Goats can probably distinguish subtle emotional changes in the calls of other goats, according to a new study led by Queen Mary University of London.
The researchers measured behavioural and physiological changes in goats to determine if they can differentiate between calls linked to positive and negative emotions.
They found that when the emotion of a call changed, the likeliness of the goats to look towards the source of the sound also changed suggesting that they can distinguish the emotional content of calls of another goat.
The study, published in the journal Frontiers in Zoology, also shows that the goats' heart-rate variability - the variation in time between each heartbeat - was greater when positive calls were played compared to when negative calls were played.
Together, these results provide the first strong evidence that goats are not only able to distinguish call variants based on the emotion that they convey, but also that their own emotions are potentially affected.
The study was carried out in collaboration with the University of Roehampton, ETH Zurich and University of Turin.
Luigi Baciadonna, lead author of the study from Queen Mary University of London, said: "Despite its evolutionary importance, social communication of emotions in non-human animals is still not well understood. Our results suggest that non-human animals are not only attentive, but might also be sensitive to the emotional states of other individuals."
Many social animals live under environmental conditions where individuals are not always in visual contact with one another during the day or night, and therefore, could acquire an evolutionary advantage through the discrimination of the emotional content of the calls of others from their species.
Elodie Briefer, co-corresponding author of the study, who was based at ETH Zurich during the research and is now at the University of Copenhagen, said: "Expressing emotions using vocalisations and being able to detect and share the emotional state of another animal from the same species may facilitate coordination among the individuals in a group and strengthen social bonds and group cohesion."
Dr Alan McElligott who led the study at Queen Mary University of London and is now based at the University of Roehampton, added: "Perceiving the emotional state of another individual through its vocalisations and being affected by those vocalisations has important implications for how we care for domestic animals, and in particular livestock species."
In the study, the researchers recorded calls of goats which conveyed either positive or negative emotions. They then played one of these calls through a loudspeaker to another goat. They subsequently exposed that goat to a variant of the same call type associated with the opposite emotion. This was followed by a final call which was randomly selected.
The researchers also controlled variables often neglected in this field of research by assessing the emotional state of both the caller and the receiver. In addition, only contact calls were used so that the reaction of the receiver would be purely dependent on the encoded emotions, rather than the function of vocalisations.
Livio Favaro, another author of the study from University of Turin, said: "These findings can contribute to our understanding of the evolution of emotion perception in non-human animals."
- Research paper: 'Goats distinguish between positive and negative emotion-linked vocalisations'. Luigi Baciadonna, Elodie F. Briefer, Livio Favaro and Alan G. McElligott. Frontiers in Zoology.
- IMAGES AND VIDEO: https://bit.ly/2XqXzgv
- Pictures of the goats taken from Buttercups Sanctuary for Goats in Kent. Photo credits included in the file names.
- The video shows Heidi while being tested using a Positive Negative Positive (PNP) calls sequence. In particular, the video shows Heidi being played two positive calls, a negative call and then a randomly selected call from the first phase of calls. The duration of looking behaviour towards the source of the sound and the cardiac activity were recorded simultaneously. The cardiac activities were recorded using a non-invasive Bluetooth device (BioHarness Physiology Monitoring System) fixed to a belt placed around the goat's chest.
- For a copy of the paper please contact below
Queen Mary University of London
Tel: 020 7882 3004
About Queen Mary
Queen Mary University of London is a research-intensive university that connects minds worldwide.
A member of the prestigious Russell Group, we work across the humanities and social sciences, medicine and dentistry, and science and engineering, with inspirational teaching directly informed by our world-leading research.
In the most recent Research Excellence Framework we were ranked 5th in the country for the proportion of research outputs that were world-leading or internationally excellent. We have over 25,000 students and offer more than 240 degree programmes. Our reputation for excellent teaching was rewarded with silver in the most recent Teaching Excellence Framework. Queen Mary has a proud and distinctive history built on four historic institutions stretching back to 1785 and beyond. Common to each of these institutions - the London Hospital Medical College, St Bartholomew's Medical College, Westfield College and Queen Mary College - was the vision to provide hope and opportunity for the less privileged or otherwise under-represented.
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About University of Roehampton
The University of Roehampton, London, is an established international higher-education institution providing a high-quality learning and research experience with the aim of developing personal growth and driving social change.
The University has a proud and distinguished history dating back to the 1840s and it was one of the first institutions in the UK to admit women to its colleges of higher education. This tradition of commitment to equality continues to be part of the ethos of the University, which has one of the most diverse and thriving communities of students in the UK; its 9,000 student body includes international students from over 146 countries.
Today the University is renowned for its broad range of expertise across teacher training, business, social sciences, the arts and humanities, as well as human and life sciences, with world leading and internationally recognised research in these fields. http://www.roehampton.ac.uk
Frontiers in Zoology