02751nas a2200277 4500008004100000245007300041210006900114490000800183520187700191653002702068653003002095653002402125653002102149653003202170653002102202100003202223700002502255700001802280700002002298700002202318700002602340700001902366700001902385700002302404856004602427 2022 eng d00aThe effect of inundation on frog communities and chorusing behaviour0 aeffect of inundation on frog communities and chorusing behaviour0 v1453 a
Globally, river regulation has degraded wetlands, including parts of the Murray-Darling Basin (MDB), an ecologically significant basin in Australia. Frogs in a floodplain environment largely depend on habitats created by river flows, but little is known about how frogs in the northern MDB are impacted by river regulation. We tested how wetland inundation affected frogs in a catchment of the northern MDB. We surveyed frogs between 2015 and 2019 to determine long-term changes in the community composition associated with wetland inundation from river flows. Additionally, we recorded nightly soundscapes for four days before and after the arrival of river flows between 2019 and 2020. The abundance and richness of frog species increased during larger inundation events leading to altered community composition (beta diversity). Warmer temperatures increased frog species richness, and frog community dominance decreased with decreasing vegetation cover (i.e., the relative abundance became more even across species). The abundance of five frog species (Limnodynastes tasmaniensis, Limnodynastes fletcheri, Crinia parinsignifera, Litoria peronii, and Litoria latopalmata) was higher in response to increased inundation extent. The total species richness of chorusing frogs increased after the arrival of river flows; six species chorused over the four nights preceding flow, whereas eight species chorused following the flow arrival, but the responses varied among species and sites. Frog species richness increased at three sites after flows, but not at others. After inundation, the choruses of Limnodynastes tasmaniensis increased whereas Limnodynastes fletcheri decreased. Our findings indicate that wetland inundation is beneficial for frog communities and suggest that chorusing behaviour varied in response to river flows inundating floodplain wetlands.
10aEnvironmental watering10aFalse-colour Spectrograms10aFloodplain wetlands10aLong term survey10apassive acoustic monitoring10aRiver regulation1 aSarke, Mohammad, Abdur Razz1 aMcKnight, Donald, T.1 aRyder, Darren1 aWalcott, Amelia1 aOcock, Joanne, F.1 aSpencer, Jennifer, A.1 aPreston, David1 aBrodie, Sheryn1 aBower, Deborah, S. uhttps://bio.acousti.ca/zh-hans/node/5848502013nas a2200181 4500008004100000245008500041210006900126490000600195520141700201653002601618653002401644653003201668653002201700653001701722100002301739700002301762856004601785 2022 eng d00aMid-frequency song and low-frequency calls of sei whales in the Falkland Islands0 aMidfrequency song and lowfrequency calls of sei whales in the Fa0 v93 aAlthough sei whales (Balaenoptera borealis) are distributed throughout the globe, their behaviour and vocal repertoire are poorly described. We used passive acoustic monitoring to describe the vocal behaviour of sei whales in the Falkland Islands, between December 2018 and April 2019. We isolated more than 2000 low-frequency calls for manual classification, of which 510 calls with high signal-to-noise ratio were quantitatively measured. Five categories of stereotyped call types in the 15–230 Hz range were described, some with multiple subcategories. These included some similar to previously described calls (e.g. downsweeps), but others that were novel in acoustic structure and frequency band. In the mid-frequency range, we documented a highly stereotyped, hierarchically structured and rhythmically repetitive song display. Songs were arranged in phrases with a structure composed of repetitive sub- phrases, and a diverse variety of sounds in the 1–5 kHz range. Singing commenced in late February, despite the presence of whales and calls since early December, and continued through April. These acoustic properties and behavioural characteristics indicate that this is likely a male breeding display similar to songs and singing of other balaenopterids. This is the first detailed description of a song display for sei whales, highlighting the importance of the Falkland Islands.
10aBalaenoptera borealis10alow-frequency calls10apassive acoustic monitoring10asinging behaviour10asong display1 aCerchio, Salvatore1 aWeir, Caroline, R. uhttps://bio.acousti.ca/zh-hans/node/5848402298nas a2200253 4500008004100000245011100041210006900152520150700221653001701728653001501745653001701760653001201777653001901789653001601808653003201824653001601856653001801872100002001890700001901910700002301929700002601952700002201978856004402000 2022 eng d00aTemporal occurrence of three blue whale populations in New Zealand waters from passive acoustic monitoring0 aTemporal occurrence of three blue whale populations in New Zeala3 aDescribing spatial and temporal occurrence patterns of wild animal populations is important for understanding their evolutionary trajectories, population connectivity, and ecological niche specialization, with relevance for effective management. Throughout the world, blue whales produce stereotyped songs that enable identification of separate acoustic populations. We harnessed continuous acoustic recordings from five hydrophones deployed in the South Taranaki Bight (STB) region of Aotearoa New Zealand from January 2016 to February 2018. We examined hourly presence of songs from three different blue whale populations to investigate their contrasting ecological use of New Zealand waters. The New Zealand song was detected year-round with a seasonal cycle in intensity (peak February–July), demonstrating the importance of the region to the New Zealand population as both a foraging ground and potential breeding area. The Antarctic song was present in two distinct peaks each year (June–July; September–October) and predominantly at the offshore recording locations, suggesting northbound and southbound migration between feeding and wintering grounds. The Australian song was only detected during a 10-day period in January 2017, implying a rare vagrant occurrence. We therefore infer that the STB region is the primary niche of the New Zealand population, a migratory corridor for the Antarctic population, and outside the typical range of the Australian population.
10abioacoustics10ablue whale10adistribution10aecology10amarine mammals10aNew Zealand10apassive acoustic monitoring10apopulations10avocalizations1 aBarlow, Dawn, R1 aKlinck, Holger1 aPonirakis, Dimitri1 aColberg, Mattea, Holt1 aTorres, Leigh, G. uhttps://doi.org/10.1093/jmammal/gyac10602987nas a2200229 4500008004100000245013700041210006900178520218000247653001902427653001702446653001502463653001902478653002602497653003202523100002402555700002802579700002002607700001502627700002002642700002802662856006702690 2020 eng d00aEcological indices in long-term acoustic bat surveys for assessing and monitoring bats' responses to climatic and land-cover changes0 aEcological indices in longterm acoustic bat surveys for assessin3 aBats are well known for playing an important role in several ecosystem services such as arthropod population control, insect pest suppression in agricultural systems and vector disease control, but also for acting as ecological indicators. Their population dynamics are strongly linked to environmental variations and, in some cases, reflect the health status of ecosystems. Hence, some species have an excellent potential as ecological indicators due to their sensitivity to ecosystem changes. Despite the general decrease of many bat populations worldwide and the recent upsurge in the use of autonomous acoustic detectors, the acoustic monitoring of bat assemblages is still an emerging field in bat research and conservation. Probably due to a general lack of methodological standards and the lack of common ecological indices, few long-term bat acoustic monitoring programs are currently active and data is rarely shared and compared between regions. In this study we propose and adapt a set of different ecological indices that can be used in acoustic surveys designed to detect changes in bat diversity, activity and assemblage composition, all of which can be linked to species’ climatic and habitat-related preferences. Using a dataset collected during three years of bat monitoring in Catalonia (NE Iberian Peninsula), we used three traditional indices (richness, activity and Shannon diversity) and developed four new ecological indices (Community Thermal Index, Community Precipitation Index, Community Openness Index and Community Specialization Index) that enabled us to study bat communities and compare them at different spatial and temporal scales. Here, we demonstrate the applicability of these indices in bat monitoring programs. We also provide a consistent tool for generating easy-to-interpret ecological indices when monitoring the short- and long-term responses of bats under the current scenario of global change. Using standardized protocols and robust ecological indices enables studies and datasets to be compared, which in turn promotes the development of proper management and conservation measures via international cooperation.
10aBat monitoring10abioacoustics10aChiroptera10aClimate change10aEcological indicators10apassive acoustic monitoring1 aTuneu-Corral, Carme1 aPuig-Montserrat, Xavier1 aFlaquer, Carles1 aMas, Maria1 aBudinski, Ivana1 aLópez-Baucells, Adrià uhttps://linkinghub.elsevier.com/retrieve/pii/S1470160X1930843X02251nas a2200313 4500008004100000245009200041210006900133520124800202653002801450653001701478653003201495653001501527100002701542700002801569700001801597700002301615700003001638700002201668700002101690700002801711700002201739700002101761700001701782700002801799700002601827700002201853700001901875856004301894 2018 eng d00aIt's time to listen: there is much to be learned from the sounds of tropical ecosystems0 aIts time to listen there is much to be learned from the sounds o3 aKnowledge that can be gained from acoustic data collection in tropical ecosystems is low-hanging fruit. There is every reason to recordand with every day, there are fewer excuses not to do it. In recent years, the cost of acoustic recorders has decreased substantially(some can be purchased for under US$50, e.g., Hillet al.2018) and the technology needed to store and analyze acoustic data is contin-uously improving (e.g., Corrada Bravoet al.2017, Xieet al.2017). Soundscape recordings provide a permanent record of a site at agiven time and contain a wealth of invaluable and irreplaceable information. Although challenges remain, failure to collect acoustic datanow in tropical ecosystems would represent a failure to future generations of tropical researchers and the citizens that benefit fromecological research. In this commentary, we (1) argue for the need to increase acoustic monitoring in tropical systems; (2) describe thetypes of research questions and conservation issues that can be addressed with passive acoustic monitoring (PAM) using both short-and long-term data in terrestrial and freshwater habitats; and (3) present an initial plan for establishing a global repository of tropical recordings.
10aconservation technology10aecoacoustics10apassive acoustic monitoring10aSoundscape1 aDeichmann, Jessica, L.1 aAcevedo-Charry, Orlando1 aBarclay, Leah1 aBurivalova, Zuzana1 aCampos-Cerqueira, Marconi1 ad'Horta, Fernando1 aGame, Edward, T.1 aGottesman, Benjamin, L.1 aHart, Patrick, J.1 aKalan, Ammie, K.1 aLinke, Simon1 aNascimento, Leandro, Do1 aPijanowski, Bryan, C.1 aStaaterman, Erica1 aAide, Mitchell uhttp://doi.wiley.com/10.1111/btp.1259302431nas a2200205 4500008004100000245009800041210006900139520172100208653002101929653001401950653002601964653003301990653003202023653002202055100002002077700002402097700002502121700001802146856006102164 2019 eng d00aUsing acoustic metrics to characterize underwater acoustic biodiversity in the Southern Ocean0 aUsing acoustic metrics to characterize underwater acoustic biodi3 aAcoustic metrics (AM) assist our interpretation of acoustic environments by aggregating a complex signal into a unique number. Numerous AM have been developed for terrestrial ecosystems, with applications ranging from rapid biodiversity assessments to characterizing habitat quality. However, there has been comparatively little research aimed at understanding how these metrics perform to characterize the acoustic features of marine habitats and their relation with ecosystem biodiversity. Our objectives were to 1) assess whether AM are able to capture the spectral and temporal differences between two distinct Antarctic marine acoustic environment types (i.e., pelagic vs. on‐shelf), 2) evaluate the performance of a combination of AM compared to the signal full frequency spectrum to characterize marine mammals acoustic assemblages (i.e., species richness–SR–and species identity) and 3) estimate the contribution of SR to the local marine acoustic heterogeneity measured by single AM. We used 23 different AM to develop a supervised machine learning approach to discriminate between acoustic environments. AM performance was similar to the full spectrum, achieving correct classifications for SR levels of 58% and 92% for pelagic and on‐shelf sites respectively and > 88% for species identities. Our analyses show that a combination of AM is a promising approach to characterize marine acoustic communities. It allows an intuitive ecological interpretation of passive acoustic data, which in the light of ongoing environmental changes, supports the holistic approach needed to detect and understand trends in species diversity, acoustic communities and underwater habitat quality.
10aAcoustic metrics10aAntarctic10acommunity composition10amarine acoustic environments10apassive acoustic monitoring10aspecies diversity1 aRoca, Irene, T.1 aVan Opzeeland, Ilse1 aPettorelli, Nathalie1 aQuick, Nicola uhttps://onlinelibrary.wiley.com/doi/abs/10.1002/rse2.12902435nas a2200205 4500008004100000245009800041210006900139520172500208653002101933653001401954653002601968653003301994653003202027653002202059100002002081700002402101700002502125700001802150856006102168 2019 eng d00aUsing acoustic metrics to characterize underwater acoustic biodiversity in the Southern Ocean0 aUsing acoustic metrics to characterize underwater acoustic biodi3 aAcoustic metrics (AM) assist our interpretation of acoustic environments by aggregating a complex signal into a unique number. Numerous AM have been developed for terrestrial ecosystems, with applications ranging from rapid bio- diversity assessments to characterizing habitat quality. However, there has been comparatively little research aimed at understanding how these metrics perform to characterize the acoustic features of marine habitats and their relation with ecosystem biodiversity. Our objectives were to 1) assess whether AM are able to capture the spectral and temporal differences between two distinct Antarctic marine acoustic environment types (i.e., pelagic vs. on-shelf), 2) evaluate the performance of a combination of AM compared to the signal full frequency spectrum to characterize marine mammals acoustic assemblages (i.e., species richness–SR–and species identity) and 3) estimate the contribution of SR to the local marine acoustic heterogeneity measured by single AM. We used 23 differ- ent AM to develop a supervised machine learning approach to discriminate between acoustic environments. AM performance was similar to the full spec- trum, achieving correct classifications for SR levels of 58% and 92% for pelagic and on-shelf sites respectively and > 88% for species identities. Our analyses show that a combination of AM is a promising approach to characterize marine acoustic communities. It allows an intuitive ecological interpretation of passive acoustic data, which in the light of ongoing environmental changes, supports the holistic approach needed to detect and understand trends in species diver- sity, acoustic communities and underwater habitat quality.
10aAcoustic metrics10aAntarctic10acommunity composition10amarine acoustic environments10apassive acoustic monitoring10aspecies diversity1 aRoca, Irene, T.1 aVan Opzeeland, Ilse1 aPettorelli, Nathalie1 aQuick, Nicola uhttps://onlinelibrary.wiley.com/doi/abs/10.1002/rse2.12903293nas a2200301 4500008004100000022001300041245010500054210006900159260001600228300001100244490000800255520235700263653001602620653002402636653003202660653002002692653003202712653002002744100001702764700001902781700002702800700002202827700002502849700002202874700002502896700002402921856004602945 2019 eng d a1470160X00aAn optimised passive acoustic sampling scheme to discriminate among coral reefs’ ecological states0 aoptimised passive acoustic sampling scheme to discriminate among cJan-12-2019 a1056270 v1073 aIn the present era of rapid global change, innovative monitoring methods can greatly enhance our ability to detect ecological disturbances and prioritise conservation areas in a timely and cost-effective manner. While Passive Acoustic Monitoring (PAM) has recently emerged as a promising tool for monitoring ecological states in marine environments, the specifics of how to apply this method remains poorly defined. In this study we examined how different combinations of sampling settings (frequency bandwidth, time of sampling (day/night), and sample duration) influenced the ability of two acoustic indices, the Sound Pressure Level (SPL) and the Acoustic Complexity Index (ACI), to discriminate different ecological states (ecostates) of coral reefs. We applied an iterative approach to select the most efficient and consistent combinations of sampling settings to use for these two acoustic indices, depending on the stability of their discriminating power across different time scales (successive days, moon phases, and seasons), and the minimum sampling effort required for reliable ecostate assessment. The ability of SPL and ACI to discriminate ecostate-specific soundscapes was more stable and required less sampling effort at nighttime. For indices calculated in the higher frequency band (>2 kHz), very short recording times (≤20 min divided into 5 s samples) were sufficient to discriminate ecostates, whereas longer recording times (≥200 min divided into 5 min samples) were necessary when using indices calculated in the lower frequency bands (<1 kHz). An optimised sampling scheme, i.e. the group of the five best combinations of settings to discern among coral reef ecostates, was determined at Reunion Island, Indian Ocean, then tested at New Caledonia, Pacific Ocean. Here, the classifications obtained through visual surveys and with the optimised acoustic sampling scheme were congruent. The concordance of our results with visual fish counts confirms the potential of ecoacoustics to rapidly and reliably characterise coral reefs’ ecostate, allowing managers to prioritise conservation areas among numerous sites, and detect ecological changes over time. Our study provides clear guidelines for monitoring soundscapes by means of the ecoacoustic indices most widely used in the marine realm.
10aCoral reefs10aEcoacoustic indices10aEcological state (ecostate)10aMarine habitats10apassive acoustic monitoring10aSampling scheme1 aElise, Simon1 aBailly, Arthur1 aUrbina-Barreto, Isabel1 aMou-Tham, Gérard1 aChiroleu, Frédéric1 aVigliola, Laurent1 aRobbins, William, D.1 aBruggemann, Henrich uhttps://bio.acousti.ca/zh-hans/node/5735102843nas a2200313 4500008004100000022001300041245009400054210006900148260001600217300001100233490000800244520191200252653001702164653001602181653002402197653002802221653003202249653001502281100001702296700002702313700001802340700002402358700001902382700001702401700002002418700002102438700002402459856004602483 2019 eng d a1470160X00aAssessing key ecosystem functions through soundscapes: A new perspective from coral reefs0 aAssessing key ecosystem functions through soundscapes A new pers cJan-12-2019 a1056230 v1073 aThe functioning of tropical coral reefs is imperilled by climate change, overfishing, and decreasing water quality. Maintaining their capacity to provide goods and services will critically depend on our ability to monitor their functioning at appropriate spatial and temporal scales. Given the constraints of traditional methods to respond to those needs, the potential of complementary tools such as Passive Acoustic Monitoring (PAM) is emerging. Coral reef soundscapes (i.e. ambient sound) encompass sounds produced by numerous organisms. Soundscape characteristics quantified by ecoacoustic indices have been found to reflect general ecosystem properties, such as diversity and abundance of fishes, and coral cover. The present study tested, on the virtually pristine coral reefs around Europa Island, South-West Indian Ocean, the capacity of acoustic indices to assess key ecosystem functions. Soundscapes were recorded during 2 h, and ecosystem functions were evaluated using video footage of the fish assemblages and underwater photogrammetry of the benthic landscapes. We found significant and strong correlations between six ecoacoustic indices and six key ecosystem functions, including habitat features and fish assemblage characteristics. The six ecoacoustic indices were representative of several combinations of frequency, amplitude and time analysis domains, highlighting the diversity of the functional information conveyed by soundscapes. Our findings reveal that a 2 h daytime recording on a coral reef could provide sufficient acoustic information to characterise major ecosystem functions of a site. This should facilitate the detection of functional disturbances at temporal and spatial scales adapted to the rapidity of upcoming climate changes. Our results also highlight the potential of ecoacoustics to bring novel and relevant insights in the functioning of ecosystems.
10aconservation10aCoral reefs10aEcoacoustic indices10aKey ecosystem functions10apassive acoustic monitoring10aSoundscape1 aElise, Simon1 aUrbina-Barreto, Isabel1 aPinel, Romain1 aMahamadaly, Vincent1 aBureau, Sophie1 aPenin, Lucie1 aAdjeroud, Mehdi1 aKulbicki, Michel1 aBruggemann, Henrich uhttps://bio.acousti.ca/zh-hans/node/5734503492nas a2200253 4500008004100000022001300041245013000054210006900184260001600253300001400269490000700283520249700290653001802787653002702805653002502832653001902857653003202876100001802908700002202926700001502948700002202963700002002985856023303005 2019 eng d a1470160X00aAn evaluation of the efficiency of passive acoustic monitoring in detecting deer and primates in comparison with camera traps0 aevaluation of the efficiency of passive acoustic monitoring in d cJan-03-2019 a753 - 7620 v983 aIn recent years, camera traps have rapidly become popular for the large-scale monitoring of wildlife distributionand population; however, we should not ignore the uncertainty regarding the reliability of camera-basedmonitoring by inexperienced data gatherers. This study introduces passive acoustic monitoring (PAM) as aneasier technique for monitoring terrestrial mammals that uses the sound cues that they produce. To validate theefficacy of PAM, we quantitatively compared the detection areas and rates between sound cues (from PAM) andvisual cues (from camera traps) of two mammals—the sika deerCervus nipponand the Japanese macaqueMacacafuscata—across seven study sites in eastern Japan with different population densities. To collect sound cues, weset up multiple autonomous recording units at the sites and continuously recorded ambient sounds, following apre-determined schedule. The total recording time reached 9081 h for deer and 8235 h for macaques. We thenbuilt sound recognizers to automatically detect eight target call types from the recorded data. To collect visualcues, we also set multiple camera traps at the same sites and for the same observation periods. The keyfindingswere as follows: (1) the fully automated procedures that only used the recognizers to detect sound cues producednumerous false positive detections when the call type possessed vocal plasticity and variations; (2) the semi-automated procedures, which included an additional step to validate the automated detections by manualscreening, exhibited a great improvement in the detectability and recall rates of the half of the target calls,reaching > 0.70; (3) when using the semi-automated procedures, the frequency of deer and macaque detectionsper trap-day derived from the sound cues were in most cases approximately dozens of times and several times,respectively, higher than that derived from the visual cues; (4) the main advantage of PAM may be its superiordetection areas, which were 100–7000 times wider than those of camera traps; and (5) the current success of therecognition of different call types of each species could broaden the use of PAM, which is not possible for cameratraps. PAM could provide socio-behavioral data (i.e., the frequencies and types of inter-individual vocal com-munications) that could help understand the status of population dynamics and the group compositions, inaddition to information related to the presence or absence of species.
10aCervus nippon10aEcoacoustic monitoring10aLag-phase management10aMacaca fuscata10apassive acoustic monitoring1 aEnari, Hiroto1 aEnari, Haruka, S.1 aOkuda, Kei1 aMaruyama, Tetsuya1 aOkuda, Kana, N. uhttps://linkinghub.elsevier.com/retrieve/pii/S1470160X18309257https://api.elsevier.com/content/article/PII:S1470160X18309257?httpAccept=text/xmlhttps://api.elsevier.com/content/article/PII:S1470160X18309257?httpAccept=text/plain02322nas a2200217 4500008004100000245013200041210006900173520157600242653002001818653002401838653001301862653001801875653003001893653003201923653002101955100001901976700001901995700002602014700001802040856004602058 2018 eng d00aImplementing conservation measures for the North Atlantic right whale: considering the behavioral ontogeny of mother-calf pairs0 aImplementing conservation measures for the North Atlantic right 3 aUnderstanding the behavioral ecology of a species is fundamental to effective conservation and management efforts. This study quantifies the behavioral ontogeny of North Atlantic right whale mother‐calf pairs from birth to weaning spanning three critical habitat areas off the eastern coast of the United States and Canada. Data from 55 focal follows of 34 mother‐calf pairs were collected from 2011 to 2015. Resting behaviors dominated the activity budgets for both mother and calf during the first 5 months, putting them at increased risk of vessel collisions. There was an increase in the proportion of active behaviors (travel, foraging, social activity) in both mother and calf as the calf matured. Importantly, the type of active behaviors, in particular surface skim feeding and surface active social behavior, meant that the risk of vessel collision to the pair did not decrease as the calf matured. Mother‐calf right whale pairs showed very low calling rates on the calving grounds, suggesting that passive acoustic monitoring may not be an effective mitigation tool during the early months. However, calling rates increase once the pair leave the calving areas with both calf age and activity levels increasing, at which point passive acoustic monitoring becomes valuable. Protective measures need to take these rapid developmental changes throughout calf growth into account to improve the efficacy of protection measures for the endangered North Atlantic right whale and other species where behavioral ecology changes rapidly during maturation.
10aactivity budget10abehavioral ontogeny10acallrate10amarine mammal10aNorthAtlantic right whale10apassive acoustic monitoring10avessel collision1 aCusano, D., A.1 aConger, L., A.1 aVan Parijs, Sofie, M.1 aParks, S., E. uhttps://bio.acousti.ca/zh-hans/node/5325402615nas a2200301 4500008004100000245008200041210006900123260001600192300000900208490000600217520172400223653001501947653001201962653002801974653001002002653002202012653001202034653003202046653002202078653001502100653002102115100001902136700002902155700003002184700002802214700002702242856004402269 2017 eng d00aSpecies Richness (of Insects) Drives the Use of Acoustic Space in the Tropics0 aSpecies Richness of Insects Drives the Use of Acoustic Space in cJan-11-2017 a10960 v93 aAcoustic ecology, or ecoacoustics, is a growing field that uses sound as a tool to evaluate animal communities. In this manuscript, we evaluate recordings from eight tropical forest sites that vary in species richness, from a relatively low diversity Caribbean forest to a megadiverse Amazonian forest, with the goal of understanding the relationship between acoustic space use (ASU) and species diversity across different taxonomic groups. For each site, we determined the acoustic morphospecies richness and composition of the biophony, and we used a global biodiversity dataset to estimate the regional richness of birds. Here, we demonstrate how detailed information on activity patterns of the acoustic community (<22 kHz) can easily be visualized and ASU determined by aggregating recordings collected over relatively short periods (4–13 days). We show a strong positive relationship between ASU and regional and acoustic morphospecies richness. Premontane forest sites had the highest ASU and the highest species richness, while dry forest and montane sites had lower ASU and lower species richness. Furthermore, we show that insect richness was the best predictor of variation in total ASU, and that insect richness was proportionally greater at high-diversity sites. In addition, insects used a broad range of frequencies, including high frequencies (>8000 Hz), which contributed to greater ASU. This novel approach for analyzing the presence and acoustic activity of multiple taxonomic groups contributes to our understanding of ecological community dynamics and provides a useful tool for monitoring species in the context of restoration ecology, climate change and conservation biology.
10aamphibians10aARBIMON10aBiodiversity monitoring10abirds10acommunity ecology10ainsects10apassive acoustic monitoring10arapid assessments10aSoundscape10aspecies richness1 aAide, Mitchell1 aHernández-Serna, Andres1 aCampos-Cerqueira, Marconi1 aAcevedo-Charry, Orlando1 aDeichmann, Jessica, L. uhttp://www.mdpi.com/2072-4292/9/11/109602236nas a2200253 4500008004100000245017200041210006900213260001600282300001400298490000700312520141300319653002101732653001001753653003201763653001801795653001301813100002101826700002001847700001601867700001501883700002201898700001901920856004301939 2018 eng d00aDescription and classification of Indian Ocean humpback dolphin ( Sousa plumbea ) whistles recorded off the Sindhudurg coast of Maharashtra, India0 aDescription and classification of Indian Ocean humpback dolphin cJan-07-2018 a755 - 7760 v343 aThe Indian Ocean humpback dolphin (Sousa plumbea), a common cetacean species in India, has a diverse vocal repertoire, which to date has not been described in detail. This study focused on analyzing their whistle vocalizations. Humpback dolphins were recorded off the Sindhudurg coast of Maharashtra, India, and 2,260 whistles were analyzed for their acoustic characteristics. Whistles spanned a wide frequency range between 2.3 kHz and 33.0 kHz, with durations ranging from 0.01 s to 1.60 s. Whistles were categorized into seven contour classes based on their qualitative prop- erties. A classification and regression tree (CART) analysis was used to quantify vari- ability between the seven contour classes using the measured acoustic features. Based on the CART analysis, frequency gradient, minimum slope, maximum slope, begin- ning and ending slope accounted for most variability between whistle types. CART resulted in an overall classification accuracy of 89.5%. This study provides a detailed description of acoustic features and qualitative properties of humpback dolphin whis- tles from the northwestern coast of India. Further comparisons of acoustic data from Sousa populations along the Indian coast are necessary to determine possible geo- graphic variations in whistle characteristics and whether the variations are driven by environmental or genetic factors or a combination of both.
10ahumpback dolphin10aIndia10apassive acoustic monitoring10aSousa plumbea10awhistles1 aBopardikar, Isha1 aSutaria, Dipani1 aSule, Mihir1 aJog, Ketki1 aPatankar, Vardhan1 aKlinck, Holger uhttp://doi.wiley.com/10.1111/mms.v34.302806nas a2200181 4500008004100000245013700041210006900178260001600247300001400263490000800277520219800285653001402483653001402497653003202511653001702543100001902560856004502579 2018 eng d00aTemporal patterns of chimpanzee loud calls in the Issa Valley, Tanzania: Evidence of nocturnal acoustic behavior in wild chimpanzees0 aTemporal patterns of chimpanzee loud calls in the Issa Valley Ta cJan-07-2018 a530 - 5400 v1663 aObjectives: Much is known about chimpanzee diurnal call patterns, but far less about night-time vocal behavior. I deployed a passive acoustic monitoring (PAM) system to assess 24-hr temporal acoustic activity of wild, unhabituated chimpanzees that live in a woodland mosaic habitat similar to hominin landscapes from the Plio-Pleistocene. A primary aim was to apply findings to our broader understanding to chimpanzee 24-hr activity patterns, and what implications this may have for reconstructing hominin adaptations to similarly hot, dry, and open landscapes. I also tested whether chimpanzees conform to the acoustic adaptation hypothesis, and produce loud calls dur- ing periods of optimal sound transmission.
Methods: Nine custom-made solar-powered acoustic transmission units (SPATUs) recorded con- tinuously for 250 days over 11 months in the Issa Valley, western Tanzania. I complemented acoustic data with environmental data from weather stations as well as behavioral data collected on chimpanzee nest group sizes to assess the relationship between party size and calling.
Results: Chimpanzees called at all hours of the day and night in both wet and dry seasons, and night and day calls exhibited parallel rates/month, although twilight calls were produced signifi- cantly more in the dry, compared to the wet season. Calls were more likely during warmer temperatures and lower humidity. Call rate was positively associated with (nest) party size and counter-calls exhibited no temporal variation in their origins (similar vs. adjacent valleys).
Conclusions: Chimpanzees were acoustically active throughout the 24-hr cycle, although at low rates compared to diurnal activity, revealing night-time activity in an ape otherwise described as diurnal. Chimpanzee loud calls partially, and weakly, conformed to the acoustic adaptation hypoth- esis and likely responded to social, rather than environmental factors. Call rates accurately reflect grouping patterns and PAM is demonstrated to be an effective means of remotely assessing activ- ity, especially at times and from places that are difficult to access for researchers.
Passive acoustic monitoring is a potentially valuable tool in biodiversity hotspots, where surveying can occur at large scales across land conversion types. However, in order to extract meaningful biological information from resulting enormous acoustic datasets, rapid analytical techniques are required. Here we tested the ability of a suite of acoustic indices to predict avian bioacoustic activity in recordings collected from the Western Ghats, a biodiversity hotspot in southwestern India. Recordings were collected at 28 sites in a range of land-use types, from tea, coffee, and cardamom plantations to remnant forest stands. Using 36 acoustic indices we developed random forest models to predict the richness, diversity, and total number of avian vocalizations observed in recordings. We found limited evidence that acoustic indices predict the richness and total number of avian species vocalizations in recordings (R2 < 0.51). However, acoustic indices predicted the diversity of avian species vocalizations with high accuracy (R2 = 0.64, mean squared error = 0.17). Index models predicted low and high diversity best, with the highest residuals for medium diversity values and when continuous biological sounds were present (e.g., insect sounds >8 sec). The acoustic complexity index and roughness index were the most important for predicting avian vocal diversity. Avian species richness was generally higher among shade-grown crops than in the open tea plantation. Our results suggest that models incorporating acoustic indices can accurately predict low and high avian species diversity from acoustic recordings. Thus, ecoacoustics could be an important contributor to biodiversity monitoring across landscapes like the Western Ghats, which are a complex mosaic of different land-use types and face continued changes in the future.
10adiversity10alandscape10apassive acoustic monitoring10ashade-grown crop10aspecies richness10aWestern Ghats1 aAgnihotri, Samira1 aRobin, V., V.1 aGoel, Anurag1 aBalakrishnan, Rohini uhttps://www.veruscript.com/journals/journal-of-ecoacoustics/acoustic-diversity-in-an-indian-hotspot/02616nas a2200301 4500008004100000245008200041210006900123260001600192300000900208490000600217520172400223653001501947653001201962653002801974653001002002653002202012653001202034653003202046653002202078653001602100653002102116100001902137700002902156700003002185700002802215700002702243856004402270 2017 eng d00aSpecies Richness (of Insects) Drives the Use of Acoustic Space in the Tropics0 aSpecies Richness of Insects Drives the Use of Acoustic Space in cJan-11-2017 a10960 v93 aAcoustic ecology, or ecoacoustics, is a growing field that uses sound as a tool to evaluate animal communities. In this manuscript, we evaluate recordings from eight tropical forest sites that vary in species richness, from a relatively low diversity Caribbean forest to a megadiverse Amazonian forest, with the goal of understanding the relationship between acoustic space use (ASU) and species diversity across different taxonomic groups. For each site, we determined the acoustic morphospecies richness and composition of the biophony, and we used a global biodiversity dataset to estimate the regional richness of birds. Here, we demonstrate how detailed information on activity patterns of the acoustic community (<22 kHz) can easily be visualized and ASU determined by aggregating recordings collected over relatively short periods (4–13 days). We show a strong positive relationship between ASU and regional and acoustic morphospecies richness. Premontane forest sites had the highest ASU and the highest species richness, while dry forest and montane sites had lower ASU and lower species richness. Furthermore, we show that insect richness was the best predictor of variation in total ASU, and that insect richness was proportionally greater at high-diversity sites. In addition, insects used a broad range of frequencies, including high frequencies (>8000 Hz), which contributed to greater ASU. This novel approach for analyzing the presence and acoustic activity of multiple taxonomic groups contributes to our understanding of ecological community dynamics and provides a useful tool for monitoring species in the context of restoration ecology, climate change and conservation biology.
10aamphibians10aARBIMON10aBiodiversity monitoring10abirds10acommunity ecology10ainsects10apassive acoustic monitoring10arapid assessments10asoundscapes10aspecies richness1 aAide, Mitchell1 aHernández-Serna, Andres1 aCampos-Cerqueira, Marconi1 aAcevedo-Charry, Orlando1 aDeichmann, Jessica, L. uhttp://www.mdpi.com/2072-4292/9/11/109602310nas a2200217 4500008004100000022001400041245009700055210006900152260001600221490000700237520161500244653002101859653002801880653002501908653003201933653001701965653002401982100002102006700002002027856004502047 2017 eng d a1712-656800aAutonomous recording units in avian ecological research: current use and future applications0 aAutonomous recording units in avian ecological research current cJan-01-20170 v123 aAcoustic surveys are a widely used sampling tool in ecological research and monitoring. They are used to monitor populations and ecosystems and to study various aspects of animal behavior. Autonomous recording units (ARUs) can record sound in most environments and are increasingly used by researchers to conduct acoustic surveys for birds. In this review, we summarize the use of ARUs in avian ecological research and synthesize current knowledge of the benefits and drawbacks of this technology. ARUs enable researchers to do more repeat visits with less time spent in the field, with the added benefits of a permanent record of the data collected and reduced observer bias. They are useful in remote locations and for targeting rare species. ARUs are mostly comparable to human observers in terms of species richness, but in some cases, they detect fewer species and at shorter distances. Drawbacks of ARUs include the cost of equipment, storage of recordings, loss of data if units fail, and potential sampling trade-offs in spatial vs. temporal coverage. ARUs generate large data sets of audio recordings, but advances in automated species recognition and acoustic processing techniques are contributing to make the processing time manageable. Future applications of ARUs include biodiversity monitoring and studying habitat use, animal movement, and various behavioral ecology questions based on vocalization activity. ARUs have the potential to make significant advances in avian ecological research and to be used in more innovative ways than simply as a substitute for a human observer in the field. 10aacoustic surveys10aBiodiversity monitoring10anoninvasive sampling10apassive acoustic monitoring10apoint counts10avocal communication1 aShonfield, Julia1 aBayne, Erin, M. uhttp://www.ace-eco.org/vol12/iss1/art14/03724nas a2200289 4500008004100000245006500041210006500106260001600171300001400187490000700201520284800208653002103056653001703077653002303094653002203117653001803139653001603157653003203173653004103205100002303246700001603269700002403285700002503309700002203334700002503356856005303381 2013 eng d00aEstimating animal population density using passive acoustics0 aEstimating animal population density using passive acoustics cJan-05-2013 a287 - 3090 v883 aReliable estimation of the size or density of wild animal populations is very important for effective wildlife management, conservation and ecology. Currently, the most widely used methods for obtaining such estimates involve either sighting animals from transect lines or some form of capture-recapture on marked or uniquely identifiable individuals. However, many species are difficult to sight, and cannot be easily marked or recaptured. Some of these species produce readily identifiable sounds, providing an opportunity to use passive acoustic data to estimate animal density. In addition, even for species for which other visually based methods are feasible, passive acoustic methods offer the potential for greater detection ranges in some environments (e.g. underwater or in dense forest), and hence potentially better precision. Automated data collection means that surveys can take place at times and in places where it would be too expensive or dangerous to send human observers.
Here, we present an overview of animal density estimation using passive acoustic data, a relatively new and fast-developing field. We review the types of data and methodological approaches currently available to researchers and we provide a framework for acoustics-based density estimation, illustrated with examples from real-world case studies. We mention moving sensor platforms (e.g. towed acoustics), but then focus on methods involving sensors at fixed locations, particularly hydrophones to survey marine mammals, as acoustic-based density estimation research to date has been concentrated in this area. Primary among these are methods based on distance sampling and spatially explicit capture-recapture. The methods are also applicable to other aquatic and terrestrial sound-producing taxa.
We conclude that, despite being in its infancy, density estimation based on passive acoustic data likely will become an important method for surveying a number of diverse taxa, such as sea mammals, fish, birds, amphibians, and insects, especially in situations where inferences are required over long periods of time. There is considerable work ahead, with several potentially fruitful research areas, including the development of (i) hardware and software for data acquisition, (ii) efficient, calibrated, automated detection and classification systems, and (iii) statistical approaches optimized for this application. Further, survey design will need to be developed, and research is needed on the acoustic behaviour of target species. Fundamental research on vocalization rates and group sizes, and the relation between these and other factors such as season or behaviour state, is critical. Evaluation of the methods under known density scenarios will be important for empirically validating the approaches presented here.
10aacoustic surveys10abioacoustics10adensity estimation10adistance sampling10afixed sensors10ahydrophones10apassive acoustic monitoring10aspatially explicit capture-recapture1 aMarques, Tiago, A.1 aThomas, Len1 aMartin, Stephen, W.1 aMellinger, David, K.1 aWard, Jessica, A.1 aHarris, Danielle, V. uhttp://doi.wiley.com/10.1111/brv.2013.88.issue-202493nas a2200265 4500008004100000245009300041210006900134260001600203520166400219653002601883653001801909653001701927653002001944653002101964653003101985653002302016653003202039653002102071653001002092100002102102700002702123700001502150700001302165856004902178 2017 eng d00aAcoustic monitoring for conservation in tropical forests: examples from forest elephants0 aAcoustic monitoring for conservation in tropical forests example cJan-01-20173 a1. The accelerating loss of biodiversity worldwide demands effective tools for monitoring animal populations and informing conservation action. In habitats where direct observation is difficult (rain forests, oceans), or for cryptic species (shy, nocturnal), passive acoustic monitoring (PAM) provides cost-effective, unbiased data collec- tion. PAM has broad applicability in terrestrial environments, particularly tropical rain forests.
2. Using examples from studies of forest elephants in Central African rainforest,we show how PAM can be used to investigate cryptic behaviour, mechanisms of communication, estimate population size, quantify threats, and assess the efficacy of conservation strategies. We discuss the methodologies, requirements, and challenges of obtaining these data using acoustics. Where applicable, we compare these methods to more traditional approaches.
3. While PAM methods and associated analysis are maturing rapidly, mechanisms are needed for processing the dense raw data efficiently with standard computer hardware, speeding development of detection algorithms, and harnessing communication networks to move data from the field to research facilities.
4. Passive acoustic monitoring is a viable and cost-effective tool for conservation and should be incorporated in monitoring schemes much more broadly. The capability to quickly assess changes in behaviour, population size, and landscape use, simultaneously over large geographical areas, makes this approach attractive for detecting human-induced impacts and for assessing the success of conservation strategies.