Abstract: The existence of 'animal personality', i.e. consistent individual differences in behaviour across time and contexts, is an evolutionary puzzle that has recently generated considerable research interest. Although social factors are generally considered to be important, it is as yet unclear how they might select for personality. Drawing from ecological niche theory, we explore how social conflict and alternative social options can be key factors in the evolution and development of consistent individual differences in behaviour. We discuss how animal personality research might benefit from insights into the study of alternative tactics and illustrate how selection can favour behavioural diversification and consistency due to fitness benefits resulting from conflict reduction among social partners.

Abstract: The effect of stabling for the first time on the behaviour and welfare of young and naïve horses has not yet been studied in detail. In this study we examined the effect of two typical housing systems on their subsequent behavioural and physiological responses upon first time stabling. Thirty-six 2-year-old Dutch warmbloods, 18 geldings and 18 mares were included in the study. Half of the horses were stabled in individual stables (10.5m2) and the other half in pair housing (48m2 for two horses). The study lasted 12 weeks. At the end of the study the physiological and temperamental responses of the horses on the different treatments was tested using a CRF challenge test (to test the HPA-axis function) and a Novel Object test (to test temperamental differences) respectively. Especially in the first week after stabling pair housed horses spent more time eating whereas individually housed horses spent more time either standing vigilant or sleeping. Stress-related behaviours like neighing, pawing, nibbling and snorting were all displayed significantly more frequently in the individually housed horses (P<0.01). At the end of the study 67% of the individually housed horses was seen performing one or more stereotypies (P<0.01). The cortisol response and ACTH response on the CRF challenge test were lower for horses in the individually housed boxes. It is suggested that this depression in socially isolated animals is caused by a desensitisation of the HPA axis in response to stress-induced elevations in ACTH and cortisol. In general there was no effect of the treatment on the reactivity of the horses during the Novel Object test. However, there were significant relations between the responses of horses in the Novel Object test and in the stable environment. It is concluded that sudden isolated stabling is stressful to young and naïve horses, resulting in a high prevalence of stereotypies and abnormal behaviours. This study also provided some support for the notion that social stress in horses may be associated with a blunted adrenocortical response to CRF challenge. The finding that responses of horses to a behavioural test are correlated with home environment behaviours suggests that individual horses exhibit consistent behavioural traits across different contexts, and opens the possibility of using behavioural tests in horses to predict more general underlying behavioural characteristics.

Abstract: The conflicting results regarding the study of motor laterality in horses may indicate that there does not exist a proper method to assess the degree and the direction of motor bias in these animals. Unfortunately, even less is known about the development of laterality in horses, and to what extent early manipulations can still exert their effects in adulthood. We propose a new method that can be easily applied at a very early age thus avoiding testing adult horses eventually biased by human handling and/or training. Forty-six horses (29 nine-month-old foals and 17 two-year old horses) were handled since birth bilaterally and housed in groups in wide areas. At the time of the analysis, in order to minimize environmental and sensorial disturbances, each horse was tested in a round pen individually or as dyad mother-foal. The ability/inability to properly execute a circle at trot was then recorded, assuming the direction of derailment, i.e. the cutting of the circle, as an indicator of motor bias. From the results of the study it is arguable that motor laterality in horses is acquired over time: in fact foals tested while their mothers were being subjected to longeing showed a higher percentage of ambidextrous animals, while two-year-old horses appeared biased toward the right (p<0.05). Results are discussed in the light of the scientific knowledge about equine biomechanics, taking into account horses' locomotion that leads to the advancement of the body mass through the activation of a kinetic chain that originates from the hindquarters.

Abstract: The aim of this study was to conduct a series of paper-based exercises in order to assess the negative (adverse) welfare impacts, if any, of common interventions on domestic horses across a broad range of different contexts of equine care and training. An international panel (with professional expertise in psychology, equitation science, veterinary science, education, welfare, equestrian coaching, advocacy, and community engagement; n = 16) met over a four-day period to define and assess these interventions, using an adaptation of the domain-based assessment model. The interventions were considered within 14 contexts: C1 Weaning; C2 Diet; C3 Housing; C4 Foundation training; C5 Ill-health and veterinary interventions (chiefly medical); C6 Ill-health and veterinary interventions (chiefly surgical); C7 Elective procedures; C8 Care procedures; C9 Restraint for management procedures; C10 Road transport; C11 Activity—competition; C12 Activity—work; C13 Activity—breeding females; and C14 Activity—breeding males. Scores on a 1–10 scale for Domain 5 (the mental domain) gathered during the workshop were compared with overall impact scores on a 1–10 scale assigned by the same panellists individually before the workshop. The most severe (median and interquartile range, IQR) impacts within each context were identified during the workshop as: C1 abrupt, individual weaning (10 IQR 1); C2 feeding 100% low-energy concentrate (8 IQR 2.5); C3 indoor tie stalls with no social contact (9 IQR 1.5); C4 both (i) dropping horse with ropes (9 IQR 0.5) and forced flexion (9 IQR 0.5); C5 long-term curative medical treatments (8 IQR 3); C6 major deep intracavity surgery (8.5 IQR 1); C7 castration without veterinary supervision (10 IQR 1); C8 both (i) tongue ties (8 IQR 2.5) and (ii) restrictive nosebands (8 IQR 2.5); C9 ear twitch (8 IQR 1); C10 both (i) individual transport (7.00 IQR 1.5) and group transport with unfamiliar companions (7 IQR 1.5); C11 both (i) jumps racing (8 IQR 2.5) and Western performance (8 IQR 1.5); C12 carriage and haulage work (6 IQR 1.5); C13 wet nurse during transition between foals (7.5 IQR 3.75); and C14 teaser horse (7 IQR 8). Associations between pre-workshop and workshop scores were high, but some rankings changed after workshop participation, particularly relating to breeding practices. Domain 1 had the weakest association with Domain 5. The current article discusses the use of the domain-based model in equine welfare assessment, and offers a series of assumptions within each context that future users of the same approach may make when assessing animal welfare under the categories reported here. It also discusses some limitations in the framework that was used to apply the model.

Abstract: The ability to innovate and the social transmission of innovations have played a central role in human evolution. However, innovation is also crucial for other animals, by allowing them to cope with novel socioecological challenges. Although innovation plays such a central role in animals' lives, we still do not know the conditions required for innovative behaviour to emerge. Here, we focused on interindividual differences in innovation by (1) extensively reviewing existing literature on innovative behaviour in animals and (2) quantitatively testing the different evolutionary hypotheses that have been proposed to explain interindividual variation in innovation propensity during foraging tasks. We ran a series of phylogenetically controlled mixed-effects meta-regression models to determine which hypotheses (if any) are supported by currently available empirical studies. Our analyses show that innovation is more common in individuals that are older and belong to the larger sex, but also in more neophilic and/or explorative individuals. Moreover, these effects change depending on the study setting (i.e. wild versus captive). Our results provide no clear support to the excess of energy or the bad competitor hypotheses and suggest that study setting and interindividual differences in traits related to personality are also important predictors of innovation.