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Kitchen, D. M., Cheney, D. L., & Seyfarth, R. M. (2005). Male chacma baboons (Papio hamadryas ursinus) discriminate loud call contests between rivals of different relative ranks. Anim. Cogn., 8(1), 1–6.
Abstract: Males in multi-male groups of chacma baboons (Papio hamadryas ursinus) in Botswana compete for positions in a linear dominance hierarchy. Previous research suggests that males treat different categories of rivals differently; competitive displays between males of similar rank are more frequent and intense than those between disparately ranked males. Here we test whether males also respond differently to male-male interactions in which they are not directly involved, using playbacks of the loud 'wahoo' calls exchanged between competing males in aggressive displays. We played paired sequences of vocal contests between two adjacently ranked and two disparately ranked males to ten subjects, half ranking below the signalers in the call sequences and half above. Subjects who ranked above the two signalers showed stronger responses than lower-ranking subjects. Higher-ranking subjects also responded more strongly to sequences involving disparately ranked, as opposed to adjacently ranked opponents, suggesting that they recognized those individuals' relative ranks. Strong responses to sequences between disparately ranked opponents might have occurred either because such contests typically involve resources of high fitness value (defense of meat, estrous females or infants vulnerable to infanticide) or because they indicate a sudden change in one contestant's condition. In contrast, subjects who ranked lower than the signalers responded equally strongly to both types of sequences. These subjects may have been able to distinguish between the two categories of opponents but did not respond differently to them because they had little to lose or gain by a rank reversal between males that already ranked higher than they did.
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Jolly, A. (1998). Pair-bonding, female aggression and the evolution of lemur societies. Folia Primatol (Basel), 69 Suppl 1, 1–13.
Abstract: Lemur societies have been described as convergent with those of anthropoids, including Papio-like female-bonded multi-male groups. Recent research, however, shows at least 5 pair-bonded species among the Lemuridae and Indriidae. Three more, Eulemur mongoz, Eulemur fulvus and Varecia variegata, have societies combining aspects of pairing with aspects of troop life. The best-known female-bonded societies, those of Lemur catta, Propithecus diadema edwardsi and Propithecus verreauxi, may be assemblages of mother-daughter dyads, capable of high aggression towards other females, but derived from more solitary female ancestors, perhaps also living as pairs. The internal structure of such lemur groups differs from the more extensive kin groups of catarrhines. This in turn may relate to the lemurs' level of social intelligence and to lemur female dominance over males.
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Mitman, G. (1990). Dominance, leadership, and aggression: animal behavior studies during the Second World War. J Hist Behav Sci, 26(1), 3–16.
Abstract: During the decade surrounding the Second World War, an extensive literature on the biological and psychological basis of aggression surfaced in America, a literature that in general emphasized the significance of learning and environment in the origins of aggressive behavior. Focusing on the animal behavior research of Warder Clyde Allee and John Paul Scott, this paper examines the complex interplay among conceptual, institutional, and societal forces that created and shaped a discourse on the subjects of aggression, dominance, and leadership within the context of World War II. The distinctions made between sexual and social dominance during this period, distinctions accentuated by the threat of totalitarianism abroad, and the varying ways that interpretations of behavior could be negotiated attests to the multiplicity of interactions that influence the development of scientific research.
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Overdorff, D. J., Erhart, E. M., & Mutschler, T. (2005). Does female dominance facilitate feeding priority in black-and-white ruffed lemurs (Varecia variegata) in southeastern Madagascar? Am. J. Primatol., 66(1), 7–22.
Abstract: Although many Malagasy lemurs are thought to be female dominant and to have female feeding priority, to date the relationship between these behaviors has been rigorously established only in Lemur catta, and other ways that females might achieve feeding priority have not been examined closely. Erhart and Overdorff [International Journal of Primatology 20:927-940, 1999] suggested that one way female primates achieve feeding priority is to initiate and lead groups to food, thereby gaining access to the food first and positively influencing their food intake compared to other group members. Here we describe female dominance patterns and potential measures of feeding priority in two groups of black-and-white ruffed lemurs (Varecia variegata) that were observed over a 15-month period in southeastern Madagascar. We predicted that the females would 1) be consistently dominant to males, 2) lead groups to food sources more often than males, and 3) have higher feeding rates compared to males when they arrived at food sources first. The results were dissimilar between the study groups. During the study, the oldest adult female in group 1 died. There was no evidence for female dominance in this group, and the remaining (likely natal) female did not lead the group more often, nor did she have a higher food intake than males. Group 1 dispersed shortly after the time frame reported here. In contrast, the resident female in group 2 was dominant to group males (based on agonistic interactions), led the group to food sources more often, and experienced a higher food intake when she arrived first at a food source. How these patterns vary over time and are influenced by the number of females in groups, group stability, food quality, and reproductive condition will be examined in future analyses.
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Feist, J. D., & McCullough, D. R. (1975). Reproduction in feral horses. J Reprod Fertil Suppl, (23), 13–18.
Abstract: A behavioural study of feral horses was conducted on the Pryor Mountain Wild Horse Range in the western United States. All 270 horses on the Range were identified individually. The sex ratio was nearly balanced. Foal to adult female ratio was 43-2:100. Morality was concentrated among foals and old horses. Horses were organized as forty-four harem groups each with a dominant stallion, one to two immature stallions, one to three immature mares, one to three adult mares and their yearling and foal offspring, and 23 bachelor groups of one to eight stallions. Harem groups were quite stable year-round because of dominance and leadership by the stallions and group fidelity by mares and their offsring. Most changes occurred during the breeding season and involved immature females. Defeat of dominant stallions was infrequent. Immature males were tolerated because of their submissive behaviour. Bachelor stallion groups were inherently unstable. Mares came into heat after foaling in May/June, and were mated by harem stallions only.
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Houpt, K. A., & Wolski, T. R. (1980). Stability of equine hierarchies and the prevention of dominance related aggression. Equine Vet J, 12(1), 15–18.
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.
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Saayman, G. S. (1971). Behaviour of the adult males in a troop of free-ranging Chacma baboons (Papio ursinus). Folia Primatol (Basel), 15(1), 36–57.
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Rands, S. A., Cowlishaw, G., Pettifor, R. A., Rowcliffe, J. M., & Johnstone, R. A. (2008). The emergence of leaders and followers in foraging pairs when the qualities of individuals differ. BMC Evol Biol, 8, 51.
Abstract: BACKGROUND: Foraging in groups offers animals a number of advantages, such as increasing their likelihood of finding food or detecting and avoiding predators. In order for a group to remain together, there has to be some degree of coordination of behaviour and movement between its members (which may in some cases be initiated by a decision-making leader, and in other cases may emerge as an underlying property of the group). For example, behavioural synchronisation is a phenomenon where animals within a group initiate and then continue to conduct identical behaviours, and has been characterised for a wide range of species. We examine how a pair of animals should behave using a state-dependent approach, and ask what conditions are likely to lead to behavioural synchronisation occurring, and whether one of the individuals is more likely to act as a leader. RESULTS: The model we describe considers how the energetic gain, metabolic requirements and predation risks faced by the individuals affect measures of their energetic state and behaviour (such as the degree of behavioural synchronisation seen within the pair, and the value to an individual of knowing the energetic state of its colleague). We explore how predictable changes in these measures are in response to changes in physiological requirements and predation risk. We also consider how these measures should change when the members of the pair are not identical in their metabolic requirements or their susceptibility to predation. We find that many of the changes seen in these measures are complex, especially when asymmetries exist between the members of the pair. CONCLUSION: Analyses are presented that demonstrate that, although these general patterns are robust, care needs to be taken when considering the effects of individual differences, as the relationship between individual differences and the resulting qualitative changes in behaviour may be complex. We discuss how these results are related to experimental observations, and how the model and its predictions could be extended.
Keywords: Animals; *Feeding Behavior; *Food Chain; *Models, Biological; *Social Dominance
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Broom, M. (2002). A unified model of dominance hierarchy formation and maintenance. J. Theor. Biol., 219(1), 63–72.
Abstract: In many different species it is common for animals to spend large portions of their lives in groups. Such groups need to divide available resources amongst the individuals they contain and this is often achieved by means of a dominance hierarchy. Sometimes hierarchies are stable over a long period of time and new individuals slot into pre-determined positions, but there are many situations where this is not so and a hierarchy is formed out of a group of individuals meeting for the first time. There are several different models both of the formation of such dominance hierarchies and of already existing hierarchies. These models often treat the two phases as entirely separate, whereas in reality, if there is a genuine formation phase to the hierarchy, behaviour in this phase will be governed by the rewards available, which in turn depends upon how the hierarchy operates once it has been formed. This paper describes a method of unifying models of these two distinct phases, assuming that the hierarchy formed is stable. In particular a framework is introduced which allows a variety of different models of each of the two parts to be used in conjunction with each other, thus enabling a wide range of situations to be modelled. Some examples are given to show how this works in practice.
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Houpt, K. A. (1976). Animal behavior as a subject for veterinary students. Cornell Vet, 66(1), 73–81.
Abstract: Knowledge of animal behavior is an important asset for the veterinarian; therefore a course in veterinary animal behavior is offered at the New York State College of Veterinary Medicine as an elective. The course emphasizes the behavior of those species of most interest to the practicing veterinarian: cats, dogs, horses, cows, pigs and sheep. Dominance heirarchies, animal communication, aggressive behavior, sexual behavior and maternal behavior are discussed. Play, learning, diurnal cycles of activity and sleep, and controls of ingestive behavior are also considered. Exotic and zoo animal behaviors are also presented by experts in these fields. The critical periods of canine development are related to the optimum management of puppies. The behavior of feral dogs and horses is described. The role of the veterinarian in preventing cruelty to animals and recognition of pain in animals is emphasized. Whenever possible behavior is observed in the laboratory or on film.
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