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: We examined whether very young dairy calves are able to discriminate between two people, and whether they use the colour of clothing or other indices to do so. During the familiarisation phase, one person (the familiar rewarder), who always wore the same colour clothes, gave milk, spoke gently and patted the calves in their individual pen for 6 days each week. During the test phase, the calf had to make a choice in an Y-maze placed in front of the gate of its stall. When the calves chose the familiar rewarder, they received 200 ml of milk as reinforcement. When they made the incorrect choice, they received nothing and were returned to their stall. On each test day, the calves made eight choices. The criterion of success was that the calf made at least six correct choices in eight trials on each of two consecutive test days (P<0.021 by the binomial law). The first experiment was carried out with fourteen 1-week-old male and female Holstein calves to see if calves could approach a person, who changed position in the maze, in order to obtain a feed reward. The familiar rewarder wore the same clothes as during the period of familiarisation and was in one arm of the Y-maze. The other arm was empty and the position of the familiar rewarder in the maze was randomised. Eleven of the 14 calves reached the criterion for success, after only three tests. The second experiment, carried out with five 2-week-old calves, examined whether the calves can differentiate the familiar rewarder (wearing the same clothing as during the period of familiarisation) from another person (the non-rewarder) wearing clothes of a different colour. The criterion of success was reached by all five calves. The third experiment was carried out with seven 2-week-old calves. It examined whether the calves can differentiate the familiar rewarder and the non-rewarder, when the two people are wearing clothes of the same colour (i.e. the same colour worn by the familiar rewarder during the phase of familiarisation). None of the calves were able to reach the criterion of success within a limited number of four test days. Often, calves would always choose the same arm of the maze. The fourth experiment was carried out on six 1-month-old calves. It was similar to experiment 3 with the difference that the familiar rewarder and the non-rewarder both wore the same colour clothes, but which were not the same colour as worn during the phase of familiarisation. Only one calf achieved the criterion of success within two test days. Results demonstrated that colour cues help very young calves to discriminate between two people, when these people wear different colour clothing. Some calves may be able to use other indicators than the colour of clothing. The Y-maze method is an promising way of examining calves' abilities to recognise people.

Abstract: A study was made of the behavior of young male Misaki feral horses in the developmental stage, by observing nine of them once a week from January 1988 to December 1996. The relationship between behavior before separation and in the developmental stage was also investigated. This stage begins just after young males separate from their natal band or mothers, and it continues until they start to form harems. The duration of the developmental stage in the study ranged from 0.6 to 3.9 years, depending on the age of the young males at the time of separation. Young males associated with three types of social groups at the beginning of the developmental stage, according to their social groups before separation. These were bachelor groups, harem groups and wandering female groups. During this period, males joined the three groups, mixed sex groups and sometimes were solitary. It was considered that these associations provided a good opportunity for males to acquire different behavioral patterns and experiences before they entered the next stage. Depending on the groups with which they associated, young males that spent more time with bachelor groups had the longest average developmental stage. They associated with harem groups more often during the breeding season and more frequently with other groups or were solitary during the non-breeding season. This may be a transition period because by the end of this stage all males had spent time in solitude before forming their own harem bands.

Abstract: Social relationships of 30 N'dama cows during supplementary feeding, post-grazing, were studied over a period of 1.5 years. Dominance ranks determined during idling and feeding periods were strongly correlated (Spearman's rank correlation (rs = 0.964, P < 0.01). The number of animals dominated by a cow during feeding was strongly (P < 0.01) related to liveweight (r = 0.822) and age (r = 0.755). Low status cows ate less frequently than medium and high status animals, while middle ranking cows were ejected more frequently from the feed trough than other dominance groups. Animals had preferences in the use of feed troughs, with social rank being the dominant factor determining the location of feed trough space used. Cows of similar status were generally preferred feeding and movement neighbours and antagonists. However, the dominance rank of an animal and its preferred neighbour during idling were not significantly correlated (rs = 0.220, P > 0.05). Voluntary leadership ranks into and out of the pen were, respectively, related closely (P < 0.01) to feeding dominance ranks (rs = 0.661, 0.640) and idling dominance ranks (rs = 0.621, 0.669).

Abstract: The behavior of nine lowland gorillas (Gorilla gorilla gorilla) living in three social groups at Zoo Atlanta was compared in an indoor holding area versus an outdoor exhibit. Focal animal data were collected for each animal during 15 min observation sessions, alternating between indoors and outdoors. A variety of solitary and social behaviors differed in the two conditions. All individual and social behaviors that showed a difference, except eating, occurred more indoors than outdoors. These included aggressive displays, reclining, self manipulation, and social examination of others. Additionally, the gorillas spent more time closer together in the indoor condition. A variety of other behaviors measured did not change between the two environments. There was a clear effect on behavior of the different housing conditions in which the gorillas were kept. It is suggested that the differences in aggressive behavior may be related to environmental complexity. It is further suggested that zoos should be aware that differences in behavior reported by caretaking staff, researchers and visitors may be a reflection of the differing environmental circumstances in which the animals are observed.