Abstract: An important question in the study of animal communication is whether non-human animals are able to produce communicative gestures, i.e. nonvocal bodily actions directed to a recipient, physically ineffective but with a meaning shared in the social group [1]. Passive gestures are instrumental, tuned to the mere presence/absence of others, whereas active informers recognize receivers as communicative agents and activate shared-attention mechanisms for identifying their attentional state (SAM [2]; e.g. Schwab and Huber [3]). Six operational criteria must be evaluated to classify a signal as referential and intentional [4]: (1) alternative gazes between the partner and the target; (2) apparent attention-getting behaviours are deployed; (3) an audience is required to exhibit the behaviour; (4) the attentional status of an observer influences the propensity to exhibit behaviours; (5) communication is persistent and (6) there is elaboration of communicative behaviour when apparent attempts to manipulate the partner fail. Dogs [5] and non-human primates (reviewed in Liebal and Call [6]) can tune a human receiver’s attention to the object of interest by combining directional and attention-getting signals, such as turning the head or body, gazing to the receiver, and/or establishing eye contact. Research on other species is scarce.
Horses rely on humans to survive in domestic settings and may have evolved skills for communicating flexibly with them [7]. Horses understand human attentional cues (such as body and head orientation, eyes opened/closed) [8], permanent pointing [9] and, to some extent, gazing [10]. Here we tested the ability of 14 outdoor, herd-living domestic horses to communicate referentially with a human partner about the location of a desired target, a bucket of food out of reach. After the baiting of two buckets placed in opposite, unreachable locations were shown by the experimenter, the subject would walk to one of the two buckets. Because approaching a bucket would reveal that the food is out of reach, we expected the horse to look back to the experimenter, then to the bucket, and alternate this gazing several times to indicate its intention. To test whether our prediction is correct and alternate gazing is indeed the result of the horse's referential communication, we video-recorded the behaviour of the subjects in the test (FORWARD) and three control conditions: (1) FORWARD: experimenter oriented to the center of the arena, (2) BACK: experimenter backward oriented in respect to the arena, (3) ALONE: experimenter absent, (4) MANY: as FORWARD plus a familiar human oriented to the subject behind the bucket (Figure 1). We used a conservative criterion of back gazing by considering only turning the head back more than 90 degrees. The results confirmed our prediction. The horses alternated gazes between the partner and the buck significantly more often in the FORWARD than in all the other conditions (Table 1), thus satisfying operational criteria #1, #3 and #4. They also alternated head nods with gazes to the partner significantly more often during the FORWARD condition. We thus considered head nods not an instrumental signal of arousal, but an attention-getting behaviour with communicative function. Subjects used both head nods and neck stretched toward the buck more often in the FORWARD than in the BACK and the ALONE conditions, thus satisfying criteria #2, #3 and #4. In condition MANY, the frequency of head nods did not differ from condition FORWARD, probably because nods were directed to the additional partner behind the buck. This also satisfies criteria #4. The horses gazed to the partner most often in the FORWARD than in the BACK and the MANY conditions, but not in the ALONE. In this condition, subjects could observe the partner walking further from the test arena. To test for the different functions of gazes in presence and in absence of the partner, we compared their average duration between the two conditions: the significantly longer duration of gazes when the subject was alone suggests the instrumental monitoring function of gazes in this experimental condition.
Altogether, the findings suggest that domestic horses possess the ability to use referential communication in an interspecific context, but additional analyses are needed to test for operational criteria #5 and #6. Flexible and voluntary use of communicative signals reveal sophisticated cognitive processes involved in the strategic emission of these signals, and the finding of referential communication skills in an ungulate species forces us to reconsider the evolutionary path of intelligence. Furthermore, ungulates are used intensively by humans (transportation, meat, agriculture, leisure activities), and their welfare is often compromised. Determining whether ungulates can communicate their needs and preferences is paramount to a proper ethical management.

Abstract: With most modern horse husbandry systems, horses’ locomotory behavior is quantitatively as well as qualitatively considerably altered, compared to the slow and continuous movement shown by horses living under conditions similar to those they have evolved under. This lack of locomotion as well as the change in quality of locomotion is thought to be responsible for a number of health issues seen in present day horses. The aim of the present study was to assess behaviour and particularly locomotion in horses kept in a husbandry system specifically designed to stimulate locomotory behaviour in horses. This type of husbandry system is named “Paddock Trail”, (PT) but is also known as “Paddock Paradise”, and the key concept of this husbandry system involves strategic placement of small portions of feed along a track which is an integral part of this husbandry system. For the present study, 11 horses, not used for riding or other activities and kept in one Paddock Trail husbandry system were available. Seven horses used in equine assisted therapy lessons and housed individually in conventional paddock-boxes (IB) served as a control group. Both groups of horses were composed of a similar mixture of horses with regard to age and breeds. Using time-sampling, behaviour of the horses was observed in 8 bouts (4 morning and 4 afternoon sessions) of 5 hours each. In addition, the average speed and distance covered was assessed in 3 (PT) and 5 (IB) horses, respectively, using a GPS system. Since the GPS signal is blocked by buildings and reliable recording would not be possible indoors, the IB horses were recorded only during their work in the therapy sessions. The behavioural observations revealed that the PT horses allocated a larger proportion of time to locomotory behaviour compared to the IB horses (on average 12 vs 3% of the 5 h observation periods; P<0,05), and in turn resting behaviour was reduced in PT horses compared to IB horses (30 vs. 46%; P<0,05). Time spent grazing (10 vs. 8%) and feeding other than grazing (47 vs. 44%) did not differ significantly between the two groups of horses in the two different husbandry systems (P>0,1). In addition, resting and feeding behaviour was influenced by social rank, such that higher ranking horses spent more time feeding and less time resting compared to horses of lower ranks (both P<0,05). Within the 5 hour observation periods, horses of the PT system covered on average a distance of 2,7 km at an average speed of 0,5 km/h. In comparison, IB horses covered during their work in the therapy sessions on average a distance of 2,1 km at an average speed of 3,6 km/h for a duration of 35 minutes. Although the confounding of groups of horses with husbandry system and although the GPS data does not allow for a direct comparison of the husbandry systems and does not cover the entire 24 hours of a day, these data indicate along with the behavioural observations that the PT system stimulates the horses to increase their locomotory behaviour.
Keywords horse, husbandry, paddock trail, locomotion, behaviour

Abstract: For human athletes, any physical performance classically begins with a warm-up including a phase of cardio-respiratory activation as well as a phase of neuro-muscular mobilization. For the equine athletes similar routines are widely followed despite limited scientific studies addressing its effectiveness. Although physiological bases are of a similar nature in humans and horses, the latter are showing a different “telos” related to their status of prey. Indeed, their survival depends on their ability to detect any predator or potential danger in their environment and to estimate the need to run away. Therefore warm-up techniques should be adapted to this specificity and we added a walk phase preceding the usual warm-up during which the horse was allowed to visually assess its environment without constraint imposed by its rider, reins being long. We assumed that this walk phase would allow a more relaxed mental state and then a decrease in cognitive resources involved in environmental monitoring. Consequently this would release cognitive resources then available for the communication between the horse and the rider.
The autonomous nervous system (ANS) regulates the heart rate via the sympathetic and the parasympathetic nervous systems. The sympathovagal balance and the heart rate variability are considered as good indicators of an acute stress state as well as emotional states. These measures are frequently used to estimate well-being in animals. During the walk phase, we observed a significant decrease of the heart rate (HR), a significant increase of its variability and a significant modification of the sympathovagal balance in favour of a higher contribution of the parasympathetic control. We also measured the non-linear correlation dimension which reflects the degree of freedom of a system. To the best of our knowledge, this method was used until now only in humans to whom it was shown that its decrease is related to stressful events and is associated with a bad prognosis for survival. During the walk phase in horses, the dimension of correlation of cardiac activity was increased.
From a behavioural point of view, we observed a significant decrease of side movements related to head orientation as well as significant changes in ears position, the latter being preferentially directed forwards at the beginning of the walk phase and laterally at the end. As previous research suggests that ears position and head orientation can be involved in attentional mechanisms in horses, our results suggest a decrease of the attention focused on the environment. Furthermore, a significant lowering of the neck was observed as well as a significant decrease of behaviours related to stress.
To conclude our results suggest that a walk phase preceding the usual warm-up of horses would contribute to improve their mental state in favour of more relaxation and of a decrease of the attentional resources invested in environmental monitoring.