Biology subjects

Boissy, A.

Publications and source records attributed to Boissy, A..

4 recordsLinked to original sources

bioRxiv2025

Socio-acoustic co-selection? Vocal encoding of sociability prevails over emotions in sheep bleats

Vocalisations of animals are good indicators of their emotions. Temperament is known to influence the regulation and expression of emotions. However, how animal temperament affects their vocalisations and particularly their vocal expressions of emotions remains largely unexplored. Sociability is often measured as the behavioural reactivity to social separation and is a temperament trait intrinsically linked to emotional reactivity. Most social species respond to this challenging situation using contact calls. Here, we investigated whether the acoustic structure of these calls reflect sociability, emotions or both. Among 152 recorded female lambs, 42 belonged to two diverging sheep lines selected for high or low sociability. High bleats were recorded both in isolation (social challenge, all lambs) then before receiving a food treat (non-social challenge, selected lambs) to investigate the link between vocalisations, emotions and heritable sociability. The acoustic features of isolation bleats differed between lines, but it was not the case for pre-food treat bleats. Surprisingly, the genetic selection index and social behaviour explained better the structure of isolation bleats than the arousal. Last, encoding of individuality in isolation bleats was impaired by the genetic selection. Our findings show that selecting for sociable animals affects vocal signatures in calls produced during a social challenge, leading us to hypothesize a socio-acoustic co-selection.

animal behavior and cognition↗

bioRxiv2020

Maternal reactivity of ewes at lambing is genetically linked to their behavioral reactivity in an arena test

In sheep, the bond between the dam and her lambs is established during the first hours of a lamb s life. Genetic variability for behavioral reactivity of ewes assessed in an arena test performed 24 h after lambing has already been reported. However, there is no evidence that this reactivity represents the ewe s maternal reactivity at lambing in outdoor conditions. The objective of this study was to investigate whether or not the behavioral reactivity of ewes in the arena test is genetically related to their maternal reactivity measured at lambing. A total of 935 Romane ewes were studied. The maternal reactivity of ewes at the outdoor lambing site was recorded in response to a human approach and to the handling of the lambs. Their behavioral reactivity was also recorded 24 h post-lambing in the arena test that involved a separation from the litter and a human presence. Flight distance, aggressive reaction, time to restore contact with the litter at the lambing site and maternal behavior scores were moderately heritable (0.18 to 0.34), and vocalizations were slightly heritable (0.16). All of these behaviors were genetically correlated with the behavioral reactivity in the arena test. The highest genetic correlations (from 0.60 to 0.90) were found for maternal behavioral scores, flight distance and high-pitched bleats. In conclusion, behavioral reactivity in the arena test can be used to assess early maternal reactivity in standardized conditions. Such phenotyping could be used for genetic improvement of maternal behavior in sheep.

genetics↗

bioRxiv2020

A non-invasive radar system for automated behavioural tracking: application to sheep

Automated quantification of the behaviour of freely moving animals is increasingly needed in ethology, ecology, genetics and evolution. State-of-the-art approaches often require tags to identify animals, high computational power for data collection and processing, and are sensitive to environmental conditions, which limits their large-scale utilisation. Here we introduce a new automated tracking system based on millimetre-wave radars for real time robust and high precision monitoring of untagged animals. To validate our system, we tracked 64 sheep in a standard indoor behavioural test used for genetic selection. First, we show that the proposed radar application is faster and more accurate than conventional video and infrared tracking systems. Next, we illustrate how new behavioural estimators can be derived from the radar data to assess personality traits in sheep for behavioural phenotyping. Finally, we demonstrate that radars can be used for movement tracking at larger spatial scales, in the field, by adjusting operating frequency and radiated electromagnetic power. Millimetre-wave radars thus hold considerable promises for high-throughput recording of the behaviour of animals with various sizes and locomotor modes, in different types of environments.

animal behavior and cognition↗

bioRxiv2020

Piglets vocally express the anticipation of (pseudo)-social contexts in their grunts

Emotions not only arise in reaction to an eliciting event but also while anticipating it, making this context a way to assess the emotional value of events. Anticipatory studies have poorly considered vocalisations whereas they carry information about the emotional state. We studied the grunts of piglets that anticipated two (pseudo)social events known to elicit positive emotions more or less intense: arrival of a familiar conspecifics and arrival of a familiar human. Both time and spectral features of the vocal expression of piglets differed according to the emotional context. Piglets produced low-frequency grunts at a higher rate when anticipating conspecifics compared to human. Spectral noise increased when piglets expected conspecifics, whereas the duration and frequency range increased when expecting a human. When the arrival of conspecifics was delayed grunts duration increased, while when the arrival of the human was delayed spectral parameters were comparable to those during isolation. This shows that vocal expressions in piglets during anticipation are specific to the expected reward and to the time duration between signal and the delivery of the reward. Vocal expression (time and spectral features) is thus a good way to explore emotional state of piglets during anticipation of challenging events.

animal behavior and cognition↗