Multi-Index Ecoacoustics Analysis for Terrestrial Soundscapes: A New Semi-Automated Approach Using Time-Series Motif Discovery and Random Forest Classification

Frontiers in Ecology and Evolution, Journal Year: 2021, Volume and Issue: 9

Published: Dec. 17, 2021

High rates of biodiversity loss caused by human-induced changes in the environment require new methods for large scale fauna monitoring and data analysis. While ecoacoustic is increasingly being used shows promise, analysis interpretation big produced remains a challenge. Computer-generated acoustic indices potentially provide biologically meaningful summary sound, however, temporal autocorrelation, difficulties statistical multi-index lack consistency or transferability different terrestrial environments have hindered application those contexts. To address these issues we investigate use time-series motif discovery random forest classification multi-indices through two case studies. We semi-automated workflow combining (acoustic complexity, entropy, events per second) to categorize sounds unfiltered recordings according main source sound present (birds, insects, geophony). Our approach showed more than 70% accuracy label assignment both datasets. The categories assigned were broad, but believe this great improvement on traditional single index environmental as can now give ecological meaning way that does not expert knowledge manual validation only necessary small subset data. Furthermore, which largely ignored researchers, has been effectively eliminated technique applied here first time expect our will greatly assist researchers future it allow datasets be rapidly processed labeled, enabling screening undesired sounds, such wind, target biophony (insects birds) bioacoustics research.

Language: Английский

---

Soundscape components inform acoustic index patterns and refine estimates of bird species richness

Frontiers in Remote Sensing, Journal Year: 2023, Volume and Issue: 4

Published: May 15, 2023

Ecoacoustic monitoring has proliferated as autonomous recording units (ARU) have become more accessible. ARUs provide a non-invasive, passive method to assess ecosystem dynamics related vocalizing animal behavior and human activity. With the ever-increasing volume of acoustic data, field grappled with summarizing ecologically meaningful patterns in recordings. Almost 70 indices been developed that offer summarized measurements bioacoustic activity conditions. However, their systematic relationships varying sonic conditions are inconsistent lead non-trivial interpretations. We used an dataset over 725,000 min recordings across 1,195 sites Sonoma County, California, evaluate relationship between 15 established using five soundscape components classified convolutional neural network: anthropophony (anthropogenic sounds), biophony (biotic geophony (wind rain), quiet (lack emergent sound), interference (ARU feedback). generalized additive models ecoacoustic indicators avian diversity. Models included explained degrees performance (avg. adj-R 2 = 0.61 ± 0.16; n 1,195). For example, we found normalized difference index was most sensitive while being less influenced by ambient sound. all were affected non-biotic sound sources degrees. combined highly predictive modeling bird species richness (deviance 65.8%; RMSE 3.9 species; 1,185 sites) for targeted, morning-only periods. Our analyses demonstrate confounding effects on indices, recommend applications be based anticipated environments. instance, presence extensive rain wind, suggest minimally geophony. Furthermore, evidence measure biodiversity (bird richness) is aggregate biotic (biophony). This adds recent work identifies reliable generalizable biodiversity.

Language: Английский

---

It is not just about birds: what do acoustic indices reveal about a Costa Rican tropical rainforest?

Neotropical Biodiversity, Journal Year: 2021, Volume and Issue: 7(1), P. 431 - 442

Published: Jan. 1, 2021

Acoustic monitoring is used to assess biodiversity across large spatial and temporal scales. However, extracting meaningful information from data sets might be exceedingly time consuming. For this reason, acoustic indices have been proposed as proxies for monitoring. Although hold great promise standardizing analysis, the complexity of conditions requires careful examination relationship between an index underlying process interest. We evaluated 11 at two operational levels: (1) community level (an aggregation species that produces sound), using birds example how well predict bird (abundance, richness, evenness diversity); (2) soundscape (the collection biological, geophysical anthropogenic sounds a landscape), classify study sites according their ecological condition. To among these variables, we selected with different (in terms vegetation structure traffic noise) within Braulio Carrillo National Park (BCNP), Costa Rica. sampled 12 sampling points four visits each site June 2017 August 2018. continuously recorded sunrise sunset, 10 minutes every hour, during consecutive days per visit. In addition, performed counts visit (sunrise sunset). correlation analysis 4 indices. analyzed ability Furthermore, Bird abundance richness were positively correlated negatively diversity index, but whole set predicted weakly. classification was conducted high average precision 0.93 (sd = 0.08). appear more promising evaluating condition than abundance, or specific animal groups, in case birds, tropical rainforests.

Language: Английский

---

Temporal dynamics of acoustic diversity in managed forests

Frontiers in Ecology and Evolution, Journal Year: 2024, Volume and Issue: 12

Published: Sept. 24, 2024

Introduction In production forests, management can have cascading effects on biodiversity and ecosystem services. Acoustic diversity reflects the of vocalizing animals has also considerable recreational value for human well-being, but relationship between acoustic forest remains largely unexplored Method We recorded plots along a gradient silvicultural intensity (SMI) in three regions Germany. explored diurnal seasonal temporal dynamics index (ADI) from March to July using generalized additive mixed models (GAMMs). further investigated interrelation intensity, structural diversity, as well tree bird species richness abundance equation modeling (SEM). Results Silvicultural had significant ADI May June dawn till dusk, variance explained by SMI was low. confirmed our hypothesis that reduced due its abundance. Discussion indices provide valuable insights into how affects activity soniferous communities. discuss this indicate both changes their vocal activity. address potential implications management.

Language: Английский

---

Relationship between acoustic indices, length of recordings and processing time: a methodological test

Biota Colombiana, Journal Year: 2021, Volume and Issue: 22(1)

Published: Jan. 1, 2021

Ecoacoustic approaches have the potential to provide rapid biodiversity assessments and avoid costly fieldwork. Their use in studies for improving management conservation of natural landscapes has grown considerably recent years. Standardised methods sampling acoustic information that deliver reliable consistent results within between ecosystems are still lacking. Sampling frequency duration particularly important considerations because shorter, intermittent recordings mean recorder batteries last longer data processing is less computationally intensive, but a smaller proportion available soundscape sampled. Here, we compare indices time subsamples increasing clipped from 94 one-hour recordings, test how different behave, order identify minimum sample length required. Our suggest short distributed across survey period accurately represent patterns, while optimizing collection processing. ACI H most stable indices, showing an ideal schedule ten 1-minute samples hour. Although ADI, AEI NDSI well patterns under same schedule, these more robust continuous recording formats. Such targeted subsampling could greatly reduce storage computational power requirements large-scale long-term projects.

Language: Английский

---