Abstract: Using heart rate (HR) measurements we investigated whether potential calming effects of social licking were evident for both active (performers) and passive (receivers) licking partners. A HR decline was assumed to indicate relaxation and thus the experience of positive emotions. Effects of the licking category (spontaneous, solicited), the animals' basic activity (standing, lying) and the licked body region (head, neck, rest) were also considered. Two studies (A, B) were carried out in the same loose housed Austrian Simmental dairy herd. HR was recorded in up to 20 focal animals on 16 and 18 days, respectively. Using either direct observations (A) or video recordings (B), social licking interactions were continuously observed. The cow's basic activity was recorded using scan sampling at 5 min intervals. Linear mixed effects models were applied separately for Study A and B in order to compare the mean HR of the licking bouts with the mean of the respective 5 min pre- and post-licking periods. In receivers we found a significant calming effect in terms of a HR decline during allogrooming in both studies (A: -1.3 beats per minute, B: -1.1 bpm). This effect was more pronounced when animals were standing (A/B: -2.4 bpm/-3.8 bpm). However, it was not affected by the licked body region. In dairy cows performing social licking, we did not find an overall calming effect. On the contrary, in Study B, HR significantly increased during licking in lying performers (+2.5 bpm). This reaction was even stronger, when licking was directed to the receivers' head (+3.5 bpm) or neck (+3.0 bpm) as compared to the rest of the body (+1.4 bpm). The licking category had no effect on HR changes during the licking events. Our findings suggest that relaxation effects induced by social licking differ between performers and receivers and are affected by the cows' basic activity. In receivers, there were clear indications of a calming effect implying the experience of positive affective states. In performers, such calming effects during social licking were not identified.

Abstract: Intergroup affiliation among female rhesus macaques, Macaca mulatta, was examined in the captive free-ranging colony of Morgan Island, S.C., USA. The provisioned colony has many social groups (35) and is maintained at a relatively high population density (21 animals/ha) with a relatively low adult male to female ratio (1:8.8). Focal and ad libitum samples were collected on 32 adults (3 males and 29 females) from two groups. Although infrequent, grooming was observed between adult females from different groups, and alpha females were the main participants in these interactions. Colony records indicated that none of the intergroup grooms was between females formerly from a common group. Relations between familiar neighboring groups may be maintained by a combination of both affiliative and aggressive behavior.

Abstract: Heart rate telemetry was explored as a means to access animal emotion during social interactions under naturalistic conditions. Heart rates of 2 middle-ranking adult females living in a large group of rhesus macaques (Macaca mulatta) were recorded along with their behavior. Heart rate changes during 2 types of interactions were investigated, while controlling for the effects of posture and activity. The risk of aggression associated with the approach of a dominant individual was expected to provoke anxiety in the approachee. This prediction was supported by the heart rate increase after such an approach. No increase was found when the approacher was a kin or a subordinate individual. The tension-reduction function of allogrooming was also supported. Heart rate decelerated faster during the receipt of grooming than in matched control periods.