TY - JOUR T1 - Acoustic signals in cicada courtship behaviour (order Hemiptera, genus Tibicina) JF - Journal of Zoology Y1 - 1999 A1 - Sueur, Jerome A1 - Aubin, Thierry KW - audible and silent wing-flicks KW - cicadas Tibicina KW - courtship KW - male–female duet KW - sound communication AB -

During pair formation, cicadas produce acoustic signals that allow sexual partners to meet. The male is generally the emitter, producing calling songs at long range and courtship songs at short range, and the female generally the receiver. The male–female courtship behaviour of seven taxa belonging to the Palaearctic genus Tibicina is described here for the first time. Male courtship songs consisted of a succession of groups of pulses arranged in two sub‐groups. They were short in duration with strong amplitude variations. In all taxa, courtship songs were preceded by a series of 1–5 audible wing‐flicks. Differences in courtship song structure between two pairs of sympatric species, respectively T. corsica corsica/T. nigronervosa and T. corsica fairmairei/T. tomentosa, suggest that courtship signals could act as distinctive species mating recognition systems. In response to male acoustic signalling, females of T. c. corsica, T. c. fairmairei and T. nigronervosa produced audible wing‐flicks such that both sexes established an acoustic duet ending in physical contact. In addition, males and females of T. tomentosa produced silent wing‐flicks, a previously unknown behaviour, which could facilitate pheromone diffusion. Females did not exhibit a species‐specific temporal pattern in acoustic reply to male courtship song and female wing‐flick behaviour does not seem necessary for pair formation. Nevertheless, this strategy through male and female signalling ensured a reciprocal phonotactic approach that probably enhanced the likelihood for the two sexes to meet in complex habitats.

VL - 262 UR - http://doi.wiley.com/10.1017/S0952836903004680 IS - 3 JO - J. Zoology ER - TY - JOUR T1 - Freshwater ecoacoustics as a tool for continuous ecosystem monitoring JF - Frontiers in Ecology and the Environment Y1 - 2018 A1 - Linke, Simon A1 - Gifford, Toby A1 - Desjonquères, Camille A1 - Tonolla, Diego A1 - Aubin, Thierry A1 - Barclay, Leah A1 - Karaconstantis, Chris A1 - Kennard, Mark J. A1 - Rybak, Fanny A1 - Sueur, Jerome KW - anthropogenic noise KW - fishes KW - freshwater KW - macroinvertebrates KW - monitoring KW - physicochemical AB -

Abstract
Passive acoustic monitoring is gaining popularity in ecology as a practical and non‐invasive approach to surveying ecosystems. This technique is increasingly being used to monitor terrestrial systems, particularly bird populations, given that it can help to track temporal dynamics of populations and ecosystem health without the need for expensive resampling. We suggest that underwater acoustic monitoring presents a viable, non‐invasive, and largely unexplored approach to monitoring freshwater ecosystems, yielding information about three key ecological elements of aquatic environments – (1) fishes, (2) macroinvertebrates, and (3) physicochemical processes – as well as providing data on anthropogenic noise levels. We survey the literature on this approach, which is substantial but scattered across disciplines, and call for more cross‐disciplinary work on recording and analysis techniques. We also discuss technical issues and knowledge gaps, including background noise, spatiotemporal variation, and the need for centralized reference collection repositories. These challenges need to be overcome before the full potential of passive acoustics in dynamic detection of biophysical processes can be realized and used to inform conservation practitioners and managers.

UR - https://doi.org/10.1002/fee.1779 ER - TY - JOUR T1 - Estimating animal acoustic diversity in tropical environments using unsupervised multiresolution analysis JF - Ecological Indicators Y1 - 2018 A1 - Ulloa, Juan Sebastian A1 - Aubin, Thierry A1 - Llusia, Diego A1 - Bouveyron, Charles A1 - Sueur, Jerome KW - Acoustic community KW - Ecoacoustic monitoring KW - Nocturnal soundscape KW - Unsupervised machine learning KW - Wavelets AB -

Ecoacoustic monitoring has proved to be a viable approach to capture ecological data related to animal communities. While experts can manually annotate audio samples, the analysis of large datasets can be significantly facilitated by automatic pattern recognition methods. Unsupervised learning methods, which do not require labelled data, are particularly well suited to analyse poorly documented habitats, such as tropical environments. Here we propose a new method, named Multiresolution Analysis of Acoustic Diversity (MAAD), to automate the detection of relevant structure in audio data. MAAD was designed to decompose the acoustic community into few elementary components (soundtypes) based on their time–frequency attributes. First, we used the short-time Fourier transform to detect regions of interest (ROIs) in the time–frequency domain. Then, we characterised these ROIs by (1) estimating the median frequency and (2) by running a 2D wavelet analysis at multiple scales and angles. Finally, we grouped the ROIs using a model-based subspace clustering technique so that ROIs were automatically annotated and clustered into soundtypes. To test the performance of the automatic method, we applied MAAD to two distinct tropical environments in French Guiana, a lowland high rainforest and a rock savanna, and we compared manual and automatic annotations using the adjusted Rand index. The similarity between the manual and automated partitions was high and consistent, indicating that the clusters found are intelligible and can be used for further analysis. Moreover, the weight of the features estimated by the clustering process revealed important information about the structure of the acoustic communities. In particular, the median frequency had the strongest effect on modelling the clusters and on classification performance, suggesting a role in community organisation. The number of clusters found in MAAD can be regarded as an estimation of the soundtype richness in a given environment. MAAD is a comprehensive and promising method to automatically analyse passive acoustic recordings. Combining MAAD and manual analysis would maximally exploit the strengths of both human reasoning and computer algorithms. Thereby, the composition of the acoustic community could be estimated accurately, quickly and at large scale.

VL - 90 UR - http://linkinghub.elsevier.com/retrieve/pii/S1470160X1830181X JO - Ecological Indicators ER - TY - JOUR T1 - When males whistle at females: complex FM acoustic signals in cockroaches JF - Naturwissenschaften Y1 - 2006 A1 - Sueur, Jerome A1 - Aubin, Thierry KW - acoustic communication KW - Cockroach KW - courtship KW - Elliptorhina chopardi KW - frequency modulations KW - two-voice system AB -

Male cockroaches of the species Elliptorhina chopardi expel air through a pair of modified abdominal spiracles during courtship. This air expulsion simultaneously produces air and substrate-borne vibrations. We described and compared in details these two types of vibrations. Our analysis of the air-borne signals shows that males can produce three categories of signals with distinct temporal and frequency parameters. “Pure whistles” consist of two independent harmonic series fast frequency modulated with independent harmonics that can cross each other. “Noisy whistles” also possess two independent voices but include a noisy broad-band frequency part in the middle. Hiss sounds are more noise-like, being made of a broad-band frequency spectrum. All three call types are unusually high in dominant frequency (>5 kHz) for cockroaches. The substrate-borne signals are categorised similarly. Some harmonics of the substrate-borne signals were filtered out, however, making the acoustic energy centered on fewer frequency bands. Our analysis shows that cockroach signals are complex, with fast frequency modulations and two distinct voices. These results also readdress the question of what system could potentially receive and decode the information contained within such complex sounds.

VL - 93 UR - http://link.springer.com/10.1007/s00114-006-0135-9 IS - 10 JO - Naturwissenschaften ER - TY - JOUR T1 - Species Identity Coding by the Song of a Rainforest Warbler: An Adaptation to Long-Range Transmission? JF - Acta Acustica united with Acustica Y1 - 2014 A1 - Aubin, Thierry A1 - Mathevon, Nicolas A1 - da Silva, Maria Luisa AB -

In tropical forest, visual communication is limited by obstacles and birds use mainly the acoustic channel to communicate at long range. However, in this dense vegetation environment, sounds may be greatly altered during transmission overdistance. To be e ff ecti ve,information transfer must rely upon parameters resistant to degra- dation, e.g., aslowly-modulated and low-pitched signal. Nevertheless, acommon bird of the Brazilian Atlantic forest, the White-bro wed Warbler Basileuterus leucoblep harus (Oscines, Parulidae ), presents aterritorial song having the opposite characteristics: awide frequenc yband and high-pitched signal. Thus, the aim of our study wastocharacterize the propag ation-induced modifi cations of this signal, and to identify its species-specifi ccod- ing parameters. According to propag ation experiments performed in the field at di ff erent distances, it appears that the signal is particularly sensiti ve to degradation through the vegetation: the fineacoustic structures (rapid frequenc yand amplitude modulations )are strongly modifi ed, and the highest pitched notes tend to disappear at a relati vely short distance (about 25 m).Playback experiments showthat, for species-specifi crecognition, birds use the only feature that is resistant to degradation, i.e., the overall slowfrequenc ymodulation of the song phrase, and ignore those parameters sensiti ve to propag ation distance. Moreo ver, birds do not need to hear the whole song, apart of it being su ffi cient to elicit abehavioural response. Thus, in spite of its structure, the song of the White- browed Warbler succeeds in conveying, overalong range (more than 100m )and through the dense vegetation, the information required for species- specifi crecognition.

VL - 100 UR - http://openurl.ingenta.com/content/xref?genre=article&issn=1610-1928&volume=100&issue=4&spage=748 IS - 4 JO - Acta Acustica united with Acustica ER - TY - JOUR T1 - Seewave, a free modular tool for sound analysis and synthesis JF - Bioacoustics Y1 - 2008 A1 - Sueur, Jerome A1 - Aubin, Thierry A1 - Simonis, Caroline AB -

We review Seewave, new software for analysing and synthesizing sounds. Seewave is free and works on a wide variety of operating systems as an extension of the R operating environment. Its current 67 functions allow the user to achieve time, amplitude and frequency analyses, to estimate quantitative differences between sounds, and to generate new sounds for playback experiments. Thanks to its implementation in the R environment, Seewave is fully modular. All functions can be combined for complex data acquisition and graphical output, they can be part of important scripts for batch processing and they can be modified ad libitum. New functions can also be written, making Seewave a truly open-source tool.

VL - 18 UR - http://www.tandfonline.com/doi/abs/10.1080/09524622.2008.9753600 IS - 2 JO - Bioacoustics ER -