Abstract: We investigated perseveration and detour behaviour in 36 equids (Equus caballus, E. asinus, E. caballus × E. asinus) and compared these data to those of a previous study on domestic dogs (Canis familiaris). The animals were required to make a detour through a gap at one end of a straight barrier in order to reach a visible target. After one, two, three or four repeats (A trials), the gap was moved to the opposite end of the barrier (B trials). We recorded initial deviations from the correct solution path and the latency to crossing the barrier. In the A trials, mules crossed the barrier significantly faster than their parental species, the horses and donkeys. In the B trials, following the change of gap location, all species showed a reduction in performance. Both dogs and horses exhibited significant spatial perseveration, going initially to the previous gap location. Donkeys and mules, however, performed at chance level. Our results suggest that hybrid vigour in mules extends to spatial abilities.

Abstract: Abstract  When apes are not fully understood by humans, they persist with attempts to communicate, elaborating their behaviours to better convey their meaning. Such abilities have never been investigated in dogs. The present study aimed to clarify any effect of the visual attentional state of the owner on dogs’ (Canis familiaris) social-communicative signals for interacting with humans, and to determine whether dogs persist and elaborate their behaviour in the face of failure to communicate a request. Gaze at a hidden target or at the owner, gaze alternation between a hidden target and the owner, vocalisations and contacts in 12 guide and 12 pet dogs were analysed (i) when the dogs were asked by their owners (blind or sighted) to fetch their inaccessible toy and (ii) when the dogs were subsequently given an unfamiliar object (apparent unsuccessful communication) or their toy (apparent successful communication). No group differences were found, indicating no effect of the visual status of the owner on the dogs’ socio-communicative modes (i.e. no sensitivity to human visual attention). Results, however, suggest that the dogs exhibited persistence (but not elaboration) in their “showing” behaviours in each condition, except that in which the toy was returned. Thus, their communication was about a specific item in space (the toy). The results suggest that dogs possess partially intentional non-verbal deictic abilities: (i) to get their inaccessible toy, the dogs gazed at their owners as if to trigger their attention; gaze alternation between the owner and the target direction, and two behaviours directed at the target were performed, apparently to indicate the location of the hidden toy; (ii) after the delivery of the toy, the dogs behaved as if they returned to the play routine, gazing at their owner whilst holding their toy. In conclusion, this study shows that dogs possess partially intentional non-verbal deictic abilities: they exhibit successive visual orienting between a partner and objects, apparent attention-getting behaviours, no sensitivity to the visual status of humans for communication, and persistence in (but no elaboration of) communicative behaviours when apparent attempts to “manipulate” the human partner fail.

Abstract: Domestic dogs (Canis familiaris) and great apes from the genus Pan were tested on a series of object choice tasks. In each task, the location of hidden food was indicated for subjects by some kind of communicative, behavioral, or physical cue. On the basis of differences in the ecologies of these 2 genera, as well as on previous research, the authors hypothesized that dogs should be especially skillful in using human communicative cues such as the pointing gesture, whereas apes should be especially skillful in using physical, causal cues such as food in a cup making noise when it is shaken. The overall pattern of performance by the 2 genera strongly supported this social-dog, causal-ape hypothesis. This result is discussed in terms of apes' adaptations for complex, extractive foraging and dogs' adaptations, during the domestication process, for cooperative communication with humans.

Abstract: Domestic dogs are unusually skilled at reading human social and communicative behavior--even more so than our nearest primate relatives. For example, they use human social and communicative behavior (e.g. a pointing gesture) to find hidden food, and they know what the human can and cannot see in various situations. Recent comparisons between canid species suggest that these unusual social skills have a heritable component and initially evolved during domestication as a result of selection on systems mediating fear and aggression towards humans. Differences in chimpanzee and human temperament suggest that a similar process may have been an important catalyst leading to the evolution of unusual social skills in our own species. The study of convergent evolution provides an exciting opportunity to gain further insights into the evolutionary processes leading to human-like forms of cooperation and communication.