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The impact of noise from open-cast mining on Atlantic forest biophony
... Documented effects of noise on wildlife include modulations in acoustic communication [4][5][6], as well as other behavioral changes, such as decreased time spent foraging and sleeping [5], and physiological responses, such as increased secretion of hormones indicative of stress [5]. In addition, ecological impacts, such as changes in species distribution, richness and composition have been documented, e.g., [7,8]. Noise is cited by some authors as significantly contributing to biodiversity decline in all ecosystems in the world [9]. ...
... However, this process can be negatively affected by anthropogenic noise through masking. Masking occurs when a sound is emitted at the same time as animal vocalizations, and at the same frequency, with enough energy that it affects the perception of the signal of interest [7]. The degree to which an acoustic signal is masked by noise depends on the degree of spectral and temporal overlap between signal and noise, as well as the auditory sensitivity of the receiver [9]. ...
... Due to its nature, opencast mining inevitably leads to serious habitat loss with several significant impacts on the environment [14]. Among the various impacts generated by mining, the production of noise from truck traffic, explosions and machinery operation has the potential to mask animal sounds and affect their long-term behavior and distribution [7]. Despite the existence of research that shows the impacts of mining noise on wildlife, there are still no laws in Brazil that regulate and require the monitoring of this anthropogenic noise on animals, or that establish a maximum level of noise pollution in areas not inhabited by humans [15]. ...
Simple Summary
Communication is one way that animals use to obtain and defend resources, escape predators and attract sexual partners. However, this process can be disrupted by anthropogenic noise, which often differs from natural sounds in frequency, duration and intensity. This study aimed to understand whether, and how, calls emitted by black-tufted marmosets (Callithrix penicillata) are affected by mining noise. We compared ambient noise and the acoustic parameters of the contact calls of these animals in two study areas, one near and one far from the Brucutu Mine, Minas Gerais, Brazil. We found background noise to be higher in the area near the mine, and marmoset vocalizations more frequent, compared to the far area. Calls emitted in the near area also differed in spectral parameters from the far area, which suggests an effort by the animals to adapt their vocal activity to a noisier environment. Our results indicate that mining noise may affect the acoustic communication of black-tufted marmosets. These results may be taken as a starting point for establishing public policies to promote preventive and/or mitigative measures to protect wildlife around sites of mining activity. Moreover, measures to regulate any noisy activities in relation to wild animals are pressing since these are lacking in Brazil.
Abstract
All habitats have noise, but anthropogenic sounds often differ from natural sounds in terms of frequency, duration and intensity, and therefore may disrupt animal vocal communication. This study aimed to investigate whether vocalizations emitted by black-tufted marmosets (Callithrix penicillata) were affected by the noise produced by mining activity. Through passive acoustic monitoring, we compared the noise levels and acoustic parameters of the contact calls of marmosets living in two study areas (with two sampling points within each area)—one near and one far from an opencast mine in Brazil. The near area had higher anthropogenic background noise levels and the marmosets showed greater calling activity compared to the far area. Calls in the near area had significantly lower minimum, maximum and peak frequencies and higher average power density and bandwidth than those in the far area. Our results indicate that the mining noise affected marmoset vocal communication and may be causing the animals to adjust their acoustic communication patterns to increase the efficiency of signal propagation. Given that vocalizations are an important part of social interactions in this species, concerns arise about the potential negative impact of mining noise on marmosets exposed to this human activity.
... The inability to detect environment acoustic signals is clearly one of the most important effects of noise due to it masking the sounds produced by the animals Erbe et al., 2016). Anthropogenic noise can be produced in the same frequencies of the vocalizations produced by the animals, and this can disrupt information transmission (Patricelli and Blickley, 2006;Siemers and Schaub, 2011;McMullen et al., 2014;Duarte et al., 2015;Templeton et al., 2016;Duarte et al., 2018). Environmental level acoustic disturbances may have long term consequences on a population, such as: an increase in the exhibition of anti-predator behaviours in unnecessary situations due to the confusion effect of noise (Wale et al., 2013;Voellmy et al., 2014;Meillère et al., 2015); changes in characteristics of vocalizations (Patricelli and Blickley, 2006;Kleist et al., 2016); an increase in stress and associated diseases (Kight and Swaddle, 2011;Rolland et al., 2012); and population decreases (Francis and Barber, 2013;McClure et al., 2013). ...
... Mineral production is an important worldwide economic activity (Ferranti et al., 2002;Duarte et al., 2015), which causes several negative impacts (Stamps and Krishnan, 2014). Some of the potential impacts from mining activity are: radioactive waste production; fires caused by coal; soil pollution and subsidence; water, air, and noise pollution (CRPM -Serviço Geológico do Brasil (2002)). ...
... Brazil is a major mineral producer, and this activity is distributed throughout the country, but much of this activity is concentrated in Minas Gerais state (Vieira, 2011). There are many noise sources from mining activity, however, the major source is the intense traffic of machines and large vehicles (Duarte et al., 2015). ...
Impacts of noise pollution are recognized as a source of stress for animals and as a form of environmental degradation. Behavioural changes associated with noise, such as reduction of reproductive success, reduction in feeding behaviour, increase in vigilance behaviours and inability to detect environment acoustic signals, are observed. The aim of the present study was to evaluate how noise influences aggressive behaviour of the saffron finch (Sicalis flaveola). We conducted tests of territoriality-aggressiveness against conspecifics. Seven individuals were tested, with six tests per individual being conducted in two treatments (traffic pollution and ambient noise), totalling 84 tests. The noise treatment significantly altered the agonistic interactions of the saffron finches, with territorial males exhibiting less aggressive behaviours towards intruders.
... This potentially impacts the wildlife of the area affecting their movements, habits and preferences as they tend to avoid areas with chronic noise (Wisconsin Dept. of Natural Resources, 2012). Duarte et al. (2015) found that mining noise affected the biophony of the region by altering the temporal dynamics and daily patterns of animal sounds, thereby significantly affecting the communityspecies composition, where animals near and far from mining sites depicted different behavioural patterns (Duarte et al., 2015). ...
... This potentially impacts the wildlife of the area affecting their movements, habits and preferences as they tend to avoid areas with chronic noise (Wisconsin Dept. of Natural Resources, 2012). Duarte et al. (2015) found that mining noise affected the biophony of the region by altering the temporal dynamics and daily patterns of animal sounds, thereby significantly affecting the communityspecies composition, where animals near and far from mining sites depicted different behavioural patterns (Duarte et al., 2015). ...
The Standing Committee of the National Board for Wild Life (SC-NBWL) had been receiving several mining proposals for consideration from around Ranthambhore Tiger Reserve (RTR), and often in a piecemeal manner. This had made it difficult for SC-NBWL to assess these projects’ overall impacts on wildlife and forest connectivity in RTR’s surrounding landscape. On the receipt of two mining proposals, a decision was taken in the SC-NBWL’s 70th meeting held in October 2022 to defer all mining proposals around RTR until a ‘Cumulative Impact Study Report’ was prepared by the Wildlife Institute of India, Dehradun (WII) towards protecting wildlife habitats and corridors in RTR’s vicinity. Accordingly, an area of c. 3,798 sq.km within Rajasthan in a 10 km-radius width around RTR was delineated as the “Cumulative Impact Study Area” (or CISA) encompassing parts of the administrative districts of Karauli, Sawai Madhopur, Tonk, Bundi and Kota. The CISA also encompasses parts of RTR Division-I, RTR Division-II, Ramgarh-Vishdhari Tiger Reserve (RVTR), National Chambal Sanctuary Project, and Social Forestry/ Territorial Divisions of Karauli, Sawai Madhopur, Tonk, Bundi and Kota. RTR (core & buffer) itself though is not part of the CISA as the assignment concerns areas in its vicinity. The CISA is described in terms of its forests, wildlife (including surrounding Protected Areas and connectivity between them), land use/ land cover, geology, geomorphology, climate etc. Impacts of mining activities on ecosystems, biodiversity and the environment, in general, are also described.
Utilising available data from ongoing or completed research projects within WII and other data as available from published literature and government repositories, an area of c. 2136 sq.km within the CISA (56.26%) has been determined as “critical zone” for wildlife, especially concerning their persistence in the larger Ranthambhore landscape. These are areas with the occupancy and/ or (modelled) potentially suitable habitat of globally threatened and/ or locally rare Schedule-I mammalian species, as per the amended (until 2022) Wild Life Protection Act, 1972, such as tiger Panthera tigris (EN), leopard Panthera pardus (VU), caracal Caracal caracal (LC, but India’s most threatened wild cat species), Indian grey wolf Canis lupus pallipes (LC, but genetically distinct subspecies and locally rare), dhole (or Asiatic wild dog) Cuon alpinus (EN), Indian pangolin Manis crassicaudata (EN) and sloth bear Melursus ursinus (VU), including their identified movement corridors. The delineated critical zone also includes areas within PAs around RTR and areas satisfying the current legal definition of an Eco-Sensitive Zone (ESZ), within which all commercial mining is prohibited, as per the Ministry of Environment, Forest and Climate Change’s (MoEF&CC) February 2011 guidelines on the matter. Within the CISA, a “non-critical zone” from the perspective of inhabiting wildlife of c. 1,661 sq.km (43.74%) is identified where mining activities may be appropriately appraised, subject to site-specific critical and cumulative impact assessments of the received proposals. If received/ pending proposals are positively appraised, the lessees/ user agencies must strictly adhere to all relevant extant laws, rules and guidelines issued by the Union and State governments from time to time, along with following all relevant orders passed by Hon’ble higher courts of judicature and statutory clearance conditions issued by national and state-level authorities.
Pillar locations’ coordinates (intermediate/ all corners) and other associated details of a total 145 mining leases within the CISA were informed through the concerned district offices of the Department of Mining and Geology (DMG), Govt. of Rajasthan. Of these, a majority (100) mining leases are located within Karauli district, while there are none in the Tonk district. It is, however, unclear if the data provided through DMG offices is comprehensive or complete. The statuses of these leases – whether operational/ lease expired/ applied for renewal etc. – is also either unclear or not known. Given these facts, we found that a total of sixty (60) mining leases – twenty-seven (27), six (06), three (03) and twenty-four (24) in Karauli, Sawai Madhopur, Bundi and Kota districts, respectively – are located within the “critical zone” for wildlife delineated in this assessment. Of these 60 leases, thirteen (13) are located either partly or wholly within the legally valid ESZs (as on date of submission of this report) where commercial mining and associated industries is listed as a prohibited activity, while as many as twenty-two (22) mining leases are located within identified wildlife corridors (all in the Ranthambhore-Ramgarh Vishdhari-Mukundara corridor). Three (03) mining leases – two in Bundi district (ML nos. 389/1998, 333/2002) and one in Kota district (23/2003) – are, in fact, located within both ESZs and wildlife corridors.
We observe an enormous scope to regulate and streamline mining activities around RTR towards a more sustainable framework accounting for the needs of both people/ industries and wildlife. While sufficient information on flora and fauna exists (and is being generated) within RTR, a general lack of scientific investigations coupled with insufficient monitoring of wildlife in RTR’s immediate vicinity limits this assessment exercise. This is especially concerning since RTR acts as a significant source population of threatened wildlife, including tiger, in the Central India-Eastern Ghats (CIEG) landscape, enabling their long-term persistence in and gradual range expansion into other parts of Rajasthan and the larger CIEG. Hence, we recommend carrying out comprehensive wildlife diversity, distribution, movements, species-habitat relationships, human-wildlife interactions and other such studies towards generating relevant information on these aspects in RTR’s vicinity. If several mining and/ or allied industries (such as mineral grinding/ processing plants) are proposed/ exist closely situated to each other, we also recommend conducting cumulative impact (of mining and allied industrial units) assessment studies funded through the State government ascertaining impacts of these activities on biodiversity, ecosystems, environment, and on the lives and livelihoods of human communities living nearby by reputed research institutions having such expertise, using modern research and analytical tools. Such studies may be commissioned immediately for the already existing cluster of proposals in the CISA where mining and/ or allied activities have been taking place since the past few decades (Karauli, Bundi and Kota clusters).
The formation and effective functioning of a participatory monitoring mechanism is necessary to ensure that the short- and long-term requirements and concerns of the most important stakeholders – wild life and local human communities – are not overlooked. We also provide relevant shape and Keyhole Markup Language (KML) files along with full-resolution images and maps generated from this project as a “Decision Support System” to the NBWL towards more informed proposal appraisals in the future. Informed decision-making with respect to resource extractive projects backed with robust and regular on-ground data/ monitoring of statutory and relevant laws, rules, guidelines, policies and compliance conditions will greatly facilitate the persistence of threatened species, and ensure the long-term survival and persistence of threatened wildlife in the biodiversity-rich and crucial larger Ranthambhore landscape.
... Isso implica em maior gasto de energia na comunicação entre parceiros sexuais ou, até mesmo, maior custo associado à proteção do território e emissão de sinais de alerta contra predadores (Brumm, 2004). Duarte et al. (2015), em um estudo na Floresta Atlântica do Sudeste do Brasil, demonstraram que o ruído da mineração afeta tanto a composição das aves quanto o comportamento do canto em locais próximos de minas. Assim, o ruído antropogênico, em conjunto com a perda de habitat, podem potencializar ainda mais o deslocamento das aves para habitats distantes da mina (Duarte et al., 2015;Pontes et al., 2016). ...
... Duarte et al. (2015), em um estudo na Floresta Atlântica do Sudeste do Brasil, demonstraram que o ruído da mineração afeta tanto a composição das aves quanto o comportamento do canto em locais próximos de minas. Assim, o ruído antropogênico, em conjunto com a perda de habitat, podem potencializar ainda mais o deslocamento das aves para habitats distantes da mina (Duarte et al., 2015;Pontes et al., 2016). Dessa maneira, esperamos que a abundância nas áreas florestais adjacentes seja maior por um período após deslocamento das espécies e diminua à medida em que as relações ecológicas intraespecíficas e interespecíficas aumentarem pela competição por recursos e territórios (Büchi & Vuilleumier, 2014). ...
RESUMO O principal objetivo do nosso trabalho foi o levantamento da composição (riqueza e abundância) da avifauna em um remanescente florestal de Mata Atlântica em Santa Catarina, suscetível à ampliação e intervenção de uma pedreira para subsidiar futuras análises de impactos ambientais dessa atividade. Registramos 142 espécies de aves, distribuídas em 16 ordens e 42 famílias. A partir dos resultados, concluímos que a riqueza total de espécies não deve ser afetada pela ampliação da área de lavra sob o remanescente. No entanto, constatamos que a abundância das aves foi menor nas proximidades da borda da mata, especialmente das aves endêmicas, ameaçadas e especialistas de sub-bosque. Dessa maneira, esperamos que a abundância nas áreas florestais adjacentes seja maior por um período, após o deslocamento das espécies, e diminua ao longo do tempo, à medida em que as relações ecológicas intraespecíficas e interespecíficas aumentem pela competição por recursos e território no habitat. Alertamos que se o tamanho do remanescente não for suficiente para populações viáveis, nossa hipótese é que haja um lapso temporal até que as espécies mais sensíveis desapareçam do local. O tamanho e qualidade do fragmento remanescente deve ser fundamental para minimizar os impactos da atividade e garantir a persistência das populações de aves sensíveis e especializadas na região. Por esse motivo, se a expansão da mina ocorrer, advertimos para que os remanescentes florestais do entorno sejam preservados para garantir a migração e persistência de aves sensíveis, principalmente insetívoras de sub-bosque relatadas em nosso estudo. Nesse contexto, apontamos cinco medidas prioritárias que devem ser implementadas pelo empreendedor, caso o órgão licenciador delibere em favor da ampliação/manutenção da atividade minerária: 1) aquisição dos remanescentes do entorno para transformá-los em RPPN, 2) reposição florestal equivalente à área desmatada, 3) contribuir com as ações do Plano de Ação Nacional para conservação das aves da Mata Atlântica por meio de medida compensatória, 4) diminuição da área de mina para exploração e 5) monitoramento de aves durante a instalação e operação do empreendimento.
... The noise produced by these activities has the potential to influence, mostly negatively, an animal's well-being (Kight and Swaddle, 2011;Middel and Verones, 2017). Many studies have reported that anthropogenic noise can impact wildlife in several ways, such as: triggering negative physiological impacts; increasing production of hormones associated with the stress response; increasing heart rate; negatively impacting on the hearing ability (Ortega, 2012;Duarte et al., 2015;Drolet et al., 2016;Mancera et al., 2017) and on vocal communication (Dooling and Blumenrath, 2013;Gil, Brumm, 2014;Gil et al., 2015); and changing antipredatory behaviours (Brumm and Slabbekoorn, 2005;Wale et al., 2013;Meillère et al., 2015;Spiga et al., 2017). All these effects can, in the long term, diminish the animal's fitness and well-being (Kling & Swaddle, 2011;Ortega, 2012). ...
... The mining vehicular traffic noise was choose because the noise produced by this type of vehicles was a flat and constant noise, with little variation (Duarte et al., 2015). This type of noise would be ideal to test how noise affected foraging efficiency in the saffron finch. ...
Noise pollution exerts negative well-being effects on animals, especially for captive individuals. A decrease in feeding, reproduction, attention, and an increase in stress are examples of negative effects of noise pollution on animals. Noise pollution can also negatively impact animals' lives by decreasing the efficiency of food choice: attention decrease can cause animals choose the least profitable food, which can affect their fitness. The aims of this study were to analyse the effects of noise on feeding behaviour and food preference of saffron finches. Foraging tests were performed under background sound pressure levels and under a noisy condition. The behaviours exhibited by the birds during the tests were recorded using focal sampling with instantaneous recording of behaviour every 10seconds. Results showed that finches consumed more the higher energetic food, and that noise pollution did not impact food consumption by the birds. Noise changed the number of visits on the feeders, and increased the expression of the 'lower the head' and vigilance behaviours during feeding. These findings could be important for wild and captive animals because an increase in vigilance and in changes in foraging behaviour could ultimately impact their fitness. Thus, mitigation measures should be taken in relation to noise impact on wildlife, this is especially the case for captive animals, which have no chance to avoid noisy environments.
... Studies on the effects of large-scale opencast mining activities on bat communities in tropical regions are scant and few exist for temperate regions (see Armstrong, 2010;Duarte et al., 2015;Theobald et al., 2020). Factors shown to influence total bat activity and species richness included distance from the boundary of the mine, woodland cover, climatic variables (Theobald et al., 2020) and machinery noise negatively impacting soundscape complexity (Duarte et al., 2015). ...
... Studies on the effects of large-scale opencast mining activities on bat communities in tropical regions are scant and few exist for temperate regions (see Armstrong, 2010;Duarte et al., 2015;Theobald et al., 2020). Factors shown to influence total bat activity and species richness included distance from the boundary of the mine, woodland cover, climatic variables (Theobald et al., 2020) and machinery noise negatively impacting soundscape complexity (Duarte et al., 2015). ...
Bats are known to be sensitive to changes in their environment. The impact of natural vegetation cover, artificial light intensity and noise (dBA) were investigated on the bat community on the opencast Venetia diamond mine using mixed-effects models. Clutter-feeding bats were virtually absent compared to surrounding natural habitats, suggesting the negative impact of vegetation removal and/or light and/or noise pollution. Mixed-effect models revealed that natural vegetation was the most important factor impacting species richness and overall bat activity. In general, bat activity of both open-air and clutter-edge foragers was negatively impacted over areas close to mining operations that were devoid of vegetation cover. Artificial light only significantly affected feeding activity with less feeding activity in the lit areas. Anthropogenic noise had no significant impact on bat activity and species richness. Our study highlights the importance of vegetation cover and the complexity of the interaction between bats and the environment incorporating anthropogenic factors (artificial lighting, continuous noise, and habitat degradation) and natural factors such as minimum temperature, moon phase, and season that confound trends in bat species richness and responses in relation to opencast mining.
... If the negative effects of anthropogenic noise have been thoroughly studied at the individual level through animal behavior and animal physiology studies (Slabbekoorn and Ripmeester 2008;Barber et al. 2009;Brumm 2013;Shannon et al. 2015), less research has been conducted at larger ecological scales. Anthropophony has been shown to be a prevalent part of preserved soundscapes (Francis et al. 2011a, b;Mullet et al. 2015), and to have a role in the structure of soundscapes, in relation to massive noise generators, such as industrial sites (Duarte et al. 2015;Deichmann et al. 2017) or highways (Munro et al. 2018;Khanaposhtani et al. 2019). Anthropogenic noise can alter the benefits that humans may experience from natural soundscapes (Francis et al. 2017). ...
... This decomposition appears as a challenge since biotic, abiotic and human sound sources can display great diversity regarding amplitude, time and frequency pattern, and moreover, they often overlap and interfere with each other. So far, such decomposition was operated either manually through listening and spectrographic visualization (Matsinos et al. 2008;Liu et al. 2013;Duarte et al. 2015;Mullet et al. 2015;Gasc et al. 2018;Rountree et al. 2020) or on the basis of frequency delimitation, anthropophony mainly occurring between 1 and 2 kHz (Joo et al. 2011;Gage and Axel 2014;Fairbrass et al. 2017;Ross et al. 2018;Doser et al. 2020). However, the choice of frequency limits is questionable as animals can produce sound at a lower or higher frequency range (Kasten et al. 2012). ...
Context
One mainstay of soundscape ecology is to understand acoustic pattern changes, in particular the relative balance between biophony (biotic sounds), geophony (abiotic sounds), and anthropophony (human-related sounds). However, little research has been pursued to automatically track these three components.
Objectives
Here, we introduce a 15-year program that aims at estimating soundscape dynamics in relation to possible land use and climate change. We address the relative prevalence patterns of these components during the first year of recording.
Methods
Using four recorders, we monitored the soundscape of a large coniferous Alpine forest at the France-Switzerland border. We trained an artificial neural network (ANN) with mel frequency cepstral coefficients to systematically detect the occurrence of silence and sounds coming from birds, mammals, insects (biophony), rain (geophony), wind (geophony), and aircraft (anthropophony).
Results
The ANN satisfyingly classified each sound type. The soundscape was dominated by anthropophony (75% of all files), followed by geophony (57%), biophony (43%), and silence (14%). The classification revealed expected phenologies for biophony and geophony and a co-occurrence of biophony and anthropophony. Silence was rare and mostly limited to night time.
Conclusions
It was possible to track the main soundscape components in order to empirically estimate their relative prevalence across seasons. This analysis reveals that anthropogenic noise is a major component of the soundscape of protected habitats, which can dramatically impact local animal behavior and ecology.
... . Other influential factors were reported in seven of the 12 studies, including biophonic sounds(Duarte et al. 2015;Bobryk et al. 2016;Raynor et al. 2017;Turner et al. 2018;Myers et al. 2019;Doser et al. 2020), geophonic noiseTurner et al. 2018) and anthropogenic noiseDuarte et al. 2015;Bobryk et al. 2016;Turner et al. 2018). ...
... . Other influential factors were reported in seven of the 12 studies, including biophonic sounds(Duarte et al. 2015;Bobryk et al. 2016;Raynor et al. 2017;Turner et al. 2018;Myers et al. 2019;Doser et al. 2020), geophonic noiseTurner et al. 2018) and anthropogenic noiseDuarte et al. 2015;Bobryk et al. 2016;Turner et al. 2018). ...
Technologies to monitor species are constantly evolving including the use of acoustic recordings to determine species presence, activity patterns and population dynamics. The Acoustic Complexity Index (ACI) aims to determine ecologically relevant changes in the soundscape by measuring the variability within biotic sounds whilst remaining insensitive to anthrophony. Previous findings relating to this index and its correlations with avian species richness and diversity, environmental and anthropogenic factors were amalgamated in this review to guide the future use of this monitoring technique. A total of 25 papers were returned following a literature search in June 2020 targeting studies in which these relationships were analysed. Current literature shows inconclusive relationships between the ACI and avian species richness and diversity. Also, those studies analysing relationships between the index, environmental and anthropogenic factors provided contrasting results due to the lack of replication between studies. The future implementation of a standardised approach towards data collection should lead to more compelling conclusions. Relationships between the soundscape and the environment should be evaluated on an individual site basis due to the influence species composition has on the acoustic environment. Further study is required to determine the relationship between anthropogenic factors, the ACI and avian assemblages.
... Mine processing activities release of quantities of particulate materials that can contribute with atmospheric emissions, wastewater effluents, result in waste or tailings, which turn lead to potentially toxic elements (PTEs) contamination in soil, sediment, and, in some cases, water in the affected region. Besides the intrinsic contamination of soil and sediment (Kelderman and Osman 2007;Antunes et al. 2018), these pockets of waste can contribute as a source of contamination for an entire aquatic system (Duarte et al. 2015;Wright et al. 2015). ...
... After the construction of the concrete box, it was carried out the cleaning of the land, collecting the tailings deposited, and depositing it there (CETESB 2021). Besides this action, for long time, these tailing piles were subject to the influence of rainfall, river floods, winds, etc., in addition to direct contact with the local population and rainforest fauna (Buschle et al. 2010;Duarte et al. 2015). It is important to point that the freshwater wealth of this region is important to supply the local population (more than 480 thousand inhabitants); moreover, it can be strategic for supplying the São Paulo city population (more than 21 million inhabitants) if the current water supply system collapses. ...
The determination of As and Pb was performed in surface water, pore water, and sediment from eight samples along the Ribeira do Iguape Valley watershed, Brazil, an old mining region, to assess the mobility and improve understanding of the environmental risk that these elements currently cause. Methods using ICP-MS were applied for the determination of these elements in all samples. The concentration ranges for As (0.11 ± 0.02 µg L−1 to 0.44 ± 0.02 µg L−1) and Pb (0.31 ± 0.01 µg L−1 to 2.02 ± 0.01 µg L−1) in water were very low, being possible fit them into highest natural water quality, according to the Brazilian regulation. Sediment samples collected at point P5 (Betari River) revealed As (113 ± 1 mg kg−1) and Pb (672 ± 9 mg kg−1) concentrations above the acceptable standards adopted by the local authorities. The application of sequential extraction procedures to this sample showed that more than 90% of Pb seem to be strongly bound to the sediment matrix, while arsenic showed higher mobility, between 60 and 90%, probably due to the action of acid agents. Arsenic speciation in pore water of this sample, using HPLC–ICP-MS, revealed the presence of As (III) as prevalent specie. At the point P5, near to the oldest mine (Furnas Mine), Pb is strongly associated with the sediment matrix, while As has a potential for migration in low pH conditions; in other collection points, the concentrations of these elements are below to the values recommended by regulation.
... Due to the overlap of petrel-inhabited and mineral-rich areas, this industry poses severe threats to the local Tahiti Petrel population (Pascal et al. 2008). These threats include habitat fragmentation and destruction (Reville et al. 1990, L'Huillier et al. 2010, light and noise pollution (Bayne et al. 2008, Francis et al. 2009, Saha and Padhy 2011, Duarte et al. 2015, Rodríguez et al. 2015, and a facilitated spread of invasive species, especially mammalian predators (Croxall et al. 2012, Rodríguez et al. 2019. Despite the known sensitivity of seabird colonies to such disturbances worldwide (Croxall et al. 2012, Rodríguez et al. 2019, the mechanisms underlying the observed population declines are rarely described. ...
... A time lag could then occur between the destruction of the Tahiti Petrel habitat and when it starts nesting again. Second, the noise, light or particulate pollution linked to the mining activity possibly represent additional disturbances that prevent petrels from finding alternative nesting sites and may lead to desertion of the breeding site (Reville et al. 1990, Saha and Padhy 2011, Smith et al. 2012, Duarte et al. 2015. Intense light pollution can also disorient Tahiti Petrels, as burrow-nesting seabirds are guided and attracted by lights when they fly at night. ...
New Caledonia hosts a large part of the world’s breeding population of the Tahiti Petrel Pseudobulweria rostrata. This rare, cryptic and little-studied seabird nests locally in the mountains up to 1,200 m in altitude, particularly in ultramafic (i.e. nickel-rich) areas where mining activity is a major threat. The considerable development of mining activities in New Caledonia over the past decade raises concerns about its potential impacts on breeding populations through both direct habitat destruction and side effects such as pollution or repeated disturbances. This context calls for a dedicated assessment of the persistence of local populations to guide the design of an adapted conservation strategy and potential restoration programmes. We investigated the impact of mining activities on a Tahiti Petrel population when surveyed pre-mining (2004–2007) and following a period of full mining (2017–2018). The vocal activity was assessed at a total of 114 night-call count stations spread over the Koniambo massif. Areas with ground-originated vocal activity were then searched during daytime for nesting evidence. Finally, georeferenced aerial photos were used to estimate habitat degradation as the percentage of bare soil cover (PBSC) within a 400-m radius around each call count station. Our study revealed a dramatic decline in the Tahiti Petrel vocal activity and a desertion of breeding habitats during the full-mining period compared to the pre-mining period. In light of these results, we recommend designing safe breeding areas and combining restoration methods including social attraction, predation control and artificial burrows at mining sites.
... In particular, a variety of acoustic indices have been developed over the last decade to act as automatically-calculable proxies for various species richness and biodiversity metrics (Depraetere et al., 2012;Gage and Axel, 2014;Kaufman, 2001;Pieretti et al., 2011). Though lacking in species-specific information, these metrics have been used to study the effect of increasing natural resource extraction activities on the biophony in tropical forests, for example (Alvarez-Berríos et al., 2016;Deichmann et al., 2017;Duarte et al., 2015). The diversity of results from these studies demonstrate that an understanding of the complicated relationship between human activity and animal vocalization patterns is worth pursing in other contexts. ...
... While audio sampling was continuous for this dataset, in many bioacoustic surveys, one minute or fewer of audio data is collected for every ten minutes (Aide et al., 2013;Aide et al., 2017;Alvarez-Berríos et al., 2016;Deichmann et al., 2017;Depraetere et al., 2012;Duarte et al., 2015;Gage and Axel, 2014;Xie et al., 2016). To examine the effect that intermittent sampling has on the observed bioacoustics trends, the data was reanalyzed using only the first minute from each ten minute interval. ...
The effect of anthropogenic activity on animal communication is of increasing ecological concern. Passive acoustic recording offers a robust, minimally disruptive, long-term approach to monitoring species interactions, particularly because many indicator species of environmental health factors such as biodiversity, habitat quality, and pollution produce distinct vocalizations. Machine learning algorithms have been used in recent decades to automatically analyze the large quantities of audio data that result. In this study, a microphone array was used to collect continuous audio data at a site in the Capital Region of New York State for twelve months, resulting in over 8000 h of recordings. A 19-class database containing a variety of bio- and anthrophony was used to train a convolutional neural network in order to generate a reliable record of species-specific calling activity for the entire study period. These results were used to calculate an acoustics-based pseudo-species richness and abundance distribution. Additionally, heatmap plots were used to visualize (i) the time of day (x), sound category (y), and predicted number of sonic events for an average 30-day period and (ii) the day of the year (x), time of day (y), and predicted number of sonic events for each sound category. The correlations between these sonic events and various abiotic factors such as number of daylight hours, temperature, and weather activity were also examined.
... (Farina et al., 2011b). The ACI algorithm has already been successfully applied in terrestrial habitats (Pieretti & Farina, 2013;Bobryk et al., 2015), including forest fragments in neotropics Duarte et al., 2015). ...
... Pieretti & Farina (2013) showed that both ACI values and noise were significantly higher with increasing proximity to a road, suggesting a more active singing/vocalising community in those sites where noise was more intense. Duarte et al., (2015) also found higher ACI values throughout the day in a noisy area, despite having less species compared to a silent area, indicating the possible use of compensatory mechanisms to communicate in presence of noise. ...
Anthropogenic noise, which is part of an urban soundscape, can negatively affect the behaviour of wild animals. Here we investigated how biophony (animal sounds) was affected by noise in an urban Brazilian forest fragment. Our hypothesis was that noise and biophony would differ between the border and the centre of the forest fragment (i.e., lower biophony predicted in noisy areas). Two passive acoustic monitoring devices were used to record soundscapes one week per month, 24 hour per day, from May to July 2012. The Acoustic Complexity Index (ACI) was used to quantify biophony and the Power Spectral Density (PSD) to quantify urban noise. PSD and ACI were higher on the border than in the centre of the fragment. PSD was lower in July, while the ACI did not significantly vary between months. Noise levels were also higher on the border. Conversely, potential species richness was higher in the centre of the forest fragment. Higher biophony at noisy sites can be interpreted as behavioural responses of species for communicating in noisy areas. Alternatively, they could be the result of species segregation by degree of vocal plasticity or due to differences in composition of communities.
... Although snowmobiling can promote the use and appreciation of CW and other wild areas, the combination of high speed, rapid maneuverability, and loud noise make snowmobiling a conspicuous and alarming stimulus in the landscape (Mahoney et al. 2001). Like many other machine-generated sound sources (e.g., mining activity, aircraft, automobiles), the presence of snowmobiles and the acoustic footprint they create influence the distribution and composition of sounds in nature (Duarte et al. 2015;Mullet et al. 2016). Hence, the sounds produced by snowmobiling can degrade and negatively affect CW resources and devalue human experience in CW settings, all of which contradict the purposes of the Wilderness Act. ...
... Added to this, summer months not only exhibit an increase in aircraft activity, but also constitute the sounds of motorboats and A large body of work has been accumulating on the subject of noise impacts on the behavior, communication, physiology, and reproductive success of terrestrial wildlife that significantly influences ecological processes (Creel et al. 2002;Reihndt 2003;Francis et al. 2009;Barber et al. 2010;Brumm 2010;Chan and Blumstein 2011;Ortega 2012;McClure et al. 2013). More recently, the field of ecoacoustics (Sueur and Farina 2015) is beginning to find evidence of noise impacts on soundscapes as a whole, rather than individual species (Duarte et al. 2015). However, the empirical evidence that shows noise impacts on bird communication and changes in the occupancy of sound-producing wildlife in noisy habitats suggests that natural soundscapes to which these species contribute are being considerably altered. ...
... Perhaps one of the most well known is 'Fruta del Norte', which became famous for its large deposits of copper and gold (Leary et al. 2016). At the current pace, mining activities, especially opencast mining (Duarte et al. 2015), in this southern part of the country will undoubtedly impact nature's fragile equilibrium. The onset of the Chinese Ecuacorriente S.A., just 28 km north of Fruta del Norte, is the best example of such an impact. ...
The ant genus Nesomyrmex is a tropical and subtropical taxon of tree ants with 83 known species around the world. Despite this diversity, the only treatment of American species was published in 1959. For Ecuador, nine species are recorded for the genus, although the material deposited in national collections suggests a greater richness. In the present study, we describe a new species, Nesomyrmex paquisha sp. n., from Cordillera del Cóndor, an isolated mountain range in the southern Ecuadorian Amazon. This new species can be distinguished from other Neotropical congeners by the combination of the following characters: first tergum of gaster microreticulate; propodeal spine length shorter than eye length; metanotal groove present; petiole obovoid without prominent tubercles; pospetiolar dorsal sculpture rugose; mesosomal profile straight; apex of scape not reaching posterior margin of head, and 12 antennomeres. We identified three species recorded for the first time in Ecuador: Nesomyrmex anduzei (Weber, 1943), Nesomyrmex pittieri (Forel, 1899), and Nesomyrmex tonsuratus Kempf, 1959. We also provide new site records of Nesomyrmex pulcher (Emery, 1917) for this country. We provide high-resolution images and distribution maps for the new species and for the new records. In addition, we present an identification key for all Nesomyrmex species known from Ecuador. Finally, we discuss the importance of the canopy fogging method for gaining insights into arboreal ant diversity. We also provide a critique of the current environmental impacts caused by a Chinese mining company in Cordillera del Cóndor, which is biologically important as a center of endemism for numerous organisms
... Over the last century, the pace of land transformation has accelerated and continues to expand (Palmer et al. 2004), driven by urbanisation, infrastructure development, and increasing demand for resources and products, intensifying pressure on natural ecosystems globally (Williams 2013;Kehoe et al. 2017;Adla et al. 2022). The synchronous impacts of agricultural activities, grazing, and industrial facilities, combined with the continuous effects of vehicle traffic, the presence and construction of both industrial and civil infrastructures, and noise pollution, are widely recognised within the scientific community (Duarte et al. 2015;Souza et al. 2015;Sordello et al. 2019;Ortiz et al. 2021). These human-induced pressures trigger chain reactions, generating both short-and long-term impacts on biodiversity (Sponsel 2013). ...
The combined pressures of anthropogenic activities require rapid assessments of environmental impacts on ecosystems to develop strategies for sustainable management and biodiversity conservation. This study investigates the consequences of the anthropogenic effects in the upper Val d’Agri (Basilicata, Italy) by employing a multi-taxonomic analysis to investigate spatial dynamics and species responses to these pressures. By cataloguing 151 diverse species of small mammals, reptiles, birds, ground beetles, and lichens, we established a valuable baseline for analysing the local biodiversity. We assessed the relationship between anthropic impacts (industrial areas, roads, agriculture, forestry, etc.), vegetation cover, and species diversity. Our findings revealed a negative relationship between the number of species and proximity to industrial areas, emphasising the impact of these activities. Moreover, we observed a predominance of generalist biological traits across taxa in all the study sites rather than an increase in species specialisation with increased distance. This may suggest a homogenising effect caused by various anthropogenic activities that cause habitat fragmentation and species mortality, underlining the lasting influence of these activities on the biodiversity of the upper Agri Valley. Additionally, our study identifies numerous protected species, highlighting their vulnerability and emphasising the necessity for targeted conservation efforts to safeguard their existence.
... The machinery noise in Brazil at a mining site was found to impact wildlife. Species numbers declined at sites nearer the mine and were higher farther away (Duarte M L et al., 2015). ...
... Research studies have shown that individuals exposed to noise, particularly from traffic, occupational settings, and entertainment venues, are more prone to significant NIHL than those not exposed. Acute exposure to deafening noise can also lead to tympanitis and eardrum rupture, causing severe pain and impairing hearing abilities (Bratu et al., 2020;Duarte et al., 2015;Gupta et al., 2018;Mocek, 2020). According to a study conducted by (Onder et al., 2012), field people have a sixfold higher risk of NIHL than operators and drivers, and this has been observed to increase by up to 11 times with age. ...
Noise pollution is an unintentional consequence of mining activities, needing rigorous assessment, monitoring, and mitigation techniques to reduce its impact on local residents and ecosystems. The study specifically examines the noise pollution from rare earth mining activities in the Neendakara-Kayamkulam (NK) coastal belt, Kollam, Kerala, India, a region rich in ilmenite, rutile, sillimanite, zircon, and monazite. Despite the known environmental and health impacts of noise pollution, there is limited specific data on its magnitude and sources in this region, as well as a lack of effective mitigation strategies tailored to rare earth mining operations. Studies have indicated that mining operations, such as the movement of heavy mineral sands, considerably elevate noise levels, which have an effect on the environment’s quality and public health. This study seeks to fill the gap by geospatial mapping and assessing the noise levels and recommend measures to effectively mitigate noise pollution. Systematic noise measurements were conducted at 48 suitable locations within the NK coastal belt, including residential, commercial, industrial, coastal, and silence zones. The noise levels vary from 49.1 dB(A) near a religious place to 82.4 dB(A) near the local industry. The study employs geospatial noise mapping and land cover superimposition to implement class-specific mitigation measures for noise pollution in a coastal vicinity mixed land use area, including natural and vegetative barriers, operational scheduling, zoning, and land use planning.
... As far as we know, only one study conducted in a Brazilian city used acoustic indices to evaluate how biodiversity (avifauna) responds to sound pollution in a native fragment (Machado et al., 2017). Other studies used acoustic indices as a biodiversity surrogate, but they were not conducted in urban areas (Campos et al., 2021;Duarte et al., 2015;Jorge et al., 2018;Oliveira et al., 2021). Thus, this is the first study aimed to precisely evaluate the behaviour of acoustic indices in a gradient of different environments, including natural, rural and urban environments in the Neotropics. ...
... This is a methodology that consists of using automated recorders, which allows us to answer ecological questions on a large spatial scale (Sugai et al. 2018). Recently, PAM has been used to obtain data for different perspectives, such as species inventory in a given region, describing the acoustic phenology of populations, temporal and spatial patterns of communities, and the effects of noise caused by anthropogenic impacts (Llusia et al. 2013a(Llusia et al. , 2013bDuarte et al. 2015;Schalk & Saenz 2016;Souza et al. 2020;Sugai et al. 2021;Muzzi et al. 2023). For this method, we used a Tigrinus® GT001-T1.0V ...
... Noise emissions from various mechanical activities can have detrimental effects on animal health (Craven et al., 2009;New et al., 2014;Kunc et al., 2016;Slabbekoorn et al., 2019), compromising auditory abilities, inducing physiological stress (Popper, 2003;Halvorsen et al., 2012;Mancera et al., 2017), disrupting communication and behavior (Sarà et al., 2007;Gil et al., 2015;Gendron et al., 2020), and increasing stress-response hormones (Wale et al., 2013a;Hawkins and Chapman, 1975;Smith et al., 2004;Duarte et al., 2015), potentially impacting animal health and survival (Popper, 2003;Purser and Radford, 2011), especially in captive settings like farms and reserves (Popper and Hawkins, 2019;Sherwen and Hemsworth, 2019;Duarte et al., 2023). These noiseinduced effects may manifest as reduced feeding behavior due to heightened vigilance (Evans et al., 2018;Giordano et al., 2022), leading to diverted attention (Mendl, 1999;Chan and Blumstein, 2011), potentially causing misjudgments in prey identification and feeding responses (Purser and Radford, 2011;Holles et al., 2013). ...
Aquaculture systems, replete with equipment noise originating from aerators, pumps, feeders, and filtration systems, are known to exert substantial influence on fish behavior and growth. In this research, the focus was directed towards comprehending the impacts of aerator noise on the swimming, feeding, and growth progression of largemouth bass. In the course of a 50-day experimental period, the bass population was segmented into two groups: aerator noise (90.3dB re μPa RMS⁻¹) and ambient noise (70.4dB re μPa RMS⁻¹). The findings indicated discernible disparities in the swimming behavior and feeding between the two groups. Specifically, bass in the noise group maintained greater average angular distance and physical separation from their nearest counterparts than the bass in the ambient group, which were 43.61 ± 1.89° and 85.47 ± 1.72mm for the ambient group and 48.32 ± 0.49° and 97.01 ± 0.57mm for the noise group. Furthermore, the feeding kinetic energy was markedly lower in the noise group as compared to the ambient group. For the first time, the Shannon-Wiener diversity index was leveraged to gauge the diversity of fish swimming behavior, with the results signifying the diversity index of the noise group was 2.69 ± 0.07 higher than that of the ambient group, which was 2.51 ± 0.02. Lastly, the noise group demonstrated compromised growth performance, with a significantly lower average weight as opposed to the ambient group, along with marked variations in the specific growth rate. These findings offer a telling revelation about the profound impacts of aerator noise on the behavioral and growth of largemouth bass, thereby forming a valuable referential base for future research centered on the effects of noise pollution on aquatic organisms.
... This finding is evidence that noise is competing for acoustic space with anuran vocalisations at the site near the road. Noise can affect species richness and abundance and change the composition of animal communities, including those of anurans (Francis & Barber, 2013;Duarte et al., 2015, Alvarez-Berríos et al., 2016Potvin, 2016;Grace & Noss, 2018). As noise can compete with animal vocalisations for acoustic niches, it is expected that species that are more sensitive to noise (such as those that vocalise at lower frequencies, for example) will avoid noisy areas . ...
... The highest rate of biophony based on two indices was related to SO park and The highest abundance and number of species observed were related to SO park and NS park. While in contrast to MA and FA parks, the abundance of species was at the lowest possible level, which demonstrated that the abundance and number of species have greatly affected the biosounds (Duarte et al., 2015). ...
Biophony and anthrophony analysis as part of the urban soundscape is an efficient approach to bird biodiversity monitoring and to studying the impact of noise pollution in urban parks. Here, we analyzed the soundscape composition to monitor the diversity of birds using acoustic indices and machine learning in 21 urban parks of Isfahan, Iran, in spring 2019. To achieve this purpose four-step method was considered: (i) choosing parks and sampling of sound and bird species; (ii) calculated the six acoustic indices; (iii) calculated the six biodiversity indices; and (iv) statistical analysis for predicting biodiversity index from acoustic indices. Three regression models including support vector machine (SVM), random forest (RF), and elastic net regularization (GLMNET) applied the acoustic indices with minimum and maximum recorded thresholds to feature extraction to measure biodiversity indicators. The optimization model was applied to reduce the independent variables. Generally, more than 18,000 samples were modeled for the dependent variables in each model. The regression results demonstrated that the highest R square was related to the songbird (0.93), evenness (0.92), and richness (0.9) indecies in the SVM model and the Shannon index (0.86) in the RF model. The results of acoustics analysis demonstrated that the Acoustic Entropy Index (H), Normalized Difference Soundscape Index (NDSI), Bioacoustics Index (BI), and Acoustic Complexity Index (ACI) indices were suitable because they could serve as proxies for bird richness and activity that reflect differences in habitat quality. Our findings offer using acoustic indicators as an efficient approach for monitoring bird biodiversity in urban parks.
... As previously stated, single index data can be problematic because they cannot be consistently interpreted across different taxonomic groups or environments. For example, studies using ACI have shown that this index was positively correlated with bird species (Jorge et al., 2018;Mitchell et al., 2020), but also rain and wind (Duarte et al., 2015). Acoustic entropy has been found to have higher values in biodiversity rich habitats (Sueur et al., 2008), although higher values in quiet recordings and lower values in recordings dominated by insects have also been documented (Bradfer-Lawrence et al., 2019). ...
High rates of biodiversity loss caused by human-induced changes in the environment require new methods for large scale fauna monitoring and data analysis. While ecoacoustic monitoring is increasingly being used and shows promise, analysis and interpretation of the big data produced remains a challenge. Computer-generated acoustic indices potentially provide a biologically meaningful summary of sound, however, temporal autocorrelation, difficulties in statistical analysis of multi-index data and lack of consistency or transferability in different terrestrial environments have hindered the application of those indices in different contexts. To address these issues we investigate the use of time-series motif discovery and random forest classification of multi-indices through two case studies. We use a semi-automated workflow combining time-series motif discovery and random forest classification of multi-index (acoustic complexity, temporal entropy, and events per second) data to categorize sounds in unfiltered recordings according to the main source of sound present (birds, insects, geophony). Our approach showed more than 70% accuracy in label assignment in both datasets. The categories assigned were broad, but we believe this is a great improvement on traditional single index analysis of environmental recordings as we can now give ecological meaning to recordings in a semi-automated way that does not require expert knowledge and manual validation is only necessary for a small subset of the data. Furthermore, temporal autocorrelation, which is largely ignored by researchers, has been effectively eliminated through the time-series motif discovery technique applied here for the first time to ecoacoustic data. We expect that our approach will greatly assist researchers in the future as it will allow large datasets to be rapidly processed and labeled, enabling the screening of recordings for undesired sounds, such as wind, or target biophony (insects and birds) for biodiversity monitoring or bioacoustics research.
... Therefore, the number of visitors and recreation activities can be a major cause of soundscape changes and the perceptions and satisfaction of visitors' experiences in national parks. Changing soundscape also indirectly affects the image of the national park (Benfield et al. 2010), wildlife communication and stress or behavioral changes of wildlife over the long term (Duarte et al. 2015), that lead to alteration of ecosystem structure and functions (Francis et al. 2012). Unfortunately, anthropogenic noise is rarely considered as threats to protected areas (Butchart et al. 2010) and is uneasy to mitigate or even control (Herrera-Montes 2018) and often not limited to the recreational zone because it can permeate the natural soundscape (Pijanowski et al. 2011). ...
Soundscape is an important component of national parks that are established for conserving biodiversity, natural resources and ecological processes, as well as serving tourism to inculcate conservation awareness. Nevertheless, anthropogenic noise from visitors is difficult to control and can disturb wildlife and visitor experiences. This study aims to illustrate the quality of soundscape in recreational areas of Khao Yai National Park (KYNP) based on soundscape components, sound pressure level, perception and the satisfaction of visitors on soundscape, and satisfaction on Sound pressure level in term of LAeq (dBA). Significant differences in the overall soundscape components, sound pressure level, perception and satisfaction on soundscape and satisfaction on sound pressure level at each recreational area were found. Noise from tourism also impacted the presence of wildlife in recreational areas. A correlation was identified between a higher nature-based experience and higher satisfaction on biophony and geophony. Soundscape satisfaction was influenced by satisfaction on sound pressure level, perceived soundscape, and some demographical factors (gender, the day of visit, hometown, recreational areas, visit frequency, income, education, and occupation). KYNP must monitor soundscape components, soundscape satisfaction, and sound pressure levels to maintain the quality of natural soundscape and visitor experiences in the recreational areas. Further research is recommended on using the proportion of soundscape components and sound pressure level as a key monitoring tool to determine the practical carrying capacity of tourists, as soundscape components can be changed due to sound pressure level and also affect the soundscape satisfaction of tourists.
... Sounds play a fundamental role for many species and ecosystems, and acoustic data has being used to study vertebrates and invertebrates in a variety of functions and contexts, thus contributing to understanding key ecological processes (Bradbury and Vehrencamp, 1998). Acoustic tools are less invasive and provides data about variation on temporal and spatial patterns of species richness (Depraetere et al., 2012;Duarte et al., 2015), as well as changes in the behaviour of vocal species (Parks et al., 2011). Passive acoustic monitoring has become popular due to recent advances in technologies for data acquisition, storage capacity, analyses methods and tools (Burivalova et al., 2019;Gibb et al., 2019;Merchant et al., 2015). ...
Advances in technologies for data acquisition, storage and analysis have boosted Acoustic Ecology studies, but protocols are still lacking. There is a need of more research to understand which methodologies can be applied to answer ecological questions in different environments with varying temporal and spatial dynamics. Tropical forests are generally more complex than temperate ones, both in terms of use of acoustic space and species diversity. The seasonally dry tropical forest (SDTF) in Brazil, known as Caatinga, is a threatened biome, with two marked seasons that shape vegetation and animal activity patterns. In this study, we investigate the applicability of passive acoustics in monitoring SDTF, describing the soundscape and tracking diel patterns and seasonal
changes. Combining multiple indices, visualization through false colour spectrograms and clustering, we describe the acoustic activity of the main faunal groups that compose the biophonic orchestra in a SDTF area in the Northeast of Brazil. Distinct patterns were found between day – when birds and wind were the main sound sources – and night – with Orthopterans occupying a large frequency band. Other sound sources in the SDTF soundscape included cicada, rain, and anthropogenic influence such as domestic animals, cars and gunshots. Clustering of eleven acoustic indices was useful to distinguish sound patterns from several sources, especially in the dry season. Further investigation within each cluster showed specific relationships among selected indices
and different sound sources. Birds were associated with Entropy of the Spectral Peaks (EPS) and Orthopterans also had a relationship with EPS, as well as with Entropy of Average Spectrum (EAS) and High Frequency Cover (HFC). Variation in diel values of these selected indices, as well as the number of samples included in each cluster category, were successfully used to describe the acoustic activity of Birds and Orthopterans and to track changes between rainy and dry seasons. A better understanding of the soundscape dynamics in a highly seasonal tropical environment was achieved by applying cheap and reliable novel methodologies to study biodiversity in geopolitical regions where funding for conservation initiatives is limited.
... 3B, 4). Considering the sound as a life trait in singing animals that quickly responds to environmental changes (Farina and Fuller, 2017), the stronger relationship between acoustic indices and ecological integrity in these times could be pointing to species of birds and insects -with high acoustic activity in these times -as the most sensitive taxa to modifications of the landscape (e.g., Aide et al., 2013;Duarte et al., 2015;Burivalova et al., 2019). The identification of these periods would help future conservation practitioners using soundscape analysis to design and prioritize monitoring schemes in montane tropical landscapes, as the combination between specific hours and acoustic indices could be used as "indicators" (like indicator species) reflecting the main changes in the ecological integrity of a given area. ...
tSoundscape research has acquired a paramount role in biodiversity conservation as it may provide timelyand reliable information about the ecological integrity. The relationship between soundscape complexityand ecological integrity in highly biodiverse environments, as well as the factors affecting this relation-ship require a thorough understanding. We determined how the soundscape relates to the landscapeecological integrity at different spatial and temporal scales in a montane forest in the northern Andes ofColombia. Between May–July 2018 we obtained acoustic recordings from 31 sampling sites in the pro-tected area of a hydropower plant, and estimated nine acoustic indices and an ecological integrity index(EII) derived from fragmentation, connectivity, and habitat quality. Five of the acoustic indices, linked tothe evenness of the acoustic signals and levels of the biophonic signals, were associated with changesin the EII and indicated the presence of more even, saturated, and acoustically rich soundscapes in siteswith higher integrity. Relationships between acoustic indices and the EII were stronger at a smaller spa-tial scale (100 m) and responded to daily variation of the soundscape, with the strongest associationsoccurring mainly from sunrise to noon. We show that acoustic indices measuring the evenness of theacoustic activity distribution and the number of frequency peaks reliably reflect the changes in the eco-logical integrity, and can be integrated with remote sensing as a tool for landscape management. Ourresults highlight the soundscape analysis as a feasible approach for the monitoring and conservationplanning of acoustically unknown and threatened Andean landscapes.
... Long-term ecoacoustic monitoring can also be a useful approach to monitor impacts of technophonic disturbance on ecosystems. Many studies have identified species that have adjusted call regimes and call properties in order to avoid masking by noise (Brumm, 2004;Duarte et al., 2015;Foote et al., 2004), but there is an energetic cost that may have consequence on population fitness. A comparison of intermittent train noise and busy road transport routes found that train noise had a significant impact on low frequency calling species such as koalas (Wiącek et al., 2015). ...
As the rate of urbanisation continues to increase, widespread habitat clearing within peri-urban landscapes contributes to significant environmental impacts, including loss of biological diversity. Acoustic recording has recently been identified as an effective tool for monitoring biodiversity and ecosystem health. With increasing pressure from urbanisation, it is critical that spatial and temporal variability in biodiversity is mapped across future development sites to enable sound decision-making and to deliver ecological urban design outcomes. This study used ecoacoustic monitoring to map biodiversity patterns in space and time to identify hot spots and hot moments of biodiversity activity across a peri-urban landscape in south-east Queensland, Australia. In this study, a hot spot represents an increase in acoustic activity at a given spatial location, whereas hot moments represent an increase in acoustic activity at a given time point. An acoustic index (Acoustic Complexity Index, ACI) was used as a proxy for biodiversity and visualised through spatial interpolation. The acoustic data were statistically modelled using Boosted Regression Trees (BRT). This approach enabled predictors related to acoustic complexity to be identified, including vegetation and landform. Results of this study have shown that ecoacoustic data can be used to map hot spots and hot moments of biodiversity and support more informed conservation decision-making in future urban planning frameworks, to avoid or mitigate negative impacts on biodiversity.
... The machinery noise in Brazil at a mining site was found to impact wildlife. Species numbers declined at sites nearer the mine and were higher farther away [16]. ...
... As an innovative and alternative approach, ecoacoustics has recently proven to be effective to access and interpret changes in animal communities in face of anthropogenic disturbances (Pijanowski et al., 2011;Duarte et al., 2015;Sueur and Farina, 2015;Gasc et al., 2018). Ecoacoustics considers environmental sounds as a proxy for the ecological processes that regulate the distribution of species (Sueur and Farina, 2015). ...
Wildfire is a natural process in Brazilian savannas, but human activities alter fire regimes and threaten biodiversity. In this study, weused an ecoacoustics approach to assess fauna responses and recovery after wildfire in a Brazilian savanna. Six passive acoustic monitoring devices were used to record soundscapes before and after a wildfire a at burned and non-burned sites for one year and one month (September 2012 to September 2013). Power Spectral Density and the Acoustic Complexity Index were used to track biophony. Before the fire, the two sites had similar biophonic patterns (PSD: T=1136, Z=1.52, P=0.12; ACI: T=1117, Z=1.10 , P=0.26) and soniferous species richness (Site 1=52 and Site 2=49). However, in the first two sessions of recordings after the fire, biophony became higher at the burned site during the day (PSD: T=211 and 233; Z=4.13 and 6.41; ACI: T=120 and 469, Z=5.14 and 7.07; all P<0.00). During the night, biophony was usually higher at the non-burned site until May 2013 (PSD: T=0 to 453; Z=3.30 to 5.90; ACI: T=333 to 491, Z=3.80 to 4.93; all P<0.00). Biophony became similar (P=0.17 to 0.38) at the two sites or higher (P=0.00 to 0.01) at the burned site from July to September 2013 (PSD: T=55 to 1167; Z=1.35 to 6.89; ACI: T=719 to 1365, Z=0.87 to 3.04). After the fire, a reduction of soniferous species at the burned site was observed for insects and bats. Both biophonic activity and soniferous species showed a tendency to recover one year after the fire, but there were still less species in September 2013 (non-burned=43 and burned=37) when compared to September 2012 at both sites (Site 1= 52 and Site 2=49). Our results showed that changes in the natural regimes of fire can negatively impact the biodiversity and reinforce the need for monitoring protocols and inspection of wildfires.
... Urban forests are also an important habitat for birds and other animals (Daniels and Kirkpatrick, 2006). Biophony, a category of soundscape that includes birdsongs, barks, and other animal sounds, is produced by various organisms in a given habitat (Duarte et al., 2015). These sounds can be pleasant and help reduce the pressure experienced by people living in high-density cities (Meyer et al., 2019;Pijanowski et al., 2011). ...
Birds are dominant creatures that produce abundant sounds in urban forest ecosystems, and birdsongs are a desired soundscape to reduce noise pollution in biophilic cities. The aim of this study was to explore the impact of soundscape drivers on perceived birdsongs and to model the associated drivers. Questionnaires and acoustic measurements of biophony and birdsongs were conducted at 41 observation sites in three urban forest locations in Vancouver, Canada. Pearson’s correlations were then used to analyze relationships between the soundscape drivers. Potential soundscape drivers were modeled using template matching (TM) and back propagation neural network (BP neural network). Findings suggest that there is an interaction between perceived birdsongs and the pleasantness of perceived birdsongs (PPB), eventfulness of perceived birdsongs (EPB), and number types of perceived birdsongs (NTP). Results also show that high frequency contents have an effect on perceived birdsongs in urban forests. We established a perceived birdsongs model (PBM) that effectively simulates the process from soundscape information to perceived birdsongs in urban forests, and the methodology developed in this study could be useful for conducting soundscape assessment and promoting soundscape conservation in other urban forests.
... TFBs were not quantitatively optimised, but rather subjective approximations that aimed to effectively capture broad taxonomic groupings in tropical forest landscapes. Temporal limits were determined by patterns in animal communication in the diel cycle, to encapsulate dawn, dusk, daytime and night-time periods (Pieretti et al., 2015;Rodriguez et al., 2014); commonly used sampling periods in acoustic recording (Sugai et al., 2019). 'Dawn' was assigned to the period from 30 min prior to sunrise and for the following 2 hr, while 'Dusk' was the 2-hr period ending at 30 min after sunset. ...
Acoustic indices are increasingly employed in the analysis of soundscapes to ascertain biodiversity value. However, conflicting results and lack of consensus on best practices for their usage has hindered their application in conservation and land‐use management contexts. Here we propose that the sensitivity of acoustic indices to ecological change and fidelity of acoustic indices to ecological communities are negatively impacted by signal masking. Signal masking can occur when acoustic responses of taxa sensitive to the effect of interest are masked by less sensitive acoustic groups, or target taxa sonification is masked by non‐target noise. We argue that by calculating acoustic indices at ecologically appropriate time and frequency bins, masking effects can be reduced and the efficacy of indices increased.
We test this on a large acoustic dataset collected in Eastern Amazonia spanning a disturbance gradient of undisturbed, logged, burned, logged‐and‐burned, and secondary forests. We calculated values for two acoustic indices: the Acoustic Complexity Index and the Bioacoustic Index, across the entire frequency spectrum (0‐22.1 kHz), and four narrower subsets of the frequency spectrum; at dawn, day, dusk and night.
We show that signal masking has a large impact on the sensitivity of acoustic indices to forest disturbance classes. Calculating acoustic indices at a range of narrower time‐frequency bins substantially increases the classification accuracy of forest classes by random forest models. Furthermore, signal masking led to misleading correlations, including spurious inverse correlations, between biodiversity indicator metrics and acoustic index values compared to correlations derived from manual sampling of the audio data.
Consequently, we recommend that acoustic indices are calculated either at a range of time and frequency bins, or at a single narrow bin, predetermined by a priori ecological understanding of the soundscape.
... Despite the rainy days, which were excluded from the analysis when too noisy, we believe this is the best period of the year to capture the most active soniferous species because it coincides with the reproductive period of most species. During reproductive season the animal community gets especially active exhibiting several different behaviours and therefore being the best period of the year for acoustic monitoring (Duarte et al., 2015). Sound data was acquired using 22 Song Meters 3 (Wildlife Acoustics) at 48 kHz sampling rate, 16 bits recordings. ...
The ecoacoustics approach for environmental recordings analysis is used to understand and identify big ecological patterns related to different sound sources, like animals, humans and the environment itself. Sounds can vary according to several features that can be on its surroundings or far away, therefore they are very much reliant on scale. Because humans are changing the environment so much and we cannot account for all those changes in the same speed as they happen, we need fast evaluation tools, such as remote sensing and acoustic monitoring (considered the equivalent of spatial remote sensing for sounds). Considering that the scale of effect was never measured for soundscapes before, we aimed to see in what scale different acoustic indices were responsive. Also, we tested how acoustic indices are influenced by natural vegetation cover. We recorded environmental sounds in Atlantic Forest fragments during three months on the rainy season. Then we calculated different acoustic indices and the percentage of natural vegetation cover in different scales. Our results corroborated our initial hypotheses: different indices respond to different scales and their medians varied according to the amount of vegetation cover on the surroundings. More studies are needed with less fragmented areas, to test indices behaviour in a continuum, but we consider this work an important starting point to understand acoustic indices behaviour in tropical areas, especially in such degraded and threatened area as Atlantic Forest.
... Although we advocate here that acoustic indices and their visualization are a useful tool for biodiversity monitoring, their use as a surrogate for rapid biodiversity assessment should be taken cautiously. Indices provide useful ecological information in different environments worldwide (Depraetere et al., 2012;Towsey et al., 2014b;Duarte et al., 2015;Fuller et al., 2015;Machado et al., 2017;Sueur, 2018), but it is not yet clear what is the relationship between each acoustic index and animal species richness (Eldridge et al., 2018), diversity, and abundance. It is also not clear how these indices will respond to acoustic communities composed by native species and domestic animals, as is commonly found in areas surrounding protected areas. ...
Protected areas (PAs) monitoring is a technical bottleneck that limits the implementation of decision-making processes for natural resource and wildlife management. Recent methodological advances make passive acoustic monitoring and associated acoustic index analysis an increasingly suitable method for PAs monitoring. Acoustic indices are mathematical filters that can provide standardised comparative information about the acoustic energy , which can be applied to compare communities. In this study we test whether acoustic indices are sufficiently sensitive to detect differences in the soundscape within each of the four seasons between a PA (the Serra do Cipó National Park, Brazil) and a surrounding farmland area. Statistical analysis of results from 12 acoustic indices is used to identify which of 20 acoustic regions, defined by frequency range and time period, present the greatest differences between the two sites. The soundscapes of the two sites differed most in autumn within the acoustic region 6, representing 05:30-09:00am and a range of 0.988-3.609 kHz. This acoustic region exhibited significant differences for all the 12 indices tested. Visual examination of 65 long-duration false-colour (LDFC) spectrograms resulted in the selection of 865 (from 1365) sound files with acoustic events within the range of acoustic region 6. Sonotype analysis of the 865 files showed that the soundscape outside the park is strongly influenced by human activity, with domestic animals rare in the park soundscape (1% of the sound files), but very common in the surrounding farmland environment (63% of the sound files). The main goal of monitoring programmes detecting biodiversity trends across space and time, which is here achieved via passive acoustic monitoring and acoustic indices. This confirms the utility of the techniques used here for PA monitoring, especially for detecting trends in anthropogenic disturbance, which is a common threat to natural habitats in parks and reserves in the tropics.
Under the current global biodiversity crisis, there is a need for automated and non-invasive monitoring techniques that are able to gather large amounts of information cost-effectively at large scales. One such technique is passive acoustic monitoring, which is commonly coupled with automatic identification of animal species based on their sound. Automated sound analyses usually require the training of sound detection and identification algorithms. These algorithms are based on annotated acoustic datasets which mark the occurrence of sounds of particular species. However, compiling large annotated acoustic datasets is time consuming and requires experts, and therefore they normally cover a reduced spatial and taxonomic scale. This data paper presents WABAD, the World Annotated Bird Acoustic Dataset for passive acoustic monitoring. WABAD is designed to provide the public, the research community, and conservation managers with a novel and globally representative annotated acoustic dataset. This database includes 5,044 minutes of audio files annotated to species-level by local experts with the start and end time, and the upper and lower frequencies of each identified bird vocalisation in the recordings. The database has a wide taxonomic and spatial coverage, including information on 90,662 vocalisations from 1,147 bird species recorded at 70 recording sites in 27 countries and distributed across 13 biomes. WABAD can be used, for example, for developing and/or validating automatic species detection algorithms, answering ecological questions, such as assessing geographical variations on bird vocalisations, or comparing acoustic diversity indices with species-based diversity indices. The dataset is published under a Creative Commons Attribution Non Commercial 4.0 International copyright.
The acoustic complexity index (ACI) is a commonly used metric in ecoacoustics, demonstrating reliability across diverse environments and ecological conditions. However, this index requires specific procedures to be applied correctly. Based on the Canberra metric, the ACI is an unsupervised metric formulated to extract information from fast Fourier transform (FFT) sonic matrices. The ACI measures contiguous differences in acoustic energy of each frequency bin along temporal steps (ACItf) and a temporal interval along the frequency bins (ACIft). Aggregating data after an FFT with a clumping procedure allows for better scaling of sonic signals before computing the ACI. A filter must be applied to reduce the effects of nonenvironmental signals produced by microphone electrical noise . Due to the singularity of the index for values of 0, ACI requires ad hoc procedures to exclude element pairs for which one of the elements is equal to 0 from the comparisons. The spectral and temporal sonic signatures are vectors obtained from the sequence of ACItf and ACIft values, respectively. The comparison between sonic signatures using the chord distance index returns spectral and temporal sonic dissimilarities, allowing the evaluation of sonic patterns at different temporal and spatial resolutions. Sonic variability, sonic evenness, and the effective number of frequency bins are further derivative metrics that help interpret sonic heterogeneity by distinguishing the temporal and spatial heterogeneity of sonoscapes. Moreover, this paper proposes changing the terminology of ‘acoustic complexity index' to ‘sonic heterogeneity index.'
Among surface mining methods, strip mining is a widely used technique for extracting mineral resources. This method is suitable for most near-surface stratiform sedimentary deposits and has historically been linked to surface mining of deposits such as coal, phosphates, and other natural substances. Given the significant economic interest that strip mining represents, it is in the best interest of mining companies to exploit as much of the reserves as possible using this technique, as it offers many advantages compared to open-pit or underground methods, particularly regarding safety and ore recovery rates. Today, the exploited deposits have become deeper, making the strip mining process more complex. Hence, there is a need for certain adaptations and the introduction of new techniques to address these geological conditions that threaten the feasibility of this method. This article explores the challenges that strip mining faces in contexts of thick overburden and subsequently presents the various techniques proposed by researchers worldwide aimed at overcoming these difficulties. The paper is based on an in-depth review of existing literature that deals with case studies of open-cast mines in different contexts. The examination of various approaches and techniques used for optimizing exploitation under thick overburden conditions by strip mining, along with their limitations, is presented.
The proliferation of global regulations concerning sustainability and environmental protection poses a significant challenge to maintaining corporate sustainability. Consequently, companies must strategically respond to navigate these regulations in their management plans. The objective of this research was to analyze how Korean companies(LG Energy Solution, Samsung SDI, SK On) are responding to sustainable mining and procurement and how they adopt environmentally friendly practices in their mineral supply chain for battery manufacturing. We also proposed new actions to enhance their management strategies for sustainable mineral resource management. Our observations indicated that companies should implement a long-term performance measurement throughout their mineral supply chain. Additionally, there is an urgent need to develop a more proactive environmental management plan when evaluating suppliers from mineral extraction to utilization, adhering to global guidelines such as OECD regulation. In addition to the widely adopted monitoring of greenhouse gas emissions, priority assessments must be undertaken concerning soil and water pollution, waste management, and biodiversity loss within the supply chain linked with climate change under the nature-positive concept. We recommended the establishment of a recycling system for battery waste(i.e., minerals), which is essential for a resilient battery supply chain.
Using passive acoustic methods for biodiversity conservation and effective ecosystem monitoring is hindered by laborious, human-mediated processes of accurately identifying biologic and anthropogenic sounds within large datasets. Soundscape ecology provides a potential means of addressing this need through the use of automated acoustic-based biodiversity indices, which show promise in representing biodiversity in terrestrial environments. However, the direct relationship between specific underwater sounds and acoustic index measurements are largely unexplored. Using passive acoustic data collected from three broadband hydrophones within the Ocean Observatories Initiative’s cabled arrays in the Pacific northwest, we identified periods of vocalizing marine mammals and sources of anthropogenic noise. Automated calculations of seven acoustic indices were compared were compared across biologic and anthropogenic sound type and call parameters. Although several index measurements did not vary significantly, the Acoustic Complexity Index (ACI) measurements increased in response to echolocation clicks from sperm whales (Physeter macrocephalus) and burst pulses originating from unidentified delphinid species. Measurements of the Bioacoustic Index (BI) decreased dramatically in responses sperm whale echolocation clicks, a more obvious trend when loud clicks were parsed from moderate and quite clicks. Correlations coefficient and confidence interval values between ACI and BI measurements and call characteristics from sperm whales indicate a moderate to strong relationship, which was not found in correlations with delphnid calls. A generalized linear mixed-effect model indicated multiple species and sound types contribute significantly to the variation of several index measurements. Noise generated by passing ships consistently resulted in decreased values for the Normalized Difference Soundscape Index (NDSI) and Total Entropy (H) as compared to quiet periods and periods with vocalizing marine mammals. These findings provide information on the relationship between several acoustic indices and specific underwater sounds produced by marine mammals and anthropogenic sources. This ground-truthing endeavor expands the understanding of acoustic indices and their potential use as a tool for conservation and ecosystem health management purposes.
Nature is one of the greatest gifts to human life. Environment study and awareness play
important role in conservation. This book Environment Conservation, Challenges Threats
Relation Of Climate Change with Diseases, Eco-Friendly Energy Resources, Air Pollution's,
Environmental And Health Effects, Threats in Conservation of Biodiversity in India,
Sustainable Agriculture and Future Challenges, Biodiversity Conservation: Need &
Challenges, Human Interference on Environment, Industrial Growth with Relation To
Environment, Noise Pollution, Mushrooms as Scavenger: Mycoremediation, Medicinal
Potential Of Flaxseed (Linum Usitatissimum), Environment Degradation in India,' Ecotourism, Conventional Agriculture and Post-Harvest Slash-Burn: Impact on Soil
Sustainability And Our Future. This book covers subjects like Ecology, biodiversity,
demography, laws, Environment, Phycology, microbiology, pathology, demography,
pharmacology mycology, agriculture, horticulture, physiology, etc. In this book, subjects are relevant to all those who are interested in biodiversity conservation. challenges in
conservation, threats in biodiversity, and strategies in biodiversity This book with valuable
book chapters from eminent scientists, academicians, and researchers will surely be a part of utmost information for the coming new research taken by the researchers in the field of Environment and biodiversity sciences and other disciplines in the future.
Passive recording technologies have become a valuable tool for ecologists to accumulate large data sets on vocalizing species assemblages and to study the response of biodiversity to regional and global environmental change. However, the process of interpreting these recordings and identifying species can be time-consuming. To automate this process, and to derive diversity metrics directly from the audio files, soundscape ecologists developed and published many bioacoustics indices, which are calculated using computer algorithms that mathematically summarize the acoustic energy in a recording. Of these indices, the acoustic complexity index (ACI) is perhaps the most widely proposed surrogate of bird species richness. Although several studies have shown the ACI to have positive correlations with species richness, it remains unknown how well the ACI will perform over large, habitat-diverse, regions. Our aim, here, was to examine whether site-level bird species richness (alpha diversity) correlated with the ACI across a large heterogenous mountain region. Further, we explored whether the elevational trends for alpha diversity and the ACI exhibited similar unimodal patterns with corresponding maximums and whether any shifts in the elevation of these maximums could be tracked over time in response to climate change. We deployed recording devices along two extensive transects on the Pacific Crest Trail in California, USA; these included a 689-km trail section in northern California and a 531-km section in southern California. Point counts for birds from the field were combined with the interpretation of the recordings to estimate alpha diversity using a Bayesian multispecies occupancy model. We found that alpha diversity exhibited a positive linear relationship with the ACI on both trail sections. However, these relationships were not strong (low R² values). Similar mid-elevation maximums for alpha diversity and the ACI were observed along the northern trail section. Power analysis revealed that with repeated annual surveys using our protocols, we could detect an average shift in the elevation of either maximum species richness or ACI of approximately 100 m over 20 years (i.e., 5 m/yr), which could be improved in precision to 50 m (i.e., 2.5 m/yr) with a 5-fold increase in survey effort. Although there was considerable unexplained variation in our diversity- and ACI-elevation trends, which we suspect was due to microhabitat and microclimate effects, we concluded that the ACI was a useful, albeit coarse, surrogate of alpha diversity across large regions. The ACI warrants consideration by ecologists and land managers for application in large-scale monitoring programs.
Nature is one of the greatest gifts to human life. Environment study and awareness play
important role in conservation. This book Environment Conservation, Challenges Threats
Relation Of Climate Change With Diseases, Eco-Friendly Energy Resources, Air Pollution's,
Environmental And Health Effects, Threats In Conservation Of Biodiversity In India,
Sustainable Agriculture And Future Challenges, Biodiversity Conservation: Need &
Challenges, Human Interference On Environment, Industrial Growth With Relation To
Environment, Noise Pollution, Mushrooms As Scavenger: Mycoremediation, Medicinal
Potential Of Flaxseed (Linum Usitatissimum), Environment Degradation In India,' Eco-
Tourism, Conventional Agriculture And Post Harvest Slash-Burn: Impact On Soil
Sustainability And Our Future. This book covers subjects like Ecology, biodiversity,
demography, laws, Environment, Phycology, microbiology, pathology, demography,
pharmacology mycology, agriculture, horticulture, physiology, etc. In this book, subjects are
relevant to all those who are interested in biodiversity conservation. challenges in
conservation, threats in biodiversity, and strategies in biodiversity This book with valuable
book chapters from eminent scientists, academicians, and researchers will surely be a part of utmost information for the coming new research taken by the researchers in the field of
Environment and biodiversity sciences and other disciplines in the future
The acoustic complexity indices represent a family of metrics formulated to extract information from sonic matrices. These indices are based on the differences of acoustic energy measured along a temporal interval of a sonic matrix across all the spectral lines (ACIft) and along each individual spectral line (ACItf) obtaining respectively a temporal and a frequential sonic signature. The distribution of information in time and in frequency returns respectively an ACIft evenness and an ACItf evenness that, when combined in a ternary code with ACIft, compose the codes of Ecoacoustic Events (EE). The Ecoacoustic Events are defined as an emergent aggregation of sonic information that assumes a sense for a species or for an ecological process. In order to obtain realistic data, every sonic matrix must be cleaned from low energetic elements, mainly artifacts, by applying adapt energy filters that are also used to delimit near and far acoustic fields contributing to better understand the relationships between sounds and the environment. A clumping procedure can aggregate original data before the application of ACI metrics. The Sonic Signature Dissimilarity (SSD) is used to assess the distance in ACItf between two sonic matrices. The application of the Shannon theory returns the value of entropy of ecoacoustic events. The application of different temporal scales to the ACI computation allows to overpass the uncertainty in the selection of the more adapt temporal resolution obtaining a fractal dimension of ecoacoustic events and of sonic dissimilarity.
Dealing with landscape changes in space and time is an important activity in terms of the process of future development of the selected area. In particular, it is necessary to focus on territories that are exposed to the effects of extraction activities. The main objective of the paper was the mapping of spatio-temporal changes in the landscape in connection with the extraction of minerals due to mining activities on the landscape using satellite images and data from the Corine land cover (CLC) database in the environment of geographic information systems. The selected study area is specific to the presence of four mineral deposits (three of which are under active mining). The Rohožník-Konopiská deposit was abandoned and the area was subsequently reclaimed. The study used Corine land cover (CLC) data and Landsat 5, 7, 8 satellite images for selected years in the period 1990–2021. The Normalized Difference Vegetation Index (NDVI) was calculated for vegetation cover analysis, which was further combined with the forest spatial division units (FSDU) layer. Areas in the immediate vicinity of the open-pit mine were selected for detailed analysis of vegetation changes. Using the FSDU data, an average NDVI index value was calculated using the Zonal statistics function for each plot. The results showed that over the selected period there have been changes indicating an improvement in the landscape condition by reclamation operations at two deposits, Rohožník-Konopiská (inactive) and Sološnica-Hrabník (active). The analyzed CLC data detected the change at the Rohožník-Konopiská deposit, but the active deposit Sološnica-Hrabník was not detected in these data. The loss of vegetation on the other two deposits is mainly due to pre-mining preparatory work, which causes the removal of soil and vegetation layers.
Soundscape (biophonies) analysis using acoustic indices provides researchers with valuable ecological information to assess biodiversity, species behavior, and noise pollution. In this study, to analyze biophonies and anthrophony in six urban parks in Isfahan city in spring, six acoustic indices, including Acoustic complexity index (ACI), Acoustic Diversity Index (ADI), Acoustic Evenness Index (AEI), and Bioacoustic Index (BI), Normalized Difference Soundscape Index (NDSI) and Entropy Index (H) were used and quantified using Seewave Package in R software. In the next step, using ANOVA test, we evaluated the significance of difference between values of the indices among the six parks. We also calculated the degree of correlation between pairs of the indices among and within the parks using Tukey test. According to the results of ANOVA and Tukey tests, the highest values of BI, NDSI, ACI, ADI, AEI and H indices were obtained for Sofeh Park with values of 51.63, 0.99, 2267, 1.46, 0.89 and 0.82, respectively and the lowest values of the These indices were also calculated for Mahmoud-Abad (16.56 and - 0.49), Isargaran (1787) and Bagh-Ghadir (0.05, 0.67 and 0.41) Parks. Among the indices, the most significant difference was calculated for the two indices of ADI and NDSI and between the Sofeh and Mahmoud-Abad Parks indicating the effect of factors such as edge effect and birds diversity on these indices. So according to the results it can be concluded that NDSI and BI indices are suitable tools for evaluating ecosystem quality and management of ecological sound spaces in urban parks, so that they can be used in green space management and urban biodiversity assessment.
Worldwide urban expansion and deforestation have caused a rapid decline of non-human primates in recent decades. Yet, little is known to what extent these animals can tolerate anthropogenic noise arising from roadway traffic and human presence in their habitat. We studied six family groups of titis residing at increasing distances from a busy highway, in a park promoting ecotourism near Santa Cruz de la Sierra, Bolivia. We mapped group movements, sampled the titis' behavior, collected fecal samples from each study group and conducted experiments in which we used a mannequin simulating a human intrusion in their home range. We hypothesized that groups of titi monkeys exposed to higher levels of anthropogenic noise and human presence would react weakly to the mannequin and show higher concentrations of fecal cortisol compared with groups in least perturbed areas. Sound pressure measurements and systematic monitoring of soundscape inside the titis' home ranges confirmed the presence of a noise gradient, best characterized by the root-mean-square (RMS) and median amplitude (M) acoustic indices; importantly, both anthropogenic noise and human presence co-varied. Study groups resided in small, overlapping home ranges and they spent most of their time resting and preferentially used the lower forest stratum for traveling and the higher levels for foraging. Focal sampling analysis revealed that the time spent moving by adult pairs was inversely correlated with noise, the behavioral change occurring within a gradient of minimum sound pressures ranging from 44 dB(A) to 52 dB(A). Validated enzyme-immunoassays of fecal samples however detected surprisingly low cortisol concentrations, unrelated to the changes observed in the RMS and M indices. Finally, titis' response to the mannequin varied according to our expectation, with alarm calling being greater in distant groups relative to highway. Our study thus indicates reduced alarm calling through habituation to human presence and suggests a titis' resilience to anthropogenic noise with little evidence of physiological stress. How to cite this article Hernani Lineros LM, Chimènes A, Maille A, Dingess K, Rumiz DI, Adret P. 2020. Response of Bolivian gray titi monkeys (Plecturocebus donacophilus) to an anthropogenic noise gradient: behavioral and hormonal correlates. PeerJ 8:e10417 http://doi.
In Amazon, the construction of hydroelectric dams is a growing factor in the biodiversity loss. In such environments, fragments acts as true islands, presenting low species richness on small islands. Consequently, tools that can monitor changes in communities are becoming increasingly important. In the first chapter, we evaluated the performance of seven acoustic indices (biodiversity indices based on the soundscapes analysis) in forest islands within an anthropogenic archipelago of central Amazonia, to address the following questions: (1) is there a relationship between bird richness and acoustic indices? (2) what is the relationship between soundscape patterns and landscape features such as island size? (3) how do soundscapes change throughout the day in islands of different sizes? and finally; (4) how do birds and cicadas use their acoustic space on islands of different sizes? In fragmented environments it is also necessary uncover the physiological mechanisms underlying the success of organisms living in disturbed habitats. In the second chapter, we use the corticosterone levels present in bird feathers as a measure of physiological stress, assessing whether corticosterone levels reflect the effects of landscape fragmentation related to the island size. For the first chapter, 12 islands and two areas of continuous forest were sampled. Using two autonomous recorders per area, one-minute recordings were made at five-minute intervals, for 24 hours, for three consecutive days. The acoustic indices exhibited different patterns, with marked changes between day and night. Our results show that five indices (acoustic complexity, acoustic diversity, acoustic entropy, median of the amplitude envelope and spectral flatness) reflect the species richness in each area. When we correlate the acoustic indices with island size, only the acoustic entropy index had significant results, presenting higher values with increasing area size. For the second chapter, we captured birds in 13 islands of varying size and in two continuous forests and analysed feather corticosterone levels of 265 individuals from eight different species. Our findings did not support the hypothesis that corticosterone varies in relation to island size, except for Hypocnemis cantator, which presented the predicted pattern: decreasing feather corticosterone levels with increasing island size. Overall, we conclude that even in a highly diverse environment, such as tropical forests, acoustic indices provide an excellent complementary tool for biodiversity assessment when provided with a ground-truthed database. Further studies are necessary to assess the reliability of corticosterone levels as a physiological measurement of stress and to determine which parameters are useful to understand how insularization caused by human activities may influence the resistance of avian populations to habitat disturbances.
Ecoacoustics is a new discipline that investigates the ecological role of sounds in
landscapes. The methods becoming available in this field have great potential for multitaxa animal surveys and routine biodiversity assessments, a topic of great interest among the scientific community, general public, and governments around the world. Despite this potential, foundational assumptions of the field still need to be tested empirically, especially in tropical regions, where most of the world’s animal diversity is located but where ecoacoustic studies rarely have been implemented. In this dissertation, I used ecoacoustic data collected over two years in the Brazilian Amazon to test the
applicability of three different but complementary approaches to analyze large, audio
files data sets (over 3000 hours of sound recordings). In Chapter 1, I provide a brief
review of the ecoacoustic field and soundscapes. In Chapter 2, I confirm two central
assumptions from the field of ecoacoustics, that habitats have unique and predictable
acoustic signatures, and that soundscapes are intrinsically linked to changes in vegetation structure. In Chapter 3, I found that ecoacoustic surveys can be used to study the 24-h calling behavior of howler monkeys, an animal producing a loud call that is a key
component of Neotropical soundscapes, and identify key differences in their calls
between day and night. In Chapter 4, I used ecoacoustic surveys and successfully
employed automatic classifiers to retrieve information about two threatened bird species
in the Amazon. In Chapter 5, I summarize my findings and discuss future research
directions in the ecoacoustics field. The results from Chapters 2 to 4 confirm the great
potential to establish ecoacoustic surveys and associated methods as a complementary
strategy for muti-taxa animal surveys in the tropical region.
https://digitalcommons.usu.edu/etd/7919/
The rapidly developing field of ecoacoustics offers methods that can advance multi-taxa animal surveys at policy-relevant extents. While the field is promising, there remain foundational assumptions that need to be tested across different biomes before the methods can be applied widely. Here we test two of these assumptions in the Amazon: 1) that acoustic indices can be used to predict soundscapes of different habitat types, and 2) that acoustic indices are related to vegetation structure. We recorded soundscapes and collected vegetation data in 143 sites spanning six natural and two human-modified habitats in Viruá National Park, Roraima, Brazil. We grouped the eight habitats into three categories based on vegetative characteristics and flooding regime: open habitats, flooded-forests, and non-flooded forests. Thirteen acoustic indices were calculated from 92,283 one-minute recordings to describe the soundscapes of the habitats. We found that each habitat type had unique and predictable soundscapes. Random forest models were 74% accurate at predicting the eight habitats types and 87% accurate at predicting the three broader habitats categories. The most important acoustic indices to distinguish habitats were the third quartile and centroid. Canopy cover significantly affected 11 of 13 acoustic indices, and while other vegetation variables (e.g., shrub cover and number of trees) appeared in top models for some indices, their effects were not significant. The best indices linking soundscapes to vegetation structure were the acoustic evenness index and skewness, with canopy cover explaining 81% and 52% of the variance in these indices, respectively. These results expand our knowledge regarding which acoustic indices best connect changes in habitats to changes in soundscapes. These findings are particularly important for diverse ecosystems, like the Amazon, which are known to have complex soundscapes with sound-producing animals that are difficult to detect with traditional survey methods (e.g., visual transects). Ultimately, our results suggest that soundscapes are able to track changes in biodiversity levels across major habitat types of the Amazon.
Acoustic recordings of the environment are an important aid to ecologists monitoring biodiversity and environmental health. However, rapid advances in recording technology, storage and computing make it possible to accumulate thousands of hours of recordings, of which, ecologists can only listen to a small fraction. The big-data challenge addressed in this paper is to visualize the content of long-duration audio recordings on multiple scales, from hours, days, months to years. The visualization should facilitate navigation and yield ecologically meaningful information.
It is presented a bird survey of Rio Cipó valley from May 1998 to November 2002. The region is within the premises of 'Parque Nacional da Serra do Cipó', one of the most important conservation units of southeastern Brazil. Bird census were carried out through transect, mist-net captures and recording bird vocalizations. Species richness was estimated by jackknife method. It was recorded 226 species, belonging to 43 families. This represents 27% of all 837 bird species recorded at the Cerrado (a Savannah-like biome) region of central Brazil. A total of 2,249 bird individuals were captured with 4,486.82 net-hours. This represented 119 bird species of 23 families. Species richness was estimated at 239 ± 5 species. Six species are considered endemic to this biome: Augastes scutatus (Temminck, 1824) (Trochilidae), Hylocryptus rectirostris (Wied-NeuWied, 1821) (Furnariidae), Antilophia galeata (Lichtenstein, 1832) (Pipridae), Cyanocorax cristatellus (Temminck, 1823) (Corvidae), Charitospiza eucosma (Oberholser, 1905), Saltator atricollis (Vieillot, 1817), and Porphyrospiza caerulescens (Wied-Neuwied, 1830) (Emberizidae). Three species are considered near-threatened to extinction: Sarcoramphus papa (Linnaeus, 1758) (Cathartidae), Cypsnagra hirundinacea (Lesson, 1831), and Charitospiza eucosma (Emberizidae). The Rio Cipó valley holds a significant number of the Cerrado bird species. Some habitats within this biome are becoming rare in the Cerrado region such as gallery forests, and the temporary lagoons along the rivers. Even waterfalls are disappearing in other regions of Brazil. In this sense, the 'Parque Nacional da Serra do Cipó' is achieving one of its aims, which is biodiversity conservation.
M ALE HUMPBACK WHALES (MEGAPTERA NOVAE-ANGLIAE) (fi g. 1) produce "songs"—long, patterned sequences of sounds—that are presumed to function as a reproductive display on the breeding grounds (Payne and McVay 1971; Winn and Winn 1978; Tyack 1981). Many preferred breeding areas are conservation hot spots protected by marine parks, and the whale-watching industry has fl ourished in those sites (Hoyt 2001). Noise generated from whale-watching boat traffi c can mask important aspects of whale communication. This raises concerns about the potential infl uence of noise on repro-ductive success and population growth. Gray whales may tempo-rarily or permanently abandon critical areas because of excessive exposure to boat noise (Bryant et al. 1984). Therefore, managers in parks created to protect and conserve whales are often faced with the task of managing noise-generating tourism activities, especially in breeding areas. Because whales are acoustic specialists (Richardson et al. 1995), investigations can rely on listening to understand their social system. Recent advances in passive acoustic technology allow researchers to follow the movements of whales by locating and tracking vocalizing individuals. By continuously sampling and simultaneously following multiple whales, investigators can describe the movements of cohorts of individuals. By comparing whale tracks with the tracks and acoustic characteristics of human activities, investigators can measure whale responses to human-caused disturbance, such as an approaching vessel. Figure 1. A humpback whale (Megaptera novaeangliae) exposes its tail or fl uke, a common occurrence while singing, in Abrolhos Marine National Park. Scientists use the unique black-and-white markings of the underside of the fl uke to identify individuals. Brazilian Navy facilities are visible on Santa Bárbara Island in the background.
Since the moratorium on whaling, the Brazilian government and local Non-Govermental Organizations (NGOs) have adopted and encouraged a more sustainable use of whales as tourist attractions. Nevertheless, concerns about boat traffic impacts on whale population health have arisen, especially in protected areas such as marine parks. The Abrolhos Marine National Park is the seasonal habitat for the breeding population of humpback whales in the Western South Atlantic. We acoustically monitored 7% of the park area during 26 days using marine autonomous recording units and evaluated the responses of whales to boat traffic by measuring changes in male singing activity. The recorded humpback whale songs were analyzed to locate and count individual singers. We modeled the fluctuation in the number of singers over time in response to: number of acoustic boat events, tide height, lunar phase, hour of the day, the quadratic function of hour of day, day of the season, and presence of light. Generalized linear models were used to fit the singer count data into a Poisson distribution and log link. We found an important negative effect of boat traffic on singing activity. There is evidence that the interaction between phases of the moon and the quadratic function of hour of day also affect singing behavior. Adaptive management should aim at reducing the number of noise events per boat, which can improve the whale watching experience and reduce the impact on male singing behavior.
Natural landscapes are increasingly subjected to anthropogenic pressure and fragmentation resulting in reduced ecological condition. In this study we examined the relationship between ecological condition and the soundscape in fragmented forest remnants of south-east Queensland, Australia. The region is noted for its high biodiversity value and increased pressure associated with habitat fragmentation and urbanisation. Ten sites defined by a distinct open eucalypt forest community dominated by spotted gum (Corymbia citriodora ssp. variegata) were stratified based on patch size and patch connectivity. Each site underwent a series of detailed vegetation condition and landscape assessments, together with bird surveys and acoustic analysis using relative soundscape power. Univariate and multivariate analyses indicated that the measurement of relative soundscape power reflects ecological condition and bird species richness, and is dependent on the extent of landscape fragmentation. We conclude that acoustic monitoring technologies provide a cost effective tool for measuring ecological condition, especially in conjunction with established field observations and recordings.
It is presented a bird survey of Rio Cipó valley from May 1998 to November 2002. The region is within the premises of 'Parque Nacional da Serra do Cipó', one of the most important conservation units of southeastern Brazil. Bird census were carried out through transect, mist-net captures and recording bird vocalizations. Species richness was estimated by jackknife method. It was recorded 226 species, belonging to 43 families. This represents 27% of all 837 bird species recorded at the Cerrado (a Savannah-like biome) region of central Brazil. A total of 2,249 bird individuals were captured with 4,486.82 net-hours. This represented 119 bird species of 23 families. Species richness was estimated at 239 ± 5 species. Six species are considered endemic to this biome: Augastes scutatus (Temminck, 1824) (Trochilidae), Hylocryptus rectirostris (Wied-NeuWied, 1821) (Furnariidae), Antilophia galeata (Lichtenstein, 1832) (Pipridae), Cyanocorax cristatellus (Temminck, 1823) (Corvidae), Charitospiza eucosma (Oberholser, 1905), Saltator atricollis (Vieillot, 1817), and Porphyrospiza caerulescens (Wied-Neuwied, 1830) (Emberizidae). Three species are considered near-threatened to extinction: Sarcoramphus papa (Linnaeus, 1758) (Cathartidae), Cypsnagra hirundinacea (Lesson, 1831), and Charitospiza eucosma (Emberizidae). The Rio Cipó valley holds a significant number of the Cerrado bird species. Some habitats within this biome are becoming rare in the Cerrado region such as gallery forests, and the temporary lagoons along the rivers. Even waterfalls are disappearing in other regions of Brazil. In this sense, the 'Parque Nacional da Serra do Cipó' is achieving one of its aims, which is biodiversity conservation.
It is presented a bird survey of a forest fragment at the upper Rio Doce valley carried out from April 2002 to November 2004. The region is within one of the most important Brazilian hot spot for biological conservation: the Atlantic Forest. The fragment is within 'Estação de Desenvolvimento Ambiental de Peti' (EPDA-Peti) under the premises of a hydroelectric power station run by the Minas Gerais Energetic Company. It holds 605 ha of a mosaic of secondary growth forest patches from different ages, characterised mainly by semi deciduous forest. Bird census were carried out through transect, mist-net captures, point counts and recording bird vocalizations. The present survey was compared to an unpublished survey performed in 1989 to find out possible extinctions and colonization. It was recorded 231 species, belonging to 57 families. This represents 33% of all 682 bird species recorded for the Atlantic forest biome of east Brazil. Thirty-three species are considered endemic to the Atlantic Forest and one is considered endemic to the Cerrado biome of central Brazil. Five species are threatened in the state of Minas Gerais and one species is globally threatened to extinction, the red-billed curassow Crax blumenbachii Spix, 1825 (Cracidae). It was found 35 species not reported before for the area. Also, 52 species went locally extinct from the fragment. The EPDA-Peti holds a significant number of the Atlantic Forest bird species, and long-term bird monitoring on such fragments will reveal important aspects for the understanding of colonization and extinction in the biome.
Here we provide a list of amphibians and reptiles of Estação de Pesquisa e Desenvolvimento Ambiental de Peti, an Atlantic rainforest reserve located in the mountains of the Espinhaço Range, State of Minas Gerais, southeastern Brazil. This list originated from a 78-days inventory conducted in the area 13 years after a first inventory. We actively searched for amphibians and reptiles in forest trails and anuran breeding sites. Between April 2002 and October 2004 we recorded 48 species belonging to Anura (29 species), Gymnophiona (1), Chelonia (1), Crocodylia (1), and Squamata (16 species: one amphisbaenian, five lizards and 10 snakes). Thirteen species were not recorded in the first inventory, and 14 species previously recorded were not found in the present work. Possible explanations for these differences are discussed. Although none of the recorded species is included in the available lists of threatened species for the State of Minas Gerais and Brazil, the reserve must be considered an important source of natural habitats to the local herpetofauna.
The first iteration of the niche hypothesis and the foundational concepts for the field of Soundscape Ecology.
This study presents the results of an inventory of the mammal fauna of the Estação de Preservação e Desen- volvimento Ambiental de Peti (EPDA-Peti) a reserve in the transition between the Atlantic Forest and the Cerrado. Eight field campaigns (including trapping for small mammals and mist-netting for bats) were conducted between May 2002 and July 2004. Forty-six mammals belonging to eight orders were recorded. Fifteen species not recorded in previous inventories at the Station were identified; on the other hand, 14 mammals listed in previous studies were not recorded now. The most abundant small mammals at the EPDA- Peti were Oligorizomys flavescens, Akodon cursor, Trinomys setosus and Bolomys lasiurus. The small mammal community from the campo rupestre (high altitude, rocky grassland) habitat is distinct from that found in the forest. In spite of the reserve's small size, mammal species' richness is relatively high. Possible reasons for this are the diversity of habitats and the fact that EPDA-Peti is located in a transitional zone between the Atlantic Forest and the Cerrado.
Traditionally, animal species diversity and abundance is assessed using a variety of methods that are generally costly, limited in space and time, and most importantly, they rarely include a permanent record. Given the urgency of climate change and the loss of habitat, it is vital that we use new technologies to improve and expand global biodiversity monitoring to thousands of sites around the world. In this article, we describe the acoustical component of the Automated Remote Biodiversity Monitoring Network (ARBIMON), a novel combination of hardware and software for automating data acquisition, data management, and species identification based on audio recordings. The major components of the cyberinfrastructure include: a solar powered remote monitoring station that sends 1-min recordings every 10 min to a base station, which relays the recordings in real-time to the project server, where the recordings are processed and uploaded to the project website (arbimon.net). Along with a module for viewing, listening, and annotating recordings, the website includes a species identification interface to help users create machine learning algorithms to automate species identification. To demonstrate the system we present data on the vocal activity patterns of birds, frogs, insects, and mammals from Puerto Rico and Costa Rica.
Noise emanating from human activity has become a common addition to natural soundscapes and has the potential to harm wildlife and erode human enjoyment of nature. In particular, motor vehicles traveling along roads and trails produce high levels of both chronic and intermittent noise, eliciting varied responses from a wide range of animal species. Anthropogenic noise is especially conspicuous in natural areas where ambient background sound levels are low. In this article, we present an acoustic method to detect and analyze motor vehicle noise. Our approach uses inexpensive consumer products to record sound, sound analysis software to automatically detect sound events within continuous recordings and measure their acoustic properties, and statistical classification methods to categorize sound events. We describe an application of this approach to detect motor vehicle noise on paved, gravel, and natural-surface roads, and off-road vehicle trails in 36 sites distributed throughout a national forest in the Sierra Nevada, CA, USA. These low-cost, unobtrusive methods can be used by scientists and managers to detect anthropogenic noise events for many potential applications, including ecological research, transportation and recreation planning, and natural resource management.
Breeding birds (songbirds, shorebirds, and ptarmigan) were surveyed at the Ekati Diamond Mine in Canada's Northwest Territories from 1996 through 2003. Surveys were conducted on permanent, 25 ha mine and control plots. Five metrics (relative density of individual species, relative density of all birds, species richness using rarefaction curves, and species diversity using two indices) were used to assess potential impacts up to a distance of 1 km from the mine. Six species were more common on mine plots, and three were more common on control plots. Species diversity was slightly higher on mine plots when measured with Fisher's alpha index. No other metrics suggested strong impacts. This study suggests that the mine has had a relatively limited impact on the upland breeding bird community within 1 km of the footprint but has provided habitat for at least one synanthropic bird species. Further monitoring of breeding birds on the tundra should include pre-development control data and demographic variables such as reproductive success and survival.
Conservation biology and comparative psychology rarely intersect, in part because conservation biology typically emphasizes populations whereas comparative psychology concentrates on individual organisms. However, both fields could benefit from their integration. Conservation biology can profit from an enhanced understanding of individual-level impacts of habitat alteration and the resulting implications for conservation mitigation strategies. Comparative psychology can gain from increased attention to the mechanisms of adjustment used by organisms to "in vivo experiments" created by anthropogenic change. In this paper, we describe a conceptual framework useful for applying our understanding of animal communication to conservation biology. We then review studies of animal communication with conservation implications, and report our own preliminary work that demonstrates our framework in action. Copyright Information:
Since acoustic communication is considerably constrained by environmental noise, some animals have evolved adaptations to counteract its masking effects. Humans and New World monkeys increase the duration of brief vocalizations (below a few hundred milliseconds) as the background noise level rises, a behaviour that increases the detection probability of signals in noise by temporal summation. We found that domestic fowl, Gallus gallus domesticus, exhibited the Lombard effect, that is, a regulation of vocal amplitude depending on the background noise level. This vocal mechanism for communication in noise is also found in mammals and other bird species. However, in contrast to primates, the chickens did not regulate the duration of their brief call syllables. This evidence for a lack of regulation of syllable duration may hint at limitations in the degrees of freedom for signal coding. Overall, our findings indicate that the common problem of acoustic communication in noise has led to the evolution of a common solution, the Lombard effect, but also to special adaptations in different taxa.
More humans reside in urban areas than at any other time in history. Protected urban green spaces and transportation greenbelts support many species, but diversity in these areas is generally lower than in undeveloped landscapes. Habitat degradation and fragmentation contribute to lowered diversity and urban homogenization, but less is known about the role of anthropogenic noise. Songbirds are especially vulnerable to anthropogenic noise because they rely on acoustic signals for communication. Recent studies suggest that anthropogenic noise reduces the density and reproductive success of some bird species, but that species which vocalize at frequencies above those of anthropogenic noise are more likely to inhabit noisy areas. We hypothesize that anthropogenic noise is contributing to declines in urban diversity by reducing the abundance of select species in noisy areas, and that species with low-frequency songs are those most likely to be affected. To examine this relationship, we calculated the noise-associated change in overall species richness and in abundance for seven common songbird species. After accounting for variance due to vegetative differences, species richness and the abundance of three of seven species were reduced in noisier locations. Acoustic analysis revealed that minimum song frequency was highly predictive of a species' response to noise, with lower minimum song frequencies incurring greater noise-associated reduction in abundance. These results suggest that anthropogenic noise affects some species independently of vegetative conditions, exacerbating the exclusion of some songbird species in otherwise suitable habitat. Minimum song frequency may provide a useful metric to predict how particular species will be affected by noise. In sum, mitigation of noise may enhance habitat suitability for many songbird species, especially for species with songs that include low-frequency elements.
The effect of anthropogenic noise on terrestrial wildlife is a relatively new area of study with broad ranging management implications. Noise has been identified as a disturbance that has the potential to induce behavioral responses in animals similar to those associated with predation risk. This study investigated potential impacts of a variety of human activities and their associated noise on the behavior of elk (Cervus elaphus) and pronghorn (Antilocapra americana) along a transportation corridor in Grand Teton National Park.
We conducted roadside scan surveys and focal observations of ungulate behavior while concurrently recording human activity and anthropogenic noise. Although we expected ungulates to be more responsive with greater human activity and noise, as predicted by the risk disturbance hypothesis, they were actually less responsive (less likely to perform vigilant, flight, traveling and defensive behaviors) with increasing levels of vehicle traffic, the human activity most closely associated with noise. Noise levels themselves had relatively little effect on ungulate behavior, although there was a weak negative relationship between noise and responsiveness in our scan samples. In contrast, ungulates did increase their responsiveness with other forms of anthropogenic disturbance; they reacted to the presence of pedestrians (in our scan samples) and to passing motorcycles (in our focal observations).
These findings suggest that ungulates did not consistently associate noise and human activity with an increase in predation risk or that they could not afford to maintain responsiveness to the most frequent human stimuli. Although reduced responsiveness to certain disturbances may allow for greater investment in fitness-enhancing activities, it may also decrease detections of predators and other environmental cues and increase conflict with humans.
Fitness in birds has been shown to be negatively associated with anthropogenic noise, but the underlying mechanisms remain obscure. It is however crucial to understand the mechanisms of how urban noise impinges on fitness to obtain a better understanding of the role of chronic noise in urban ecology. Here, we examine three hypotheses on how noise might reduce reproductive output in passerine birds: (H1) by impairing mate choice, (H2) by reducing territory quality and (H3) by impeding chick development.
We used long-term data from an island population of house sparrows, Passer domesticus, in which we can precisely estimate fitness. We found that nests in an area affected by the noise from large generators produced fewer young, of lower body mass, and fewer recruits, even when we corrected statistically for parental genetic quality using a cross-fostering set-up, supporting H3. Also, individual females provided their young with food less often when they bred in the noisy area compared to breeding attempts by the same females elsewhere. Furthermore, we show that females reacted flexibly to increased noise levels by adjusting their provisioning rate in the short term, which suggests that noise may be a causal factor that reduces reproductive output. We rejected H1 and H2 because nestbox occupancy, parental body mass, age and reproductive investment did not differ significantly between noisy and quiet areas.
OUR RESULTS SUGGEST A PREVIOUSLY UNDESCRIBED MECHANISM TO EXPLAIN HOW ENVIRONMENTAL NOISE CAN REDUCE FITNESS IN PASSERINE BIRDS: by acoustically masking parent-offspring communication. More importantly, using a cross-fostering set-up, our results demonstrate that birds breeding in a noisy environment experience significant fitness costs. Chronic noise is omnipresent around human habitation and may produces similar fitness consequences in a wide range of urban bird species.
Foram analisados dados diários de 203 estações pluviométricas localizadas na região Sudeste do Brasil, com o objetivo de caracterizar climaticamente e analisar a tendência do comportamento do período chuvoso. Os resultados indicam que o período chuvoso inicia mais cedo (entre 13 e 22 de setembro) e tem maior duração (210 a 229 dias) na região litorânea de São Paulo. Comportamento oposto ao observado nas regiões Norte e Vale do Jequitinhonha, em Minas Gerais, onde o período chuvoso inicia em média, entre os dias 23 de outubro a 2 de novembro, durando apenas 136 a 155 dias. As datas de início e a duração do período chuvoso estão fortemente correlacionadas entre si, bem como, entre o total de precipitação e a duração do período chuvoso em praticamente todo o Sudeste do Brasil. De modo geral, desde meados da década de 1970, o período chuvoso tem iniciado precocemente e durado mais no Sudeste do Brasil. Quanto à quantidade de chuva, esta tem ocorrido em maiores quantidades somente na área MG3 (sudeste de Minas Gerais) e no estado de São Paulo.
1. Traffic affects large areas of natural habitat worldwide. As a result, the acoustic signals used by birds and other animals are increasingly masked by traffic noise. Masking of signals important to territory defence and mate attraction may have a negative impact on reproductive success. Depending on the overlap in space, time and frequency between noise and vocalizations, such impact may ultimately exclude species from suitable breeding habitat. However a direct impact of traffic noise on reproductive success has not previously been reported.
2. We monitored traffic noise and avian vocal activity during the breeding season alongside a busy Dutch motorway. We measured variation in space, time and spectrum of noise and tested for negative effects on avian reproductive success using long‐term breeding data on great tits Parus major .
3. Noise levels decreased with distance from the motorway, but we also found substantial spatial variation independent of distance. Noise also varied temporally with March being noisier than April, and the daytime being noisier than night‐time. Furthermore, weekdays were clearly noisier than weekends. Importantly, traffic noise overlapped in time as well as acoustic frequency with avian vocalization behaviour over a large area.
4. Traffic noise had a negative effect on reproductive success with females laying smaller clutches in noisier areas. Variation in traffic noise in the frequency band that overlaps most with the lower frequency part of great tit song best explained the observed variation.
5. Additionally, noise levels recorded in April had a negative effect on the number of fledglings, independent of clutch size, and explained the observed variation better than noise levels recorded in March.
6. Synthesis and applications . We found that breeding under noisy conditions can carry a cost, even for species common in urban areas. Such costs should be taken into account when protecting threatened species, and we argue that knowledge of the spatial, temporal and spectral overlap between noise and species‐specific acoustic behaviour will be important for effective noise management. We provide some cost‐effective mitigation measures such as traffic speed reduction or closing of roads during the breeding season.
1. Animals produce sounds for diverse biological functions such as defending territories, attracting mates, deterring predators, navigation, finding food and maintaining contact with members of their social group. Biologists can take advantage of these acoustic behaviours to gain valuable insights into the spatial and temporal scales over which individuals and populations interact. Advances in bioacoustic technology, including the development of autonomous cabled and wireless recording arrays, permit data collection at multiple locations over time. These systems are transforming the way we study individuals and populations of animals and are leading to significant advances in our understandings of the complex interactions between animals and their habitats.
The extensive literature documenting the ecological effects of roads has repeatedly implicated noise as one of the causal
factors. Recent studies of wildlife responses to noise have decisively identified changes in animal behaviors and spatial
distributions that are caused by noise. Collectively, this research suggests that spatial extent and intensity of potential
noise impacts to wildlife can be studied by mapping noise sources and modeling the propagation of noise across landscapes.
Here we present models of energy extraction, aircraft overflight and roadway noise as examples of spatially extensive sources
and to present tools available for landscape scale investigations. We focus these efforts in US National Parks (Mesa Verde,
Grand Teton and Glacier) to highlight that ecological noise pollution is not a threat restricted to developed areas and that
many protected natural areas experience significant noise loads. As a heuristic tool for understanding past and future noise
pollution we forecast community noise utilizing a spatially-explicit land-use change model that depicts the intensity of human
development at sub-county resolution. For road noise, we transform effect distances from two studies into sound levels to
begin a discussion of noise thresholds for wildlife. The spatial scale of noise exposure is far larger than any protected
area, and no site in the continental US is free form noise. The design of observational and experimental studies of noise
effects should be informed by knowledge of regional noise exposure patterns.
KeywordsAnthropogenic noise–Wildlife–Acoustical fragmentation–Acoustic modeling–Soundscape
Primate long-distance calls have typically been interpreted as communication signals between conspecific groups (the ‘resource defence hypothesis’), but their potential role as anti-predator alarm calls has received comparably little attention. Male diana monkeys,Cercopithecus diana dianain the Taı̈ forest of Côte d’Ivoire often utter long-distance calls, either spontaneously or in reaction to a variety of stimuli, including predators and non-predators. The present study focuses only on predation contexts and provides evidence for communication to both predators and conspecifics. Males called only in response to predators whose hunting success depends on unprepared prey, that is, leopards and crowned hawk eagles, but not in response to pursuit hunters, such as chimpanzees and humans, which can pursue the caller in the canopy. Calling was regularly combined with approaching the predator. Both observations suggest that male long-distance calls are used to signal detection to the predator (‘perception advertisement hypothesis’). Analysis of male long-distance calls given to leopards and eagles showed that they differed according to a number of acoustic parameters. The two call variants were played to different diana monkey groups; conspecifics responded to them as though the original predator were present. We conclude that, in addition to their function in perception advertisement, diana monkey long-distance calls function as within-group semantic signals that denote different types of predators.
Male–female pair bonds are common to most bird species, and these bonds affect fundamental aspects of mating systems and the strength of selection, for example, by limiting extrapair paternity. Therefore, understanding factors that strengthen and erode pair bonds are important in elucidating the selection pressures that avian populations will experience. Here, we studied the effects of environmental noise on pair bonds and the strength of pair preferences (i.e. preferences for a pair-bonded partner versus an unfamiliar individual) in the monogamous zebra finch, Taeniopygia guttata, a model species in studies of sexual selection. Based on a previous study, we hypothesized that high-amplitude environmental noise would decrease the strength of pair preferences. Explicitly, we tested whether females' relative preference for their pair-bonded males, compared with extrapair males, decreased as the amplitude of environmental white noise increased. Our results generally supported our hypothesis, as females' preference for their pair-bonded males significantly decreased under conditions of high environmental noise. This erosion of preference may result from the masking or distortion of the paired males' pair-bond maintaining call, although the decrease in preference could also occur because a female cannot recognize her pair-bonded male. Our findings suggest that songbird populations in areas with high environmental noise may have (temporarily or permanently) weakened pair bonds, suggesting that extrapair behaviours could increase in areas of greater environmental noise.
Urbanization has not only altered land cover types, but also changed acoustic environments to which animals must adapt or emigrate for effective communication. Although many studies have addressed the effects of urban noise on acoustic communication of vocal organisms, little work has been done to understand the acoustic characteristics and the interaction between biological and anthropogenic sounds across urban–rural landscapes. The objectives of this study were to investigate the spatial and temporal patterns of soundscape characteristics along an urban–rural gradient, and how soundscape properties are related to avian species community. We established 17 locations across the city of Lansing, Michigan from February to December 2006 to record environmental sounds. A multilevel regression model (MLRM) was used to understand the variability of acoustic power of biological and anthropogenic sounds (biophony and anthrophony) with temporal and spatial data structures. Canonical Correspondence Analysis (CCA) was employed to investigate how bird species respond along an environmental gradient.
Bioacoustics is historically a discipline that essentially focuses on individual behaviour in relation to population and species evolutionary levels but rarely in connection with higher levels of ecological complexity like community, landscape or ecosystem. However, some recent bioacoustic
researches have operated a change of scale by developing acoustic indices which aim is to characterize animal acoustic communities and soundscapes. We here review these indices for the first time. The indices can be divided into two classes: the α or within-group indices and the β or between-group indices. Up to 21 α acoustic indices were proposed in less than six years. These indices estimate the amplitude, evenness, richness, heterogeneity of an acoustic community or soundscape. Seven β diversity indices were suggested to compare
amplitude envelopes or, more often, frequency spectral profiles. Both α and β indices reported congruent and expected results but they may still suff er some bias due, for instance, to anthropic background noise or variations in the distances between vocalising animals
and the sensors. Research is still needed to improve the reliability of these new mathematical tools for biodiversity assessment and monitoring. We recommend the contemporary use of some of these indices to obtain complementary information. Eventually, we foresee that this new field of research
which tries to build bridges between animal behaviour and ecology should meet an important success in the next years for the assessment and monitoring of marine, freshwater and terrestrial biodiversity from individual-based level to landscape dimension.
The Red-billed Leiothrix (Leiothrix lutea) is an invasive species which has recently been found to be locally abundant in eastern Liguria (Italy). The song production of this bird was recorded over the course of an entire year (2011) and evaluated using both aural information and applying innovative automatic processing metrics. Our findings revealed that the Red-billed Leiothrix has loud vocalizations that are heard for most of the year, including in July and August when other birds are silent. Its song production has been estimated to amount to 37% of the sounds uttered by the entire bird community. The next most vocal species are the European Robin (36%), the Common Blackbird (18%), the Subalpine Warbler (5%) and the Sardinian Warbler (1%). The Red-billed Leiothrix can be seen as a new acoustically dominant species and, consequently, a potential modifier of the soundscape patterns of the indigenous bird community. The modification of acoustic traits in the repertoire of both indigenous species and the Red-billed Leiothrix is to be expected according to a co-evolution hypothesis.
An altered acoustic environment can have severe consequences for natural communities, especially for species that use acoustic signals to communicate and achieve breeding success. Numerous studies have focused on traffic noise disturbance, but the possible causes of road effects are inter-correlated and the literature on noise qua noise is sometimes contradictory. To provide further empirical data in this regard, the authors investigated the spatio-temporal variability of the singing dynamics of an avian community living in an acoustic context altered by traffic noise. Fieldwork was carried out in a wood of Turkey oaks (central Italy) bordered on one side by a main road. The soundscape was examined by positioning eight digital recorders, distributed in two transects perpendicular to the road, and recording between 6:30 and 8.30 a.m. for 12 continuous sessions. The acoustic complexity index was used to obtain a quantification of singing dynamics, which were positively correlated with traffic noise. This may indicate that birds try to propagate their signals with greater emphasis (e.g., amplified redundancy or loudness of the songs) to override the masking effect of noise. Nevertheless, an ecotonal effect could have influenced the correlation results, with this enhanced dynamic possibly being due to a more densely populated environment.
Traffic noise is known to have a negative impact on bird populations in general, but little is known about the mechanisms by which sound pollution affects bird communities. However, a knowledge of these mechanisms is imperative if we want to account for the differences in susceptibility to traffic noise that exist between species, and may thus be critical for conservation action. To address this issue, population assessments were carried out in a contiguous area of oak-beech forest at differing distances from a much frequented motorway to determine the road effect on the whole bird community. As expected, species richness and diversity decreased towards the motorway, and bird abundance was significantly lower along the motorway than in the control area. However, a few species defied the negative impact of the motorway. The songs of the more abundant passerines were analysed with regard to three frequency parameters to determine whether or not a relationship exists between the song pitch of a species and its sensitivity to noise pollution. A significant relationship was found between dominant frequency and decline in abundance towards the motorway, which indicates that having a higher-pitched song with frequencies well above those of traffic noise makes a bird less susceptible to noise pollution. These results suggest that acoustic masking is one of the mechanisms by which traffic noise negatively affects passerine density along roads.
Acoustic signals constitute a source of information that can be used to measure the spatial and temporal distributions of vocal organisms in ecosystems. Measuring and tracking those species that produce sounds can reveal important information about the environment. Acoustic signals have been used for many years to census vocal organisms. Moreover, acoustics can be used to compute indexes for measuring biodiversity and the level of anthropogenic disturbance. We developed the software and system that automate the process of cataloging acoustic sensor observations into the Remote Environmental Assessment Laboratory (REAL) digital library that can be accessed through a website (http://lib.real.msu.edu). The REAL digital library enables access and analysis of collected acoustic sensor observations. We report on current library status and the mechanisms that enable the selection, extraction and analysis of acoustic data to support investigations on automating species census as well as measuring diversity and disturbance. We implemented numeric and symbolic search mechanisms and unsupervised learning techniques to ease retrieval of acoustic information, including recordings and processed data, pertinent to visitor goals.
Urbanization has not only altered land cover types, but also changed acoustic environments to which animals must adapt or emigrate for effective communication. Although many studies have addressed the effects of urban noise on acoustic communication of vocal organisms, little work has been done to understand the acoustic characteristics and the interaction between biological and anthropogenic sounds across urban–rural landscapes. The objectives of this study were to investigate the spatial and temporal patterns of soundscape characteristics along an urban–rural gradient, and how soundscape properties are related to avian species community. We established 17 locations across the city of Lansing, Michigan from February to December 2006 to record environmental sounds. A multilevel regression model (MLRM) was used to understand the variability of acoustic power of biological and anthropogenic sounds (biophony and anthrophony) with temporal and spatial data structures. Canonical Correspondence Analysis (CCA) was employed to investigate how bird species respond along an environmental gradient.We found that soundscape characteristics were associated with the structure and composition of urban–rural landscapes. Biophony was inversely correlated with anthrophony along an urban–rural gradient. The results of the MLRM showed that the acoustic variability of biophony and anthrophony were associated with landscape attributes. The CCA revealed that the distribution of bird species was significantly related to the percent area of different land cover types. The study suggests that recording acoustic characteristics in urban systems can offer opportunities to not only measure ambient noise levels, but also understand how each component of soundscape is related to another.
Acoustics, the science of sound, has developed into a broad interdisciplinary field encompassing the academic disciplines of physics, engineering, psychology, speech, audiology, music, architecture, physiology, neuroscience, and others. The Springer Handbook of Acoustics is an unparalleled modern handbook reflecting this richly interdisciplinary nature edited by one of the acknowledged masters in the field, Thomas Rossing. Researchers and students benefit from the comprehensive contents spanning: animal acoustics including infrasound and ultrasound, environmental noise control, music and human speech and singing, physiological and psychological acoustics, architectural acoustics, physical and engineering acoustics, signal processing, medical acoustics, and ocean acoustics. This handbook reviews the most important areas of acoustics, with emphasis on current research. The authors of the various chapters are all experts in their fields. Each chapter is richly illustrated with figures and tables. The latest research and applications are incorporated throughout, e.g. computer recognition and synthesis of speech, physiological acoustics, psychological acoustics, thermoacoustics, diagnostic imaging and therapeutic applications and acoustical oceanography. With a Foreword by Manfred R. Schroeder
The animal soundscape is a field of growing interest because of the implications it has for
human–landscape interactions. Yet, it continues to be a difficult subject to investigate, due to the huge
amount of information which it contains. In this contribution, the suitability of the Acoustic Complexity
Index (ACI) is examined. It is an algorithm created to produce a direct quantification of the complex
biotic songs by computing the variability of the intensities registered in audio-recordings, despite the
presence of constant human-generated-noise. Twenty audio-recordings were made at equally spaced
locations in a beech mountain forest in the Tuscan-Emilian Apennine National Park (Italy) between June
and July 2008. The study area is characterized by the absence of recent human disturbance to forest
assets but the presence of airplane routes does bring engine noise that overlaps and mixes with the natural
soundscape, which resulted entirely composed by bird songs. The intensity values and frequency bin
occurrences of soundscapes, the total number of bird vocalizations and the ACI were processed by using
the Songscope v2.1 and Avisoft v4.40 software. The Spearman’s rho calculation highlighted a significant
correlation between the ACI values and the number of bird vocalizations, while the frequency bin occurrence
and acoustic intensity were weaker correlated to bird singing activity because of the inclusion of
all of the other geo/anthro-phonies composing the soundscape. The ACI tends to be efficient in filtering
out anthrophonies (such as airplane engine noise), and demonstrates the capacity to synthetically and
efficiently describe the complexity of bird soundscapes. Finally, this index offers new opportunities for
the monitoring of songbird communities faced with the challenge of human-induced disturbances and
other proxies like climate and land use changes.
Bird song is one of the most remarkable and impressive sounds in the natural world, and has inspired not only students of natural history, but also great writers, poets and composers. Extensively updated from the first edition, the main thrust of this book is to suggest that the two main functions of song are attracting a mate and defending territory. It shows how this evolutionary pressure has led to the amazing variety and complexity we see in the songs of different species throughout the world. Writing primarily for students and researchers in animal behavior, the authors review over 1000 scientific papers and reveal how scientists are beginning to unravel and understand how and why birds communicate with the elaborate vocalizations we call song. Highly illustrated throughout and written in straightforward language, Bird Song also holds appeal for amateur ornithologists with some knowledge of biology.
The soundscape represents the acoustic footprint of a landscape, and may well be a source of a vast amount of information that could be used efficiently in, for example, long-term bird aggregation monitoring schemes. To depict such soundscape footprint, specific indexes are requested. In particular, the aim of this paper was to extensively describe the Acoustic Complexity Index (ACI) and to successively apply it to process the sound files recorded in an ecologically fragile area in a Mediterranean maqui (Eastern Liguria, Italy). Daily acoustic animal activity was sampled in 90 one-minute files between the end of May and the end of July, 2010, using a pre-programmed recording procedure (Songmeter, Wildlife Acoustic). The WaveSurfer software, powered by the Soundscape Metric plug-in, was then utilized to quickly process these data. This approach allows the identification of the compositional changes and acoustic fluctuations activity of a local community (in the proposed case prevalently composed by birds and cicadas). In particular, two distinct patterns emerged during the investigation. From 20 May to 4 July, the soundscape was dominated by birds but, after that period, the onset of the cicadas' songs completely changed the sound dynamics. The proposed methodology has been demonstrated to be a powerful tool to identify the complex patterns of the soundscape across different temporal scales (hours, days and intraseason). This approach could also be adopted in longterm studies to monitor animal dynamics under different environmental scenarios.
There is a great need for increased use and further development of automated sound recording and analysis of avian sounds. Birds are critical to ecosystem functioning so techniques to make avian monitoring more efficient and accurate will greatly benefit science and conservation efforts. We provide an overview of the hardware approaches to automated sound recording as well as an overview of the prominent techniques used in software to automatically detect and classify avian sound. We provide a comparative summary of examples of three general categories of hardware solutions for automating sound recording which include a hardware interface for a scheduling timer to control a standalone commercial recorder, a programmable recording device, and a single board computer. We also describe examples of the two main approaches to improving microphone performance for automated recorders through small arrays of microphone elements and using waveguides. For the purposes of thinking about automated sound analysis, we suggest five basic sound fragment types of avian sound and discuss a variety of techniques to automatically detect and classify avian sounds to species level, as well as their limitations. A variety of the features to measure for the various call types are provided, along with a variety of classification methods for those features. They are discussed in context of general performance as well as the monitoring and conservation efforts they are used in.
Anthropogenic noise is rapidly increasing in wilderness areas as a result of industrial expansion. While many road studies have attempted to assess the effects of industrial noise on birds, conflicting factors such as edge effects often inhibit the ability to draw strong conclusions.
We assessed pairing success and age distribution of male ovenbirds Seiurus aurocapilla in the boreal forest of Alberta, Canada, in areas around noise‐generating compressor stations compared with areas around habitat‐disturbed, but noiseless, wellpads. This allowed us to control for edge effects, human visitation and other factors that are not controlled for in studies of noise generated by roads. Generalized estimating equations (GEE) were used to assess the impacts of noise on ovenbird pairing success, age structure and body morphology.
We found a significant reduction in ovenbird pairing success at compressor sites (77%) compared with noiseless wellpads (92%). These differences were apparent regardless of territory quality or individual male quality. Significantly more inexperienced birds breeding for the first time were found near noise‐generating compressor stations than noiseless wellpads (48% vs. 30%).
While there are multiple proximate explanations for these results, the ultimate cause of the changes seems to be noise pollution. We hypothesize that noise interferes with a male's song, such that females may not hear the male's song at greater distances and/or females may perceive males to be of lower quality because of distortion of song characteristics.
Synthesis and applications. This work demonstrates that chronic background noise could be an important factor affecting bird populations. It can impact upon pairing success and age structure of passerines; in boreal Alberta this could pose a problem for certain species as energy development expands rapidly.
The impact of environmental background noise on the performance of territorial songs was examined in free‐ranging nightingales ( Luscinia megarhynchos Brehm). An analysis of sound pressure levels revealed that males at noisier locations sang with higher sound levels than birds in territories less affected by background sounds.
This is the first evidence of a noise‐dependent vocal amplitude regulation in the natural environment of an animal.
The results yielded demonstrate that the birds tried to mitigate the impairments on their communication caused by masking noise. This behaviour may help to maintain a given transmission distance of songs, which are used in territory defence and mate attraction. At the same time, birds forced to sing with higher amplitudes have to bear the increased costs of singing.
This suggests that in songbirds the level of environmental noise in a territory will contribute to its quality and thus considerably affect the behavioural ecology of singing males.
1. The effects of roads on wildlife populations are widespread and well documented. Many studies have shown that bird abundance, occurrence and species richness are reduced near roads, with the largest reductions where traffic levels are high. Negative correlations have been reported between bird richness/abundance and traffic noise but the possible causes of road effects are inter‐correlated. It is important to disentangle the different effects so that appropriate mitigation measures can be implemented.
2. We tested the hypothesis that traffic noise is a key negative effect by testing three predictions: (i) bird richness/abundance should reach a maximum at the same distance from roads that traffic noise reaches a minimum; (ii) the effect of traffic noise on bird richness/abundance should be stronger than the effect of distance from the road on bird richness/abundance; and (iii) sites with more traffic noise at a given distance from the road should show lower bird richness/abundance than sites with less traffic noise at the same distance.
3. We collected breeding bird occurrence and traffic noise data along twenty 600‐m transects perpendicular to roads at 10 high‐traffic road sites.
4. Traffic noise decreased and bird species richness increased with increasing distance from the roads. However, none of the predictions derived from the traffic noise hypothesis was supported.
5. Synthesis and applications. Our results suggest that traffic noise is not the main cause of the negative relationship between bird species richness/abundance and proximity to roads. Instead, traffic mortality may be the main mechanism causing this relationship. We suggest that mitigation of road impacts on birds should focus mainly on reducing mortality rather than reducing traffic noise. In particular, engineering road surfaces, tyres and vehicle engines to reduce noise would not mitigate road effects; instead, structures to keep birds away from roads or force them to fly above the traffic would be more effective.
Traffic noise is known to have a negative impact on bird populations in general, but little is known about the mechanisms by which sound pollution affects bird communities. However, a knowledge of these mechanisms is imperative if we want to account for the differences in susceptibility to traffic noise that exist between species, and may thus be critical for conservation action. To address this issue, population assessments were carried out in a contiguous area of oak-beech forest at differing distances from a much frequented motorway to determine the road effect on the whole bird community. As expected, species richness and diversity decreased towards the motorway, and bird abundance was significantly lower along the motorway than in the control area. However, a few species defied the negative impact of the motorway. The songs of the more abundant passerines were analysed with regard to three frequency parameters to determine whether or not a relationship exists between the song pitch of a species and its sensitivity to noise pollution. A significant relationship was found between dominant frequency and decline in abundance towards the motorway, which indicates that having a higher-pitched song with frequencies well above those of traffic noise makes a bird less susceptible to noise pollution. These results suggest that acoustic masking is one of the mechanisms by which traffic noise negatively affects passerine density along roads.
At Panguana, a study in the upper Amazon basin, 7 different aquatic breeding sites of anurans were investigated from Nov. 1, 1981 to Oct. 31, 1982. Rainfall in this area is seasonal. Only 20% of the total annual precipitation was maesured during the dry period, which lasted from mid-March until mid-September 1982. The reproductive periods of the species were highly affected by the rainfall distribution. Calling males and/or gravid females of 46 species were found during the study period. 37.0% of the anuran species were exclusively, and 43.5% predominantly, active during the rainy season. Plots of 100 m2 were established at 6 aquatic sites in primary rainforest. A total of 2126 frogs was counted; 93.2% of these were made during the rainy season. A maximum of 378 individuals were found during one check in the plot at the permanent pond. At this site high concentrations of individuals and large choruses were found at the beginning of the rainy season. As soon as favourable temporary aquatic sites were established, reproductive activities decreased at the permanent pond and increased at temporary breeding sites.
Food-associated calls in some birds and primates have been described as representational signals, with external reference to food objects. However, alternative interpretations suggest that these calls might also communicate an animal's preference for food or predict its subsequent behaviour. The vocal behaviour of cotton-top tamarins, Saguinus oedipus, was investigated in food and non-food related conditions. Recordings were made from nine adult cotton-top tamarins during presentation of a variety of foods. Two types of cells (C-chirps and D-chirps) occurred at a much higher rate than they did when no food was present or when animals were given non-food manipulable objects. Each of the two call types was associated with a different food-associated behavioural context. Great variation occurred within and between individuals in the number of calls elicited by different food types. Two-choice food-preference trials of six different foods presented individual tamarins with each combination of food pairs. All individuals had a transitive food preference hierarchy and each individual had a different preference hierarchy. Correlations between food preference rank and rate of calling were positive for eight of the nine animals, and the overall correlation of food preference with calling rate was significant suggesting that cotton-top tamarins use their calls to communicate honestly about their own food preferences.
There is growing concern that anthropogenic noise could interfere with animal behaviours by masking the perception of acoustic communication signals. To date, however, few experimental studies have tested this general hypothesis. One common source of anthropogenic noise is the sound of roadway traffic. We tested the hypothesis that road traffic noise can mask a female's perception of male signals in the grey treefrog, Hyla chrysoscelis, by comparing the effects of traffic noise and the background noise of a breeding chorus on female responses to advertisement calls. In this species, advertisement calls are necessary and sufficient to attract females for breeding. Using a phonotaxis assay, we presented females with an advertisement call broadcast at one of nine signal levels (37–85 dB, 6-dB steps) in one of three masking conditions: (1) no masking noise, (2) a noise simulating a moderately dense breeding chorus, or (3) a noise modelled after road traffic noise recorded in two wetlands near major roads. Females showed similar increases in response latency and decreases in orientation towards the target signal in the presence of both the chorus noise and the traffic noise maskers. Moreover, response thresholds were elevated by about 20–25 dB in the presence of both noise maskers compared to the unmasked condition. Our results suggest that realistic levels of traffic noise could place constraints on the active space of the acoustic signals of some animals.
When animals colonize cities they often have to adapt their physiology, life history and behaviour to the novel environment. Songbirds rely on acoustic communication for reproduction, and recent studies indicate that songs vary between urban and nonurban habitats. In cities, birds sing louder or use higher frequencies compared to their conspecifics in forests. These habitat-specific differences in song have been interpreted as an adaptation of the city birds to mitigate acoustic masking by low-frequency traffic noise. We compared the songs of blackbirds, Turdus merula, from the city centre of Vienna and the Vienna Woods and found that forest birds sang at lower frequencies and with longer intervals between songs. This difference in song pitch might reflect an adaptation to urban ambient noise. However, the song divergence could also be the result of more intense vocal interaction in the more densely populated city areas or a side-effect of physiological adaptation to urban habitats. We emphasize the need for experimental studies in blackbirds, but also in other species, to clarify a possible causal link between urban acoustics and song characteristics of city birds.