Emotion, Pain, & Sentience

Adult chicken hens express their affective states via bare facial skin blushing and head feather movements

In mammals, facial expressions serve as a window into a variety of affective states. Emotional facial expressions in birds have received little scientific attention. Juvenile hens showed variations in their facial display, facial redness and head feather position, depending on...

Year Published: 2025Topics: Emotion, Pain, & SentienceAnimal Type: Bird, Chicken

Citation: Soulet, D., Love, S. A., Blache, M.-C. et al. 2025. Adult chicken hens express their affective states via bare facial skin blushing and head feather movements. Animal Behaviour 227, 123277.

A case of thanatosis in domestic sheep

Thanatosis (feigning death, defensive tonic immobility) is a widespread anti-predator behavioural strategy in animals. Animals that have evolved this behaviour react to physical contact with the predator by displaying a persistent tonic immobility that makes them look like dead prey....

Year Published: 2025Topics: Emotion, Pain, & Sentience, Natural BehaviorAnimal Type: Sheep

Citation: Skok, J., Prevolnik Povše, M., Škorjanc, D. 2025. A case of thanatosis in domestic sheep. Behaviour 162(6–8), 569–578.

Grief-like distress responses in horses after the death of a conspecific

As a social species, it would be anticipated that horses may display altered behaviours toward dying or dead conspecifics. However, there is remarkably little literature on this subject. The aim of this study was to identify behavioural changes in horses...

Year Published: 2025Topics: Emotion, Pain, & SentienceAnimal Type: Equine

Citation: Ricci-Bonot, C., Wilson, E., Uccheddu, S. et al. 2025. Grief-like distress responses in horses after the death of a conspecific. Applied Animal Behaviour Science 292, 106799.

Do the ear and tail positions reflect the emotional state of calves?

This study aimed to determine the associations between ear and tail position and stroking or umbrella stimuli in dairy calves at different stimulus application times (before the test, pretest, test, and posttest). Thirty-two mixedbred Holstein calves of different ages were...

Year Published: 2024Topics: Emotion, Pain, & Sentience, Welfare AssessmentAnimal Type: Cattle

Citation: Machado, M., Silveira, R. M. F., Bittar, C. M. M. et al. 2024. Do the ear and tail positions reflect the emotional state of calves? Journal of Animal Behaviour and Biometeorology 12(2), e2024017.

Review of depressive-like behaviours in some group-living mammals

Thanks to animal models of depression, we are getting closer to understand the nature of this disorder in humans – but depressive disorders may not be specific only to humans. Although due to the inability to collect a verbal report...

Year Published: 2025Topics: Emotion, Pain, & SentienceAnimal Type: Baboon, Capuchin, Chimpanzee, Equine, Gibbon, Lemur, Macaque, Marine Mammal, Marmoset, Nonhuman Primate, Other Animal, Other Nonhuman Primate, Owl Monkey, Squirrel Monkey, Vervet (African Green Monkey)

Citation: Ilmer, I., Smoleń, T. 2025. Review of depressive-like behaviours in some group-living mammals. Applied Animal Behaviour Science 292, 106753.

The challenge of identifying positive emotional indicators in equids: A scoping review to evaluate if this approach is putting the cart before the horse (Equus caballus)

Driven by multiple converging factors, highlighting the negative impact of equestrian sports on equine welfare, recent scientific research has focussed on recognising positive states in horses (Equus caballus). In particular, this has yielded an increasing number of studies prioritising the...

Year Published: 2025Topics: Emotion, Pain, & Sentience, Welfare AssessmentAnimal Type: Equine

Citation: Humphreys, S., Freire, R., Waran, N. et al. 2025. The challenge of identifying positive emotional indicators in equids: A scoping review to evaluate if this approach is putting the cart before the horse (Equus caballus). Applied Animal Behaviour Science 292, 106760.

Changing priorities about protective shelters: A review of a key method to investigate possible pain in crustaceans

Testing if non-human taxa experience pain is difficult because we need to exclude the possibility that responses are nociceptive reflexes. One approach is to identify an essential, high priority, resource and then ask if the animal will abandon and subsequently...

Year Published: 2025Topics: Emotion, Pain, & SentienceAnimal Type: Crustacean, Invertebrate

Citation: Elwood, R. W. 2025. Changing priorities about protective shelters: A review of a key method to investigate possible pain in crustaceans. Biology Letters 21(9), 20250342.

Single oral dose of gabapentin reduces vigilance and increases play behavior without changing mobility in New Zealand white rabbits (Oryctolagus cuniculus)

OBJECTIVE To evaluate rabbit behavioral responses and activity after gabapentin administration. METHODS In this study, 5 intact female and 3 intact male New Zealand white rabbits aged 8 to 12 months were administered a single oral 25-mg/kg dose of gabapentin....

Year Published: 2025Topics: Emotion, Pain, & SentienceAnimal Type: Rabbit

Citation: Conway, R. E., Desmarchelier, M., Burton, M. et al. 2025. Single oral dose of gabapentin reduces vigilance and increases play behavior without changing mobility in New Zealand white rabbits (Oryctolagus cuniculus). Journal of the American Veterinary Medical Association 263(3), 335–342.

The use of infra-red thermography to study emotions of wild crested macaques (Macaca nigra) in their natural habitat

Infra-red thermography (IRT) has been validated across a range of taxa as a non-invasive method to quantify physiological changes (variation in skin temperature) that serve as a proxy for emotional arousal in humans and other animals. While its effectiveness has...

Year Published: 2025Topics: Emotion, Pain, & Sentience, Welfare AssessmentAnimal Type: Macaque, Nonhuman Primate

Citation: Berthier, J. M., Wheeler, B. C., Qomariah, I. N. et al. 2025. The use of infra-red thermography to study emotions of wild crested macaques (Macaca nigra) in their natural habitat. Physiology & Behavior 296, 114904.

Pain and pessimism affect calves’ play behaviours post-disbudding

Calves are expected to play less when in pain, and more pessimistic individuals may be more affected by painful events, such as hot-iron disbudding (i.e., horn-bud removal). We explored 1) the impact of disbudding on different play behaviours, predicting that...

Year Published: 2025Topics: Body Modification/Mutilation, Emotion, Pain, & SentienceAnimal Type: Cattle

Citation: St John Wallis, A., Held, S. D. E., Mendl, M. T. et al. 2025. Pain and pessimism affect calves’ play behaviours post-disbudding. Discover Animals 2(1), 50.