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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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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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Heitor, F., do Mar Oom, M., & Vicente, L. (2006). Social relationships in a herd of Sorraia horses Part I. Correlates of social dominance and contexts of aggression. Behav. Process., 73(2), 170–177.
Abstract: Factors related to dominance rank and the functions of aggression were studied in a herd of Sorraia horses, Equus caballus, under extensive management. Subjects were 10 adult mares 5-18 years old and a stallion introduced into the group for breeding. Dominance relationships among mares were clear, irrespective of rank difference, and remained stable after introduction of the stallion. The dominance hierarchy was significantly linear and rank was positively correlated with age and total aggressiveness. Higher-ranking mares received lower frequency and intensity of agonistic interactions. Nevertheless, higher-ranking dominants were not more likely to elicit submission from their subordinates than lower-ranking dominants. Neither close-ranking mares nor mares with less clear dominance relationships were more aggressive towards each other. Agonistic interactions seemed to be used more importantly in regulation of space than to obtain access to food or to reassert dominance relationships. Contexts of aggression were related to mare rank. The results suggest that dominance relationships based on age as a conventional criterion were established to reduce aggressiveness in a herd where the costs of aggression are likely to outweigh the benefits.
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Rogers, L. J. (2000). Evolution of hemispheric specialization: advantages and disadvantages. Brain Lang, 73(2), 236–253.
Abstract: Lateralization of the brain appeared early in evolution and many of its features appear to have been retained, possibly even in humans. We now have a considerable amount of information on the different forms of lateralization in a number of species, and the commonalities of these are discussed, but there has been relatively little investigation of the advantages of being lateralized. This article reports new findings on the differences between lateralized and nonlateralized chicks. The lateralized chicks were exposed to light for 24 h on day 19 of incubation, a treatment known to lead to lateralization of a number of visually guided responses, and the nonlateralized chicks were incubated in the dark. When they were feeding, the lateralized chicks were found to detect a stimulus resembling a raptor with shorter latency than nonlateralized chicks. This difference was not a nonspecific effect caused by the light-exposed chicks being more distressed by the stimulus. Instead, it appears to be a genuine advantage conferred by having a lateralized brain. It is suggested that having a lateralized brain allows dual attention to the tasks of feeding (right eye and left hemisphere) and vigilance for predators (left eye and right hemisphere). Nonlateralized chicks appear to perform these dual tasks less efficiently than lateralized ones. Reference is made to other species in discussing these results.
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Jonart, L. M., Hill, G. E., & Badyaev, A. V. (2007). Fighting ability and motivation: determinants of dominance and contest strategies in females of a passerine bird. Anim. Behav., 74(6), 1675–1681.
Abstract: The communication of aggressive motivation or fighting ability has important fitness consequences for competing animals. Selection should favour rapid and honest communication between opponents to settle dominance relationships while avoiding prolonged and intense fighting. We investigated factors that influence fighting strategies and contest outcomes in female house finches, Carpodacus mexicanus, specifically focusing on the following questions. (1) What social contexts trigger an aggressive response? (2) Does body size and condition contribute to female fighting ability? (3) Do contextual factors, such as mate presence, nest status, nest proximity, and site experience contribute to fighting motivation? (4) Does contest intensity and duration increase as the differences in fighting ability between opponents decrease? (5) What is the relative contribution of fighting ability and aggressive motivation to the outcome of a contest? We found that aggression was triggered most frequently by female intrusions in the vicinity of nest and by extrapair female intrusions on an established pair. Female fighting and contest outcomes were strongly influenced by body condition and body size, and females were more motivated to initiate fights and won more contests when their mates were present. Females at the later breeding stages and those fighting closer to their nests were dominant and won more fights compared to females at earlier breeding stages or further from their nests. Females initiated a greater proportion of contests against opponents with similar local familiarity and breeding history. Escalated and prolonged contests, while rare, occurred exclusively between females of the most similar body size and condition. When differences in body condition between opponents are not easily perceived, contestants might escalate contests for more reliable assessments of relative fighting ability. Finally, body condition was not a strong determinant of contest outcome in the contexts with easily assessed differences in the resource value (e.g. mate presence), but without these motivational differences, body condition was the ultimate determinant of contest outcomes.
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Schmidt, R., Amrhein, V., Kunc, H. P., & Naguib, M. (2007). The day after: effects of vocal interactions on territory defence in nightingales. T. J. Anim. Ecol., 76(1), 168–173.
Abstract: 1. Models on territory acquisition and tenure predict that territorial animals benefit by adjusting territorial defence behaviour to previous challenges they had experienced within the socially complex environment of communication networks. 2. Here, we addressed such issues of social cognition by investigating persisting effects of vocal contests on territory defence behaviour in nightingales Luscinia megarhynchos (Brehm). 3. Using interactive playback during nocturnal song of subjects, a rival was simulated to countersing either aggressively (by song overlapping) or moderately (by song alternating) from outside the subjects' territory. Thereby, the time-specific singing strategy provided an experimentally controlled source of information on the motivation of an unfamiliar rival. 4. Expecting that nightingales integrate information with time, the same rival was simulated to return as a moderately singing intruder on the following morning. 5. The results show that the vigour with which male nightingales responded to the simulated intrusion of an opponent during the day depended on the nature of the nocturnal vocal interaction experienced several hours before. 6. Males that had received the song overlapping playback the preceding night approached the simulated intruder more quickly and closer and sang more songs near the loudspeaker than did males that had received a song alternating playback. 7. This adjustment of territory defence strategies depending on information from prior signalling experience suggests that integrating information with time plays an important part in territory defence by affecting a male's decision making in a communication network.
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Hewitt, S. E., Macdonald, D. W., & Dugdale, H. L. (2009). Context-dependent linear dominance hierarchies in social groups of European badgers, Meles meles. Anim. Behav., 77(1), 161–169.
Abstract: A social hierarchy is generally assumed to exist in those mammalian societies in which the costs and benefits of group living are distributed unevenly among group members. We analysed infrared closed-circuit television footage, collected over 3 years in Wytham Woods, Oxfordshire, to test whether social groups of European badgers have dominance hierarchies. Analysis of directed aggression between dyads revealed linear dominance hierarchies in three social-group-years, but patterns within social groups were not consistent across years. Dominance hierarchies were significantly steeper than random in five out of six social-group-years. In those social-group-years where a linear hierarchy was determined, there was an effect of sex on dominance rank, with females gaining significantly higher rank than males in two social-group-years. Overall, rank was not related to age, nor did it appear to affect the likelihood of an individual being wounded, or an individual's breeding status. The latter resulted from nonorthogonality between sex and breeding status, as there were only two breeding males. Overall, hierarchies were primarily dominated by breeding females, and may occur when breeding competition arises. Relatedness, unreciprocated allogrooming and sequential allomarking were not consistently related to levels of directed aggression across social-group-years. We suggest that dominance structures within European badger groups may be context dependent, with future study required to complete our understanding of where, and when, they arise.
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Drummond, H. (2006). Dominance in vertebrate broods and litters. Quarterly Review of Biology, 81(1), 3–32.
Abstract: Drawing on the concepts and theory of dominance in adult vertebrates, this article categorizes the relationships of dominance between infant siblings, identifies the behavioral mechanisms that give rise to those relationships, and proposes a model to explain their evolution. Dominance relationships in avian broods can be classified according to the agonistic roles of dominants and subordinates as “aggression-submission,” “aggression-resistance, ” “aggression-aggression,” “aggression-avoidance,” “rotating dominance,” and “flock dominance.” These relationships differ mainly in the submissiveness/pugnacity of subordinates, which is pivotal, and in the specificity/generality of the learning processes that underlie them. As in the dominance hierarchies of adult vertebrates, agonistic roles are engendered and maintained by several mechanisms, including differential fighting ability, assessment, trained winning and losing (especially in altricial species), learned individual relationships (especially in precocial species), site-specific learning, and probably group-level effects. An evolutionary framework in which the species-typical dominance relationship is determined by feeding mode, confinement, cost of subordination, and capacity for individual recognition, can be extended to mammalian litters and account for the aggression-submission and aggression-resistance observed in distinct populations of spotted hyenas and the “site-specific dominance” (teat ownership) of some pigs, felids, and hyraxes. Little is known about agonism in the litters of other mammals or broods of poikilotherms, but some species of fish and crocodilians have the potential for dominance among broodmates. Copyright © 2006 by The University of Chicago. All rights reserved.
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Austin, N. P., & Rogers, L. J. (2012). Limb preferences and lateralization of aggression, reactivity and vigilance in feral horses, Equus caballus. Anim. Behav., 83(1), 239–247.
Abstract: Observational field studies were conducted on two remote populations of feral horses in Australia to determine whether lateralization is a characteristic of Equus caballus as a species or results from handling by humans. Group 1 had been feral for two to five generations and Group 2 for 10–20 generations. In both groups, left-side biases were present during agonistic interactions and in reactivity and vigilance. Therefore, as in other vertebrates, the right hemisphere appears to be specialized to control agonistic behaviour and responses to potential threats. The leftwards bias was stronger in measures of behaviour involving more aggression and reactivity. Preferences to place one forelimb in front of the other during grazing were also determined. No population bias of forelimb preference was found, suggesting that such limb preferences present in domestic horses may be entrained. Since stronger individual limb preferences were found in immature than in adult feral horses, limb preference may be modified by maturation or experience in the natural habitat. Stronger limb preference was associated significantly with elevated attention to the environment but only in younger feral horses. No sex differences in lateralization were found. The findings are evidence that horses show visual lateralization, as in other vertebrates, not dependent on handling by humans. Limb preference during grazing, by contrast, does appear to depend on experience.
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Cozzi, A., Sighieri, C., Gazzano, A., Nicol, C. J., & Baragli, P. (2010). Post-conflict friendly reunion in a permanent group of horses (Equus caballus). Behav. Process., 85(2), 185–190.
Abstract: Gregarious animals living in permanent social groups experience intra-group competition. Conflicts over resources can escalate into costly aggression and, in some conditions, non-dispersive forms of conflict resolution may be favoured. Post-conflict friendly reunions, hence reconciliation, have been described in a variety of species. The aim of this study was to explore, for the first time, the occurrence of reconciliation in a group of domestic horses (Equus caballus) and learn more about strategies used to maintain group cohesion. The behaviour of seven horses living as permanent group in an enclosure for at least 2 years was observed by video for 108 h from June to August 2007. We used a Post-Conflict/Matched Control method to assess the existence of reconciliation and third-party affiliation. Behaviours recorded Post-Conflict, or during Matched Control periods, were classified as affiliative based on previous descriptions of visual communication patterns in horses. The proportion of attracted pairs over total post-conflict situations was significantly greater than the proportion of dispersed pairs, both during dyadic interactions (p < 0.001) and during triadic interactions (p = 0.002). The results of the present study show that both dyadic reconciliation and third-party post-conflict affiliative interactions form important social mechanisms for managing post-conflict situations in horses.
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