Life Sciences Commons^™

Goats Distinguish Between Positive And Negative Emotion-Linked Vocalisations, Luigi Baciadonna, Elodie Briefer, Livio Favaro, A. G. Mcelligott

Bioacoustics Collection

Background: Evidence from humans suggests that the expression of emotions can regulate social interactions and promote coordination within a group. Despite its evolutionary importance, social communication of emotions in non-human animals is still not well understood. Here, we combine behavioural and physiological measures, to determine if animals can distinguish between vocalisations linked to different emotional valences (positive and negative). Using a playback paradigm, goats were habituated to listen to a conspecific call associated with positive or negative valence (habituation phase) and were subsequently exposed to a variant of the same call type (contact call) associated with the opposite valence (dishabituation …

Bat Detective—Deep Learning Tools For Bat Acoustic Signal Detection, Oisin Mac Aodha, Rory Gibb, Kate E. Barlow, Michael Firman, Robin Freeman, Briana Harder, Libby Kinsey, Gary R. Mead, Stuart E. Newson, Ivan Pandourski, Stuart Parsons, Jon Russ, Abigel Szodoray-Paradi, Elena Tilova, Mark Girolami, Gabriel Brostow, Kate E. Jones

Bioacoustics Collection

Passive acoustic sensing has emerged as a powerful tool for quantifying anthropogenic impacts on biodiversity, especially for echolocating bat species. To better assess bat population trends there is a critical need for accurate, reliable, and open source tools that allow the detection and classification of bat calls in large collections of audio recordings. The majority of existing tools are commercial or have focused on the species classification task, neglecting the important problem of first localizing echolocation calls in audio which is particularly problematic in noisy recordings. We developed a convolutional neural network based open-source pipeline for detecting ultrasonic, full-spectrum, search-phase …

Encoding Of Emotional Valence In Wild Boar (Sus Scrofa) Calls, Anne-Laure Maigrot, Edna Hillmann, Elodie Briefer

Bioacoustics Collection

Measuring emotions in nonhuman mammals is challenging. As animals are not able to verbally report how they feel, we need to find reliable indicators to assess their emotional state. Emotions can be described using two key dimensions: valence (negative or positive) and arousal (bodily activation or excitation). In this study, we investigated vocal expression of emotional valence in wild boars (Sus scrofa). The animals were observed in three naturally occurring situations: anticipation of a food reward (positive), affiliative interactions (positive), and agonistic interactions (negative). Body movement was used as an indicator of emotional arousal to control for the effect of …

Perception Of Emotional Valence In Horse Whinnies, Elodie Briefer, Roi Mandel, Anne-Laure Maigrot, Sabrina Briefer Freymond, Iris Bachmann, Edna Hillmann

Bioacoustics Collection

Background: Non-human animals often produce different types of vocalisations in negative and positive contexts (i.e. different valence), similar to humans, in which crying is associated with negative emotions and laughter is associated with positive ones. However, some types of vocalisations (e.g. contact calls, human speech) can be produced in both negative and positive contexts, and changes in valence are only accompanied by slight structural differences. Although such acoustically graded signals associated with opposite valence have been highlighted in some species, it is not known if conspecifics discriminate them, and if contagion of emotional valence occurs as a result. We tested …

Vocal Individuality And Species Divergence In The Contact Calls Of Banded Penguins, Livio Favaro, Claudia Gili, Cristiano Da Rugna, Guido Gnone, Chiara Fissore, Daniel Sanchez, Alan G. Mcelligott, Marco Gamba, Daniela Pessani

Bioacoustics Collection

Penguins produce contact calls to maintain social relationships and group cohesion. Such vocalisations have recently been demonstrated to encode individual identity information in the African penguin. Using a source-filter theory approach, we investigated whether acoustic cues of individuality can also be found in other Spheniscus penguins and the acoustic features of contact calls have diverged within this genus. We recorded vocalisations from two ex-situ colonies of Humboldt penguin and Magellanic penguin (sympatric and potentially interbreeding in the wild) and one ex-situ group of African penguins (allopatric although capable of interbreeding with the other two species in captivity). We measured 14 …

Expression Of Emotional Arousal In Two Different Piglet Call Types, Linhart Pavel, Victoria F. Ratcliffe, David Reby, Marek Špinka

Bioacoustics Collection

Humans as well as many animal species reveal their emotional state in their voice. Vocal features show strikingly similar correlation patterns with emotional states across mammalian species, suggesting that the vocal expression of emotion follows highly conserved signalling rules. To fully understand the principles of emotional signalling in mammals it is, however, necessary to also account for any inconsistencies in the way that they are acoustically encoded. Here we investigate whether the expression of emotions differs between call types produced by the same species. We compare the acoustic structure of two common piglet calls—the scream (a distress call) and the …

A General Framework For Animal Density Estimation From Acoustic Detections Across A Fixed Microphone Array, Ben C. Stevenson, David L. Borchers, Res Altwegg, René Swift, Douglas M. Gillespie, G. John Measey

Bioacoustics Collection

1. Acoustic monitoring can be an efficient, cheap, non‐invasive alternative to physical trapping of individuals. Spatially explicit capture–recapture (SECR) methods have been proposed to estimate calling animal abundance and density from data collected by a fixed array of microphones. However, these methods make some assumptions that are unlikely to hold in many situations, and the consequences of violating these are yet to be investigated.
2. We generalize existing acoustic SECR methodology, enabling these methods to be used in a much wider variety of situations. We incorporate time‐of‐arrival (TOA) data collected by the microphone array, increasing the precision of calling animal density estimates. …

Real-Time Bioacoustics Monitoring And Automated Species Identification, T. Mitchell Aide, Carlos Corrada-Bravo, Marconi Campos-Cerqueira, Carlos Milan, Giovany Vega, Rafael Alvarez

Bioacoustics Collection

Traditionally, animal species diversity and abundance is assessed using a variety of methods that are generally costly, limited in space and time, and most importantly, they rarely include a permanent record. Given the urgency of climate change and the loss of habitat, it is vital that we use new technologies to improve and expand global biodiversity monitoring to thousands of sites around the world. In this article, we describe the acoustical component of the Automated Remote Biodiversity Monitoring Network (ARBIMON), a novel combination of hardware and software for automating data acquisition, data management, and species identification based on audio recordings. …

Estimating Animal Population Density Using Passive Acoustics, Tiago A. Marques, Len Thomas, Stephen W. Martin, David K. Mellinger, Jessica A. Ward, Danielle Harris, Peter L. Tyack

Bioacoustics Collection

Reliable estimation of the size or density of wild animal populations is very important for effective wildlife management, conservation and ecology. Currently, the most widely used methods for obtaining such estimates involve either sighting animals from transect lines or some form of capture-recapture on marked or uniquely identifiable individuals. However, many species are difficult to sight, and cannot be easily marked or recaptured. Some of these species produce readily identifiable sounds, providing an opportunity to use passive acoustic data to estimate animal density. In addition, even for species for which other visually based methods are feasible, passive acoustic methods offer …

Your Attention Please: Increasing Ambient Noise Levels Elicits A Change In Communication Behaviour In Humpback Whales (Megaptera Novaeangliae), Rebecca A. Dunlop, Douglas H. Cato, Michael J. Noad

Bioacoustics Collection

High background noise is an important obstacle in successful signal detection and perception of an intended acoustic signal. To overcome this problem, many animals modify their acoustic signal by increasing the repetition rate, duration, amplitude or frequency range of the signal. An alternative method to ensure successful signal reception, yet to be tested in animals, involves the use of two different types of signal, where one signal type may enhance the other in periods of high background noise. Humpback whale communication signals comprise two different types: vocal signals, and surface-generated signals such as ‘breaching’ or ‘pectoral slapping’. We found that …

Automatic Recognition Of Frog Calls Using A Multi-Stage Average Spectrum, Wen-Ping Chen, Song-Shyong Chen, Chun-Cheng Lin, Ya-Zhung Chen, Wen-Chih Lin

Bioacoustics Collection

The automatic recognition of animal sounds is one of the powerful techniques for replacing the traditional ecological survey method that mainly depends on manpower, which is hence both costly and time consuming. This study developed an automatic frog call recognition system based on the combination of a pre-classification method of the syllable lengths and a multi-stage average spectrum (MSAS) method. In this system, the input frog syllables are first classified into one of the four groups determined by the pre-classification method according to syllable length. Then the proposed MSAS method is used to extract the standard feature template to analyze …