Abstract: Domestic dogs comprehend human gestural communication flexibly, particularly the pointing gesture. Here, we examine whether dogs interpret pointing informatively, that is, as simply providing information, or rather as a command, for example, ordering them to move to a particular location. In the first study a human pointed toward an empty cup. In one manipulation, the dog either knew or did not know that the designated cup was empty (and that the other cup actually contained the food). In another manipulation, the human (as authority) either did or did not remain in the room after pointing. Dogs ignored the human’s gesture if they had better information, irrespective of the authority’s presence. In the second study, we varied the level of authority of the person pointing. Sometimes this person was an adult, and sometimes a young child. Dogs followed children’s pointing just as frequently as they followed adults’ pointing (and ignored the dishonest pointing of both), suggesting that the level of authority did not affect their behavior. Taken together these studies suggest that dogs do not see pointing as an imperative command ordering them to a particular location. It is still not totally clear, however, if they interpret it as informative or in some other way.

Abstract: Equine vocalization and acoustic sounds can communicate a horse’s emotional state, physiological state, and situation to other individuals, including other horses and humans. These vocalizations and acoustic sounds can be divided into several types. The whinny, nicker, squeal, blow, snore, snort, roar, and groan are typical types of horse vocalizations and acoustic sounds. The sound localization thresholds of horses are markedly poorer than those of other large mammals, such as humans and elephants. The audiogram of horse has shown their best sensitivity and hearing range in which it perceives sound. Laryngeal diseases, such as laryngeal hemiplegia, dorsal displacement of the soft palate, and alar fold paralysis, can cause laryngeal sounds in the upper airway. The analyses of horses’ vocalizations and laryngeal sounds that are reviewed in this article were conducted with computer-aided analysis programs using spectrograms and spectra that evaluate several parameters, including amplitude, fundamental frequency, duration, and formants. Laryngeal sound analysis could be a useful method for diagnosing upper airway diseases. This article presents a review of the literature describing scientific analyses of horse vocalizations and acoustic sounds to elucidate equine acoustic communications and aid in the development of horse-human bonds.

Abstract: Gestures and facial displays are involved in regulating many aspects of mammal social life such as aggression, dominance-subordinate relationships, appeasement and play. Playful activity is an interesting behaviour for examining the role of signals as intentional communication systems. When animals play they perform patterns that are used in other serious contexts. To avoid miscommunication, many species have evolved signals to maintain a playful mood. Bonobos, Pan paniscus, with their flexible social relationships and playful propensity, may represent a good model species to test some hypotheses on adult play signalling. I analysed the potential roles of facial play expressions and solitary play in soliciting and regulating social play and found that adult bonobos used the play face (relaxed open-mouth display) in a selective manner. Play faces were more frequent during social than solitary play and, within social play, polyadic sessions (even though less frequent than dyadic sessions) were characterized by a higher frequency of signals. Following the rule of play intensity matching, play faces were more frequent when the two players matched in age and size (sessions among adults). Moreover, among dyads there was a positive correlation between the frequency of aggressive interactions performed and the frequency of play signals used, thus suggesting that signals are crucial in play negotiations among individuals showing high baseline levels of aggression. Finally, solitary play, especially when it involved pirouettes and somersaults, had an important role in triggering social play.

Abstract: Horses have been considered to rely on human gesticular cues (McKinley and Sambrook 2000, Anim Cogn 3:13-22; and recently Maros et al. 2008, Anim Cogn 11:457-466), however large variability among individuals tested in two-ways object choice tasks was found. Part of the horses in those studies (40 and 26 %, respectively) even failed to pass adequately through the training session which preceded the testing phase and served to learn a horse to carry out a task. Therefore, we alternated the experimental design designed by McKinley and Sambrook (reduced number of testing trials to 10 per horse to keep its attention, applied just one, a dynamic-sustained pointing cue with touching the bucket, etc.), and tested an effect of training method, sex, age, and learning on proportion of correct choices. We hypothesised, that horses trained by “traditional” method (TTM) will get lower score than those experienced with “horsemanship-based” methods (HTM), being characterized by closer and more frequent human-horse contact and also extended exercising “from the ground” with frequent using of arms cues. Despite simplification of the methods, only about 60 % of tested horses passed through the training phase (i.e., learned to come to and upturn the bucket with hidden treat). Successful completion of training phase was reached regardless of age or sex of a horse, but by the training method; HTM horses ran better compared to TTM ones. No significant effect of age, sex, or learning (i.e., trial order within all 10), and training method as well was found on proportion of correct trials in the testing phase. Horses made a correct choice in more than 70% of trials. Individual scores ranged from 50 to 100 %. In conclusion, horses showed high level of comprehension of human pointing gesture, regardless of their sex or age. No effects of training method or learning process within a test suggest low impact of handling and learning on the level of comprehension at least of the most vivid human pointing gesture. Horses trained by methods based on “natural human-horse communication” did enhance cooperation with people.

Abstract: In 2001, Xitco et al. (Anim Cogn 4:115-123) described spontaneous behaviors in two bottlenose dolphins (Tursiops truncatus) that resembled pointing and gaze alternation. The dolphins' spontaneous behavior was influenced by the presence of a potential receiver, and the distance between the dolphin and the receiver. The present study adapted the technique of Call and Tomasello [(1994) J Comp Psychol 108:307-317], used with orangutans to test the effect of the receiver's orientation on pointing in these same dolphins. The dolphins directed more points and monitoring behavior at receivers whose orientation was consistent with attending to the dolphins. The results demonstrated that the dolphins' pointing and monitoring behavior, like that of apes and infants, was linked to the attentional behavior of the receiver.