Abstract: Social animals gain benefits from cooperative behaviours. However, social systems also imply competition and conflict of interest. To cope with dispersal forces, group-living animals use several peace-keeping tactics, which have been deeply investigated in primates. Other taxa, however, have been often neglected in this field research. Wolves (Canis lupus) with their high sociality and cooperative behaviour may be a good model species to investigate the reconciliation process. In this study, we provide the first evidence for the occurrence of reconciliation in a group of zoo-kept wolves. The conciliatory contacts were uniformly distributed across the different sex-class combinations. We found a linear dominance hierarchy in the colony under study, although the hierarchical relationships did not seem to affect the reconciliation dynamics. Moreover, both aggressors and victims initiated first post-conflict affinitive contact with comparable rates and both high- and low-intensity conflicts were reconciled with similar percentages. Finally, we found that coalitionary support may be a good predictor for high level of conciliatory contacts in this species.

Abstract: Antipredator vocalizations of social companions are important for facilitating long-term changes in the responses of prey to novel predator stimuli. However, dynamic variation in the time course of acoustic communication has important implications for learning of predator cues associated with auditory signals. While animals often experience acoustic signals simultaneously with predator cues, they may also at times experience signals and predator stimuli in succession. The ability to learn about stimuli that are perceived not only together, but also after, acoustic signals has the potential to expand the range of opportunities for learning about novel events. Earlier work in Indian mynahs (Acridotheres tristis) has revealed that subjects acquire a visual exploratory response to a novel avian mount after they have experienced it together with conspecific distress vocalizations, a call produced in response to seizure by a predator. The present study explored to what extent such learning occurred if the avian mount was experienced after, rather than simultaneously with, distress calls, such as might happen if call production is interrupted by prey death. Results showed that mynahs that experienced a novel avian mount simultaneously with the sound of distress calls exhibited a sustained exploratory response to the mount after training relative to before that was not apparent in birds that received distress calls and mount in succession. This finding suggests that vocal antipredator signals may only trigger learning of environmental stimuli with which they share some temporal overlap. Recipients may need to access complementary non-vocal cues from the prey victim to learn about predator stimuli that are perceived after vocal behaviour.

Abstract: Dominance hierarchies were studied in 11 herds of domestic horses and ponies (Equus caballus). A paired feeding test was utilized to establish the dominance--subordination relationship between each pair of animals in a herd. Aggressive actions, threats, bites, kicks and chases were also recorded. In small herds linear hierarchies were formed, but in large herds triangular relationships were observed. Aggression was correlated with dominance rank. Body weight, but not age, appear to affect rank in the equine hierarchy. Juvenile horses were more likely to share feed with each other than were adult horses and were usually subordinate to adult horses. The daughters of a dominant mare were dominant within their own herds.

Abstract: Exploratory behaviour plays an important role in most animals for gathering information about their environment. If it constitutes an adaptation to different environmental conditions exploratory behaviour should differ between species. This has been tested with several hypotheses. Sixty-one parrot species (Psittacidae) from eight tribes with different diets and habitat preferences were investigated in aviaries. Two tests were carried out. First, a novel object (wooden ring) in the familiar aviary was presented on two test days in the exploration test. Latencies until first contact with the object and the duration of exploration were recorded. Secondly, in the neophobia test, novel objects were placed beside the feeding dish and latencies until first food intake were recorded. The exploration and neophobia data were related to 12 (13) ecological variables using multiple regression analyses. Phylogenetic relationships were considered. Species that inhabit complex habitats, such as forest edges, or that feed on buds or species from islands showed the shortest latencies in the exploration test. In contrast, long latencies were related to a diet including a great amount of seeds and/or flowers. The longest duration of exploration occurred in species eating nuts or originating from islands, whereas short durations were related to feeding on seeds. Neophobia was positively related to a diet consisting of insects, and negatively to a diet of leaves. There was no relationship between measures of exploration and neophobia. Exploration and neophobia seem to be tightly related to the ecology of a species.

Abstract: Abstract  We studied sex differences in the nature of aggression and dominance behaviour in two newly formed groups of 1-year-old Icelandic horses. One herd contained nine geldings, the other nine mares. The groups were matched with regard to dominance-determining traits such as age, weaning age, composition of native herd, social experience, genetic origin, body condition and maternal dominance status. High-ranking individuals of both sexes were more aggressive, high-ranking males were older, and high-ranking females had a better body condition. Frequencies of aggressions were similar in both groups. The mares reacted significantly more by showing submission upon an aggression rather than by not responding or by escalating the aggression. For the geldings, this difference was not observed due to a lower tendency to submit. A linear dominance hierarchy was found in both groups. David`s scores provided additional information regarding cardinal rank distances and were used to calculate steepness of hierarchies. The female hierarchy was somewhat steeper compared to the male hierarchy, suggesting somewhat lower despotism among males. This was mainly a consequence of the lower unidirectionality in male submission. Male contests occurred predominantly between dyads at top and mid positions, suggesting a low degree of acceptance of the hierarchy.