Abstract: 1. The social relationships in a group of Icelandic horses without a mature stallion were studied. The horses were all familiar to each other. Mutual grooming and play relationships, spatial associations, dominance-subordinate relations and the effect of kinship on these relationships were analysed.TAGSTARTBRTAGEND 2. The social structure was clearly dominated by the behaviour of the adult mares. The horses preferred to form bonds within their social class (sex/age) and they kept close proximity with their friends. The group was effectively divided into two social subgroups, adult mares as one group and adult geldings and sub-adults as another group. The sub-adults and adult geldings formed associations, which were based on mutual grooming and play, while the adult mares did not play. Differences between the sexes were evident. Males played more than the females, had more playing partners and were more popular as playmates.TAGSTARTBRTAGEND 3. Aggression rates were low. The dominance hierarchy was linear. Adult mares ranked higher than adult geldings, sub-adults and the foals. Rank was significantly correlated with age. The closer the adult mares were in rank, the more they groomed with each other. Such relationships were not found amongst the other social group.TAGSTARTBRTAGEND 4. Kinship was calculated between all pairs of animals for up to 4 or 5 generations. Allogrooming and play frequencies and proximity were all positively correlated with kinship. Adult mares, which were close in the dominance hierarchy, were on average more related than those further apart.TAGSTARTBRTAGEND 5. The social relationships in the Icelandic herd were, to some extent, different from relationships reported from unmanaged and feral horse-herds with mature stallions and bachelors. Our results suggest that adult mares groom more in groups without a stallion. Furthermore, they have more preferred partners than in natural harems and their partners are other adult mares, not their weaned offspring as seems to be the case in feral herds. The sub-adults also seem to be more socially active in the absence of stallions. Interestingly, in the Icelandic group, the adult mares showed stallion like behaviours, like mounting and protecting foals. Only by studying the behaviour and the nature of the relationships of horses in groups of different compositions, can we expect to gain a comprehensive understanding about individual social strategies and cognitive capabilities of the species. Such knowledge is valuable for management and welfare of the horse.

Abstract: This paper reports quantitative leadership differences in semi-captive bar-headed geese (Anser indicus) at different times of the year, and in different types of groups. Leading is defined here as causing the departure or determining the direction of movement of the whole group. No permanent and exclusive leader of a pair or family group was found, rather relative leading frequencies of male, female and young showed a definite shifting pattern. Females led more often than their mates prior to breeding, and on nest pauses during the incubation period, but less often in summer, autumn and early winter. In families there was no difference between the frequencies of male and female leading. Family females led relatively more often than those of pairs without offspring. This difference was related to the presence, not the number, of young. Goslings led the family about as often as the parents during the rearing period in early summer, less often in autumn, winter and next spring. Such differences and changes are to be expected where competence in particular tasks and dependence on partners vary between group members, and where different situations require different abilities. For the geese, the results can be related to the different options of group members and to the different benefits they derive from leaving (or 'staying put') or following (or waiting for the others) in different situations.

Abstract: Male horses (Equus caballus) defend harems of females (bands) year-round and throughout their lifetimes. A male's lifetime reproductive success depends upon the number of females in his harem. Although harems have previously been reported as remaining stable over many years, during the two years of this study 30 % of the adult females in an island population of feral horses changed harems during late winter. The seasonal differences in harem stability resulted from seasonal differences in the abundance and distribution of food. The spacing between band members was greater and the frequency of social interactions between them was lower in winter than in summer. In addition, the amount of time devoted to grazing increased in winter. These differences are attributed to the lower availability of suitable vegetation duirng winter. Harem stability did not depend on the age of females, the size of the harem, nor the age of the harem stallion, but did depend on the presence of subordinate stallions attached to the band. All of the females that changed bands left single-male bands; multi-male bands were stable throughout the study.

Abstract: We spent two winters studying the social behaviour of wild woodland caribou (Rangifer tarandus caribou) at a time when their main food (ground lichens; Cladina sp.) is available only at snow craters dug by the animals. The competition for access to such craters was severe, the animals constantly trying to take over the craters of others. During a two-month period when a group maintained a constant size (20) and composition (all age-sex classes represented), we could rank the animals in a rather linear dominance hierarchy (Landau's index = 0.87). Rank was correlated with access to resources, percent of time spent active, and percent of time feeding in craters. It was also correlated with age and antler size. However, rank is not an attribute of individuals, but of a relationship between individuals. As such it is only an intervening variable between physical attributes and access to resources, a variable whose value has meaning only within a given group. Among the three attributes studied (age, sex, antler size), the latter was by far the best predictor of the occurrence and outcome of interactions. Between two individuals within any of the three age-sex classes studied (adult and yearling males and adult females), the one with larger antlers initiated significantly more often, escalated its aggression (to the point of hitting the target) less often, and enjoyed a higher success rate in obtaining resources. When their antlers were larger than those of an adult male target (i.e. males that had shed their antlers), adult females won almost all their interactions with adult males even though they escalated only one fourth of them. This clarifies the long-standing speculation that female caribou have antlers and shed them later than males, in order to overcome their sexual handicap in competition for food in the winter. We conclude that the link between rank and dominance of an individual on one hand, and some of its attributes on the other (e.g. sex, age, weight, antler size) is fundamentally realized by the animal itself through its active preference for targets it is likely to beat, i.e. targets with smaller antlers.

Abstract: The types of social organisation displayed by the African antelope species have been assigned in this paper to five classes, distinguished largely by the strategies used by the reproductively active males in securing mating rights, and the effects of those strategies on other social castes. The paper attempts to show that these strategies are appropriate to each class because of the effects of other, ecological, aspects of their ways of life. The paper describes different feeding styles among antelope, in terms of selection of food items and coverage of home ranges. It argues that these feeding styles bear a relationship to maximum group size of feeding animals through the influence of dispersion of food items upon group cohesion. The feeding styles also bear a relationship to body size and to habitat choice, both of which influence the antelope species' antipredator behaviour. Thus feeding style is related to anti-predator behaviour which, in many species, influences minimum group size. Group size and the pattern of movement over the annual home range affect the likelihood of females being found in a given place at a given time, and it is this likelihood which, to a large extent, determines the kind of strategy a male must employ to achieve mating rights. The effects of the different strategies employed by males can be seen in such aspects of each species' biology as sexual dimorphism, adult sex ratio, and differential distribution of the sexes.