02298nas 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 a

Describing 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 a

Bats 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/S1470160X1930843X03724nas a2200289 4500008004100000245006500041210006500106260001600171300001400187490000700201520284800208653002103056653001703077653002303094653002203117653001803139653001603157653003203173653004103205100002303246700001603269700002403285700002503309700002203334700002503356856005303381 2013 eng d00aEstimating animal population density using passive acoustics0 aEstimating animal population density using passive acoustics cJan-05-2013 a287 - 3090 v883 a

Reliable 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 a

1. 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.

10aanthropogenic impacts10aanti-poaching10abioacoustics10acryptic species10adensity estimate10alaw enforcement monitoring10aLoxodonta cyclotis10apassive acoustic monitoring10asignal detection10aSMART1 aWrege, Peter, H.1 aRowland, Elizabeth, D.1 aKeen, Sara1 aShiu, Yu uhttp://doi.wiley.com/10.1111/2041-210X.12730