2,076 results on '"passive acoustic monitoring"'
Search Results
2. Ziphius cavirostris presence relative to the vertical and temporal variability of oceanographic conditions in the Southern California Bight.
- Author
-
Schoenbeck, Clara, Solsona-Berga, Alba, Franks, Peter, Frasier, Kaitlin, Trickey, Jennifer, Aguilar, Catalina, Schroeder, Isaac, Širović, Ana, Bograd, Steven, Gopalakrishnan, Ganesh, and Baumann-Pickering, Simone
- Subjects
Cuviers beaked whales ,El Niño ,Southern California Bight ,echolocation clicks ,habitat model ,optimum multiparameter analysis ,passive acoustic monitoring ,water masses - Abstract
The oceanographic conditions of the Southern California Bight (SCB) dictate the distribution and abundance of prey resources and therefore the presence of mobile predators, such as goose-beaked whales (Ziphius cavirostris). Goose-beaked whales are deep-diving odontocetes that spend a majority of their time foraging at depth. Due to their cryptic behavior, little is known about how they respond to seasonal and interannual changes in their environment. This study utilizes passive acoustic data recorded from two sites within the SCB to explore the oceanographic conditions that goose-beaked whales appear to favor. Utilizing optimum multiparameter analysis, modeled temperature and salinity data are used to identify and quantify these source waters: Pacific Subarctic Upper Water (PSUW), Pacific Equatorial Water (PEW), and Eastern North Pacific Central Water (ENPCW). The interannual and seasonal variability in goose-beaked whale presence was related to the variability in El Niño Southern Oscillation events and the fraction and vertical distribution of the three source waters. Goose-beaked whale acoustic presence was highest during the winter and spring and decreased during the late summer and early fall. These seasonal increases occurred at times of increased fractions of PEW in the California Undercurrent and decreased fractions of ENPCW in surface waters. Interannual increases in goose-beaked whale presence occurred during El Niño events. These results establish a baseline understanding of the oceanographic characteristics that correlate with goose-beaked whale presence in the SCB. Furthering our knowledge of this elusive species is key to understanding how anthropogenic activities impact goose-beaked whales.
- Published
- 2024
3. Actively soniferous tropical reef fishes are diverse, vulnerable, and valuable.
- Author
-
Hodson, Emma Jayne, Cox, Kieran, Juanes, Francis, and Looby, Audrey
- Abstract
Active (i.e., intentional) fish sound production provides informative cues for numerous ecological functions, including larval recruitment or reproduction, and can facilitate monitoring and restoration. It is therefore important to have a holistic picture of actively soniferous tropical reef fish diversity, particularly in the face of growing threats such as noise pollution and habitat degradation. This study integrates fish biodiversity and sonifery datasets to assess the prevalence and ecological characteristics of actively soniferous tropical reef fishes. There are 258 known sound‐producing species, which span 46 families, encompass a variety of life‐history (e.g., lifespan) and distribution (e.g., depth) attributes, and include many vulnerable and commercially valuable species. Furthermore, up to 75% of tropical reef fish species are considered likely to produce active sounds. This synthesis should encourage a greater appreciation for active fish sound production in tropical reef environments and advance efforts to incorporate soundscape ecology into management and restoration strategies. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
4. Spatio-temporal patterns of fish acoustic communities in Western Mediterranean coralligenous reefs: optimizing monitoring through recording duration.
- Author
-
La Manna, Gabriella, Moro Merella, Mariangela, Vargiu, Riccardo, Morello, Giuseppe, Sarà, Gianluca, and Ceccherelli, Giulia
- Abstract
In this study, we explored the fish acoustic community at two coralligenous sites in Sardinia (Tavolara and Santa Teresa, western Mediterranean Sea) during the summer 2023. Our goal was to understand spatial and temporal patterns of fish acoustic activity on different temporal scales to offer insights for optimizing acoustic monitoring of this crucial ecosystem. We identified seventeen distinct sound types, revealing a diverse acoustic community. Tavolara had higher acoustic richness and abundance compared to Santa Teresa, which may be attributed to site-specific factors such as habitat structure, species composition, or levels of protection. Temporal analysis revealed clear diel patterns, with certain sounds associated with nocturnal or diurnal periods, reflecting the daily rhythms of different species. The study also examined how recording duration influenced acoustic richness, finding that longer recordings (15 minutes per hour and 15 minutes per hour at night) provided a more comprehensive detection of acoustic activity. Additionally, the number of recording days required to detect species richness varied depending on the site. While extended recordings improve the likelihood of detecting rare or sporadic sounds, they also present challenges in data management and equipment maintenance. The study underscores the importance of carefully planning sampling strategies to optimize acoustic monitoring and ensure effective and sustainable ecological research in coralligenous ecosystems. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
5. The bright side of the moon: vocal activity of the Black-banded owl (Strix huhula huhula) in the Yungas Andean forests of Argentina.
- Author
-
Schaaf, Alejandro A., Akmentins, Mauricio S., and Boullhensen, Martín
- Subjects
- *
NOCTURNAL birds , *LUNAR phases , *RARE birds , *NATURAL history , *PHENOLOGY - Abstract
In recent years, passive acoustic monitoring (PAM) has become one of the main tools for natural history and behavior studies in nocturnal birds. In this study, we explored the Black-banded owl (Strix huhula huhula) vocal activity in the Yungas Andean forests from northwestern Argentina, using one autonomous recording unit from September 2017 to February 2018. We found higher vocal activity on nights with high lunar illumination (76–100%), mainly concentrated during the early night: between 22:00–23:00 h; approximately 1–2 hours after sunset. This study shows the first acoustic phenology pattern of the black-banded owl during a year-round survey with the use of PAM in the Yungas. We highlight the importance of this type of research to gain knowledge on the vocal behavior of Neotropical nocturnal birds. Additionally we highlight the necessity of incorporating PAM, combined with occupation models, to evaluate the population status of threatened nocturnal bird species. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
6. The impact of land use on the acoustic behaviour of cicadas in the Chocó lowland tropical forest of Ecuador.
- Author
-
Gindhart, Rosa, Müller, Jörg, Burivalova, Zuzana, Blüthgen, Nico, Busse, Annika, Hoz, Maria, Donoso, David A., Feldhaar, Heike, Grella, Nina, Kortmann, Mareike, Kriegel, Peter, Kümmet, Sonja, Newell, Felicity L., Püls, Marcel, Schaefer, H. Martin, Seibold, Sebastian, Tremlett, Constance J., and Mitesser, Oliver
- Subjects
- *
FOREST regeneration , *FORESTS & forestry , *SECONDARY forests , *FOREST restoration , *RAIN forests - Abstract
The biodiversity of tropical rainforests is under extreme pressure due to the expansion of agricultural land. Beyond the immediate risk of species extinction, the intensification of land use can alter species' behaviour with consequences for the entire ecosystem. In this study we investigated the impact of land use on the acoustic behaviour of cicadas in the highly biodiverse Ecuadorian Chocó region. We used passive acoustic monitoring (PAM) for the collection of audio data, from which we identified and analysed the sound activity of cicadas and the structure of daily patterns along a chronosequence of forest recovery. At landscape scale we studied the impact of a surrounding either dominated by agricultural land use or forests on the acoustic behaviour of cicadas. Cicada sound activity was significantly lower in active agriculture compared to undisturbed old‐growth forest and increased along the forest recovery gradient. The diurnal pattern changed from simple in active agriculture to more complex and highly synchronized along the recovery gradient towards old‐growth forests. A surrounding dominated by agricultural land use additionally reduced the sound activity of cicadas and simplified the diurnal pattern in old‐growth forests. Taken together, agricultural land use at local and landscape scales affects overall activity, diurnal patterns and synchrony of vocalizing song cicadas. This is a concerning trend considering the direct link between chorusing and fitness for cicadas. However, mature restoration forests embedded in forest dominated landscape surroundings showed restored cicada song behaviours similar to those of old‐growth forests, which underlines the conservation value of advanced secondary forests and the importance to support forest regeneration in the tropics. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
7. Leveraging time-based acoustic patterns for ecosystem analysis.
- Author
-
Castro-Ospina, Andrés E., Rodríguez-Marín, Paula, López, José D., and Martínez-Vargas, Juan D.
- Subjects
- *
CONVOLUTIONAL neural networks , *ANIMAL behavior , *ECOSYSTEMS - Abstract
Passive acoustic monitoring (PAM) is an effective, non-intrusive method for studying ecosystems, but obtaining meaningful ecological information from its large number of audio files is challenging. In this study, we take advantage of the expected animal behavior at different times of the day (e.g., higher acoustic animal activity at dawn) and develop a novel approach to use these time-based patterns. We organize PAM data into 24-hour temporal blocks formed with sound features from a pretrained VGGish network. These features feed a 1D convolutional neural network with a class activation mapping technique that gives interpretability to its outcomes. As a result, these diel-cycle blocks offer more accurate and robust hour-by-hour information than using traditional ecological acoustic indices as features, effectively recognizing key ecosystem patterns. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
8. Anuran occupancy varies with stream characteristics and flow across Arizona wilderness areas.
- Author
-
Huck, Margaret A., Bateman, Heather L., de Albuquerque, Fábio Suzart, and Lewis, Jesse S.
- Subjects
- *
WILDERNESS areas , *BULLFROG , *ARID regions , *WATERSHEDS , *HYLIDAE , *EPHEMERAL streams - Abstract
Riparian ecosystems comprise less than 2% of the landscape in the arid western United States, yet they provide habitat and resources to over half of arid‐land wildlife species, including a broad diversity of anurans (frogs and toads). Despite this, relatively few studies describe riparian herpetofaunal communities in the Southwest, and remote wilderness areas are particularly undersurveyed.We employed passive acoustic monitoring to capture anuran advertisement calls in wilderness area tributaries of the Verde River, Arizona, USA. In the spring and summer of 2021 and 2022, 13–29 autonomous recording units (ARUs) were deployed along perennial, intermittent and ephemeral tributary stream reaches. We characterized sites based on the per cent of pool, riffle, run and side channel habitat within 100 m of each ARU and quantified substrate, wetted channel width and canopy cover. To relate anuran occupancy to environmental and hydrological variables, we evaluated acoustic detection data using single‐species, single‐season occupancy models.Four species were detected in this study: canyon treefrog (Hyla arenicolor), red‐spotted toad (Anaxyrus punctatus), Woodhouse's toad (Anaxyrus woodhousii) and non‐native American bullfrog (Lithobates catesbeianus), with canyon treefrog being the most ubiquitous species observed. Vocal activity of canyon treefrog was higher at perennial and intermittent sites compared to ephemeral sites, and the presence of pools was most strongly associated with canyon treefrog occupancy.Persistent, slow‐moving water best predicted the presence of breeding canyon treefrogs. Notably, this study did not detect several species with historical records in the middle Verde River catchment, including Arizona toad (Anaxyrus microscaphus) and northern leopard frog (Lithobates pipiens).Given climate change‐related flow declines and intensifying demands for water in arid lands globally, maintaining stream flows that provide consistent and suitable hydroregimes for anuran breeding and larval development is of increasing importance. Determining habitat use and flow regimes necessary to support anuran populations can aid in prioritization of conservation actions related to water management and predict how changes in water availability may impact stream‐breeding anurans. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
9. Automatic detection for bioacoustic research: a practical guide from and for biologists and computer scientists.
- Author
-
Kershenbaum, Arik, Akçay, Çağlar, Babu‐Saheer, Lakshmi, Barnhill, Alex, Best, Paul, Cauzinille, Jules, Clink, Dena, Dassow, Angela, Dufourq, Emmanuel, Growcott, Jonathan, Markham, Andrew, Marti‐Domken, Barbara, Marxer, Ricard, Muir, Jen, Reynolds, Sam, Root‐Gutteridge, Holly, Sadhukhan, Sougata, Schindler, Loretta, Smith, Bethany R., and Stowell, Dan
- Subjects
- *
ARTIFICIAL intelligence , *DEEP learning , *BIOACOUSTICS , *LIFE sciences , *ANIMAL communication - Abstract
ABSTRACT Recent years have seen a dramatic rise in the use of passive acoustic monitoring (PAM) for biological and ecological applications, and a corresponding increase in the volume of data generated. However, data sets are often becoming so sizable that analysing them manually is increasingly burdensome and unrealistic. Fortunately, we have also seen a corresponding rise in computing power and the capability of machine learning algorithms, which offer the possibility of performing some of the analysis required for PAM automatically. Nonetheless, the field of automatic detection of acoustic events is still in its infancy in biology and ecology. In this review, we examine the trends in bioacoustic PAM applications, and their implications for the burgeoning amount of data that needs to be analysed. We explore the different methods of machine learning and other tools for scanning, analysing, and extracting acoustic events automatically from large volumes of recordings. We then provide a step‐by‐step practical guide for using automatic detection in bioacoustics. One of the biggest challenges for the greater use of automatic detection in bioacoustics is that there is often a gulf in expertise between the biological sciences and the field of machine learning and computer science. Therefore, this review first presents an overview of the requirements for automatic detection in bioacoustics, intended to familiarise those from a computer science background with the needs of the bioacoustics community, followed by an introduction to the key elements of machine learning and artificial intelligence that a biologist needs to understand to incorporate automatic detection into their research. We then provide a practical guide to building an automatic detection pipeline for bioacoustic data, and conclude with a discussion of possible future directions in this field. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
10. 基于被动声学的对虾摄食行为研究进展.
- Author
-
刘慧仪, 田昌凤, 刘晃, 车轩, and 王晓萌
- Subjects
- *
WATER use , *WATER quality , *ACOUSTICS , *AQUATIC organisms , *SUSTAINABLE development - Abstract
Passive acoustic monitoring (PAM) technology enables the acquisition of acoustic information from aquatic organisms without causing disturbance or harm, facilitating various ecological studies and aiding in the management of aquaculture activities. As shrimp aquaculture technology advances, the industry's scale and density are increasing. However, challenges such as low feed utilization and water quality deterioration have severely constrained the rapid development of the industry. PAM technology can be used to study sound in the environment by using it to understand shrimp feeding behaviour, guide feeding decisions, and implement intelligent automated feeding systems, thereby improving feed utilization and mitigating water quality deterioration problems. This article primarily discusses how shrimp feed, the factors affecting their feeding, and the acoustic characteristics of the feeding process, and reviews the latest research progress and application of PAM technology in detecting acoustic signals of shrimp feeding, as well as the challenges faced by the technology in its development. The advantages and limitations of PAM technology in shrimp aquaculture are analyzed, and the future development direction is proposed to address the problems of this technology. To provide a reference for the automatic feeding system to move towards intelligence, to promote the sustainable development of shrimp aquaculture. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
11. Singing in the rain! Climate constraints on the occurrence of indri's song.
- Author
-
Ferrario, Valeria, Raimondi, Teresa, De Gregorio, Chiara, Carugati, Filippo, Cristiano, Walter, Torti, Valeria, Lewis, Rebecca N., Valente, Daria, Williams, Leah J., Raisin, Claire, Gamba, Marco, Von Hardenberg, Achaz, and Giacoma, Cristina
- Subjects
- *
ANIMAL communication , *ENDANGERED species , *RAINFALL , *WEATHER , *ANIMAL behavior - Abstract
The study of how animals adapt their behaviors depending on weather variables has gained particular significance in the context of climate change. This exploration offers insights into endangered species' potential threats and provides information on the direction to take in conservation activities. In this context, noninvasive, cost‐effective, and potentially long‐term monitoring systems, such as Passive Acoustic Monitoring (PAM), become particularly appropriate. Our study investigates the relationship between weather variables and the vocal behavior of Indri indri, the sole singing lemur species, within Madagascar's Maromizaha New Protected Area. Using PAM, we explore the factors shaping the vocalization patterns of this primate species in response to some environmental factors in their natural habitat. Analysis of an extensive audio data set collected across different years revealed the differential influence of temperature and precipitation on Indri indri vocal activity. We found that rainfall negatively influenced the emission of the vocalizations while warmer temperatures correlated with a greater emission of songs. The various environmental factors we considered also affected the timing of vocal emissions, showing the same pattern. Furthermore, our study confirms, once again, the strength of PAM as a valuable tool for studying vocal animal communication quickly, giving us information about long‐term behavioral patterns that would be difficult to get in other ways. This research gives us further valuable information about how indris use vocalizations in their environment and how they adjust to environmental changes. Research highlights: Indri indri, the only singing lemur, emits songs daily, a behavior strictly linked to intergroup territory spacing.We explored the influence of weather conditions on indris' songs in the Maromizaha New Protected Area using Passive Acoustic Monitoring (PAM) and an automated detection algorithm.Indris adjusted their singing behavior based on weather conditions: rain and low temperatures are associated with decreased frequency. Rain determined delayed song emission in the morning. This suggests this behavior's plasticity is linked to energetic costs.Our study widens the knowledge of the behavior of an endangered species of nonhuman primates. It also showcases the strength of PAM in the conservation and behavioral study of different species. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
12. Applying machine learning to primate bioacoustics: Review and perspectives.
- Author
-
Cauzinille, Jules, Favre, Benoit, Marxer, Ricard, and Rey, Arnaud
- Subjects
- *
BIG data , *ANIMAL communication , *BIOACOUSTICS , *COMPARATIVE linguistics , *SIGNAL processing , *DEEP learning , *MACHINE learning - Abstract
This paper provides a comprehensive review of the use of computational bioacoustics as well as signal and speech processing techniques in the analysis of primate vocal communication. We explore the potential implications of machine learning and deep learning methods, from the use of simple supervised algorithms to more recent self‐supervised models, for processing and analyzing large data sets obtained within the emergence of passive acoustic monitoring approaches. In addition, we discuss the importance of automated primate vocalization analysis in tackling essential questions on animal communication and highlighting the role of comparative linguistics in bioacoustic research. We also examine the challenges associated with data collection and annotation and provide insights into potential solutions. Overall, this review paper runs through a set of common or innovative perspectives and applications of machine learning for primate vocal communication analysis and outlines opportunities for future research in this rapidly developing field. Research Highlights: ‐Recent machine learning and deep learning methods provide innovative tools for the study of primate vocal communication.‐Applied to massive acoustic recordings, they offer new perspectives for better identifying and studying primate vocal productions.‐We provide a comprehensive review of established approaches and latest advances in this rapidly evolving field. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
13. Listening to animal behavior to understand changing ecosystems.
- Author
-
Oestreich, William K., Oliver, Ruth Y., Chapman, Melissa S., Go, Madeline C., and McKenna, Megan F.
- Subjects
- *
ANIMAL sounds , *ANIMAL adaptation , *ANIMAL behavior , *RESEARCH personnel , *ECOSYSTEMS , *HUMAN-animal relationships - Abstract
Behavior represents animals' primary means of responding to environmental variation and adapting to rapid environmental change. Many animals' presence, let alone behavior, is highly cryptic to human observers, presenting a significant barrier in both theoretical and applied behavioral ecology. Bioacoustic signals not only reveal animals' presence, but also encode detailed information about the behaviors in which they are engaging. The study of behavioral bioacoustics has emerged to decipher the context and function of animal sounds and to apply this comprehension to understanding animal behavior across ecological scales and levels of biological organization. Growing capacity for behavioral bioacoustics represents a profound opportunity to understand animal behavior and steward rapidly changing ecosystems in the Anthropocene. Interpreting sound gives powerful insight into the health of ecosystems. Beyond detecting the presence of wildlife, bioacoustic signals can reveal their behavior. However, behavioral bioacoustic information is underused because identifying the function and context of animals' sounds remains challenging. A growing acoustic toolbox is allowing researchers to begin decoding bioacoustic signals by linking individual and population-level sensing. Yet, studies integrating acoustic tools for behavioral insight across levels of biological organization remain scarce. We aim to catalyze the emerging field of behavioral bioacoustics by synthesizing recent successes and rising analytical, logistical, and ethical challenges. Because behavior typically represents animals' first response to environmental change, we posit that behavioral bioacoustics will provide theoretical and applied insights into animals' adaptations to global change. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
14. Individual identification in acoustic recordings.
- Author
-
Knight, Elly, Rhinehart, Tessa, de Zwaan, Devin R., Weldy, Matthew J., Cartwright, Mark, Hawley, Scott H., Larkin, Jeffery L., Lesmeister, Damon, Bayne, Erin, and Kitzes, Justin
- Subjects
- *
ANIMAL species , *RESEARCH personnel , *BIOLOGISTS , *SOUNDS , *INFANTS , *DEEP learning - Abstract
Individual acoustic signatures, if present within animal species, can provide insights into evolution and behavior, and have great potential for differentiating individuals during monitoring and research. Recent advances in bioacoustic technology combined with acoustic individual identification (AIID) have the potential to revolutionize the study of sound-producing animals; however, methods and application of AIID remain in their infancy. Evidence of individual acoustic signatures across taxa and successes in adjacent acoustic disciplines suggest that opportunities exist for developing AIID. Research and development into AIID should combine deep learning methods with the construction and sharing of labeled training datasets, and should focus on recording and classification methods that maximize the potential applications of AIID. Broadscale implementation of AIID should be achievable in the near future and will allow biologists to answer important ecological and evolutionary questions with less bias and fewer negative population effects and resources than the current approaches. Recent advances in bioacoustics combined with acoustic individual identification (AIID) could open frontiers for ecological and evolutionary research because traditional methods of identifying individuals are invasive, expensive, labor-intensive, and potentially biased. Despite overwhelming evidence that most taxa have individual acoustic signatures, the application of AIID remains challenging and uncommon. Furthermore, the methods most commonly used for AIID are not compatible with many potential AIID applications. Deep learning in adjacent disciplines suggests opportunities to advance AIID, but such progress is limited by training data. We suggest that broadscale implementation of AIID is achievable, but researchers should prioritize methods that maximize the potential applications of AIID, and develop case studies with easy taxa at smaller spatiotemporal scales before progressing to more difficult scenarios. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
15. Humpback whale (Megaptera novaeangliae) social calls in southern British Columbia.
- Author
-
Molder, Zoe A., Halliday, William D., Reidy, Rhonda, Kraemer, Chloe N., and Juanes, Francis
- Subjects
RANDOM forest algorithms ,CLUSTER analysis (Statistics) ,FOLKSONOMIES ,BIOACOUSTICS ,HUMPBACK whale ,CLASSIFICATION - Abstract
Humpback whale (Megaptera novaeangliae) nonsong vocalizations, or social calls, are much more poorly understood than humpback song. We examined humpback whale social calls from a foraging ground in southern British Columbia (BC) and developed a catalog for humpback social calls in BC. We tagged four humpback whales on the eastern edge of Swiftsure Bank, BC, in early September 2020, with a passive acoustic and movement tag. We manually classified 32 call types in our data set based on comparisons with published classifications of humpback social calls. Many of the calls identified in our data set had similar characteristics to calls from other locations. We also used two statistical classification methods, a cluster analysis and a random forest. The cluster analysis grouped 20 of these call types into four categories, and the random forest classifier was able to accurately classify all 20 call types 87.6% of the time. This study fills a geographical gap of humpback whale social calls on foraging grounds and is a first step towards categorizing the social calls of humpback whales in BC. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
16. 长江江豚对孤立栖息地斑块利用规律研究及潜在因子分析.
- Author
-
张 康, 张 平, 夏德军, 李子航, 吴 赞, 于道平, and 陈敏敏
- Abstract
Copyright of Journal of Hydrobiology / Shuisheng Shengwu Xuebao is the property of Editorial Department of Journal of Hydrobiology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2024
- Full Text
- View/download PDF
17. Bryde's whales produce Biotwang calls, which occur seasonally in long-term acoustic recordings from the central and western North Pacific.
- Author
-
Allen, Ann N., Harvey, Matt, Harrell, Lauren, Wood, Megan, Szesciorka, Angela R., McCullough, Jennifer L. K., and Oleson, Erin M.
- Subjects
BALEEN whales ,DEEP learning ,MACHINE learning ,WHALES ,ARCHIPELAGOES - Abstract
In 2014, a novel call was discovered in autonomous acoustic recordings from the Mariana Archipelago and designated a "Biotwang". It was assumed to be produced by a baleen whale, but without visual verification it was impossible to assign a species. Using a combination of visual and acoustic survey data collected in the Mariana Archipelago, we determined that Biotwangs are produced by Bryde's whales. Bryde's whales occur worldwide in tropical and warm temperate waters, but their population structure and movements are not well understood. Genetic and morphological data recognize two populations in the western North Pacific (WNP), separate from those elsewhere in the Pacific. We used a combination of manual and machine learning annotation methods to detect Biotwangs in our extensive historical passive acoustic monitoring datasets collected across the central and western North Pacific. We identified a consistent seasonal presence of Biotwangs in the Mariana Archipelago and to the east at Wake Island, with occasional occurrence as far away as the Northwestern Hawaiian Islands and near the equator (Howland Island). The seasonal occurrence of Biotwangs is consistent with Bryde's whales migrating between low and mid-latitudes, with a small peak in calling between February and April and a larger peak between August and November as the whales travel past the recording sites. Our results provide evidence for a pelagic WNP population of Bryde's whales with broad distribution, but with seasonal and inter-annual variation in occurrence that imply a complex range most likely linked to changing oceanographic conditions in this region. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
18. Comparing field performance of ultrasonic microphones to facilitate analysis of long‐term acoustic bat monitoring data.
- Author
-
Goodwin, Katy R., Kirschbaum, Alan, and Gillam, Erin H.
- Abstract
Passive acoustic monitoring is a standard technique for studying bat ecology and behavior. However, an issue that has received little attention is how to appropriately analyze data within a long‐term acoustic monitoring dataset when the equipment has been replaced and updated. Equipment changes are often inevitable, especially for microphones, which need to be replaced regularly due to extended weather exposure and associated reductions in recording quality. We compared 2 ultrasonic microphone models (Wildlife Acoustics SMM‐U1 and SMM‐U2) by deploying them side‐by‐side with the same acoustic detector unit. We tested 9 or 10 microphones per model in field deployments lasting an average of 9 nights. We compared triggering frequency, species classification, detection rates, and echolocation call parameters (as indicators of signal quality) from both microphones. The vast majority (97%) of our 25,949 paired recordings were captured simultaneously by both microphones. Yet, the SMM‐U2 outperformed the SMM‐U1 in terms of proportion of files classifiable to the species level (70% versus 61%), rate of bat detections per night (1–6.5 more detections per night depending on species), and recording quality. Based on our results, we propose a correction factor to facilitate direct comparison of datasets collected with these 2 different microphones. Our study will assist bat researchers in selecting appropriate equipment and accounting for potential biases in long‐term acoustic monitoring programs. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
19. Diverse baleen whale acoustic occurrence around two sub-Antarctic islands: A tale of residents and visitors
- Author
-
Fannie W. Shabangu, Tessa Munoz, Lora Van Uffelen, Bobbi J. Estabrook, Dawit Yemane, Kathleen M. Stafford, Trevor A. Branch, Els Vermeulen, Marcel A. van den Berg, and Tarron Lamont
- Subjects
Overwintering ground ,Stopover spot ,Feeding ground ,Year-round habitat ,Passive acoustic monitoring ,Southern Ocean ,Medicine ,Science - Abstract
Abstract Knowledge on the occurrence and behaviour of baleen whales around sub-Antarctic regions is limited, and usually based on short, seasonal sighting research from shore or research vessels and whaling records, neither of which provide accurate and comprehensive year-round perspectives of these animals’ ecology. We investigated the seasonal acoustic occurrence and diel vocalizing pattern of baleen whales around the sub-Antarctic Prince Edward Islands (PEIs) using passive acoustic monitoring data from mid-2021 to mid-2023, detecting six distinct baleen whale songs from Antarctic blue whales, Madagascan pygmy blue whales, fin whales, Antarctic minke whales, humpback whales, and sei whales. Antarctic blue and fin whales were detected year-round whereas the other species’ songs were detected seasonally, including a new Antarctic minke whale bio-duck song sub-type described here for the first time. Antarctic minke and sei whales were more vocally active at night-time whereas the other species had no clear diel vocalizing patterns. Random forest models identified month and/or sea surface temperature as the most important predictors of all baleen whale acoustic occurrence. These novel results highlight the PEIs as a useful habitat for baleen whales given the number of species that inhabit or transit through this region.
- Published
- 2024
- Full Text
- View/download PDF
20. Soundscape analysis can be an effective tool in assessing seagrass restoration early success
- Author
-
Gabriella La Manna, Ivan Guala, Arianna Pansini, Patrizia Stipcich, Nicola Arrostuto, and Giulia Ceccherelli
- Subjects
Acoustic restoration ,Fish sound ,Mediterranean sea ,Passive acoustic monitoring ,Posidonia oceanica ,Restoration success ,Medicine ,Science - Abstract
Abstract Restoration of vulnerable marine habitats is becoming increasingly popular to cope with widespread habitat loss and the resulting decline in biodiversity and ecosystem services. Lately, restoration strategies have been employed to enhance the recovery of degraded meadows of the Mediterranean endemic seagrass Posidonia oceanica. Typically, habitat restoration success is evaluated by the persistence of foundation species after transplantation (e.g., plant survival and growth) on the short and long-term, although successful plant responses do not necessarily reflect the recovery of ecosystem biodiversity and functions. Recently, soundscape (the spatial, temporal and frequency attribute of ambient sound and types of sound sources characterizing it) has been related to different habitat conditions and community structures. Thus, a successful restoration action should lead to acoustic restoration and soundscape ecology could represent an important component of restoration monitoring, leading to assess successful habitat and community restoration. Here, we evaluated acoustic community and metrics in a P. oceanica restored meadow and tested whether the plant transplant effectiveness after one year was accompanied by a restored soundscape. With this goal, acoustic recordings from degraded, transplanted and reference meadows were collected in Sardinia (Italy) using passive acoustic monitoring devices. Soundscape at each meadow type was examined using both spectral analysis and classification of fish calls based on a catalogue of fish sounds from the Mediterranean Sea. Seven different fish sounds were recorded: most of them were present in the reference and transplanted meadows and were associated to Sciaena umbra and Scorpaena spp. Sound Pressure Level (SPL, in dB re: 1 μPa-rms) and Acoustic Complexity Index (ACI) were influenced by the meadow type. Particularly higher values were associated to the transplanted meadow. SPL and ACI calculated in the 200–2000 Hz frequency band were also related to high abundance of fish sounds (chorus). These results showed that meadow restoration may lead to the recovery of soundscape and the associated community, suggesting that short term acoustic monitoring can provide complementary information to evaluate seagrass restoration success.
- Published
- 2024
- Full Text
- View/download PDF
21. Seasonal and diurnal marine mammal presence in the proposed marine protected area of Southampton Island, Hudson Bay, Nunavut as revealed by passive acoustic monitoring
- Author
-
Veronica Laura Maria Coppolaro, Kaushik Gupta, Lisa Loseto, C.J. Mundy, and Marianne Marcoux
- Subjects
marine mammal vocalizations ,passive acoustic monitoring ,Arctic ,marine protected area ,GLM ,Environmental sciences ,GE1-350 ,Environmental engineering ,TA170-171 - Abstract
Marine protected areas contribute to mitigating the effects of human activities on marine ecosystems. The waters of Southampton Island, Nunavut, Canada are under consideration to become a marine protected area, but baseline information of marine mammal presence and habitat use is lacking. This study represents the first passive acoustic monitoring of marine mammals in this area, with data collected in 2018 and 2019. Bioacoustics analyses and generalized linear models were used to investigate species seasonal and temporal vocalization trends; infer behavior and habitat use from vocal cues; and explore vocal activity correlation with sea ice. Over a diel period, bearded seals (Erignathus barbatus (Erxleben, 1777)) and walruses (Odobenus rosmarus (Linnaeus, 1758)) were found to increase their vocal activity at night, whereas belugas (Delphinapterus leucas (Pallas, 1776)) mainly vocalized during daytime. Seasonally, bearded seals were recorded only during their breeding season at sea ice break-up, while walruses vocalized consistently throughout the open-water period outside their breeding season. Beluga vocal trends suggest their use of the area as a migratory corridor during sea ice break-up and freeze-up. Finally, bowhead whales (Balaena mysticetus Linnaeus, 1758) were recorded later than expected, concurrently with the onset of their mating vocal displays during the fall migration at sea ice freeze-up.
- Published
- 2024
- Full Text
- View/download PDF
22. Implications of target signal choice in passive acoustic monitoring: an example of age‐ and sex‐dependent vocal repertoire use in African forest elephants (Loxodonta cyclotis)
- Author
-
Colin R. Swider, Daniela Hedwig, Peter H. Wrege, and Susan E. Parks
- Subjects
African forest elephants ,call type ,detection ,endangered species ,passive acoustic monitoring ,repertoire ,Technology ,Ecology ,QH540-549.5 - Abstract
Abstract Passive acoustic monitoring (PAM) is an effective remote sensing approach for sampling acoustically active animal species and is particularly useful for elusive, visually cryptic species inhabiting remote or inaccessible habitats. Key advantages of PAM are large spatial coverage and continuous, long‐term monitoring. In most cases, a signal detection algorithm is utilized to locate sounds of interest within long sequences of audio data. It is important to understand the demographic/contextual usage of call types when choosing a particular signal to use for detection. Sampling biases may result if sampling is restricted to subsets of the population, for example, when detectable vocalizations are produced only by a certain demographic class. Using the African forest elephant repertoire as a case study, we test for differences in call type usage among different age‐sex classes. We identified disproportionate usage by age‐sex class of four call types—roars, trumpets, rumbles, and combination calls. This differential usage of signals by demographic class has implications for the use of particular call types in PAM for this species. Our results highlight that forest elephant PAM studies that have used rumbles as target signals may have under‐sampled adult males. The addition of other call types to PAM frameworks may be useful to leverage additional population demographic information from these surveys. Our research exemplifies how an examination of a species' acoustic behavior can be used to better contextualize the data and results from PAM and to strengthen the resulting inference.
- Published
- 2024
- Full Text
- View/download PDF
23. Time series methods for the analysis of soundscapes and other cyclical ecological data
- Author
-
Natalie Yoh, Charlotte L. Haley, and Zuzana Burivalova
- Subjects
bioacoustics ,coherence ,ecoacoustics ,multitaper principal component analysis ,passive acoustic monitoring ,phenology ,Ecology ,QH540-549.5 ,Evolution ,QH359-425 - Abstract
Abstract Biodiversity monitoring has entered an era of ‘big data’, exemplified by a near‐continuous collection of sounds, images, chemical and other signals from organisms in diverse ecosystems. Such data streams have the potential to help identify new threats, assess the effectiveness of conservation interventions, as well as generate new ecological insights. However, appropriate analytical methods are often still missing, particularly with respect to characterizing cyclical temporal patterns. Here, we present a framework for characterizing and analysing ecological responses that represent nonstationary, complex temporal patterns and demonstrate the value of using Fourier transforms to decorrelate continuous data points. In our example, we use a framework based on three approaches (spectral analysis, magnitude squared coherence, and principal component analysis) to characterize differences in tropical forest soundscapes within and across sites and seasons in Gabon. By reconstructing the underlying, cyclic behaviour of the soundscape for each site, we show how one can identify circadian patterns in acoustic activity. Soundscapes in the dry season had a complex diel cycle, requiring multiple harmonics to represent daily variation, while in the wet season there was less variance attributable to the daily cyclic patterns. Our framework can be applied to most continuous, or near‐continuous ecological data collected at a fine temporal resolution, allowing ecologists to explore patterns of temporal autocorrelation at multiple levels for biologically meaningful trends. Such methods will become indispensable as biological big data are used to understand the impact of anthropogenic pressures on biodiversity and to inform efforts to mitigate them.
- Published
- 2024
- Full Text
- View/download PDF
24. ecoSound-web: an open-source, online platform for ecoacoustics [version 3; peer review: 3 approved]
- Author
-
Kevin F.A. Darras, Noemí Pérez, Liu Dilong, Tara Hanf-Dressler, Matthias Markolf, Thomas C Wanger, and Anna F. Cord
- Subjects
Software Tool Article ,Articles ,Soundscape ,sound analysis ,ecoacoustics ,passive acoustic monitoring ,automated sound recording ,autonomous recording units ,spectrogram ,audio annotation - Abstract
Passive acoustic monitoring of soundscapes and biodiversity produces vast amounts of audio recordings, but the management and analyses of these raw data present technical challenges. A multitude of software solutions exist, but none can fulfil all purposes required for the management, processing, navigation, and analysis of acoustic data. The field of ecoacoustics needs a software tool that is free, evolving, and accessible. We take a step in that direction and present ecoSound-web: an open-source, online platform for ecoacoustics designed and built by ecologists and software engineers. ecoSound-web can be used for storing, re-sampling, organising, analysing, and sharing soundscape recording or metadata projects. Specifically, it allows manual annotation of soniferous animals and soundscape components, automatic annotation with deep-learning models for all birds and for UK bat species, peer-reviewing annotations, analysing audio in time and frequency dimensions, computing alpha acoustic indices, and providing reference sound libraries for different taxa. We present ecoSound-web’s structure and features, and describe its operation for typical use cases such as sampling bird and bat communities, using a primate call library, and the analysis of soundscape components and acoustic indices. ecoSound-web is available from: https://github.com/ecomontec/ecoSound-web
- Published
- 2024
- Full Text
- View/download PDF
25. Diverse baleen whale acoustic occurrence around two sub-Antarctic islands: A tale of residents and visitors.
- Author
-
Shabangu, Fannie W., Munoz, Tessa, Van Uffelen, Lora, Estabrook, Bobbi J., Yemane, Dawit, Stafford, Kathleen M., Branch, Trevor A., Vermeulen, Els, van den Berg, Marcel A., and Lamont, Tarron
- Abstract
Knowledge on the occurrence and behaviour of baleen whales around sub-Antarctic regions is limited, and usually based on short, seasonal sighting research from shore or research vessels and whaling records, neither of which provide accurate and comprehensive year-round perspectives of these animals’ ecology. We investigated the seasonal acoustic occurrence and diel vocalizing pattern of baleen whales around the sub-Antarctic Prince Edward Islands (PEIs) using passive acoustic monitoring data from mid-2021 to mid-2023, detecting six distinct baleen whale songs from Antarctic blue whales, Madagascan pygmy blue whales, fin whales, Antarctic minke whales, humpback whales, and sei whales. Antarctic blue and fin whales were detected year-round whereas the other species’ songs were detected seasonally, including a new Antarctic minke whale bio-duck song sub-type described here for the first time. Antarctic minke and sei whales were more vocally active at night-time whereas the other species had no clear diel vocalizing patterns. Random forest models identified month and/or sea surface temperature as the most important predictors of all baleen whale acoustic occurrence. These novel results highlight the PEIs as a useful habitat for baleen whales given the number of species that inhabit or transit through this region. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
26. Soundscape analysis can be an effective tool in assessing seagrass restoration early success.
- Author
-
La Manna, Gabriella, Guala, Ivan, Pansini, Arianna, Stipcich, Patrizia, Arrostuto, Nicola, and Ceccherelli, Giulia
- Subjects
- *
SEAGRASS restoration , *RESTORATION ecology , *SOUNDSCAPES (Auditory environment) , *CLASSIFICATION of fish , *SOUND pressure , *POSIDONIA , *MARINE biodiversity - Abstract
Restoration of vulnerable marine habitats is becoming increasingly popular to cope with widespread habitat loss and the resulting decline in biodiversity and ecosystem services. Lately, restoration strategies have been employed to enhance the recovery of degraded meadows of the Mediterranean endemic seagrass Posidonia oceanica. Typically, habitat restoration success is evaluated by the persistence of foundation species after transplantation (e.g., plant survival and growth) on the short and long-term, although successful plant responses do not necessarily reflect the recovery of ecosystem biodiversity and functions. Recently, soundscape (the spatial, temporal and frequency attribute of ambient sound and types of sound sources characterizing it) has been related to different habitat conditions and community structures. Thus, a successful restoration action should lead to acoustic restoration and soundscape ecology could represent an important component of restoration monitoring, leading to assess successful habitat and community restoration. Here, we evaluated acoustic community and metrics in a P. oceanica restored meadow and tested whether the plant transplant effectiveness after one year was accompanied by a restored soundscape. With this goal, acoustic recordings from degraded, transplanted and reference meadows were collected in Sardinia (Italy) using passive acoustic monitoring devices. Soundscape at each meadow type was examined using both spectral analysis and classification of fish calls based on a catalogue of fish sounds from the Mediterranean Sea. Seven different fish sounds were recorded: most of them were present in the reference and transplanted meadows and were associated to Sciaena umbra and Scorpaena spp. Sound Pressure Level (SPL, in dB re: 1 μPa-rms) and Acoustic Complexity Index (ACI) were influenced by the meadow type. Particularly higher values were associated to the transplanted meadow. SPL and ACI calculated in the 200–2000 Hz frequency band were also related to high abundance of fish sounds (chorus). These results showed that meadow restoration may lead to the recovery of soundscape and the associated community, suggesting that short term acoustic monitoring can provide complementary information to evaluate seagrass restoration success. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
27. Passive acoustic monitoring of endangered endemic Afromontane tropical species: A case study with two turacos.
- Author
-
Winiarska, Dominika, Pérez‐Granados, Cristian, Budka, Michał, and Osiejuk, Tomasz S.
- Subjects
- *
ENDEMIC species , *TROPICAL forests , *SUNRISE & sunset , *ACOUSTICS , *SPECIES - Abstract
Passive acoustic monitoring (PAM) is a reliable method for studying the behaviour and ecology of vocally active animals, providing insights into species' activity patterns. Here, we utilised a year‐long recording programme conducted in six areas of the Afromontane tropical forest of Cameroon to assess the utility of PAM, describe the annual and circadian vocal activity patterns, and assess the relationship between vocal activity and climate conditions for two African turaco species: the endemic and Endangered Bannerman's turaco (Tauraco bannermani) and the common, but locally at risk, Great blue turaco (Corythaeola cristata). The automated software detected 8670 vocalisations of Bannerman's turaco and 374 of the Great blue turaco, proving the ability of passive acoustics, coupled with automated software, for monitoring these species. Our findings suggest that both turacos are sedentary and seasonal breeders, exhibiting larger peaks of vocal activity during the dry season, although both species showed smaller activity peaks during the wet season. Similar circadian patterns were observed for both species, with activity peaks occurring at dawn and dusk. Long‐term monitoring programmes of both species should be implemented in the study areas, especially regarding the Great blue turaco, which may soon disappear from Bamenda Highlands. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
28. Living Together, Singing Together: Revealing Similar Patterns of Vocal Activity in Two Tropical Songbirds Applying BirdNET.
- Author
-
Amorós-Ausina, David, Schuchmann, Karl-L., Marques, Marinez I., and Pérez-Granados, Cristian
- Subjects
- *
WILDLIFE monitoring , *MACHINE learning , *WRENS , *SONGBIRDS , *SPECIES - Abstract
In recent years, several automated and noninvasive methods for wildlife monitoring, such as passive acoustic monitoring (PAM), have emerged. PAM consists of the use of acoustic sensors followed by sound interpretation to obtain ecological information about certain species. One challenge associated with PAM is the generation of a significant amount of data, which often requires the use of machine learning tools for automated recognition. Here, we couple PAM with BirdNET, a free-to-use sound algorithm to assess, for the first time, the precision of BirdNET in predicting three tropical songbirds and to describe their patterns of vocal activity over a year in the Brazilian Pantanal. The precision of the BirdNET method was high for all three species (ranging from 72 to 84%). We were able to describe the vocal activity patterns of two of the species, the Buff-breasted Wren (Cantorchilus leucotis) and Thrush-like Wren (Campylorhynchus turdinus). Both species presented very similar vocal activity patterns during the day, with a maximum around sunrise, and throughout the year, with peak vocal activity occurring between April and June, when food availability for insectivorous species may be high. Further research should improve our knowledge regarding the ability of coupling PAM with BirdNET for monitoring a wider range of tropical species. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
29. Day-after impact of simulated rival encounter in the common cuckoo.
- Author
-
Winiarska, Dominika, Jankowiak, Łukasz, Tryjanowski, Piotr, and Osiejuk, Tomasz S.
- Subjects
- *
CUCKOOS , *KALEIDOSCOPES , *MALES , *COMPUTER software - Abstract
Studies show that the common cuckoo exhibits a strong vocal response to rival playback. In this study, we aimed to assess if males would more eagerly vocally defend their home ranges a day after a simulated rival encounter. At 48 sites in Poland, we conducted a playback experiment where we played 20 calls repeated 5 times with a 5-min break between each series. Using the automatic analysis software Kaleidoscope Pro, we detected cuckoo calls in two datasets, directly after the experiment and the day after. Our results show that even though cuckoos respond to rival calls, this response is short-lived. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
30. The Brazilian Santos basin underwater soundscape monitoring project (PMPAS-BS).
- Author
-
Moreira Lima, José Antonio, Soares Filho, William, Xavier, Fabio C., Pires de Paula, Thiago, Spengler, Angela, Gonçalves de Almeida, Fernando, Correa Pereira, Diogo Peregrino, Souza Rego, Valéria, Galotta, Cátia, Corrêa Junior, Carlos, and Bazyl, Alexandre
- Subjects
UNDERWATER noise ,NOISE ,SEDIMENTARY basins ,ACOUSTIC measurements ,UNDERWATER acoustics ,EMISSION control ,ACOUSTIC emission testing - Abstract
This paper describes the Santos Basin Underwater Soundscape Monitoring Project (PMPAS-BS), a Brazilian ocean soundscape monitoring initiative. The main objective of the project is to quantify and assess hydroacoustic noise of anthropogenic origin in a large sedimentary basin extending from 23° S to 28° S on the southeastern Brazilian continental margin of the South Atlantic Ocean. Noise associated with oil and gas (O&G) exploration and production activities is the primary target, but this oceanic region also has busy shipping lanes for commercial, military, and fishing vessels. The two main hubs of Brazil’s export and import of goods by sea are located in this region: Santos and Rio de Janeiro ports. The project has three measurement components: mobile monitoring based on gliders and drifting acoustic profilers, fixed shallow-water monitoring based on acoustic measurements at coastal stations near shipping lanes associated with exploration and production activities in the Santos Basin, and fixed oceanic monitoring based on deep-water mooring lines equipped with passive autonomous acoustic recorders near production units, shipping lanes, and areas with lower intensity of O&G activities (pristine or reference sites). Numerical modeling of anthropogenic underwater acoustic noise has also been included as a fourth project component. The PMPAS-BS covers an area of more than 251,000 km² and uses several instruments with different methods and sensors for acoustic measurements. Its results provide current sound levels over a very large region of the western South Atlantic, both in areas more and less affected by anthropogenic activities. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
31. Avian Diversity Monitoring in Mountain Beech Forests using Acoustic Indices: a Case Study in the Belasitsa Nature Park, Bulgaria.
- Author
-
Panova, Kristina R., Zlatanov, Tzvetan M., and Nikolov, Boris P.
- Subjects
BIRD conservation ,OLD growth forests ,MOUNTAIN forests ,EUROPEAN beech ,SPECIES diversity - Abstract
Acoustic methods are widely used to study bird communities. They are particularly helpful in remote and hard reachable regions. In this study, we evaluated four acoustic indices (Acoustic Complexity Index, Acoustic Diversity Index, Acoustic Evenness Index and Bioacoustic Index) for biodiversity assessment in mountain beech (Fagus sylvatica) forests inside Belasitsa Nature Park, Bulgaria. We used twelve autonomous recording units and deployed four each in three forest types: old-growth forests in Kongura Reserve, mature managed forests (80-130 years of age) and premature managed forests (50-60 years of age). First, we verified that there were correlations between the acoustic indices and bird species richness detected by manual spectrogram scanning and listening of series of 3-min sound samples. Then, we compared the values of acoustic indices among the three forest types, finding higher bird species richness and abundance in old-growth forests and mature managed forests. We found no significant difference in the bird species composition in the three beech forest types, but more hole-nesting birds and species of conservation concern were identified in the old forests. We demonstrated that acoustic indices could be used for avian diversity monitoring and conservation management in mountain beech forests. [ABSTRACT FROM AUTHOR]
- Published
- 2024
32. Insectivorous bat activity dataset across different land-use types in the Islands of São Tomé and Príncipe, Central West Africa.
- Author
-
Palmeirim, Ana Filipa, Araújo-Fernandes, Ana Catarina, Castro-Fernandes, Ana Sofia, Guedes, Patricia, Cassari, José, Mata, Vanessa A., Yoh, Natalie, Rocha, Ricardo, Martínez-Arribas, Javier, and Alves-Martins, Fernanda
- Subjects
BAT classification ,LAND use ,ENDEMIC species ,FORESTS & forestry ,CITIES & towns - Abstract
Background: São Tomé and Príncipe oceanic islands, in Central West Africa, are characterised by exceptional levels of endemism. Since human colonisation in the mid-15
th century, São Tomé and Príncipe have lost 74% and 67% of their native habitat, respectively. Today, these islands are mainly covered by remaining old-growth forests, secondary regrowth forests, shaded plantations (mostly of cocoa), oil palm plantations (in the case of São Tomé), small-scale agricultural areas and urban areas. Yet, little is known about how species on these islands are coping with land-use changes. Island ecosystems are particularly important for bats, with about 25% of the world's bat species being entirely restricted to island systems. São Tomé and Príncipe Islands comprise six and four native insectivorous bats, respectively. Two species, Chaerephon tomensis and Macronycteris thomensis, are island-endemics in São Tomé; Pseudoromicia principis is an island-endemic in Príncipe; and Miniopterus newtoni is endemic from both São Tomé and Príncipe. Here, we present a dataset comprising a comprehensive compilation of occurrence records derived from acoustic sampling of insectivorous bats across the predominant land-use types of both the São Tomé and Príncipe Islands. In each sampling site, standardised surveys consisted of deploying one Audio Moth device that recorded for 1 minute every 5 minutes over a 48-hour period. We identified a total of 19,437 bat-passes across the 115 sites surveyed in São Tomé Island and 17,837 bat-passes across the 50 sites surveyed in Príncipe Island. New information: Based on a sampling effort of 1,584 hours of recordings manually processed to identify all the contained bat passes, this dataset, publicly available on GBIF, provides comprehensive information on the activity of insectivorous bats across two endemic-rich oceanic islands in the Gulf of Guinea. For each bat pass identified, we report the identified species, geographic coordinates, land-use type, altitude, date and time. This is the first public dataset providing detailed information on species-level habitat use for insectivorous bats on oceanic islands in Africa. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
33. Cross-referencing unidentified fish sound data sets to unravel sound sources: a case study from the Temperate Northern Atlantic.
- Author
-
Vieira, Manuel, Ríos, Noelia, Muñoz-Duque, Sebastian, Pereira, Jodanne, Carriço, Rita, Fernandez, Marc, Monteiro, João G., Pessanha Pais, Miguel, Quintella, Bernardo R., Silva, Gonçalo, Silva, Rodrigo P., Fonseca, Paulo J., and Amorim, M. Clara P.
- Subjects
AQUATIC biodiversity ,NUMBERS of species ,FISH communities ,SOUNDSCAPES (Auditory environment) ,IDENTIFICATION of fishes ,CLASSIFICATION of fish ,CLADISTIC analysis - Abstract
There is growing evidence that studying aquatic acoustic communities can provide ecologically relevant information. Understanding these communities may offer unique insights into species behaviour and ecology, while consolidating passive acoustic monitoring as a tool for mapping the presence of target species or estimating changes in aquatic biodiversity. Fish can be significant soundscape contributors, but most soniferous fish species are yet to be identified. Here, we crossed information of three key fish acoustic communities in the Lusitanian Province of the Temperate Northern Atlantic (the Madeira archipelago, the Azores archipelago and Arrábida in mainland Portugal) to unveil potential sources of unidentified fish sounds. We found that the three communities shared various sound types and we were able to narrow down the list of possible fish sound sources. Several sound types were suggested to be produced by species of the Pomacentridae, Scorpaenidae and Serranidae families. We also observed that the sound type /kwa/, associated with Scorpaena spp., exhibited more variations in the geographic area where more species of this genus are known to be present. This study showcases that, as databases of unidentified fish sounds continue to grow, future comparisons of multiple acoustic communities may provide insights into unknown fish sound sources and sound types. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
34. A Deep Learning-Based Acoustic Signal Analysis Method for Monitoring the Distillation Columns' Potential Faults.
- Author
-
Wang, Honghai, Zheng, Haotian, Zhang, Zhixi, and Wang, Guangyan
- Subjects
SIGNAL-to-noise ratio ,SIGNAL processing ,CHEMICAL apparatus ,DISTILLATION ,PRODUCT quality ,DEEP learning - Abstract
Distillation columns are vital for substance separation and purification in various industries, where malfunctions can lead to equipment damage, compromised product quality, production interruptions, and environmental harm. Early fault detection using AI-driven methods like deep learning can mitigate downtime and safety risks. This study employed a lab-scale distillation column to collect passive acoustic signals under normal conditions and three potential faults: flooding, dry tray, and leakage. Signal processing techniques were used to extract acoustic features from low signal-to-noise ratios and weak time-domain characteristics. A deep learning-based passive acoustic feature recognition method was then applied, achieving an average accuracy of 99.03% on Mel-frequency cepstral coefficient (MFCC) spectrogram datasets. This method demonstrated robust performance across different fault types and limited data scenarios, effectively predicting and detecting potential faults in distillation columns. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
35. An inadequate sampling of the soundscape leads to over-optimistic estimates of recogniser performance: a case study of two sympatric macaw species.
- Author
-
Lewis, Thomas C., Gutierrez Vargas, Ignacio, Beckerman, Andrew P., and Childs, Dylan Z.
- Subjects
- *
SUPERVISED learning , *TROPICAL ecosystems , *RAIN forests , *SOUND recordings , *MACHINE learning - Abstract
Passive acoustic monitoring (PAM) – autonomously recording ambient sound – could dramatically increase the scale and robustness of species monitoring in rainforest ecosystems. PAM generates large volumes of data that require automated methods of target species detection. Species-specific recognisers, which often use supervised machine learning, can achieve this goal. However, they require a large training dataset of target and non-target signals, which is time-consuming and challenging to create. Unfortunately, very little information about creating training datasets for supervised machine learning recognisers is available, especially for tropical ecosystems. Here, we show an iterative approach to creating a training dataset that improved recogniser precision from 0.12 to 0.55. By sampling background noise using an initial small recogniser, we can address one of the significant challenges of training dataset creation in acoustically diverse environments. Our work demonstrates that recognisers will likely fail in real-world settings unless the training dataset size is large enough and sufficiently representative of the ambient soundscape. We outline a workflow that can provide users with an accessible way to create a species-specific PAM recogniser that addresses these issues for tropical rainforest environments. Our work provides important lessons for PAM practitioners wanting to develop species-specific recognisers for acoustically diverse ecosystems. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
36. Using Deep Learning to Classify Environmental Sounds in the Habitat of Western Black-Crested Gibbons.
- Author
-
Hu, Ruiqi, Hu, Kunrong, Wang, Leiguang, Guan, Zhenhua, Zhou, Xiaotao, Wang, Ning, and Ye, Longjia
- Subjects
- *
CONVOLUTIONAL neural networks , *FEATURE selection , *WILDLIFE conservation , *BIODIVERSITY conservation , *FEATURE extraction - Abstract
The western black-crested gibbon (Nomascus concolor) is a rare and endangered primate that inhabits southern China and northern Vietnam, and has become a key conservation target due to its distinctive call and highly endangered status, making its identification and monitoring particularly urgent. Identifying calls of the western black-crested gibbon using passive acoustic monitoring data is a crucial method for studying and analyzing these gibbons; however, traditional call recognition models often overlook the temporal information in audio features and fail to adapt to channel-feature weights. To address these issues, we propose an innovative deep learning model, VBSNet, designed to recognize and classify a variety of biological calls, including those of endangered western black-crested gibbons and certain bird species. The model incorporates the image feature extraction capability of the VGG16 convolutional network, the sequence modeling capability of bi-directional LSTM, and the feature selection capability of the SE attention module, realizing the multimodal fusion of image, sequence and attention information. In the constructed dataset, the VBSNet model achieved the best performance in the evaluation metrics of accuracy, precision, recall, and F1-score, realizing an accuracy of 98.35%, demonstrating high accuracy and generalization ability. This study provides an effective deep learning method in the field of automated bioacoustic monitoring, which is of great theoretical and practical significance for supporting wildlife conservation and maintaining biodiversity. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
37. Implications of target signal choice in passive acoustic monitoring: an example of age‐ and sex‐dependent vocal repertoire use in African forest elephants (Loxodonta cyclotis).
- Author
-
Swider, Colin R., Hedwig, Daniela, Wrege, Peter H., and Parks, Susan E.
- Subjects
AFRICAN elephant ,ANIMAL species ,SIGNAL detection ,REMOTE sensing ,HABITATS - Abstract
Passive acoustic monitoring (PAM) is an effective remote sensing approach for sampling acoustically active animal species and is particularly useful for elusive, visually cryptic species inhabiting remote or inaccessible habitats. Key advantages of PAM are large spatial coverage and continuous, long‐term monitoring. In most cases, a signal detection algorithm is utilized to locate sounds of interest within long sequences of audio data. It is important to understand the demographic/contextual usage of call types when choosing a particular signal to use for detection. Sampling biases may result if sampling is restricted to subsets of the population, for example, when detectable vocalizations are produced only by a certain demographic class. Using the African forest elephant repertoire as a case study, we test for differences in call type usage among different age‐sex classes. We identified disproportionate usage by age‐sex class of four call types—roars, trumpets, rumbles, and combination calls. This differential usage of signals by demographic class has implications for the use of particular call types in PAM for this species. Our results highlight that forest elephant PAM studies that have used rumbles as target signals may have under‐sampled adult males. The addition of other call types to PAM frameworks may be useful to leverage additional population demographic information from these surveys. Our research exemplifies how an examination of a species' acoustic behavior can be used to better contextualize the data and results from PAM and to strengthen the resulting inference. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
38. Birds, bats and beyond: evaluating generalization in bioacoustics models.
- Author
-
van Merriënboer, Bart, Hamer, Jenny, Dumoulin, Vincent, Triantafillou, Eleni, and Denton, Tom
- Subjects
GENERALIZATION ,BIOACOUSTICS ,BATS ,MACHINE learning - Abstract
In the context of passive acoustic monitoring (PAM) better models are needed to reliably gain insights from large amounts of raw, unlabeled data. Bioacoustics foundation models, which are general-purpose, adaptable models that can be used for a wide range of downstream tasks, are an effective way to meet this need. Measuring the capabilities of such models is essential for their development, but the design of robust evaluation procedures is a complex process. In this review we discuss a variety of fields that are relevant for the evaluation of bioacoustics models, such as sound event detection, machine learning metrics, and transfer learning (including topics such as few-shot learning and domain generalization). We contextualize these topics using the particularities of bioacoustics data, which is characterized by large amounts of noise, strong class imbalance, and distribution shifts (differences in the data between training and deployment stages). Our hope is that these insights will help to inform the design of evaluation protocols that can more accurately predict the ability of bioacoustics models to be deployed reliably in a wide variety of settings. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
39. Year-round vocal activity of two African barbet species.
- Author
-
Winiarska, Dominika, Pérez-Granados, Cristian, Budka, Michał, and Osiejuk, Tomasz S.
- Subjects
- *
PATTERN recognition systems , *SPECIES - Abstract
Passive acoustic monitoring is a reliable method to study species behaviour and ecology, enabling the discovery of species activity patterns, especially in remote locations. Here, we conducted a year-long recording study to describe annual and circadian patterns in the vocal activity of two African barbet species, the Yellow-rumped Tinkerbird Pogoniulus bilineatus and the Western Tinkerbird Pogoniulus coryphaea. We used automated software to detect vocalisations of the two species from 4893 one-hour recordings taken in Cameroon. In total, we obtained 31,526 vocalisations of Yellow-rumped Tinkerbirds and 1318 vocalisations of Western Tinkerbirds. We used generalised additive mixed models to determine whether the month or hour of recording or meteorological conditions influenced the species' vocal activity. Our results indicated that both tinkerbirds are likely seasonal breeders, as the highest vocal activity of both species was during the dry season. Both species exhibited smaller activity peaks in the wet season. Our study provides new information on the vocal activity patterns of two barbet species, which could be valuable in future monitoring and surveying efforts. This study provides an illustrative example of two useful technologies that facilitate studies in remote areas: passive acoustic monitoring for determining species' activity patterns and automatic recognition software for the rapid analysis of large datasets. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
40. Underwater soundscape in Seaview Bay, Antarctica, and triple ascending trill of the leopard seal (Hydrurga leptonyx) underwater vocalizations.
- Author
-
Han, Dong‐Gyun, Choi, Jee Woong, Kim, Jong‐U, Kim, Jeong‐Hoon, and La, Hyoung Sul
- Subjects
- *
MARINE parks & reserves , *SOUND pressure , *SOUND recordings , *SEA ice , *SOUNDS - Abstract
The underwater soundscape was recorded in Seaview Bay off Inexpressible Island, Ross Sea region Marine protected area, for 3 days in December 2021. Leopard seal Hydrurga leptonyx vocalizations were a prominent sound source that led to variations in ambient sound pressure levels in a frequency range of approximately 150–4500 Hz. Among the 14 call types previously identified, except ultrasound vocalizations, six types of broadcast calls were classified, and their acoustic characteristics were analyzed. We focused on the acoustic characteristics of four low‐frequency calls, clustered in a relatively narrow bandwidth, which have been relatively less studied. We identified a new call type of a triple ascending trill consisting of three trill parts, expanding upon the findings of previous studies. The audio data extracted from leopard seal vocalization videos, recorded by a monitoring camera on sea ice, enhanced the reliability of identifications of the underwater triple ascending trill. We present the unique results of underwater passive acoustic monitoring conducted at Seaview Bay, designated as Antarctic Specially Protected Area No 178. Our results could contribute to the development of detection and localization algorithms for leopard seal vocalizations and can be used as fundamental data for studies related to the vocalization and behavior of this species. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
41. Guidelines for appropriate use of BirdNET scores and other detector outputs.
- Author
-
Wood, Connor M. and Kahl, Stefan
- Subjects
- *
ANIMAL sounds , *RECEIVER operating characteristic curves , *IDENTIFICATION of animals , *DETECTORS , *IDENTIFICATION , *MACHINE learning - Abstract
Machine learning tools capable of identifying animals by sound have proliferated, making the challenge of interpreting their outputs much more prevalent. These tools, like their predecessors, quantify prediction uncertainty with scores that tend to resemble probabilities but are actually unitless scores that are (generally) positively related to prediction accuracy in species-specific ways. BirdNET is one such tool, a freely available animal sound identification algorithm capable of identifying > 6,000 species, most of them birds. We describe two ways in which BirdNET "confidence scores"—and the output scores of other detector tools—can be used appropriately to interpret BirdNET results (reviewing them down to a user-defined threshold or converting them to probabilities), and provide a step-by-step tutorial to follow these suggestions. These suggestions are complementary to common performance metrics like precision, recall, and receiver operating characteristic. BirdNET can be a powerful tool for acoustic-based biodiversity research, but its utility depends on the careful use and interpretation of its outputs. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
42. Passive acoustic monitoring and visual sighting survey of cetacean occurrence patterns in the Kingdom of Saudi Arabia.
- Author
-
Duporge, Isla, Lee, Robert, Eweida, Ameer, Mackelworth, Peter, Ten, Sofía, Alghamdi, Abdulaziz, Alkhamis, Razan, Cochran, Jesse, Lee, Stephen, and Klinck, Holger
- Subjects
BOTTLENOSE dolphin ,CETACEA ,BALEEN whales ,SPECIES distribution ,COASTAL development - Abstract
The available data on occurrence patterns of cetaceans in the Red Sea area of the Kingdom of Saudi Arabia is very limited. The dearth of information is of pressing conservation concern as the coastline is undergoing rapid development as part of the Kingdom's effort to diversify its national economy. To understand how these developments will impact cetaceans in the region, the first large‐scale acoustic and visual survey in the Kingdom's part of the Gulf of Aqaba and the northeastern Red Sea was undertaken in 2020. The results of the acoustic surveys reveal 3.6 encounters per 100 km of track line of odontocete species with variable distribution across the study area. No baleen whale vocalizations were detected. Through visual surveys, five odontocete species were identified within the study area: Tursiops truncatus, T. aduncus, Stenella attenuata, S. longirostris, and two opportunistic sightings of a single Grampus griseus. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
43. Time series methods for the analysis of soundscapes and other cyclical ecological data.
- Author
-
Yoh, Natalie, Haley, Charlotte L., and Burivalova, Zuzana
- Subjects
TIME series analysis ,BIG data ,PRINCIPAL components analysis ,ANTHROPOGENIC effects on nature ,BIODIVERSITY monitoring ,TROPICAL forests - Abstract
Biodiversity monitoring has entered an era of 'big data', exemplified by a near‐continuous collection of sounds, images, chemical and other signals from organisms in diverse ecosystems. Such data streams have the potential to help identify new threats, assess the effectiveness of conservation interventions, as well as generate new ecological insights. However, appropriate analytical methods are often still missing, particularly with respect to characterizing cyclical temporal patterns.Here, we present a framework for characterizing and analysing ecological responses that represent nonstationary, complex temporal patterns and demonstrate the value of using Fourier transforms to decorrelate continuous data points. In our example, we use a framework based on three approaches (spectral analysis, magnitude squared coherence, and principal component analysis) to characterize differences in tropical forest soundscapes within and across sites and seasons in Gabon.By reconstructing the underlying, cyclic behaviour of the soundscape for each site, we show how one can identify circadian patterns in acoustic activity. Soundscapes in the dry season had a complex diel cycle, requiring multiple harmonics to represent daily variation, while in the wet season there was less variance attributable to the daily cyclic patterns.Our framework can be applied to most continuous, or near‐continuous ecological data collected at a fine temporal resolution, allowing ecologists to explore patterns of temporal autocorrelation at multiple levels for biologically meaningful trends. Such methods will become indispensable as biological big data are used to understand the impact of anthropogenic pressures on biodiversity and to inform efforts to mitigate them. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
44. Counting the chorus: A bioacoustic indicator of population density
- Author
-
Amanda K. Navine, Richard J. Camp, Matthew J. Weldy, Tom Denton, and Patrick J. Hart
- Subjects
Animal density ,Bioacoustics ,Call density ,Distance sampling ,Passive acoustic monitoring ,Wildlife monitoring ,Ecology ,QH540-549.5 - Abstract
Passive acoustic monitoring has grown in utility for tracking wildlife populations, although challenges remain when using acoustic detections to monitor population size and density. Distance sampling is considered the ‘gold standard’ for estimating animal densities but has several important limitations, especially for rare, cryptic, and high-density species. Here, we test the performance of a simple, quickly derived bioacoustic indicator for monitoring population density: call density—the proportion of recording samples containing vocalizations. Over three years, we collected synchronized bioacoustic and point-transect distance sampling data for eight forest bird species native to the Island of Hawai‘i, including four endangered species, across diverse ecosystems ranging from subalpine dry woodland to montane rainforest. The species studied exhibit varied population structures, from gregarious flocks to small, territorial family groups. Our results revealed significant, strong correlations between call density and distance sampling-based animal density estimates for all species, demonstrating that call density is a reliable indicator of animal density that can be used independently or in combination with traditional monitoring methods. Our analysis uses a fixed amount of manual validation of machine learning classifier output examples, without requiring prohibitively high classifier performance, and is robust to variation in vocal activity rates across time and space, making it both adaptable and scalable. This approach could enhance passive acoustic monitoring by providing a more sensitive population health indicator than commonly used detection/nondetection methods, facilitating prompt conservation and management decisions, particularly for species that are difficult to monitor with distance sampling.
- Published
- 2024
- Full Text
- View/download PDF
45. Comparing field performance of ultrasonic microphones to facilitate analysis of long‐term acoustic bat monitoring data
- Author
-
Katy R. Goodwin, Alan Kirschbaum, and Erin H. Gillam
- Subjects
acoustic detector ,bats ,correction factor ,echolocation ,passive acoustic monitoring ,ultrasonic microphone ,General. Including nature conservation, geographical distribution ,QH1-199.5 - Abstract
Abstract Passive acoustic monitoring is a standard technique for studying bat ecology and behavior. However, an issue that has received little attention is how to appropriately analyze data within a long‐term acoustic monitoring dataset when the equipment has been replaced and updated. Equipment changes are often inevitable, especially for microphones, which need to be replaced regularly due to extended weather exposure and associated reductions in recording quality. We compared 2 ultrasonic microphone models (Wildlife Acoustics SMM‐U1 and SMM‐U2) by deploying them side‐by‐side with the same acoustic detector unit. We tested 9 or 10 microphones per model in field deployments lasting an average of 9 nights. We compared triggering frequency, species classification, detection rates, and echolocation call parameters (as indicators of signal quality) from both microphones. The vast majority (97%) of our 25,949 paired recordings were captured simultaneously by both microphones. Yet, the SMM‐U2 outperformed the SMM‐U1 in terms of proportion of files classifiable to the species level (70% versus 61%), rate of bat detections per night (1–6.5 more detections per night depending on species), and recording quality. Based on our results, we propose a correction factor to facilitate direct comparison of datasets collected with these 2 different microphones. Our study will assist bat researchers in selecting appropriate equipment and accounting for potential biases in long‐term acoustic monitoring programs.
- Published
- 2024
- Full Text
- View/download PDF
46. High-pass filters do not consistently strengthen associations between acoustic indices and avian species richness
- Author
-
Rebecca L. Ducay and Brent S. Pease
- Subjects
Filtering ,Autonomous recording devices ,Avian monitoring ,Passive acoustic monitoring ,Soundscapes ,Vehicular noise ,Ecology ,QH540-549.5 - Abstract
High-pass sound filters are a common form of audio manipulation that attenuates or removes low frequency sounds from audio recordings. While high-pass filters are used to reduce anthropogenic noise, there is limited guidance on their optimal application and their effects on acoustic indices—numerical values derived from passive acoustic monitoring (PAM) recordings to summarize acoustic information. Here, we investigated the effects of three high-pass filter treatments (482 Hz, 1 kHz, and 2 kHz) on eight commonly implemented acoustic indices and one less-commonly used convolutional neural network metric. Specifically, we used simulated soundscapes with three levels of traffic noise interference and then applied the filter treatments to field recordings collected throughout Illinois, USA during May 2022–July 2023 and derived acoustic indices to further understand these effects. Our analysis revealed that interactions between acoustic filtering and vehicular noise pollution have diverse effects on the nine acoustic indices, both in simulated soundscapes and empirical PAM recordings. In general, a 1 kHz or 2 kHz filter was necessary in order to produce significant changes in acoustic index values. However, none of the applied filtering treatments consistently strengthened correlations between the examined acoustic indices and avian species richness. The Acoustic Complexity Index (ACI), Acoustic Richness Index (AR), and CityBioNet (CB) demonstrated greater resistance to biologically non-informative changes caused by filter implementation, with CB showing a notably higher correlation with species richness compared to the other examined indices. Our findings suggest that ACI, AR, and CB may be better suited to studies of avian species richness in soundscapes with high levels of anthropogenic noise. Future research is needed to establish best practices for acoustic filtering, understand the behavior of acoustic indices under various environmental contexts, and explore alternative methodologies for avian monitoring in human-modified contexts.
- Published
- 2024
- Full Text
- View/download PDF
47. Advanced montane bird monitoring using self-supervised learning and transformer on passive acoustic data
- Author
-
Yu-Cheng Wei, Wei-Lun Chen, Mao-Ning Tuanmu, Sheng-Shan Lu, and Ming-Tang Shiao
- Subjects
Audio-masked autoencoder ,Passive acoustic monitoring ,Autonomous recording unit ,Vocal activity ,Dawn chorus ,Bird sound classifier ,Information technology ,T58.5-58.64 ,Ecology ,QH540-549.5 - Abstract
Passive acoustic monitoring combined with deep learning-based bird sound classifiers is an effective tool, particularly in remote areas. While self-supervised learning has recently excelled in natural language processing and image recognition, its application to bird sound recognition remains limited. This study proposes an innovative self-supervised learning approach, which leverages vast amounts of passive acoustic recordings for pre-training, followed by fine-tuning of target species. Compared to the three state-of-the-art models based on transfer learning from ImageNet, the proposed method demonstrated improvements in overall recognition performance, with even more significant gains for tail-end species. These results confirm that domain-specific pre-training in self-supervised learning enhances downstream recognition tasks and provides greater robustness, benefiting tail-end species in imbalanced ecological datasets. Our experiments further demonstrate that integrating open-source datasets and data augmentation techniques is the most effective strategy for mitigating data imbalances and cross-domain issues. In addition, introducing a ‘catch-all’ category into training datasets has been shown to improve model robustness in open set recognition scenarios. We also identified the minimum viable sample size requirements for our proposed model and explored the impact of overlapping bird vocalizations during dawn choruses on model performance. Targeting 31 bird species in the montane regions of subtropical Taiwan, the model achieved a class-wise mean average precision of 0.782 and an overall precision of 85.6 % at the F0.5 threshold in dawn chorus soundscape recordings. This study confirms the effectiveness and advantages of self-supervised learning in bird sound recognition, supporting long-term monitoring of bird distribution and vocal activity in remote montane areas.
- Published
- 2024
- Full Text
- View/download PDF
48. A deep learning model for detecting and classifying multiple marine mammal species from passive acoustic data
- Author
-
Quentin Hamard, Minh-Tan Pham, Dorian Cazau, and Karine Heerah
- Subjects
Ecoacoustics ,Object detection ,Offshore wind farm ,Passive acoustic monitoring ,Marine mammal ,Information technology ,T58.5-58.64 ,Ecology ,QH540-549.5 - Abstract
Underwater passive acoustics is used worldwide for multi-year monitoring of marine mammals. Yet, the large amount of audio recordings raises the need to automate the detection of acoustic events. For instance, the increasing number of Offshore Wind Farms (OWF) raises key environmental and societal issues relating to their impacts on wildlife. In this context, monitoring marine mammals along with information on their acoustic environment throughout the OWF life cycle is crucial. The objective of this study is to evaluate the ability of a single deep learning model to precisely detect and localize, in time and in frequency, the marine mammal sounds over a wide frequency range and classify them by species and sound types.A broadband hydrophone, deployed at the Fécamp OWF (Normandy, France), recorded the underwater soundscape including sounds from marine mammals occurring in the area. To visualize these sounds, 15-s spectrograms were computed. From these images, dolphin (D) and porpoise (P) sounds were manually annotated, including different types of sounds: Click-Trains (DCT, PCT), Buzzes (DB, PB) and Whistles (DW). The spectrograms were then split into five-fold cross-validation datasets, each containing one half of manual annotations and one half of only background noise. A Faster R-CNN model was trained to precisely detect and classify the marine mammal sounds in the spectrograms.Three model output configurations were used: (1) overall detection of marine mammals (presence vs. absence), (2) detection and classification of species (two classes: dolphin, porpoise) and (3) sound types (five classes: DCT, DB, DW, PCT, PB). For the simplest configuration (1) 15.4 % of the spectrogram dataset had detections while missing only 6.6 % of annotated spectrograms. For the more precise configurations, (2) and (3), the mean Average Precision (mAP) achieved were 92.3 % (2) and 84.3 % (3), and the macro average Area under the curve (AUC) 95.7 % (2) and 94.9 % (3).This model will help to speed up the annotation processes, by reducing the spectrogram quantity to be manually analyzed and having time-frequency boxes already drawn. Several model parameters can be adjusted to trade off missed detections and false positives which need to be carefully considered and adapted to the problem. For instance, these adjustments would be particularly relevant depending on the human resources available to manually check the model detections and the criticality of missing marine mammal sounds. These models are promising, ranging from the simple detection of marine mammal presence to precise ecological inferences over the long term.
- Published
- 2024
- Full Text
- View/download PDF
49. Spatio-temporal patterns of fish acoustic communities in Western Mediterranean coralligenous reefs: optimizing monitoring through recording duration
- Author
-
Gabriella La Manna, Mariangela Moro Merella, Riccardo Vargiu, Giuseppe Morello, Gianluca Sarà, and Giulia Ceccherelli
- Subjects
biodiversity ,cryptic species ,fish acoustic community ,fish sounds ,monitoring strategies ,passive acoustic monitoring ,Science ,General. Including nature conservation, geographical distribution ,QH1-199.5 - Abstract
In this study, we explored the fish acoustic community at two coralligenous sites in Sardinia (Tavolara and Santa Teresa, western Mediterranean Sea) during the summer 2023. Our goal was to understand spatial and temporal patterns of fish acoustic activity on different temporal scales to offer insights for optimizing acoustic monitoring of this crucial ecosystem. We identified seventeen distinct sound types, revealing a diverse acoustic community. Tavolara had higher acoustic richness and abundance compared to Santa Teresa, which may be attributed to site-specific factors such as habitat structure, species composition, or levels of protection. Temporal analysis revealed clear diel patterns, with certain sounds associated with nocturnal or diurnal periods, reflecting the daily rhythms of different species. The study also examined how recording duration influenced acoustic richness, finding that longer recordings (15 minutes per hour and 15 minutes per hour at night) provided a more comprehensive detection of acoustic activity. Additionally, the number of recording days required to detect species richness varied depending on the site. While extended recordings improve the likelihood of detecting rare or sporadic sounds, they also present challenges in data management and equipment maintenance. The study underscores the importance of carefully planning sampling strategies to optimize acoustic monitoring and ensure effective and sustainable ecological research in coralligenous ecosystems.
- Published
- 2024
- Full Text
- View/download PDF
50. ecoSound-web: an open-source, online platform for ecoacoustics [version 3; peer review: 3 approved]
- Author
-
Thomas C Wanger, Liu Dilong, Noemí Pérez, Matthias Markolf, Anna F. Cord, Tara Hanf-Dressler, and Kevin F.A. Darras
- Subjects
Soundscape ,sound analysis ,ecoacoustics ,passive acoustic monitoring ,automated sound recording ,autonomous recording units ,eng ,Medicine ,Science - Abstract
Passive acoustic monitoring of soundscapes and biodiversity produces vast amounts of audio recordings, but the management and analyses of these raw data present technical challenges. A multitude of software solutions exist, but none can fulfil all purposes required for the management, processing, navigation, and analysis of acoustic data. The field of ecoacoustics needs a software tool that is free, evolving, and accessible. We take a step in that direction and present ecoSound-web: an open-source, online platform for ecoacoustics designed and built by ecologists and software engineers. ecoSound-web can be used for storing, re-sampling, organising, analysing, and sharing soundscape recording or metadata projects. Specifically, it allows manual annotation of soniferous animals and soundscape components, automatic annotation with deep-learning models for all birds and for UK bat species, peer-reviewing annotations, analysing audio in time and frequency dimensions, computing alpha acoustic indices, and providing reference sound libraries for different taxa. We present ecoSound-web’s structure and features, and describe its operation for typical use cases such as sampling bird and bat communities, using a primate call library, and the analysis of soundscape components and acoustic indices. ecoSound-web is available from: https://github.com/ecomontec/ecoSound-web
- Published
- 2024
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.