Abstract: In an experiment on the effects of social environment and training on the human-animal relationship, 20 horses were handled according to a defined schedule. Eight horses were housed singly and 12 horses were housed in four groups of 3 horses. Horses were handled three times per week in 10 min sessions from an age of 6 months until 2 years of age during two winter periods. A total of 50 and 70 sessions were given in the first and second period, respectively. Five randomly allocated people performed the training. The training scheme involved leading, tying up, touching, lifting feet, etc. in 43 stages. The horse had to fulfil the performance criteria of each stage in order to get to the next stage. In the first winter period, horses were led to the stable when they had “passed” a stage or after 10 min of training. In the second winter period, horses would start off at stage 1 again, and when they “passed” a stage they went on to the next stage within the same training session. Because of the change in training procedure results were analysed separately for the two winter periods. There was a significant difference between trainers in the number of times they allowed a horse to “pass” a stage within each winter period (χ32, P<0.05; χ32, P<0.001 for the first and the second winter period, respectively). Group housed horses “passed” more stages than single housed horses (17 versus 14; 27 versus 18 in the first and second winter period, respectively; P<0.05 for the interaction). Singly housed horses bit the trainer more frequently than did group housed horses (P<0.01). The responses of group housed horses to training clearly demonstrate the benefits of raising young horses in groups.

Abstract: During 1992 and 1993, 14 reintroduced Przewalski Horses or Takhi (Equus ferus przewalskii) were studied in the Hustain Nuruu Mountain Steppe reserve in Mongolia. Most of the individuals did not know each other before reintroduction. These Takhi were the first of five groups due to be released in the reserve after an acclimatisation period of at least 1 year. During acclimatisation the Takhi, lived visually and acoustically separately, in fenced enclosures of approximately 45 ha each. The observations, mostly scan-sampling, were carried out in each season. The observation bouts were divided over six periods and over two harem herds. Two of the periods were in the same consecutive seasons, so comparison over the years was possible. Social integration within the Takhi herds was very high from the beginning, as described by the spatial relation and synchronisation data. Between 50 and 89% of the observation time, the behaviour of all herd members was synchronised. The amount of time spent grazing by the Takhi (30-68% of the daylight period) was similar to that of feral horses and Takhi in captivity and semi-reserves. The Takhi tended to rest in the morning and have a bimodal period of grazing at dawn and in the afternoon. The Takhi displayed clear habitat preferences for certain activities. They had a strong preference to rest at the highest point in their enclosure. They fed preferably on two or three different vegetation types (with five types available in each enclosure). The amount of time spent grazing during the non-growing seasons (49 +/- 15%) indicates that the feeding value and availability of food were sufficient. Health changes were detected adequately using condition scoring sheets. No supplementary food or water was supplied during the harsh winters. Moreover, low mortality rates and high reproductive success show that the mountain steppe is a habitat which is potentially suitable for establishing a healthy Takhi population. Takhi is the first species to return to its native habitat after living only in zoos for so many generations.

Abstract: Data were collected on 972 aggressions and 233 acts of mutual grooming in a herd of 9 Przewalski horses in the Hellabrunn Tierpark in Munich, West Germany. The herd was composed of 1 adult stallion, 5 adult mares and 3 foals. A distinct linear dominance hierarchy was present in the herd, with the stallion being the top-ranking animal. Age was significantly correlated with rank. Almost 40% of all aggressions consisted of herding actions by the stallion. Threats to bite (20% of all aggressions) and threats to kick (11.4%) were next in frequency of occurrence. Most mutual grooms (71%) involved grooming the front part of the body. Although mutual grooming may be used to appease higher-ranked animals, most grooming bouts were between related horses. Foals initiate 47.6% of all allogrooming. Mutual grooming may reduce weaning conflict between a mare and her foal or may result in female coalitions that defend against predators or aggression by the herd stallion.

Abstract: Social interactions were recorded in two bands of free-ranging Przewalski horses living on large (greater than 30 ha) pastures in the Netherlands. The average number of aggressive interactions per hour was 8.86 at Lelystad and 10.36 at Noorderheide. The most common aggressive interactions were lower intensity, lower cost displacements (17.2% of all aggressive acts at Lelystad, 13.2% at Noorderheide), threats to bite (42.3% and 40.7%, respectively) and threats to kick (15.4% and 23.9%, respectively). Analysis of aggression revealed that a clear, linear dominance hierarchy was present in each band. For each band there was a positive and highly significant correlation between the age of a horse and its rank in the hierarchy. In each band, the stallion was not the highest ranked horse. Non-agonistic behaviors exceeded the number of agonistic interactions (1253 vs. 558 for Lelystad; 1257 vs. 995 at Noorderheide). There was a negative correlation between the rank of a horse in the dominance hierarchy and the number of non-agonistic behaviors displayed. The group displaying the highest number of non-agonistic interactions were foals (48.9% of total non-agonistic behaviors at Lelystad; 51.1% at Noorderheide). The non-agonistic/agonistic ratio was greater than 1 for yearlings and the band stallion, as was also the case for foals, but was less than 1 for males.

Abstract: The Minnesota Zoological Garden established a bachelor (i.e. all-male) group of 8 Przewalski horses (Equus przewalskii) in 1984. Possible methods for mixing males emerged through preliminary introductions and review of the relevant literature. These included: (1) grouping colts (<=3 years old) after removing them from their natal bands; (2) introducing adult stallions to colts in spacious, controlled environments to reduce the risk of combat-related injury or death associated with largely unpredictable adult temperament; (3) introducing more than 1 animal at a time to established groups. Based on the frequency and orientation of agonistic interactions observed among the bachelors, a linear dominance hierarchy was discerned among the 4 adult stallions; all 4 colts were determined to be of equally low or seemingly non-ranking status. Social rank among the adults was most influenced by individual temperament, and contention for rank was limited almost exclusively to the 3 lower-ranking stallions; the alpha male participated in 73% of all agonistic interactions observed, but was identified as the recipient in less than 3% of these interactions. Intra-band associations were detected in the bachelor group. The most prevalent of these was among the 4 colts, found together in over 70% of the observations. Other affinities commonly observed were between the colts (as a sub-group) and different stallions. The dominant stallion, the colts' most frequent companion, actively discouraged the 3 lower-ranking stallions from associating with the colts. Further, the colts were subjected to significantly fewer agonistic behaviors than the non-alpha stallions (per colt=1.05+/-0.24 h-1; per non-alpha stallion=2.01+/-0.04 h-1). These findings support the hypothesis developed by other workers for ungulates that young bachelors are sheltered from aggression by association with an alpha male. With one exception, adult associations were rarely noted. Although combat-related injuries (superficial wounds and temporary lameness) were common among the bachelors, few required medical attention. No permanent disabilities or deaths have occurred since the group's inception. The existence of social organization and intra-band associations in the bachelor group support the suggestion that such groups were once a natural part of this species' social milieu. Bachelor groups are therefore recommended as an ethologically sound, space- and cost-effective means of managing “surplus” (i.e. non-harem) male Przewalski horses.