Abstract: The dominance hierarchy of a herd of 10 Thoroughbred mares was determined twice, at an interval of 18 months, using paired feeding tests. Each mare's rank was correlated significantly between the 2 tests. This indicated that the hierarchy within the herd was stable. The offspring of dominant and subordinate mares were also tested for dominance in their own age groups. The offspring of dominant mares tended to be near the top of the hierarchy while those of middle and low ranking mares were not consistently found in the middle or bottom of their own hierarchies. Paired feeding tests were carried out on 8 ponies. During tests the time that each pony spent eating and the ponies' aggressive interactions were recorded. Two situations were used. Each pony-pair was tested when both ponies were in the same paddock and also when they were separated by a rail fence. The subordinate ponies spent significantly more time eating and the domonant pony was significantly less aggressive, when the pony-pair was separated by a fence than when they were in one paddock. It was concluded that the dominance hierarchies of adult horse groups changed very little over time and that the foals of dominant mares will tend to be dominant in their own age groups. Management practices can be used to reduce aggression and consequent injury that may arise in group feeding situations.

Abstract: The discrimination learning ability of Quarter Horses and Thoroughbreds was compared by means of visual cues in a three-choice test with food as a reward. Quarter Horses learned significantly faster than Thoroughbreds, and learning progressed more rapidly for both breeds in a second discrimination task. Significant negative correlations were observed between age and rate of learning. Quarter Horses tended to be less reactive than Thoroughbreds, but individual emotional reactivity ratings and learning scores were not correlated. No correlation was found between social dominance and learning scores. Learning studies with horses may provide a better understanding of the behavioral traits that influence trainability in this species.

Abstract: Social dominance is usually viewed from the perspective of intragroup competition over access to limited resources. The present paper, while not denying the importance of such competition, discusses the dominance concept among monkeys and apes in the context of affiliative bonding, social tolerance, and the reconciliation of aggressive conflicts. Two basic proximate mechanisms are supposed to provide a link between dominance and interindividual affiliation, namely, formalization of the dominance relationship (i.e., unequivocal communication of status), and conditional reassurance (i.e., the linkage of friendly coexistence to formalization of the relationship). Ritualized submission is imposed upon losers of dominance struggles by winners; losers are offered a “choice” between continued hostility or a tolerant relationship with a clearly signalled difference in status. If these two social mechanisms are lacking, aggression is bound to have dispersive effects. In their presence, aggression becomes a well-integrated, even constructive component of social life. In some higher primates this process of integration has reached the stage where status differences are strongly attenuated. In these species, sharing and trading can take the place of overt competition. The views underlying this “reconciled hierarchy” model are only partly new, as is evident from a review of the ethological literature. Many points are illustrated with data on a large semi-captive colony of chimpanzees (Pan troglodytes), particularly data related to striving for status, reconciliation behavior, and general association patterns. These observations demonstrate that relationships among adult male chimpanzees cannot be described in terms of a dichotomy between affiliative and antagonistic tendencies. Male bonding in this species has not been achieved by an elimination of aggression, but by a set of powerful buffering mechanisms that mitigate its effects. Although female chimpanzees do exhibit a potential for bonding under noncompetitive conditions, they appear to lack the buffering mechanisms of the males.

Abstract: Socially feral horses live in stable social groups characterized by one adult male, a number of adult females, and their offspring up to 2 years of age. Extra males either live by themselves or with other males in bachelor groups. The bands occupy nondefended home ranges that often overlap. Many abnormal behaviors seen in domestic horses occur because some aspect of their normal social behavior cannot be carried out in captivity.

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.