spring and summer of 2017-2019. Within this acoustic experimental landscape we conducted multiple studies to test the effects of crashing surf sound on animal behavior, habitat use, and ecological interactions. Through an artificial caterpillar predation experiment modeled after Roslin et al. (2017), we found that when exposed to natural sound treatments the foraging activity of rodents and arthropods increased, while that of birds declined. A potential explanation for this pattern includes taxon-specific responses reflecting different perceived risk-reward trade-offs in natural sound conditions. To follow this up we performed occupancy modeling on data collected by camera traps set within our system. We observed different responses among groups of species with different functional roles in the community for both detection (p) and occupancy (Ψ) probabilities. Our combined results indicate different species and functional groups have unique foraging behavior and patch use responses to natural sounds, likely based on their ecological interactions. Specifically, Cricetid rodents are likely more active in areas exposed to natural sounds, possibly due to lower perceived predation risk because mesocarnivores are less active. Insectivorous birds are also likely less active under natural sounds conditions, although the frequency of the sound, and the body size and diet of the bird appear influential. Together these findings suggest that natural sounds shape not only individual behavioral adjustments, but also multi-trophic, community level interactions. Our results show that natural sounds are an important driver of ecological interactions, but much remains to be uncovered. The mechanisms by which natural sounds influence individuals, populations, and many other aspects of ecology remain unexplored and provide fertile ground for future inquiry.
... First, great horned owls are acoustic specialists and are particularly active at dawn and dusk. 36 High noise levels from commuting traffic in urban areas during twilight could impair hunting, as has been shown in several owl species, 37,38 and force urban owls to shift from foraging during dawn and dusk to other times of the night that are less noisy, but also darker, favoring improved dim light vision. Shifts in activity toward deeper times of night have been documented in other taxa; for instance, human disturbance has caused broad scale shifts to increased nocturnality among small mammals. ...
... Increased reliance on vi-sual surveillance when auditory surveillance is impaired by noise has been documented in mammals and birds, [43][44][45][46] and these consequences typically come at the cost of foraging. Because noise can drastically reduce owl prey detection 38 and hunting success, 37 it is possible that selection could act upon urban owl visual systems to compensate for the decreased reliance on hearing. These cross-modality effects should be the focus of future work, especially given that artificial night lighting can covary strongly with noise pollution in urban areas. ...
... This increase in visual vigilance behavior (i.e., scanning) can decrease the amount of time an adult spends on other behaviors like parental care and foraging (i.e., foraging-vigilance tradeoff; Sweet et al., 2022). Additionally, species that rely on audition to capture prey, such as owls, experience reduced foraging efficiency when exposed to traffic noise (Mason, McClure & Barber, 2016;Senzaki et al., 2016). Background noise can also impair localization of hidden prey for diurnal songbirds, such as the American Robin (Turdus migratorius) (Montgomerie & Weatherhead, 1997); thus, it is possible that anthropogenic noise could impair prey cue detection and hunting success in other diurnal birds as well. ...
... Because increased visual vigilance in noise comes at a cost to foraging rate (Sweet et al., 2022) and noise can reduce foraging efficiency by masking prey sounds (Montgomerie & Weatherhead, 1997;Mason, McClure & Barber, 2016;Senzaki et al., 2016), there should be a decline in provisioning rate, but not necessarily time spent within 10 m of the nest box. ...
Sensory environments are rapidly changing due to increased human activity in urban and non-urban areas alike. For instance, natural and anthropogenic sounds can interfere with parent-offspring communication and mask cues reflective of predation risk, resulting in elevated vigilance at the cost of provisioning. Here we present data from two separate studies involving anthropogenic noise and nestling provisioning behavior in Western Bluebirds ( Sialia mexicana ): one in response to short-term (1 h) experimental noise playback and a second in the context of nests located along a gradient of exposure to continuous noise. In the short-term playback experiment, nests were sequentially exposed to trials with either traffic noise or a silent audio track. The effect of the playback type interacted with the effect of the order in which trials were presented. The outcome was that provisioning rates during second trials with the silent track playback were higher than provisioning rates during noise playback on first or second trials, but not first trials with the silent track playback. Additionally, failed provisioning attempts only occurred during noise trials. In contrast, provisioning rates increased with the amplitude of noise among nests located in a gradient of continuous noise exposure. For nests along the noise gradient, the latency to resume provisioning behavior following human disturbance from approaching the nest negatively covaried with noise exposure amplitude. Specifically, birds resumed provisioning behavior more quickly with increased noise amplitude. Collectively, both studies demonstrate that noise can influence avian parental care of offspring, but the direction of the effect of noise are opposite. This difference could reflect variation in populations, noise characteristics or latent environmental contexts, or different ages of nestlings. However, it is also possible that the divergent responses reflect important differences in organismal responses to short-term versus long-term noise exposure. The possibility of mismatches in responses to short-term versus long-term noise exposure should be the focus of additional research, especially because short-term noise exposure experiments are often used to understand the consequences of noise pollution for organisms living in noisy environments.
... Among birds, owls are the most well-known group of nocturnal species and many are top predators, having a significant influence on ecosystems (Isaac et al. 2013). Since most owls rely on a remarkable acoustic sensory capacity to locate prey, high noise levels can impair their hunting success (Mason et al. 2016, Fröhlich & Ciach 2018 and hinder these predators from colonizing urbanised areas due to higher energy costs, i.e. more vocal efforts would be required since the calls would be hampered by high noise levels (Nemeth et al. 2013, Fröhlich & Ciach 2019. Owls have also evolved to hunt efficiently in dark conditions thanks to specific anatomical and physiological eye adaptations (Beckwith-Cohen et al. 2015), but how owls are distributed and how they behave in artificially illuminated landscapes needs to be investigated much further. ...
... Noise pollution hampers the hunting efficiency in aural-sensitive predators like owls, and therefore can influence the choice of hunting areas in the landscape. Negative effects of anthropogenic noise have previously been identified by both experimental studies, showing a decline in hunting efficiency in a noisy environment (Mason et al. 2016), and by field experiments, revealing a decrease in foraging efficiency due to traffic noise (Senzaki et al. 2016). Noise pollution has also been identified as a factor able to shape the structure of owl communities in urban landscapes, limiting owl species richness when noise intensity increases (Fröhlich & Ciach 2019). ...
At present, the intensification of urban landcover is one of the most critical threats for biodiversity. Common side-effects of urban sprawl are anthropogenic noise and artificial light at night (ALAN). Although their negative effects have often been described, little research has concerned nocturnal wildlife, especially avian predators. Here, we investigated the effect of urban and tree cover, traffic noise and ALAN on the presence of the Tawny Owl Strix aluco, a common night-active predator in Europe. We conducted playback surveys along an urban gradient in Turin (Italy) to detect species presence. Traffic noise was measured in the field, the cover of built-up and (semi-)natural areas was estimated using GIS and multiple measures of ALAN were acquired from a light pollution map. We modelled species presence as a function of each environmental predictor and we found a significant negative relationship with light pollution, which was the foremost urban stressor affecting Tawny Owl occurrence. Our findings suggest that Tawny Owls are more likely to be found in less artificially illuminated areas and that their distribution in urban areas is not only influenced by noise pollution and the availability of suitable habitat, but also the intensity of ALAN. Therefore, light pollution could be a key driver of the spatial distribution of Tawny Owls and potentially other nocturnal species in urban ecosystems.
... Noise pollution is known to impact behavior (e.g., hampered communicative behavior, perception of signals; Francis et al. 2011;Halfwerk et al. 2011;Derryberry et al. 2020;or altered habitat selection;Rheindt 2003;Goodwin and Shriver 2011), physiology (e.g., noise stress; Raap et al. 2017;Injaian et al. 2018;Kleist et al. 2018), and fitness of individuals (e.g., impaired survival or fecundity; Schroeder et al. 2012;Simpson et al. 2016;Senzaki et al. 2020). Impacts on individuals can have cascading effects on communities by disrupting species interactions and can ultimately lead to animal declines and reduced species richness (Francis et al. 2009(Francis et al. , 2012Siemers and Schaub 2011;Mason et al. 2016), raising serious conservation concerns (Francis and Barber 2013;Shannon et al. 2016a). ...
... We found that the noise of agricultural tractors alone does not elicit a fleeing response in male barn swallows (Figure 1). Birds and other animals typically tend to avoid areas where anthropogenic noise has a strong impact, such as the vicinity of main roads or the surroundings of industrial operation areas (Francis et al. 2009;McClure et al. 2013;Mason et al. 2016;Liu et al. 2020). Barn swallows regularly breed on buildings or other man-made structures, in places where the presence of anthropogenic noise and humans is unavoidable, such as farms, under bridges on busy highways or even along busy streets of urban settlements (Turner 2006). ...
Anthropogenic noise can affect a number of behavioral, physiological and ecological aspects of animals from major taxonomic groups, raising serious conservation concerns. For example, noise pollution impacts communicative behavior and perception of signals, movements and distribution, as well as predator-prey interactions, such as hunting success or predator detection and predation risk assessment. We have carried out an experimental playback study, in which we investigated whether exposure to anthropogenic noise (sound of a tractor) distracts free-ranging barn swallows Hirundo rustica from paying attention to an approaching human ‘predator’ (the ‘cognitive distraction’ hypothesis), or whether noise leads to increased responsiveness to this ‘predator’ (the ‘increased threat’ hypothesis). The subjects were male barn swallows attending their breeding territories during the time when the females were incubating. We found that barn swallow males initiated flight at significantly greater distances to the approaching human ‘predator’ in the noise treatment than during the quiet control trials. These results suggest that anthropogenic noise causes increased vigilance and reactivity rather than distraction, enabling birds to avoid the ‘predator’ more quickly. We further discuss the mechanism behind the increased alertness in response to noise and contrast the ‘increased threat’ mechanism, usually tested in previous studies, with an alternative ‘cognitive sensitization’ mechanism.
... This was assumed to imply that behavioural adjustments to high noise levels were possible, but costly [34]. Further negative impacts of noise were found on the hunting success of northern saw-whet owls Aegolius acadicus, which decreased with increasing noise levels [35]. With respect to physiological responses to noise, European starlings, considered to be urban exploiters, did not show any stress response to traffic noise and their fledging success was not impacted in environments with higher traffic noise [36]. ...
... They allow the impact to vary gradually, for example, by the placement of a stressor and choosing its level, and they analyse its effect on bird responses as a continuous variable. For example, for reproducing distinct levels of anthropogenic noise, recorders have been used to simulate traffic noise [16,35]. Other studies have selected different sites (e.g., streets) within exisiting infrastructures with varying levels of traffic volume and noise [20,32]. ...
With increasing urbanization and related loss of biodiversity, it has become increasingly important to understand the determinants of biodiversity in cities, and to learn how we can maintain existing habitats and improve their quality for both wildlife and humans. Detrimental effects of urbanization on animals such as noise and light pollution, have frequently been reported, but comparatively little is known about the connection between different types of traffic infrastructure and their impacts on urban birds. Here, we provide an overview of the existing knowledge about bird responses to traffic-related stressors, and most importantly, we highlight that this aspect has not been satisfactorily investigated in urban environments. Therefore, we suggest suitable study systems and designs with which the effects of traffic infrastructure on bird communities in cities could be studied, and how biodiversity, in tandem with human wellbeing, in cities would benefit from improvements to the existing infrastructures. In doing so, we aim to strengthen the connection between human wellbeing and birds through research that will ultimately facilitate the development of sustainable cities.
... PA acoustic environments, or 'soundscapes', are an important element influencing both natural and human systems, and the study of how natural and human systems interrelate through sound can potentially lead to greater management effectiveness for PA around the world (Smith and Pijanowski 2014;Francis et al. 2017;Levenhagen et al. 2020). A major area of soundscape research focuses on natural systems and bioacoustics to understand how animals use acoustic and vibrational abilities to communicate, and to detect the presence of predators and prey (Francis 2015;Mason et al. 2016;Deichmann et al. 2018). In parallel, perceptual soundscape studies have been used in PA research focused on human-systems to evaluate the sounds visitors hear in PA, develop indicators of soundscape quality, and improve visitor experiences (Miller et al. 2018;. ...
... Typically, different methods are used to study natural systems and human systems (visitor experiences) within PA. PA natural systems acoustic monitoring and research has normally focused on characterization and measurement of the sound environment in combination with behavioral observation of populations of interest (Francis 2015;Mason et al. 2016;Deichmann et al. 2018). For example, the United States National Park Service (USNPS) protocols include objective measures of sound, such as duration and dBA, to measure the extent of specific sounds (USNPS 2013). ...
Protected areas (PA) represent the primary mechanism to protect global ecosystems; yet current capacities often lead to geographic imbalances for PA management around the world. PA soundscapes have proved a valuable element to inform effective management, as natural sounds are important for healthy natural systems and rewarding visitor experiences. This article employed a systematized literature review of PA soundscape research, matching the areas of study described for the 218 articles, with PA from the World Database on Protected Areas (WDPA). The studies took place in 372 PA, which were cataloged by geographic location and size where possible, country, and continent. Data charting included extracted keywords, research objectives, methods, outcomes and future research needs. Numeric and geographic analysis focused on understanding the nature, extent, and distribution of the studies, while thematic analysis was applied to identify trends with respect to methods, outcomes, and future research. Study results identified content and geographic imbalances between studies in tropical and temperate zones, terrestrial and marine environments, and the Global South and North. Discussion considers how global initiatives may support information and resource sharing that facilitates knowledge and capacity transfer between the two regions.
... Birds rely on acoustic signals and cues to successfully communicate with conspecifics and to detect predators and prey (e.g., Montgomerie and Weatherhead 1997;Mennill et al. 2002;Templeton et al. 2005). As such, they are often used as a model taxon for examining the effects of acoustic masking, showing a reduced ability to detect (discern a signal from irrelevant sound [i.e., noise]; Luther and Gentry 2013; e.g., Lucass et al. 2016), discriminate (differentiate one signal from another, e.g., intruder song from neighbor song; Luther and Gentry 2013; e.g., Pohl et al. 2012), and localize signals (identify the location of the signal source; Senzaki et al. 2018; e.g., Mason et al. 2016) within noise-polluted environments. Recent evidence indicates that avian signalers respond to both anthropogenic and natural noise exposure by adjusting song performance (Davidson et al. 2017) and vocal activity ) under more intense ambient conditions. ...
... Irrelevant stimuli can cause a signal receiver to involuntarily divert its limited attention away from responding to relevant signals and cues (Chan et al. 2010), such as a conspecific intruder. Attributing a specific mechanism -namely acoustic masking or distraction -to behavioral responses is not always delineable from experimental results (e.g., Grade and Sieving 2016;Mason et al. 2016;Senzaki et al. 2016). However, chronic exposure to our treatment playbacks throughout the breeding season (and the water-generated noise naturally present in the unmanipulated, ambient soundscape) may have reduced the mechanistic effect of treatment-related distraction as our focal birds likely became habituated to its presence (Rankin et al. 2009). ...
Recent research suggests that anthropogenic noise can substantially alter animal behavior. Although there are many sources of natural background noise, the relative influence of these sounds on behavior has received much less attention. Using landscape-scale playbacks of rushing rivers and crashing ocean surf, we investigated how habitat appropriate natural noise alters territorial defense behaviors in lazuli buntings (Passerina amoena) occupying riparian areas and spotted towhees (Pipilo maculatus) in riparian and coastal areas when exposed to simulated intruder song. We also incorporated naturally occurring cicada noise as an acoustic source influencing lazuli bunting behavior. Both songbird species possess songs that share substantial spectral overlap with low-frequency, water-generated noise, and lazuli bunting song shares an additional high-frequency overlap with cicada calls. Thus, there is potential for background acoustic conditions to mask conspecific signals. We found that detection and discrimination of conspecific playback occurred more slowly for both species as background sound levels increased. Lazuli buntings also exhibited complex flight behavior in noise, suggesting they respond differently depending on the amplitude and type of background noise (with versus without cicada calls). Our results suggest natural noise can impair territorial defense behaviors in songbirds, highlighting natural soundscapes as an under-appreciated axis of the environment.
... Evidence mounts that anthropogenic noise has detrimental effects on animals 4 and the potential for anthropogenic noise to interfere with the detection of important environmental cues and communication signals was long suspected [5][6][7][8] . Anthropogenic noise has now been shown to hinder finding mates 9-11 , avoiding predators [12][13][14] and locating prey [15][16][17][18][19] . Such impediments to detecting, identifying, or locating sounds of interest in noisy environments could be due to interference with sensory encoding of information, cognitive processing of information (e.g., distraction), or both [20][21][22] . ...
Female crickets reared in traffic noise have been reported to be faster or slower to locate male song than those reared in silence across species. We reared female Teleogryllus oceanicus in traffic noise and silence, and had adult females locate male song broadcast amidst traffic noise or silence. We recorded activity of two auditory interneurons in a subset of individuals under identical acoustic conditions. Regardless of rearing treatment, crickets were slower to leave their shelter when presented with male song in silence than in traffic noise, while crickets reared in traffic noise were also slower to leave overall. Crickets reared in traffic noise also had higher baseline AN2 activity, but rearing condition did not affect hearing thresholds or auditory response to male song. Our results demonstrate behavioural and auditory effects of long-term exposure to anthropogenic noise. Further, they support the idea that silence itself is a potentially aversive acoustic condition.
... Anthropogenic noise has varied effects on bird population. These effects range from the masking of birds' acoustic signals (Slabbekoorn et al., 2007;Benıtez-Loṕez et al., 2010;Schroeder et al., 2012;McIntyre, 2013;Senzaki et al., 2016) to physiological stress on the birds (Barber et al., 2010), thereby leading to the reduction in breeding success and survival of birds and overall decline in their population (Habib et al., 2007;Halfwerk et al., 2011;Luo et al., 2015;Mason et al., 2016). On the whole, our result agrees with finding from other studies (Seress and Liker, 2015;Carral-Murrieta et al., 2020). ...
Introduction
The rural-urban gradient serves as a valuable context for investigating the impact of urbanization on biodiversity. While previous studies have demonstrated shifts in bird communities along this gradient, our understanding of the specific impacts of individual urban components such as man-made physical structures and anthropogenic noise along this gradient remains limited, and more so, in Afro-tropical environments.
Method
Employing the point count method, we recorded birds and also determined the levels of anthropogenic noise and physical structures, across fifteen sites along the rural-urban gradient on the Jos Plateau, Nigeria. We then investigated variations in bird communities along the urbanization gradient and assessed the influence of the two urban components -anthropogenic noise and physical structures, on bird populations.
Results
There was a decline in bird abundance and species richness along the urbanization gradient. Similarly, species common to all the urbanization categories (species present at least at one point in rural, suburban, and urban) also exhibited a decrease in abundance. The suburban area showed a greater similarity in bird community composition to the urban area than the rural area. Notably, as the level of urban development increased, numerous bird species associated with undisturbed sites gradually vanished. Both anthropogenic noise and physical structures exhibited significant negative effects on bird abundance and species richness. Interestingly, we did not find evidence to suggest that the impact of anthropogenic noise was dependent on the level of physical structures. Anthropogenic noise had a significant negative relationship with bird abundance and species richness at all levels of physical structures.
Discussion
We provide evidence that bird abundance and species richness respond negatively to urbanization-related increase in anthropogenic noise and physical structures. That the impact of anthropogenic noise on birds was independent of physical structures suggests that birds in reserved areas, including urban green areas with fewer human activities may equally be affected by noise as are birds in human-dominated areas, if noise sources are near. Overall, our research underscores the detrimental consequences of anthropogenic habitat modification, particularly the alteration of structural and acoustic properties, and emphasizes the importance of preserving undisturbed habitats and implementing ecologically mindful urban planning strategies to safeguard bird communities in the Afro-tropics.
... 42,43 The sensitive eyesight and hearing of nocturnal creatures, such as owls and bats, can be impaired by artificial noise and light, thereby hampering their ability to locate prey, such as mosquitoes and rodents, which are vectors of human disease. 44,45,46 Urban heat islands. Built-up developments can impinge on their surroundings through another mechanism: heat. ...
Urban development often generates noise and light pollution, reduces green space, produces heat islands, and increases population density that can exacerbate crime, disease transmission, anxiety, and stress. This article argues that individuals and communities have rights to not have their space impinged upon by urban plans, designs, or development. This negative right means governments have ethical obligations to develop infrastructure that mitigates adverse health consequences, preserves natural environments, safeguards ecological well-being, and promotes peace and public health.
... Road traffic noise has been shown to impede owl hunting and the masking and/or distraction effects of traffic noise are expected to potentially occur beyond 120m from a road (21) . Emulation of compressor noise 50m away (73 dBA) has been shown to half the probabilities of a northern sawwhet owl detecting and accurately striking a mouse, reducing the overall chance of chance to almost zero; Emulations of compressor noise up to 800m away (46 dBA) are still observed to negatively impact on hunting success (22) . Therefore, a scoping distance in the order of 1000m could be considered a reasonable basis for scoping for constant sources of noise. ...
... Noise can interfere with the ability of predators to hunt and prey to evade capture. For example, birds of prey rely on hearing to locate their targets, and small mammals use sound to detect approaching predators [14]. Over time, noise pollution can lead to shifts in species composition. ...
Urban natural parks represent a remarkable concept that evokes the coexistence of human habitation with a wild environment, and the associated interactions between human and natural territories. In this context, urban noise infringes upon the natural soundscape, leading to various consequences for both realms. This study seeks to characterize the impact of anthropic noise levels on biodiversity in the urban natural Văcărești Park (Bucharest, Romania), utilizing on-site measurements and software simulation techniques. The study seeks to develop a method for evaluating integrative strategies to mitigate the impact of traffic noise on wildlife in an urban wild park, without addressing the specific effects of noise on the perception and communication of individual species. By calibrating field measurements with laboratory results, a more reliable data set will be used to identify areas where the biophonic environment is impacted by anthropogenic noise. Since human-generated noise in an urban natural park predominantly originates from road traffic and industrial sites, managing traffic noise and its propagation pathways could substantially improve the park’s soundscape. Additionally, this study will apply software simulations for noise reduction strategies, such as vegetation planting and earthen embankments, to obtain suitable solutions and propose plausible and effective actions to authorities for improving the biophonic environment. This research could also serve as the basis for long-term monitoring, allowing for the assessment of the evolution and impact of implemented measures over time.
... Anthropogenic noise has been found to induce complex biological responses and influence wildlife in many ways (Shannon et al. 2016). Noise pollution can directly affect the behavior of many animals, such as mating (Bent et al. 2018;Senzaki et al. 2018;Duarte et al. 2019), foraging (Wale et al. 2013;Luo et al. 2015;Mason et al. 2016;Song et al. 2020), vigilance (Wale et al. 2013;Zhou et al. 2019), and territorial defence (Luther and Derryberry 2012). Human-generated noise can also influence multiple physiological responses that correlate with the stress response, immune regulation, hearing damage, cardiovascular health, DNA integrity, and gene expression (Kight and Swaddle 2011;Shannon et al. 2016). ...
Noise pollution has been shown to affect wild animals in various ways, but little is known about its consequences at the community level. Investigating animals’ overall vocal responses to noise across multiple sympatric species can reveal the complex nature of noise impacts but is challenging. In this study, we employed social network analysis (SNA) to evaluate how anuran communities and populations vary their calling behaviors in response to aircraft noise. SNA of anuran communities revealed that conspecific individuals increase the aggregation of their spectral (i.e., minimum frequency, maximum frequency, and dominant frequency), temporal (call duration, call rate, and call effort), and overall spectral–temporal features as an airplane passes through. SNA of populations also revealed that anurans could increase the interindividual similarity of multiple call characteristics in response to airplane noise. Furthermore, our network analysis of multiple species and multiple call traits revealed an effect of noise in species whose calling behavior did not change in previous separate analyses of each species and single traits. This study suggests that noise pollution may change the pattern of combined acoustic properties at the community level. Our findings highlight the importance of integrated methods and theories for understanding the ecological consequences of noise pollution in future studies.
... Field studies of other species also suggest that noise affects response to acoustic signals via masking, although it is usually not possible to exclude other mechanisms. Reduced signal response in overlapping noise was found in lazuli buntings, Passerina amoena, spotted towhees, Pipilo maculatus (Reed et al., 2021), northern cardinals, Cardinalis cardinalis (Grade & Sieving, 2016), great tits, Parus major (Templeton et al., 2016), and several species of owls (Mason et al., 2016;Senzaki et al., 2016). These studies tested only the effect of broadband natural or anthropogenic noise and found signal receivers responded less as the amplitude of noise increased, which was consistent with the pattern of masking, but does not rule out other mechanisms. ...
... Functional habitat loss may occur when noise results in decreased habitat quality. Indeed, species have been found to avoid or leave noisy but otherwise suitable habitats (Bayne et al., 2008;Drolet et al., 2016;Francis et al., 2009;Rheindt, 2003) for reasons including acoustic masking (Mason et al., 2016) and noise-induced physiological stress responses (Blickley, Word, et al., 2012;Des Brisay et al., 2023;Kleist et al., 2018). ...
Noise from oil and gas development is pervasive across many landscapes and creates a novel soundscape that wildlife must adapt to or avoid. In response to anthropogenic noise, many wildlife species alter their vocalizations. Some adjusted vocalizations may promote effective communication in the presence of noise by improving detection and preserving information about the sender's status. However, if adjusted vocalizations fail to improve communication in noise, both missed detections and misinterpretations of vocalizations could impact the fitness of individuals and ultimately contribute to population declines. Baird's sparrow is a species at risk in Canada that adjusts its songs in response to oil well drilling noise by altering whole-song elements such as decreasing the peak frequency of songs (Curry et al., 2017, Bioacoustics, 27(2), 105–130). We examined the efficacy of these adjusted songs in the mixed-grass prairies of southern Alberta, Canada during the Baird's sparrow breeding season (May–July 2018 and 2019) using a repeated measures study design (N = 69 dyads) in which we simulated territorial intrusions by broadcasting adjusted songs and unadjusted songs in the presence and absence of oil well drilling noise recordings. We found that focal male behaviour was mainly mediated by noise treatment when compared to song treatment. In noisy trials, males sang less, called more and performed more flybys, regardless of song treatment type. However, in noisy trials, males displayed longer song latency in response to unadjusted songs compared to adjusted songs. The results of our novel study suggest that the presence of oil well drilling noise elicits more aggressive territorial defence behaviour in Baird's sparrows or hinders the ability of individuals to locate or assess rivals. Additionally, our results suggest that adjusted songs only partially restore effective communication in noise.
... The loss of biodiversity due to urbanization and agriculture expansion produces biological and ecological modifications in vertebrate communities, causing biodiversity collapses worldwide (Sih et al. 2011;Ceballos et al. 2020). Behavioral responses provide useful evidence to recognize adjustments in stressed environmental situations (e.g., urban noises, artificial light, and human voice) Mason et al. 2016). (Hayward et al. 2011) and the masking of communication signals (Rheindt 2003;Brumm 2004). ...
The vocal behavior of Neotropical birds has received less attention compared to birds in Northern temperate regions. Many bird species rely on acoustic communication to establish and maintain territories and to interact with conspecifics. For this reason, the growing threat of noise pollution in their habitats is a cause for concern. Birds perform behavioral adjustments when confronted with atypical environmental situations (e.g. urban noises, artificial light, human voice or vegetation loss). The aim of this study was to investigate vocal adjustments of Masked Gnatcatcher (Polioptila dumicola) males in environments located near a route with varying level of traffic noise (measured in decibels) and differing percentage of cover vegetation. Linear mixed models (LMMs) were used to analyze the effects of both environmental parameters in P. dumicola song. Results reveal that P. dumicola increases the amplitude of its songs in response to higher levels of traffic noise. Cover vegetation did not show any effect on song parameters. The model with the highest significance demonstrates a positive linear relationship between amplitude and traffic noise. These findings underscore the importance of studying communication alterations in noisy environments and understanding the ecological consequences of such effects on bird populations.
... For instance, avoidance of noise among Woodhouse's scrub jay, and possibly other opportunistic nest predators, results in increases in songbird nest success with noise exposure (Francis et al. 2009) (Figure 4). Elsewhere, field and lab-based studies suggest that noise impairs hunting success among owls and bats (Siemers & Schaub 2011, Mason et al. 2016, Senzaki et al. 2016, potentially explaining declines in abundance of these taxa with respect to noise (Fröhlich & Ciach 2018, Gomes et al. 2021c). However, both noise avoidance by predators and declines in hunting efficiency could indirectly benefit prey species. ...
The way in which terrestrial organisms use the acoustic realm is fundamentally important and shapes behavior, populations, and communities, but how background acoustics, or noise, influence the patterns and processes in ecology is still relatively understudied. In this review, we summarize how background acoustics have traditionally been studied from the signaling perspective, discuss what is known from a receiver's perspective, and explore what is known about population- and community-level responses to noise. We suggest that there are major gaps linking animal physiology and behavior to fitness; that there is a limited understanding of variation in hearing within and across species, especially in the context of real-world acoustic conditions; and that many puzzling responses to noise could be clarified with a community-level lens that considers indirect effects. Failing to consider variation in acoustic conditions, and the many ways organisms use and interact via this environmental dimension, risks a limited understanding of natural systems.
Expected final online publication date for the Annual Review of Ecology, Evolution, and Systematics, Volume 54 is November 2023. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
... Similarly, it can change parasite-host interactions by affecting parasite species' ability to find their hosts (Berkhout et al., 2023). By masking important cues (Siemers and Schaub, 2011;Mason et al., 2016;Senzaki et al., 2016;Jung et al., 2020) or reducing hearing abilities e.g., Wysocki and Ladich (2005); Ladich (2013); Kastelein et al. (2016), noise can reduce the distance before which a predator or prey is perceived, and likely impedes localization of a host (McMahon et al., 2017;Phillips et al., 2019). Noise can distract from responses to predator or prey, e.g., by increasing food handling and food discrimination errors (Purser and Radford, 2011;Shafiei Sabet et al., 2015), or by distracting from alarm signals in another sensory modality (Hasan et al., 2018). ...
Anthropogenic noise is a major pollutant in terrestrial and aquatic ecosystems. Since the industrial revolution, human activities have become increasingly noisy, leading to both acute and chronic disturbance of a wide variety of animals. Chronic noise exposure can affect animals over their lifespan, leading to changes in species interactions and likely altering communities. However, the community-level impacts of chronic noise are not well-understood, which impairs our ability for effective mitigation. In this review, we address the effects of chronic noise exposure on communities and explore possible mechanisms underlying these effects. The limited studies on this topic suggest that noise can affect communities by changing the behavior and/or physiology of species in a community, which results in direct or knock-on consequences for other species in the ecosystem. Major knowledge gaps remain due to the logistically complex and financially expensive nature of the long-term studies needed to address these questions. By identifying these gaps and suggesting approaches to answer them, we provide a road map toward mitigating the effects of a noisy world.
... Interspecific interactions, such as foraging and predation, can be altered by noise pollution. This is especially true for animal species that are unable to flee from noisy sites and for predators that rely on acoustic cues to locate prey [22,48]. Different effects of noise pollution on animal foraging have been observed, such as masking of prey sounds [49], distraction of predators [50], and changes in the composition of the predator's diet [51], indicating that noise pollution effects on trophic transmission of parasites are likely. ...
Predators can affect parasite–host interactions when directly preying on hosts or their parasites. However, predators may also have non‐consumptive indirect effects on parasite–host interactions when hosts adjust their behaviour or physiology in response to predator presence.
In this study, we examined how chemical cues from a predatory marine crab affect the transmission of a parasitic trematode from its first (periwinkle) to its second (mussel) intermediate host.
Laboratory experiments revealed that chemical cues from crabs lead to a threefold increase in the release of trematode cercariae from periwinkles as a result of increased periwinkle activity. This positive effect on transmission was contrasted by a 10‐fold reduction in cercarial infection rates in the second intermediate host when we experimentally exposed mussels to cercariae and predator cues. The low infection rates were caused by a substantial reduction in mussel filtration activity in the presence of predator cues, preventing cercariae from entering the mussels. To assess the combined net effect of both processes, we conducted a transmission experiment between infected periwinkles and uninfected mussels. Infection levels of mussels in the treatments with crab cues were sevenfold lower than in mussels without crab chemical cues. This suggests that predation risk effects on mussel susceptibility can counteract the elevated parasite release from first intermediate hosts, with negative net effects on parasite transmission.
These experiments highlight that predation risk effects on parasite transmission can have opposing directions at different stages of the parasite's life cycle. Such complex non‐consumptive predation risk effects on parasite transmission may constitute an important indirect mechanism affecting prevalence and distribution patterns of parasites in different hosts across their life cycle.
... Several reviews highlight myriad (and often negative) effects that human-made noise has on a variety of taxa including insects, fish, birds, and mammals (Bowles 1995, Warren et al. 2006, Laiolo 2010, Shannon et al. 2016, Jerem and Mathews 2021. Noise can alter predator prey interactions (Siemers and Schaub 2011, Mason et al. 2016, Simpson et al. 2016, reduce reproductive success (Habib et al. 2007, Mulholland et al. 2018, influence population and community structure (Holles et al. 2013, Bunkley et al. 2017), act as a direct stressor (Graham andCooke 2008, Kleist et al. 2018), and affect ecological services such as seed dispersal and pollination (Francis et al. 2012). Many studies investigating the effects of anthropogenic noise have focused on birds because of their reliance on acoustic cues for communication (Shannon et al. 2016, Jerem andMathews 2021), and the effects have been detected across land cover types including grasslands (Rosa and Koper 2022), forests (Sánchez et al. 2022), and wetlands (Wilson et al. 2021). ...
As humans intensify their activity on landscapes, it is important to consider anthropogenic noise when managing habitat for wildlife. Wetlands along rural to urban gradients are subject to road noise pollution, and the waterbirds that live there could be at risk for behavioral disturbance. We tested the positional response of wintering waterbirds to road traffic noise (i.e., sound pressure level) in a playback study in wetlands of Arkansas, USA, from January through March 2018. Each trial consisted of 3, 20-minute phases of road noise playback designated as pre, during, and post. We repeated instantaneous scan sampling every minute during each phase to collect the number, species, and distance of each bird relative to the playback speaker. Distance bins were designated as 0–25, 26–50, 51–75, and 76–100 m from the speaker. Birds approached the speaker at closer distances during the pre phase compared to during and post phases. There was an increase in the probability of a bird occurring in the distance bin farthest from the speaker over the course of the trial. Our results suggest waterbirds might avoid noisier areas within a habitat; however, more study is needed to assess species-specific responses, determine thresholds for disturbance, and examine downstream effects of habitat avoidance. If these results persist at larger scales, the soundscape of a wetland could be an important consideration in conservation planning.
... Interspecific interactions, such as foraging and predation, can be altered by noise pollution. This is especially true for animal species that are unable to flee from noisy sites and for predators that rely on acoustic cues to locate prey [22,48]. Different effects of noise pollution on animal foraging have been observed, such as masking of prey sounds [49], distraction of predators [50], and changes in the composition of the predator's diet [51], indicating that noise pollution effects on trophic transmission of parasites are likely. ...
There is a global rise in anthropogenic noise and a growing awareness of its negative effects on wildlife, but to date the consequences for wildlife diseases have received little attention. In this paper, we discuss how anthropogenic noise can affect the occurrence and severity of infectious wildlife diseases. We argue that there is potential for noise impacts at three main stages of pathogen transmission and disease development: (i) the probability of preinfection exposure, (ii) infection upon exposure, and (iii) severity of postinfection consequences. We identify potential repercussions of noise pollution effects for wildlife populations and call for intensifying research efforts. We provide an overview of knowledge gaps and outline avenues for future studies into noise impacts on wildlife diseases.
... As the analysed trails are located in naturally valuable mountain areas, the impact of noise and anthropogenic sound pollution on natural mountain ecosystems is worth noting. Authors such as Wiącek et al. [16], Polak et al. [17], Owens et al. [18], Halfwerk et al. [19], Masayuki et al. [20], Reijnen et al. [21], Mason et al. [22], Goodvin and Shriver [23], Francis et al. [24], and Slabbekoorn et al. [25] primarily highlighted the negative effects of ski area noise on the behaviour and condition of local fauna. Creel et al. [74] and Thiel et al. [75] highlighted increased levels of corticosteroids in the faeces of animals found along ski runs. ...
Sound in the landscape is an element of the multisensory experience of the environment. In areas that are naturally valuable and additionally used for tourism, the quality of this element is much more important than in urban areas. The aim of the study was to assess the soundscape diversity of mountain trails included in the Crown of the Polish Beskids (Korona Beskidów Polskich). Two methods were used in the study: The first was sound intensity measurement using a sonometer, which provided information on the physical aspect of the landscape. The second method involved recording all sounds divided into two basic categories: anthropogenic and natural. These results made it possible to propose a new method for assessing the naturalness of the soundscape by plotting naturalness curves. In contrast to frequently used survey-based methods, in this method we minimise subjectivity, which is mainly due to the different perceptions of sounds by the assessors. Given how many psychophysical aspects can affect the reception and perception of sounds, the method of naturalness curves allows for a universal assessment of landscape quality. On all the mountain trails surveyed, the average sound intensity values exceeded 40 dB, which the authors considered to be borderline for areas of natural value and recreational use. In the study area, the influence of anthropopression on soundscape formation was found to be diverse and dependent on many factors. However, there was no clear evidence that tourism was the main negative influence. The plotted naturalness curves showed a large variation between trails, but not all trails showed a correlation between this parameter and the number of tourists on the trail.
... Owls generally ambush visible prey by flying straight towards the prey (e.g. supplementary videos in [13]), but Great Grays hunting through snow instead fly above prey and hover, then plunge straight down [1]. We created a geometric model of how snow distorts the sound as a function of owl position to test the significance of hovering over prey. ...
How do Great Gray Owls (Strix nebulosa) capture voles (Cricetidae) through a layer of snow? As snow is a visual barrier, the owls locate voles by ear alone. To test how snow absorbs and refracts vole sound, we inserted a loudspeaker under the snowpack and analysed sound from the loudspeaker, first buried, then unburied. Snow attenuation coefficients rose with frequency (0.3 dB cm-1 at 500 Hz, 0.6 dB cm-1 at 3 kHz) such that low-frequency sound transmitted best. The Great Gray Owl has the largest facial disc of any owl, suggesting they are adapted to use this low-frequency sound. We used an acoustic camera to spatially localize sound source location, and show that snow also refracts prey sounds (refractive index: 1.16). To an owl not directly above the prey, this refraction creates an 'acoustic mirage': prey acoustic position is offset from its actual location. Their hunting strategy defeats this mirage because they hover directly over prey, which is the listening position with least refraction and least attenuation. Among all birds, the Great Gray Owl has the most extreme wing morphologies associated with quiet flight. These extreme wing traits may function to reduce the sounds of hovering, with implications for bioinspiration.
... marks it as a popular tourist attraction, with up to 15,000 beachgoers a month visiting during the tourist season. Studies have shown that marine and nonaquatic vertebrates, such as the harbor porpoise, Phocoena phocoena (Linnaeus, 1758) and the northern saw-whet owl, Aegolius acadicus (Gmelin, 1788) change routes and location due to acoustic pollutants (Kastelein et al., 2013;Dyndo et al., 2015;Mason et al., 2016;Mamo et al., 2018). Decapod crustaceans are not exempt from the effect of acoustic disturbance. ...
The coastal Caribbean is a well-known harbor for biodiversity, yet it is mainly valued for its ample resources and services. Economic interests typically supersede conservation efforts, introducing anthropogenic-related factors such as noise, chemical pollution, and geographical disturbances into the littoral zone, where ecological diversity is abundant. Although human activity is known to be detrimental to biodiversity across habitats, the effect of conservation measures that limit anthropogenic activity on coastal populations remains understudied. To measure the benefit of conservation in the littoral environment, we sampled populations of the hermit crab Coenobita clypeatus (Fabricius, 1787) of highly frequented (non-protected) and protected beaches in northern Puerto Rico. We profiled 1,119 individuals by using transects, describing their size and shell utilization patterns during winter and summer. The C. clypeatus population was larger (P < 0.0001 during both seasons) and more abundant (P = 0.0006 during winter, P < 0.0038 during summer) in the protected beach than in the non-protected beach, with no effect of season. Shell utilization patterns were more consistent in the protected beach, likely due to the greater availability of gastropod shells. These results suggest that the conservation measures implemented in the protected beach promote the survival, reproduction, and growth of hermit crabs in the location. Expansion of protected habitats through governmental and civilian efforts should enhance the conservation of the biodiversity of protected areas.
... Strasser and Heath (2013) suggested that reproductive failure of American Kestrels (Falco sparverius) was due to disturbance by traffic noise. Especially for owls, noise pollution seems to substantially reduce foraging success (Mason et al. 2016, Senzaki et al. 2016). More work therefore should be done elucidating the effects of sensory pollution on raptors, with a focus on developing and testing methods to mitigate such impacts. ...
Light and noise often act as pollutants, but can also be used as tools for managing wildlife (e.g., sensory deterrents). Given that raptors are among the most threatened groups of birds, we expected there to be a moderate amount of applied research on their sensory ecology. We searched Web of Science and Google Scholar to quantify and classify the research that has been conducted on the applied sensory ecology of raptors. Of 32 studies assessing the effects of sensory pollution on raptors, we found that 10 studies examined effects of light pollution and 24 studies examined effects of noise pollution. Most of the studies regarding sensory pollution were of owls (21 studies). The United States was the site of the most noise pollution studies (seven studies) whereas Spain and Poland (two studies each) were sites of the most studies of light pollution. We found only seven studies that directly collected data regarding sensory deterrents. With so few studies examining applied aspects of the sensory ecology of raptors, we argue that effects of sensory pollution are poorly understood and the efficacy of sensory deterrents is largely unknown. Light and noise pollution are spreading across much of the globe. Applied research on the sensory ecology of raptors must be made a priority if wildlife managers are to conserve this imperiled group of birds.
... Road infrastructure can be an obstacle to the free movement of animals among habitat patches, thus hindering food acquisition and limiting gene exchange (Forman & Alexander 1998;Hewison et al. 2009;Seidler et al. 2015). Traffic noise can disrupt the propagation of acoustic signals used by animals to communicate (Siemers & Schaub 2011;Mason et al. 2016). Animals which substantially rely on hearing tend to be over-vigilant in noisy environments (Klett-Mingo et al. 2016), which, in turn, increases energy expenditure and may lead to distress and exhaustion. ...
The features of the urban landscape encouraging large ungulates expansion are not known. However, prevalence and abundance of wild boar Sus scrofa has been steadily increasing over the years, and nowadays the species has become a recognized component of urban wildlife in many parts of its range. The aim of this work was to select habitat and human-related factors that could affect the probability of the species occurrence and constitute the honest indicators of the habitat suitability for this ungulate in the urban landscape. The data on the presence of grubbed patches of ground (an honest indicator of occurrence) were collected on randomly selected sample plots (N = 100) within the city of Kraków (Poland). We found that wild boar used 45% of the sample plots. Whereas the occupied plots were spatially concentrated, the habitat variables increasing the probability of the species occurring in the urban landscape were the presence of large patches of woodland remnants and large areas of semi-natural meadows. However, the study also revealed a negative relationship between the presence of the species and artificial lighting but a positive one with anthropogenic noise pollution. Our results indicate that the urban landscape consists of surrogate habitats for this large mammal but light and noise pollution may have contrasting effects on the species’ occurrence. This indicates that the influence of human-related factors on the attractiveness of natural vegetation remnants for wildlife is more complex than merely a limiting factor. This reveals high potential of light and noise pollution as indicators of the habitat suitability for ungulates in the urban landscape.
... As we have found strong adverse effects of recent forestry activity on habitat suitability, we argue that even though forest edges may increase habitat suitability, the effect is outweighed by the forestry disturbance. Forestry reduces habitat suitability by both destruction of habitats and removal of their structural complexity (Bobiec et al., 2005) as well as with noise pollution during work, which obscures sound signal of a prey, impairing hunting behaviour (Mason et al., 2016). This disturbance is not expected to be as important near openings of natural origin, as they are usually formed by short (typically by storms) or relatively silent events (e.g., beetle outbreaks). ...
Species distribution modelling is an important tool to inform conservation, particularly if combined with site prioritization approaches. Results can then be used in both suggestion of new protected areas as well as evaluation of the existing ones. We applied MaxEnt analysis to a species of mature forests, the Eurasian Pygmy Owl (Glaucidium passerinum), which is recognized as a biodiversity indicator species. Furthermore, we used habitat suitability and uncertainty maps in site prioritization for conservation and evaluation of the existing nature conservation area (NCA) network. We found species to be strongly positively associated with time since forestry activities at a local scale (25ha) and abundance of mature forests from local through home range (450ha) to landscape (1960ha) scales. The sum of habitat suitability as a proxy for apparent population allowed us to estimate that the existing NCAs hold only 23% of the population. We found 68% of priority sites (PS) for species conservation to be outside NCAs. Strict forestry restrictions form the most suitable conservation regimes, with more than 51% of PS in NCA network having insufficient regimes. Inclusion of PS in NCAs would increase the network to 26% of the national territory with 41% of the species apparent population. Currently, the most suitable conservation regimes cover less than 2% of the country area.
... In terms of humans, for example, chronic noise exposure can cause multiple health issues ranging from hearing loss and communication handicaps to sleep deprivation and cardiovascular disease (Barber et al., 2010;Giles-Corti et al., 2016). For wild animals, human-induced noise can lower their foraging efficiency (Francis et al., 2009), retard social information transfer (Mason et al., 2016), weaken anti-predator defenses (Patricelli & Blickley, 2006;Slabbekoorn & Ripmeester, 2008), and reduce reproductive success (Senzaki et al., 2020). Furthermore, the impacts of anthropogenic noise are not confined to individuals or populations of single species but also reach the community level (Herrera-Montes & Aide, 2011; Kleist et al., 2018). ...
The expansion of anthropogenic noise poses an emerging threat to the survival and reproductive success of various organisms. Previous investigations have focused on the detrimental effects of anthropogenic noise on the foraging behavior in some terrestrial and aquatic animals. Nevertheless, the role of airport noise in impairing foraging activities of most wild animals has been neglected. Here, we aimed to assess whether foraging behavior in free‐living Japanese pipistrelle bats (Pipistrellus abramus) can be disturbed by airport noise. We used audio recording to monitor foraging activities of bats at 11 sites around the runway of a municipal airport. We quantified noise level and spectra, aircraft activity, habitat type, nightly temperature, wind speed, and moon phase for each site. The analysis revealed that noise level and aircraft activity were significant negative predictors for the number of bat passes and feeding buzzes around the runway, even after controlling for the effects of other environmental factors. There was no marked spectral overlap between bat echolocation pulses and airport noise in the presence and absence of low‐flying aircraft. The spectro‐temporal parameters of echolocation vocalizations emitted by bats were dependent on noise level, aircraft activity, and habitat type. These results provide correlative evidence that airport noise can reduce foraging activities of wild pipistrelle bats. Our findings add to the current knowledge of adverse impacts of airport noise on foraging bats in artificial ecosystems and provide a basis for further research on the mechanisms behind noise pollution near airports. We test the relationship between airport noise and foraging behavior in wild bats. The airport noise disturbs foraging activities of bats. Echolocation pulse parameters of bats are predicted by noise level and aircraft activity.
... (e.g., Forman et al. 2003;Charry and Jones 2009). Even some species that may be attracted to roadsides (e.g., to use as hunting grounds; Hindmarch et al. 2017) may suffer deleterious consequences from traffic noise (Mason et al. 2016;Senzaki et al. 2016). Decisive evidence comes from playback experiments that control for the presence of other confounding factors (e.g., mortality, chemical pollution, habitat fragmentation) associated with roads. ...
Traffic noise is one of the leading causes of reductions in animal abundances near roads. Acoustic masking of conspecific signals and adventitious cues is one mechanism that likely causes animals to abandon loud areas. However, masking effects can be difficult to document in situ and the effects of infrequent noise events may be impractical to study. Here, we present the Soundscapes model, a stochastic individual-based model that dynamically models the listening areas of animals searching for acoustic resources (“searchers"). The model also studies the masking effects of noise for human detections of the searchers. The model is set in a landscape adjacent to a road. Noise produced by vehicles traveling on that road is represented by calibrated spectra that vary with speed. Noise propagation is implemented using ISO-9613 procedures. We present demonstration simulations that quantify declines in searcher efficiency and human detection of searchers at relatively low traffic volumes, fewer than 50 vehicles per hour. Traffic noise is pervasive, and the Soundscapes model offers an extensible tool to study the effects of noise on bioacoustics monitoring, point-count surveys, the restorative value of natural soundscapes, and auditory performance in an ecological context.
... The increase in food intake that we found supports our second hypothesis, that road noise reduces prey's risk perception or masking hypothesis (Chan & Blumstein, 2011;Chan et al., 2010). An alternative explanation may be that road noise reduces actual owl predation (Mason et al., 2016), and small mammals recognize the reduction in risk and increase their foraging. Large birds like owls are sensitive to noise as it may mask acoustic cues of prey (Francis et al., 2012). ...
Anthropogenic noise has dramatically increased over the past decades with potentially significant impacts on wildlife and their community interactions. Using giving‐up densities (GUDs) paired with camera traps, we examined the concurrent influence of chronic road noise and predation risk on free‐living small mammals. Specifically, we looked for differences in foraging and vigilance behavior during various noise treatments. We found that small mammals significantly reduced food intake when exposed to predation risk; however, concurrent exposure to road noise eliminated this effect; small mammals increased food intake when exposed to road noise and risk compared to risk alone. Furthermore, road noise reduced the number of visits and time spent at foraging trays while it increased vigilance behavior of small mammals in risky situations, meaning they were able to increase their foraging efficiency. Mice also ate less when moon illumination was greater; however, this had no effect on our overall results. This is one of the first studies to concurrently examine the effects of road noise and predation risk on free‐living prey. It shows the complex responses of prey exposed to chronic noise conditions as they attempt to gain reliable information about predation risk and respond appropriately. We highlight the potential consequences road noise may have on the survival of prey as it interferes with their appropriate risk responses.
... Noise pollution has been found to suppress the distribution of owls (Silva et al. 2012, Fröhlich & Ciach 2018a, 2018b. This is believed to be primarily due to reduced hunting efficiency in noisier environments (Mason et al. 2016, Fröhlich & Ciach 2018a, similar to the effect that rainfall has on hunting success (Lengagne & Slater 2002), with prey detection that much harder. In addition, owls may also suffer enhanced energy costs due to the need for louder and/or more frequent vocalizations in higher ambient noise environments in order to be heard by conspecifics (Lengagne & Slater 2002, Nemeth et al. 2013, Cartwright et al. 2014. ...
Capsule
Tawny Owl Strix aluco site occupancy and detectability are influenced by habitat and environmental variables.
Aims: To determine factors influencing Tawny Owl occupancy and detectability around British homes and gardens using a large-scale citizen science survey across two main survey periods.
Methods
Surveys of 20 min duration were undertaken one evening a week from the homes and gardens of volunteers, for up to 26 weeks between October and March of 2005/2006 and 2018/2019, and analysed primarily using multi-season occupancy modelling.
Results
During two survey periods, more than 9000 sites were surveyed across the breeding range of the Tawny Owl within Britain. The main drivers of occupancy were found to be the extent of broadleaf woodland cover and the degree of urbanization. Detection probability was influenced by date, time, weather, and moon phase. Using the current method, a minimum of five to six survey visits per site would be required to have 95% confidence over the presence or absence of Tawny Owls at a given site, but it may be possible to optimize the survey method further to increase efficiency by surveying in the autumn or early spring, early after dusk, and on cloudless dry evenings close to the full moon.
Conclusion
The findings indicate that survey methodologies for surveying Tawny Owls can be optimized to increase the efficiency of detection, if present at a site. We highlight the need for further research on the effects of urbanization on Tawny Owls, particularly with regards to artificial light pollution and its effects on behaviour and settlement, along with the need for greater understanding of Tawny Owl activity budgets, which would aid the interpretation of survey results.
... Thus, arthropod communication and perception can be directly affected by noise via airborne sound or substrate-borne vibrations (Lampe et al. 2012, Raboin andElias 2019). Indirect effects are also possible, since noise can disrupt predator-prey interactions (Purser and Radford 2011, Gomes et al. 2016, Mason et al. 2016, Barton et al. 2018, Senzaki et al. 2020, and drives away many arthropod predators, such as birds and bats (Schaub et al. 2008, Francis et al. 2011, McClure et al. 2013, Bunkley and Barber 2015, Gomes et al. 2021b). ...
Anthropogenic noise has received considerable recent attention, but we know little about the role that sources of natural noise have on wildlife abundance and distributions. Rivers and streams represent an ancient source of natural noise that is widespread and covers much of Earth. We sought to understand the role that whitewater river noise plays on arthropod abundance in riparian habitats across a desert landscape. For two summers, we continuously broadcasted whitewater river noise and spectrally-altered river noise (shifted upwards in frequency, but maintaining the same temporal profile) to experimentally tease apart the effects of two characteristics of noise – sound levels and background spectral frequency – on arthropod abundances. We used five types of trapping methods, placed across 20 sites within the Pioneer Mountains of Idaho, USA, to collect and identify 151 992 specimens to the order level. We built Bayesian generalized linear mixed-effects models with noise characteristics and other habitat variables such as riparian vegetation, elevation, temperature, and moonlight. Of the 42 models we built (one for each order-trap type combination), 26 (62%) indicated a substantial response to at least one noise variable – sound pressure level, background spectral frequency, or an interaction between the two. Fourteen of 17 (82%) arthropod orders responded to noise in some capacity: Araneae, Coleoptera, Collembola, Dermaptera, Hemiptera, Hymenoptera, Lepidoptera, Neuroptera, Opiliones, Orthoptera, Plecoptera, Raphidioptera, Thysanoptera and Trichoptera. Only three groups appeared to be unaffected, Acari, Archaeognatha and Diptera. Results from this study suggest that the natural acoustic environment can shape arthropod abundances both directly and indirectly (via predator–prey relationships). Future work should further examine the role that the indirect effects of noise play in food webs. Natural noise should be considered an important ecological niche axis, especially as we continue to alter natural acoustic environments and replace them with anthropogenic ones.
... Both can fundamentally alter spatial orientation and create mismatched biological timings ). These sensory disturbances in turn create a myriad of behavioral alterations, affecting orientation and movement (Slabbekoorn and Bouton 2008;Cabrera-Cruz et al. 2018), communication (Francis and Barber 2013), foraging and hunting efficiency (Bennie et al. 2015;Bunkley and Barber 2015;Mason et al. 2016), altered energy budgets (Read et al. 2014;Touzot et al. 2019), and predation risk (Francis and Barber 2013;Ditmer et al. 2020), along with stress hormone dysregulation (Kleist et al. 2018). Recent research has also shown that variation in these sensory pollutants can better explain patterns of habitat selection than common ecological variables alone, such as landcover (Kleist et al. 2017;Ditmer et al. 2020) and can better reflect the dynamic human footprint relative to other measurements (e.g., housing density; Ditmer et al. 2021a). ...
Synopsis
Global expansion of lighting and noise pollution alters how animals receive and interpret environmental cues. However, we lack a cross-taxon understanding of how animal traits influence species vulnerability to this growing phenomenon. This knowledge is needed to improve the design and implementation of policies that mitigate or reduce sensory pollutants. We present results from an expert knowledge survey that quantified the relative influence of 21 ecological, anatomical, and physiological traits on the vulnerability of terrestrial vertebrates to elevated levels of anthropogenic lighting and noise. We aimed not only to quantify the importance of threats and the relative influence of traits as viewed by sensory and wildlife experts, but to examine knowledge gaps based on the variation in responses. Identifying traits that had less consensus can guide future research for strengthening ecologists’ and conservation biologists’ understanding of sensory abilities. Our findings, based on 280 responses of expert opinion, highlight the increasing recognition among experts that sensory pollutants are important to consider in management and conservation decisions. Participant responses show mounting threats to species with narrow niches; especially habitat specialists, nocturnal species, and those with the greatest ability to differentiate environmental visual and auditory cues. Our results call attention to the threat specialist species face and provide a generalizable understanding of which species require additional considerations when developing conservation policies and mitigation strategies in a world altered by expanding sensory pollutant footprints. We provide a step-by-step example for translating these results to on-the-ground conservation planning using two species as case studies.
... Typically, different methods are used to study natural systems and human systems (visitor experiences) within PAs. PA natural systems acoustic monitoring and research normally focuses on the characterization and measurement of the sound environment in combination with behavioral observation of populations of interest [28][29][30]. The United States National Park Service (USNPS) protocols include objective measures of sound, such as duration and dBA, to measure the extent of particular sounds [31]. ...
This study examined the potential for Perceived Affective Quality (PAQ; pleasantness, eventfulness, familiarity) soundscape measures developed within urban settings to enrich current soundscape management approaches within protected areas (PAs). Drawing on the premise that people bring experiences from other life contexts into PA settings and PA visitors are increasingly coming from urban areas, research integrated urban visitors’ soundscape perceptions of their home and work acoustic environments with their perceptions of acoustic environments in PAs. Two-phased survey research (n = 333) separated visitors into urban density groups and compared PAQ variables across home, work, and PA contexts. Significant differences resulted, both in ratings of the three acoustic contexts (PA, home, work) for all three PAQ components and between urban density groups. The importance of pleasantness was confirmed across all contexts; however, alone, this dimension lacked sufficient contrast to interpret the complexity of soundscape perceptions, especially considering diverse Healthy Parks, Healthy People (HPHP) visitor experience scenarios and goals. Thus, managers should consider (1) additional PAQ variables that can provide more useful and contrasting information; (2) incorporating methods that integrate PAQ measures across visitors’ different acoustic contexts, and (3) including urban density measures within HPHP research.
... For example, it is well-documented that anthropogenic sound exposure affects wildlife populations. Indeed, noise-induced reductions in foraging efficiency have been demonstrated in bats (Luo et al., 2015), owls (Mason et al., 2016), flounder larvae Pseudopleuronectes americanus (Gendron et al., 2020), and crabs (Wale et al., 2013). Chronic traffic noise can alter gene expression in bats, which associates with metabolic dysregulation and stress (Song et al., 2020). ...
Globally, anthropogenic sound and artificial light pollution have increased to alarming levels. Evidence suggests that these can disrupt critical processes that impact ecosystems and human health. However, limited focus has been given to the potential effects of sound and artificial light pollution on microbiomes. Microbial communities are the foundations of our ecosystems. They are essential for human health and provide myriad ecosystem services. Therefore, disruption to microbiomes by anthropogenic sound and artificial light could have important ecological and human health implications. In this mini-review, we provide a critical appraisal of available scientific literature on the effects of anthropogenic sound and light exposure on microorganisms and discuss the potential ecological and human health implications. Our mini-review shows that a limited number of studies have been carried out to investigate the effects of anthropogenic sound and light pollution on microbiomes. However, based on these studies, it is evident that anthropogenic sound and light pollution have the potential to significantly influence ecosystems and human health via microbial interactions. Many of the studies suffered from modest sample sizes, suboptimal experiments designs, and some of the bioinformatics approaches used are now outdated. These factors should be improved in future studies. This is an emerging and severely underexplored area of research that could have important implications for global ecosystems and public health. Finally, we also propose the photo-sonic restoration hypothesis: does restoring natural levels of light and sound help to restore microbiomes and ecosystem stability?
... En el caso de los anuros, se han observado patrones similares además de cantos mucho más complejos y con mayores tasas de repetición (Halfwerk et al., 2018). En cuanto a los aspectos ecológicos, existe evidencia que sugiere que el ruido antropogénico reduce el éxito de captura de algunos depredadores (Schaub et al., 2008;Mason et al., 2016), del mismo modo que impide el éxito de las estrategias de evasión de depredadores (Yorzinski y Hermann, 2016). Por ejemplo, se han observado disminuciones en la riqueza de especies y la abundancia relativa de ranas a distancias de 250-1,000 m de carreteras y autopistas, respectivamente (Eigenbrod et al., 2009). ...
Se presentan los resultados de mediciones semicontinuas de ruido ambiental (ruido de fondo) y de ruido antropogénico proveniente de fuentes fijas, semiestacionarias y móviles. Las mediciones se realizaron por cinco meses mediante sonómetros de campo (30-130 dB; 31.5 Hz-8 kHz) y mediante el modulo Sound Mapping para ArcGis 10.4. El promedio de ruido ambiental, libre de contaminación antropogénica, osciló entre los 40 y 42 dB con máximas de 62 dB provenientes de ruidos de insectos y anfibios característicos de la zona. El promedio de ruido generado por las fuentes fijas fue de 40-94 dB, el cual se redujo a niveles de fondo a 270-450 m, mientras que las fuentes móviles presentaron niveles de 69- 90 dB, con un área de influencia de 200-250 m. Las fuentes semiestacionarias presentaron los valores más bajos de ruido y de extensión (45 dB y 80 m).
... Acoustic hunters like owls will likely profit from reduced sound pollution. In fact, traffic noise is known to reduce foraging efficiency (Senzaki et al., 2016); the hunting success of saw-whet owls (Aegolius acadius), for example, drops by 8% per dB increase in anthropogenic noise (Mason et al., 2016). Because traffic noise hampers acoustic communication in other bird species (Derryberry et al., 2020;Leonard and Horn, 2005;Mockford and Marshall, 2009), with negative impacts on their reproductive success (Halfwerk et al., 2011), similar fitness consequences are expected for owls, which use acoustic communication to find mates and defend territories. ...
Research is underway around the world to examine how a wide range of animal species have responded to reduced levels of human activity during the COVID-19 pandemic. In this perspective article, we argue that raptors are particularly well-suited for investigating potential ‘anthropause’ effects, and that the resulting insights will provide much-needed impetus for global conservation efforts. Lockdowns likely alter many of the extrinsic factors that normally limit raptor populations. These environmental changes are in turn expected to influence – mediated by behavioral and physiological responses – the intrinsic (demographic) factors that ultimately determine raptor population levels and distributions. Using this framework, we identify a range of research opportunities and conservation challenges that have arisen during the pandemic. The COVID-19 anthropause allows raptor researchers to address fundamental and applied research objectives in a large-scale, quasi-experimental, well-replicated manner. Importantly, it will be possible to separate the effects of human disturbance and anthropogenic landscape modifications. We explain how high-quality datasets, accumulated for a diverse range of raptor species before, during, and after COVID-19 lockdowns, can be leveraged for powerful comparative analyses that attempt to identify drivers of particular response types. To facilitate and coordinate global collaboration, we are hereby launching the ‘Global Anthropause Raptor Research Network’ (GARRN). We invite the international raptor research community to join this inclusive and diverse group, to tackle ambitious analyses across geographic regions, ecosystems, species, and gradients of lockdown perturbation. Under the most tragic of circumstances, the COVID-19 anthropause has afforded an invaluable opportunity to significantly boost global raptor conservation.
... Increased levels of artificial noise can mask important signals used in both inter-and intra-specific communication (Barber et al. 2010). For instance, noise can interfere with predator detection of adventitious acoustic cues generated by prey, resulting in reduced hunting success (Mason et al. 2016, Senzaki et al. 2016). The same is likely true for a variety of interactions in which one species takes advantage of public information through eavesdropping on other species. ...
Anthropogenic noise and artificial night lighting have been shown to have substantial effects on animal behavior, physiology, and species interactions. Despite the large body of previous work, very few studies have studied the combined effects of light and noise pollution, especially experimentally in the field. Rodents are a highly diverse group that are predominantly nocturnal and occupy a wide range of habitats worldwide, frequently in close association with human development, placing them at a heightened risk from sensory disturbances. To test the singular and combined effects of various levels of anthropogenic light and noise exposure on pinyon mouse (Peromyscus truei) activity and body condition, we used standard trapping methods across a gradient of light and noise and the two combined and accounted for variation of moonlight, vegetation structure, and weather. We hypothesized that increased levels of artificial light would decrease trap success and lead to lower body condition due to an increase in perceived predation risk and that increased noise levels would increase trap success and body condition due to a reduction in predation risk and/or release from competition. Pinyon mouse trap success declined as light intensity increased, and the effect was comparable to that of moonlight, which is well known to influence rodent activity and perception of predation risk. Although noise pollution did not alter trap success of pinyon mice, individuals captured in noisier areas at the beginning of the season had lower body condition than those from quieter areas. Body condition was uninfluenced by noise and light later in the season. We also found no evidence of any additive or synergistic effects of the two stimuli. Our results provide evidence that alterations to the sensory environment from anthropogenic activity can affect wild rodents in several ways. As anthropogenic development increases to meet the demands of growing human populations, more ecosystems will be exposed to increased levels of sensory disturbance, making the understanding of how these changes affect wildlife critical to ongoing conservation efforts.
... For those that stay, environmental noise can perturb information processing by predators in two main ways: (i) masking, or energetic masking-the increased difficulty of detecting or discriminating a stimulus of interest due to an alternative source that overlaps the stimulus in spectrum, intensity and time [11]; or (ii) distraction-the increased difficulty of detecting or discriminating a stimulus of interest due to an alternative source that occupies attentional resources and processing power of the organism [12] (although see Dominoni et al. [4] for a third, less common mechanism). While studies across taxa, including fish [13,14], birds [15][16][17] and bats [18][19][20][21][22] have found serious declines in hunting success in noisy environments, the underlying mechanism remains elusive. A deeper, mechanistic understanding can provide insight into the evolutionary biology of how organisms compensate for naturally noisy environments. ...
Predators frequently must detect and localize their prey in challenging environments. Noisy environments have been prevalent across the evolutionary history of predator-prey relationships, but now with increasing anthropogenic activities noise is becoming a more prominent feature of many landscapes. Here, we use the gleaning pallid bat, Antrozous pallidus, to investigate the mechanism by which noise disrupts hunting behaviour. Noise can primarily function to mask-obscure by spectrally overlapping a cue of interest, or distract-occupy an animal's attentional or other cognitive resources. Using band-limited white noise treatments that either overlapped the frequencies of a prey cue or did not overlap this cue, we find evidence that distraction is a primary driver of reduced hunting efficacy in an acoustically mediated predator. Under exposure to both noise types successful prey localization declined by half, search time nearly tripled, and bats used 25% more sonar pulses than when hunting in ambient conditions. Overall, the pallid bat does not seem capable of compensating for environmental noise. These findings have implications for mitigation strategies, specifically the importance of reducing sources of noise on the landscape rather than attempting to reduce the bandwidth of anthropogenic noise.
Urbanization and expanding road networks threaten some avian populations through habitat loss and degradation. Barn owls ( Tyto alba ) have been particularly affected through roadway mortality, loss of grassland, and conversion or destruction of nesting sites. To combat declines and bolster reproduction, and as part of integrated pest management to reduce crop damage, some land managers provide supplemental owl nesting sites via the installation of nest boxes. If nearby habitat and land cover characteristics are not considered when placing boxes, such as major roads or other anthropogenic features, owls could be attracted to locations that could hinder populations further. We investigated the effects of roads and urban areas on barn owl breeding occupancy and productivity to provide information to help guide the placement of nest boxes. We monitored >300 nest boxes over the 2020 and 2021 breeding seasons in southwestern Idaho, USA, where substantial roadway mortality of barn owls occurs. Barn owls occupied >60% of nest boxes, but the likelihood of breeding occupancy decreased with increasing proximity of nest boxes to roads. Boxes 500 m from roads had a predicted probability of occupancy of over 0.9, which was nearly double that of boxes within 100 m. Proximity to roads also was associated with reduced productivity such that boxes within 100 m of roads were predicted to produce approximately 1 fewer fledgling than those 500 m away. There was no evidence that the proportion of urban area surrounding nest boxes substantially influenced breeding occupancy or productivity. Thus, land managers can consider placing nest boxes for barn owls farther from roads when possible as a potential tactic to increase the probability of breeding occupancy and to foster higher productivity.
Protected areas (PAs) possess generous biodiversity, making them great potential for human and wildlife well-being. Nevertheless, rising anthropogenic sounds may pose a serious challenge and threat to the habitats. Therefore, understanding the acoustic environments of PAs and implementing proper conservation strategies are essential for maintaining species richness within the territory. In this study, we investigate the spatial-temporal variations of soundscape distribution in the Dashanbao Protected Area (DPA) of China, ultimately discussing the planning and management strategies. Firstly, to systematically analyse the spatial-temporal soundscape distribution of the reserve, we generated single and multi-acoustic source maps by classifying geographical, biological, and anthropogenic sounds. In the region, we installed 35 recording points and collected sounds using the synchronic recording method. Secondly, we conducted Spearman correlation analyses to examine the relationships between the sound sources and i) temporal variations, ii) landscape feature indicators. Thirdly, we identified the dominant sound sources in the region and their conflict areas through the cross-analysis module of Grass Geographic Information Systems (GIS). Finally, we provided sound control strategies by discussing landscape indicators and land-use management policies. The results show that even though there is conservation planning in the DPA, anthropogenic sounds dominate in certain parts of the reserve depending on diurnal and seasonal cycles. This reveals deficiencies in the DPA's current planning concerning the soundscape and highlights the effectiveness of spatial-temporal mapping. Additionally, our correlation analyses demonstrate that landscape feature indicators can represent how sound environment is affected by landscape. The patch diversity (PD), landscape shape index (LSI), Shannon's Diversity Index (SHDI), woodland, shrubland, and water distance (WD) were identified as the primary predictors for both biological and anthropogenic sounds. None of the indicators exhibited a significant positive or negative correlation with geological sounds. Consequently, to enhance and conserve the acoustic quality of the region, spatial-temporal mapping with landscape indicators can be employed in the management and planning processes.
An assessment of the short-term effects of an outdoor music festival (Jova Beach Party event; July 2019; central Italy) on bird assemblages has been carried out, adopting a BACI (Before-After-Control-Impact) survey design, and using the point counts method both in the impact site (Impact, I; where the concert was held) and in comparable Control site (C). In the I site, data have been stratified both for urban (U) and agro-mosaic (M) habitats. When comparing before and after the music event, in IU site, the species richness and the Hill diversity index decreased, differently from CU where species richness a species abundance increased. Diversity profiles highlighted the impoverishment of bird assemblages after the event, but only in the Impact urban habitats. After the musical event, individual rarefaction curves for richness were lower in IU after the concert, while, differently in CU curves are higher. These data suggest an impact in bird assemblages limited to the urban site, due to the stress mainly induced by high intensity noise pollution. Musical events may disrupt the structure of synanthropic bird assemblages, inducing a dispersal of individuals towards the surrounding landscape. Starling (Sturnus vulgaris) appeared a particularly sensitive bird. However, further efforts are necessary to study the effects of these events at species level.
Lärm belastet zunehmend die Lebensräume zahlreicher Tiergruppen. Vögel verwenden vielfältige akustische Signale und sind von Störungen der akustischen Kommunikation in besonderem Maß betroffen. Ziel dieser Untersuchung war es, anhand von direkter Beobachtung, der Analyse des Rufverhaltens, der Revierwahl und dem Reproduktionserfolg auf verschiedenen Bewertungsebenen zu ermitteln, wie Uhus Bubo bubo auf starke Lärmbelastung reagieren. Für alle bekannten Brutplätze in Südbaden im Südwesten Deutschlands wurde ein Risiko- und Lärmbelastungsprofil erstellt, basierend auf der Entfernung zu relevanten Stör- und Lärmquellen. An einem lärmbelasteten Brutplatz wurde 2020-22 die Vokalisation der Uhus mittels digitaler Tonaufzeichnungen kontinuierlich erfasst. Ein per Spektiv beobachteter Uhu zeigte bei einsetzendem Schusswaffengeräusch aus 40 m Entfernung keinerlei Anzeichen von Stress und setzte die Gefiederpflege unbeeindruckt fort. Auch bei weiteren Beobachtungen in diesem und anderen Revieren gab es keine erkennbaren Reaktionen auf akute Lärmeinwirkung. Die Rufserien eines Uhupaares waren häufig vom Verkehrsgeräusch vorbeifahrender Motorfahrzeuge und Züge überlagert. Eine Änderung des Rufverhaltens (Ruffrequenz, zeitliche Abfolge) bei Lärm war nicht feststellbar. Junge Uhus setzten ihre Kontaktrufe während eines Feuerwerks unverändert fort. Von 26 untersuchten Brutpaaren siedelte die Hälfte in Revieren mit einem stark lärmbelasteten Brutplatz. Bei 133 Bruten in den Jahren 2008-23 gab es an ruhigen Brutplätzen 2,28 Junge pro Brut, an lärmbelasteten waren es 2,47. Bei der Revier- und Brutplatzwahl spielt die Lärmbelastung offenbar keine entscheidende Rolle. Auf allen vier Bewertungsebenen zeigten die Uhus des Untersuchungsgebietes eine bemerkenswerte Toleranz gegenüber unterschiedlichen anthropogenen Lärmbelastungen. [Summary: Habitats of numerous wildlife taxa are increasingly affected by high levels of ambient noise. Birds use a variety of acoustic signals and their communication vitally relies on the unimpaired transfer and perception of such signals. Here I attempt to determine, at different scales, how Eurasian Eagle Owls Bubo bubo respond to excess noise, using direct observation, analysis of their vocalisation, occupancy, and reproductive success as criteria. For all known nest sites in the study area Südbaden (Southwest Germany) a detailed risk and noise profile was established, measuring the distance to relevant sources of disturbance and noise. The complete vocalisation of the resident Eagle Owls was captured 2020-22 near a noise-affected nest site using an autonomous digital recorder. Viewed through a spotting scope, a male Eagle Owl showed no signs of stress response when suddenly exposed to the noise of firing guns from a shooting range at 40 m distance. Further observations on several individuals never revealed any immediate stress responses under acute strong noise exposure. Eagle Owl vocalisations were frequently superimposed by heavy traffic noise from motor vehicles and trains but the call sequence was not detectably disturbed or altered in response to traffic noise. Young Eagle Owls, 105-110 days of age, continued voicing their contact calls without any signs of disturbance when exposed to fireworks. One half of the resident pairs in the study area settled in territories which are acutely or chronically affected by various sources of strong noise. Reproductive success, calculated for 133 nesting events in the years 2008-23, was 2.28 young per event in quiet locations, and 2.47 at nest sites with severe noise exposure. These findings suggest that Eagle Owls chose their breeding territories and reproduce successfully irrespective of the prevalent noise level. At four different scales, this study reveals a remarkable tolerance of Eagle Owls towards various sources of anthropogenic noise.]
This chapter describes the effects of noise on animals in terrestrial and aquatic habitats. Potential adverse effects cover a range of behavioral changes and physiological responses, including—in extreme cases—physical injury and death. The types and severity of effects are related to a number of noise features, including the received noise level and duration of exposure, but also depend upon contextual factors such as proximity, familiarity, and the behavioral state in which animals were exposed. The effects of anthropogenic noise on individual animals can escalate to the population level. Ultimately, species-richness and biodiversity in an ecosystem could be affected. However, our understanding of population-level effects and ecosystem interactions is limited, yet it is an active area of study. Given that noises of human origin can be controlled, there is the potential to mitigate any negative impacts by modifying noise source characteristics or operation schedules, finding alternative means to obtain operational goals of the noise source, or excluding biologically critical habitats or seasons.
Simple Summary
Wind power can contribute to a necessary reduction in CO2 and other greenhouse gas emissions. However, wind farm construction and infrastructure might cause other problems, for example, reducing biodiversity. In parts of their distribution area, eagle owls are scarce and declining, and not much is known about their tolerance for different kind of disturbances. Here, we investigated the presence–absence of Eurasian eagle owls (Bubo bubo) in 48 territories in the central part of Norway before the construction of eight wind farms and power lines started, and shortly after the construction period. Eagle owls living within 4–5 km away from the disturbance left their territories to a higher extent than eagle owls living even further away.
Abstract
Wind power is useful for reducing greenhouse gas emissions, but the construction and operation might have negative effects on biodiversity. The purpose of this study was to investigate any effects of wind farm and power line construction on territory occupancy in the vulnerable Eurasian eagle owl. We investigated 48 eagle owl territories before and after the whole construction period and a short operation period with the use of sound meters. We found that territorial eagle owls within 4–5 km from the wind farm and power line construction disturbance left their territories to a significantly higher extent (41% reduction in the number of territories with eagle owls) compared with the eagle owls in territories further away (23% reduction). The distance from the nest site to the disturbance was significantly shorter for those territories that were abandoned compared with territories where the birds stayed. Possible reasons for this decline might be a higher mortality caused by collisions, desertion and avoidance of wind power areas caused by the noise and disturbance from their construction. In addition, there are possible indirect effects, for example reductions in prey species may force eagle owls to abandon their territories. The construction period lasted much longer than the period with active wind turbines and power lines in this investigation, but we cannot separate the effects of the two because the investigations were only possible in the eagle owl breeding season, and the wind turbines were activated shortly after the construction period. Our results imply that careful investigations are needed to detect the possible occurrence of eagle owls near any type of construction work. Studies of these territories should strongly influence how and when the construction work can be carried out, but more investigations are needed to find details about the influence of distance.
Many animals use sound as a medium for detecting or locating potential prey items or predation threats. Northern saw-whet owls ( Aegolius acadicus ) are particularly interesting in this regard, as they primarily rely on sound for hunting in darkness, but are also subject to predation pressure from larger raptors. We hypothesized that these opposing tasks should favor sensitivity to low-frequency sounds arriving from many locations (potential predators) and high-frequency sounds below the animal (ground-dwelling prey items). Furthermore, based on the morphology of the saw-whet owl skull and the head-related transfer functions of related species, we expected that the magnitude of changes in sensitivity across spatial locations would be greater for higher frequencies than low frequencies (i.e., more “directional” at high frequencies). We used auditory-evoked potentials to investigate the frequency-specific directional sensitivity of Northern saw-whet owls to acoustic signals. We found some support for our hypothesis, with smaller-magnitude changes in sensitivity across spatial locations at lower frequencies and larger-magnitude changes at higher frequencies. In general, owls were most sensitive to sounds originating in front of and above their heads, but at 8 kHz there was also an area of high sensitivity below the animals. Our results suggest that the directional hearing of saw-whet owls should allow for both predator and prey detection.
Globally, anthropogenic sound and artificial light pollution have increased to alarming levels. Evidence suggests that these can disrupt critical processes that impact ecosystems and human health. However, limited focus has been given to the potential effects of sound and artificial light pollution on microbiomes. Microbial communities are the foundations of our ecosystems. They are essential for human health and provide myriad ecosystem services. Therefore, disruption to microbiomes by anthropogenic sound and artificial light could have important ecological and human health implications. In this mini-review, we provide a critical appraisal of available scientific literature on the effects of anthropogenic sound and light exposure on microorganisms and discuss the potential ecological and human health implications. Our mini-review shows that a limited number of studies have been carried out to investigate the effects of anthropogenic sound and light pollution on microbiomes. However, based on these studies, it is evident that anthropogenic sound and light pollution have the potential to significantly influence ecosystems and human health via microbial interactions. Many of the studies suffered from modest sample sizes, suboptimal experiments designs, and some of the bioinformatics approaches used are now outdated. These factors should be improved in future studies. This is an emerging and severely underexplored area of research that could have important implications for global ecosystems and public health. Finally, we also propose the photo-sonic restoration hypothesis: does restoring natural levels of light and sound help to restore microbiomes and ecosystem stability? Preprints (www.preprints.org) | NOT PEER-REVIEWED | Posted:
Anthropogenic noise is an emerging global pollutant. Road networks and energy extraction infrastructure are both spatially extensive and rapidly expanding sources of noise. We predict that predators reliant on acoustic cues for hunting are particularly sensitive to louder environments. Here we examined the foraging efficiency of pallid bats (Antrozous pallidus) when exposed to played-back traffic and gas compressor station noise in the laboratory. We show that both types of noise at each of five exposure levels (58–76 dBA, 10–640 m from source) and low-level amplifier noise (35 dBA) increase the time required for bats to locate prey-generated sounds by twofold to threefold. The mechanism underlying these findings is unclear and, given the potential landscape-level habitat degradation indicated by our data, we recommend continued research into the effects of noise exposure on acoustically specialized predators.
Maximum likelihood or restricted maximum likelihood (REML) estimates of the
parameters in linear mixed-effects models can be determined using the lmer
function in the lme4 package for R. As for most model-fitting functions in R,
the model is described in an lmer call by a formula, in this case including
both fixed- and random-effects terms. The formula and data together determine a
numerical representation of the model from which the profiled deviance or the
profiled REML criterion can be evaluated as a function of some of the model
parameters. The appropriate criterion is optimized, using one of the
constrained optimization functions in R, to provide the parameter estimates. We
describe the structure of the model, the steps in evaluating the profiled
deviance or REML criterion, and the structure of classes or types that
represents such a model. Sufficient detail is included to allow specialization
of these structures by users who wish to write functions to fit specialized
linear mixed models, such as models incorporating pedigrees or smoothing
splines, that are not easily expressible in the formula language used by lmer.
Many authors have suggested that the negative effects of roads on animals are largely owing to traffic noise. Although suggestive, most past studies of the effects of road noise on wildlife were conducted in the presence of the other confounding effects of roads, such as visual disturbance, collisions and chemical pollution among others. We present, to our knowledge, the first study to experimentally apply traffic noise to a roadless area at a landscape scale-thus avoiding the other confounding aspects of roads present in past studies. We replicated the sound of a roadway at intervals-alternating 4 days of noise on with 4 days off-during the autumn migratory period using a 0.5 km array of speakers within an established stopover site in southern Idaho. We conducted daily bird surveys along our 'Phantom Road' and in a nearby control site. We document over a one-quarter decline in bird abundance and almost complete avoidance by some species between noise-on and noise-off periods along the phantom road and no such effects at control sites-suggesting that traffic noise is a major driver of effects of roads on populations of animals.
Anthropogenic noise is an important environmental stressor that is rapidly gaining attention among biologists, resource managers, and policy makers. Here we review a substantial literature detailing the impacts of noise on wildlife and provide a conceptual framework to guide future research. We discuss how several likely impacts of noise exposure have yet to be rigorously studied and outline how behavioral responses to noise are linked to the nature of the noise stimulus. Chronic and frequent noise interferes with animals’ abilities to detect important sounds, whereas intermittent and unpredictable noise is often perceived as a threat. Importantly, these effects can lead to fitness costs, either directly or indirectly. Future research should consider the range of behavioral and physiological responses to this burgeoning pollutant and pair measured responses with metrics that appropriately characterize noise stimuli. This will provide a greater understanding of the mechanisms that govern wildlife responses to noise and help in identifying practical noise limits to inform policy and regulation.
On the basis of the literature and my own examination of living and/or
dead but fresh owls of 16 species, bilateral asymmetry of external ears
in owls is surveyed and ear structure briefly described. Consideration
of the probability of origin of various structural similarities and
dissimilarities in the ear leads to the conclusion that ear asymmetry
has evolved independently in at least five lines, represented by the
respective genera (1) Tyto, (2) Phodilus, (3) Bubo, Ciccaba, Strix, (4)
Rhinoptynx, Asio, Pseudoscops, and (5) Aegolius. Bubo, Ciccaba, and
Strix probably represent more than one line of origin of ear asymmetry.
Available evidence suggests that bilateral ear asymmetry in owls serves
to make the vertical directional sensitivity patterns different between
the two ears for high frequencies, thus making possible vertical
localization based on binaural comparison of intensity and spectral
composition of sound. When an owl localizes prey by hearing, the
direction of the source usually forms a shallow angle with the ground.
Therefore, a certain angle of error usually converts into a longer
distance along the ground for a vertical error than for a horizontal
error. This is a crucial factor that calls for good vertical
localization ability of owls which rely on hearing for localization of
food. Selection pressure for improvement of the ability of vertical
localization of sound is believed to lie behind the evolution of all
types of bilateral ear asymmetry in owls. On the basis of comparative
ear structure the current subdivision of family Strigidae into subfamily
Buboninae and Striginae is rejected. The external ears of Rhinoptynx and
Pseudoscops are described for the first time and shown to be very
similar to those of Asio otus, demonstrating affinity between these
three genera.
Anthropogenic noise is becoming a dominant component of soundscapes across the world and these altered acoustic conditions
may have severe consequences for natural communities. We modeled noise amplitudes from gas well compressors across a 16km2 study area to estimate the influence of noise on avian habitat use and nest success. Using species with noise responses representative
of other avian community members, across the study area we estimated gray flycatcher (Empidonax wrightii) and western scrub-jay (Aphelocoma californica) occupancy, and gray flycatcher nest success, which is highly dependent on predation by western scrub-jays. We also explore
how alternative noise management and mitigation scenarios may reduce area impacted by noise. Compressor noise affected 84.5%
of our study area and occupancy of each species was approximately 5% lower than would be expected without compressor noise.
In contrast, flycatcher nest success was 7% higher, reflecting a decreased rate of predation in noisy areas. Not all alternative
management and mitigation scenarios reduced the proportion of area affected by noise; however, use of sound barrier walls
around compressors could reduce the area affected by noise by 70% and maintain occupancy and nest success rates at levels
close to those expected in a landscape without compressor noise. These results suggest that noise from compressors could be
effectively managed and, because habitat use and nest success are only two of many ecological processes that may change with
noise exposure, minimizing the anthropogenic component of soundscapes should be a conservation priority.
KeywordsAnthropogenic noise–Occupancy patterns–Natural gas well compressor–Nest success–Soundscape
Noise pollution is a novel, widespread environmental force that has recently been shown to alter the behaviour and distribution of birds and other vertebrates, yet whether noise has cumulative, community-level consequences by changing critical ecological services is unknown. Herein, we examined the effects of noise pollution on pollination and seed dispersal and seedling establishment within a study system that isolated the effects of noise from confounding stimuli common to human-altered landscapes. Using observations, vegetation surveys and pollen transfer and seed removal experiments, we found that effects of noise pollution can reverberate through communities by disrupting or enhancing these ecological services. Specifically, noise pollution indirectly increased artificial flower pollination by hummingbirds, but altered the community of animals that prey upon and disperse Pinus edulis seeds, potentially explaining reduced P. edulis seedling recruitment in noisy areas. Despite evidence that some ecological services, such as pollination, may benefit indirectly owing to noise, declines in seedling recruitment for key-dominant species such as P. edulis may have dramatic long-term effects on ecosystem structure and diversity. Because the extent of noise pollution is growing, this study emphasizes that investigators should evaluate the ecological consequences of noise alongside other human-induced environmental changes that are reshaping human-altered landscapes worldwide.
Noise pollution from human traffic networks and industrial activity impacts vast areas of our planet. While anthropogenic noise effects on animal communication are well documented, we have very limited understanding of noise impact on more complex ecosystem processes, such as predator-prey interactions, albeit urgently needed to devise mitigation measures. Here, we show that traffic noise decreases the foraging efficiency of an acoustic predator, the greater mouse-eared bat (Myotis myotis). These bats feed on large, ground-running arthropods that they find by listening to their faint rustling sounds. We measured the bats' foraging performance on a continuous scale of acoustically simulated highway distances in a behavioural experiment, designed to rule out confounding factors such as general noise avoidance. Successful foraging bouts decreased and search time drastically increased with proximity to the highway. At 7.5 m to the road, search time was increased by a factor of five. From this increase, we predict a 25-fold decrease in surveyed ground area and thus in foraging efficiency for a wild bat. As most of the bats' prey are predators themselves, the noise impact on the bats' foraging performance will have complex effects on the food web and ultimately on the ecosystem stability. Similar scenarios apply to other ecologically important and highly protected acoustic predators, e.g. owls. Our study provides the empirical basis for quantitative predictions of anthropogenic noise impacts on ecosystem processes. It highlights that an understanding of the effects of noise emissions and other forms of 'sensory pollution' are crucially important for the assessment of environmental impact of human activities.
Humans have drastically changed much of the world's acoustic background with anthropogenic sounds that are markedly different in pitch and amplitude than sounds in most natural habitats. This novel acoustic background may be detrimental for many species, particularly birds. We evaluated conservation concerns that noise limits bird distributions and reduces nesting success via a natural experiment to isolate the effects of noise from confounding stimuli and to control for the effect of noise on observer detection biases. We show that noise alone reduces nesting species richness and leads to different avian communities. Contrary to expectations, noise indirectly facilitates reproductive success of individuals nesting in noisy areas as a result of the disruption of predator-prey interactions. The higher reproductive success for birds within noisy habitats may be a previously unrecognized factor contributing to the success of urban-adapted species and the loss of birds less tolerant of noise. Additionally, our findings suggest that noise can have cascading consequences for communities through altered species interactions. Given that noise pollution is becoming ubiquitous throughout much of the world, knowledge of species-specific responses to noise and the cumulative effects of these novel acoustics may be crucial to understanding and managing human-altered landscapes.
Significance
Using landscape-scale traffic noise playbacks to create a “phantom road,” we find that noise, apart from other factors present near roads, degrades the value of habitat for migrating songbirds. We found that nearly one third of the bird community avoided the phantom road. For some bird species that remained despite noise exposure, body condition and stopover efficiency (ability to gain body condition over time) decreased compared with control conditions. These findings have broad implications for the conservation of migratory birds and perhaps for other wildlife, because factors driving foraging behavior are similar across animals. For wildlife that remains in loud areas, noise pollution represents an invisible source of habitat degradation.
As use of Akaike's Information Criterion (AIC) for model selection has become increasingly common, so has a mistake involving interpretation of models that are within 2 AIC units (ΔAIC ≤ 2) of the top-supported model. Such models are <2 ΔAIC units because the penalty for one additional parameter is 2 AIC units, but model deviance is not reduced by an amount sufficient to overcome the 2-unit penalty and, hence, the additional parameter provides no net reduction in AIC. Simply put, the uninformative parameter does not explain enough variation to justify its inclusion in the model and it should not be interpreted as having any ecological effect. Models with uninformative parameters are frequently presented as being competitive in the Journal of Wildlife Management, including 72 of all AIC-based papers in 2008, and authors and readers need to be more aware of this problem and take appropriate steps to eliminate misinterpretation. I reviewed 5 potential solutions to this problem: 1) report all models but ignore or dismiss those with uninformative parameters, 2) use model averaging to ameliorate the effect of uninformative parameters, 3) use 95 confidence intervals to identify uninformative parameters, 4) perform all-possible subsets regression and use weight-of-evidence approaches to discriminate useful from uninformative parameters, or 5) adopt a methodological approach that allows models containing uninformative parameters to be culled from reported model sets. The first approach is preferable for small sets of a priori models, whereas the last 2 approaches should be used for large model sets or exploratory modeling.
Advanced technologies in oil and gas extraction coupled with energy demand have encouraged an average of 50,000 new wells per year throughout central North America since 2000. Although similar to past trends (see the graph, this page), the space and infrastructure required for horizontal drilling and high-volume hydraulic fracturing are transforming millions of hectares of the Great Plains into industrialized landscapes, with drilling projected to continue (1, 2). Although this development brings economic benefits (3) and expectations of energy security, policy and regulation give little attention to trade-offs in the form of lost or degraded ecosystem services (4). It is the scale of this transformation that is important, as accumulating land degradation can result in continental impacts that are undetectable when focusing on any single region (5). With the impact of this transformation on natural systems and ecosystem services yet to be quantified at broad extents, decisions are being made with few data at hand (see the graph, this page).
This report provides a complete summary of what is known about basic hearing capabilities in birds in relation to the characteristics of noise generated by wind turbines. It is a review of existing data on bird hearing with some preliminary estimates of environmental noise and wind turbine noise at Altamont Pass, California, in the summer of 1999. It is intended as a resource in future discussions of the role that hearing might play in bird avoidance of turbines.
We used information compiled by the U.S. Geological Survey's Bird Banding Laboratory and geographic information systems (GIS) analysis to identify trends in annual Northern Saw-whet Owl (Aegolius acadicus) movement across eastern North America. Analysis of 81,584 Northern Saw-whet Owl banding events revealed a southbound annual fall migration front with peak banding activity occurring progressively later in the season as latitude decreases. Northbound owls comprised <9% of owls banded and recaptured elsewhere in the same season, and <5% were recaptured northbound >100 km from banding location. There was no relationship between banding latitude and adult-to-juvenile ratio. However, the proportion of adults versus juveniles banded was not uniform among banding stations, suggesting age-differentiated migration patterns may exist. Information from multiyear foreign recaptures revealed that 72% of owls banded and subsequently recaptured at the same latitude in different years were recaptured <100 km from banding location. A similar trend was found in the Appalachian Mountains, the Great Lakes Basin, and the Atlantic seaboard. This indicates that Northern Saw-whet Owls may exhibit high migration route fidelity. These findings expand the Northern Saw-whet Owl information portfolio and illustrate the versatility of aggregate data sets as a tool for answering large-scale questions regarding migration.
Analyzed the method by which the owl's sense of hearing permits it to catch prey in the dark. Hand-reared, specially trained owls participated in experiments in locating artificial sounds, pure tones, and noises. Findings indicate that the owl needs only a small portion of the frequency spectrum in the prey's rustles in order to accurately locate its prey. It was shown that the small rodents make wideband noises rich in frequencies in the range most suitable for the owl's sound location. Further, studies on sound tracking in flight implied that the owl's wing noises do not interfere with the detection of acoustic clues which would necessitate flight correction, while small rodents cannot readily detect the low frequencies of the approaching owl. A theory of sound location by owls is proposed. (20 ref) (PsycINFO Database Record (c) 2012 APA, all rights reserved)
As use of Akaike's Information Criterion (AIC) for model selection has become increasingly common, so has a mistake involving interpretation of models that are within 2 AIC units (ΔAIC ≤ 2) of the top-supported model. Such models are <2 ΔAIC units because the penalty for one additional parameter is +2 AIC units, but model deviance is not reduced by an amount sufficient to overcome the 2-unit penalty and, hence, the additional parameter provides no net reduction in AIC. Simply put, the uninformative parameter does not explain enough variation to justify its inclusion in the model and it should not be interpreted as having any ecological effect. Models with uninformative parameters are frequently presented as being competitive in the Journal of Wildlife Management, including 72% of all AIC-based papers in 2008, and authors and readers need to be more aware of this problem and take appropriate steps to eliminate misinterpretation. I reviewed 5 potential solutions to this problem: 1) report all models but ignore or dismiss those with uninformative parameters, 2) use model averaging to ameliorate the effect of uninformative parameters, 3) use 95% confidence intervals to identify uninformative parameters, 4) perform all-possible subsets regression and use weight-of-evidence approaches to discriminate useful from uninformative parameters, or 5) adopt a methodological approach that allows models containing uninformative parameters to be culled from reported model sets. The first approach is preferable for small sets of a priori models, whereas the last 2 approaches should be used for large model sets or exploratory modeling.
Extraneous sounds have a variety of effects on animals; they may interfere with communication, cause physical harm, increase wariness, influence settlement decisions, or they may cause distractions in ways that increase vulnerability to predation. We designed a study to investigate the effects of changing both the amplitude and duration of an acoustic stimulus on distraction in a terrestrial hermit crab (Coenobita clypeatus). In experiment 1, we replicated the key findings from a field result: crabs hid more slowly in response to a silent visual stimulus when we simultaneously broadcast a white noise than they did when in a silent condition. In experiment 2, we altered the noise duration and found that a long noise generated greater latencies to hide than a short noise. In experiment 3, we increased the noise amplitude and found that hide latency increased with higher-intensity auditory stimuli. These experiments demonstrate a variety of stimulus factors that influence distraction. Our results suggest that prey animals could be in greater danger from predators when in an environment with auditory distractions.
The effects of human activities in forests are often examined in the context of habitat conversion. Changes in habitat structure and composition are also associated with increases in the activity of people with vehicles and equipment, which results in increases in anthropogenic noise. Anthropogenic noise may reduce habitat quality for many species, particularly those that rely on acoustic signals for communication. We compared the density and occupancy rate of forest passerines close to versus far from noise-generating compressor stations and noiseless well pads in the boreal forest of Alberta, Canada. Using distance-based sampling, we found that areas near noiseless energy facilities had a total passerine density 1.5 times higher than areas near noise-producing energy sites. The White-throated Sparrow (Zonotrichia albicollis), Yellow-rumped Warbler (Dendroica coronata), and Red-eyed Vireo (Vireo olivaceus) were less dense in noisy areas. We used repeat sampling to estimate occupancy rate for 23 additional species. Seven had lower conditional or unconditional occupancy rates near noise-generating facilities. One-third of the species examined showed patterns that supported the hypothesis that abundance is influenced by anthropogenic noise. An additional 4 species responded negatively to edge effects. To mitigate existing noise impacts on birds would require approximately 100 billion energy-sector investment planned for the boreal forest in the next 10 years, including noise suppression technology at the outset of construction, makes noise mitigation a cost-effective best-management practice that might help conserve high-quality habitat for boreal birds.
The history of the development of statistical hypothesis testing in time series analysis is reviewed briefly and it is pointed out that the hypothesis testing procedure is not adequately defined as the procedure for statistical model identification. The classical maximum likelihood estimation procedure is reviewed and a new estimate minimum information theoretical criterion (AIC) estimate (MAICE) which is designed for the purpose of statistical identification is introduced. When there are several competing models the MAICE is defined by the model and the maximum likelihood estimates of the parameters which give the minimum of AIC defined by AIC = (-2)log-(maximum likelihood) + 2(number of independently adjusted parameters within the model). MAICE provides a versatile procedure for statistical model identification which is free from the ambiguities inherent in the application of conventional hypothesis testing procedure. The practical utility of MAICE in time series analysis is demonstrated with some numerical examples.
lme4: linear mixed-effects models using S4 classes
- D Bates
- M Maechler
- B Bolker
- S Walker
Bates, D., Maechler, M., Bolker, B., Walker, S., 2014. lme4: linear mixed-effects models
using S4 classes. R package version 1.1-6. R. http://CRAN.R-project.org/package=
lme4 (doi:).