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Pannozzo, P. L., Phillips, K. A., Haas, M. E., & Mintz, E. M. (2007). Social Monitoring Reflects Dominance Relationships in a Small Captive Group of Brown Capuchin Monkeys (Cebus apella). Ethology, 113(9), 881–888.
Abstract: Abstract In several studies of social monitoring in primates, subordinate animals directed more visual attention toward dominant animals than vice versa. This behavior is thought to enable subordinate animals to avoid conflict. We sought to clarify whether visual attention behavior functions in this manner in a small captive group of brown capuchin monkeys, Cebus apella. We tested the hypothesis that social monitoring is related to dominance status. Dominance status was determined based on the directionality of aggressive behavior, and visual attention was quantified by using focal animal sampling. Subordinate animals directed significantly more visual attention toward others than dominant animals. Subordinate animals also looked more frequently at the animals that attacked them and others the most. The results indicate that social monitoring behavior in this captive group was driven by conflict-avoidance.
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Blumstein, D. T., Barrow, L., & Luterra, M. (2008). Olfactory Predator Discrimination in Yellow-Bellied Marmots. Ethology, 114(11), 1135–1143.
Abstract: The mechanism underlying olfactory predator identification may be relatively experience-independent, or it may rely on specific experience with predators. A mechanism by which prey might identify novel predators relies on the inevitable creation of sulfurous metabolites that are then excreted in the urine of carnivorous mammals. We tested whether free-living, yellow-bellied marmots (Marmota flaviventris) and mid-sized herbivores that fall prey to a variety of carnivorous mammals could discriminate herbivore (elk-Cervus elephas) urine from predator (red fox-Vulpes vulpes, coyote-Canis latrans, mountain lion-Felis concolor, wolf-Canis lupus) urine, a novel herbivore (moose-Alces alces), and a distilled water control. We further asked how specific this assessment was by testing whether marmots responded differently to predators representing different levels of risk and to familiar vs. unfamiliar predators. We found that marmots responded more to urine from coyotes (a familiar predator on adults), mountain lions (a potentially unfamiliar predator that could kill adults) and wolves (a locally extinct predator that could kill adults) than to elk urine (a non-predator). Red fox (a predator that poses a risk only to recently emerged marmot pups) urine elicited a less substantial (but not significantly so) response than coyote urine. Marmots can identify predators, even novel ones, using olfactory cues, suggesting that experience with a specific predator is not required to identify potential threats.
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Majolo, B., Ventura, R., & Koyama, N. F. (2009). A Statistical Modelling Approach to the Occurrence and Timing of Reconciliation in Wild Japanese Macaques. Ethology, 115(2), 152–166.
Abstract: In various social species, animals have been observed to share friendly relationships with some group members and to resolve conflicts through reconciliation, the exchange of affiliative behaviour soon after a conflict that functions to restore the relationship between the former opponents. The valuable relationship hypothesis predicts that reconciliation should be observed more often after conflicts between friends. Friendly relationships can be described by three dimensions (i.e. value, security and compatibility); however, research into the relative importance of these dimensions for the occurrence of reconciliation is sparse. Moreover, reconciliation may depend on factors other than the social relationship between opponents including, for example, their social status or the context of the conflict. Our study aimed at analysing which factors are important determinants of reconciliation and at testing the valuable relationship hypothesis, by analysing the relative effects of relationship value, security and compatibility on the occurrence and timing of reconciliation. We collected data on two troops of wild Japanese macaques living on Yakushima Island, Japan, and selected the best predicting variables of reconciliation using linear mixed models. Our results show that reconciliation occurs more frequently, and earlier, after conflicts between opponents who exchange a higher percentage of grooming. Two additional variables related to relationship security and value were selected in the best models: frequency of aggression and of approaches resulting in tolerated co-feeding. Among the variables not related to relationship quality, distance between opponents at the end of the conflict, kinship, sex of the opponents and context of conflict (i.e. during feeding or social time) were included in our models. Our findings support the valuable relationship hypothesis and, in particular, highlight that the fitness-related benefits of social relationships (i.e. the relationship value) are important determinants of the evolution of friendly relationships and reconciliation.
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Griffin, A. S. (2009). Temporal Limitations on Social Learning of Novel Predators by Indian Mynahs, Acridotheres tristis. Ethology, 115(3), 287–295.
Abstract: Antipredator vocalizations of social companions are important for facilitating long-term changes in the responses of prey to novel predator stimuli. However, dynamic variation in the time course of acoustic communication has important implications for learning of predator cues associated with auditory signals. While animals often experience acoustic signals simultaneously with predator cues, they may also at times experience signals and predator stimuli in succession. The ability to learn about stimuli that are perceived not only together, but also after, acoustic signals has the potential to expand the range of opportunities for learning about novel events. Earlier work in Indian mynahs (Acridotheres tristis) has revealed that subjects acquire a visual exploratory response to a novel avian mount after they have experienced it together with conspecific distress vocalizations, a call produced in response to seizure by a predator. The present study explored to what extent such learning occurred if the avian mount was experienced after, rather than simultaneously with, distress calls, such as might happen if call production is interrupted by prey death. Results showed that mynahs that experienced a novel avian mount simultaneously with the sound of distress calls exhibited a sustained exploratory response to the mount after training relative to before that was not apparent in birds that received distress calls and mount in succession. This finding suggests that vocal antipredator signals may only trigger learning of environmental stimuli with which they share some temporal overlap. Recipients may need to access complementary non-vocal cues from the prey victim to learn about predator stimuli that are perceived after vocal behaviour.
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Roth II, T. C., Cox, J. G., & Lima, S. L. (2008). The Use and Transfer of Information About Predation Risk in Flocks of Wintering Finches. Ethology, 114(12), 1218–1226.
Abstract: ABSTRACT
Several studies in behavior have focused in some way on how groups of prey gather and use information about predation risk. Although asymmetries in information about risk exist among members of real groups, we know little about how such uneven information might affect individual or group antipredator decisions. Hence, we studied the use and transfer of information about the risk of predation in small flocks of wintering birds. House finches (Carpodacus mexicanus; 28 groups of three) were held in large enclosures divided into safe and risky patches. We controlled the information about risk available to each individual by conducting attacks with a model hawk that was visible to only a single (informed) bird. Repeated attacks on a single individual did not reduce the amount of feeding by other birds in that patch, although the time to resume feeding after observing a response to an attack event was somewhat longer than after a no attack event. These results suggest that informed individuals impart some information to naive (uninformed) birds, but this effect was not strong. In fact, the frequent return of informed individuals to feeders after observing uninformed individuals feed suggests that finches relied more on public information regarding safety than their own personal information in deciding when to feed. Group patch choice appeared to be based on a majority-rules decision, although an effect of dominance status was apparent. Our results suggest that subordinate flock members may exert a large influence over group decision-making by acting as spatial 'anchors'. |
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Dunbar, R. I. M., & Bever, J. (1998). Neocortex size predicts group size in carnivores and some insectivores. Ethology, 108(8), 695–708.
Abstract: Neocortex size has been shown to correlate with group size in primates. Data for carnivores and insectivores are used to test the generality of this relationship. The data suggest that carnivores lie on the same grade as the primates, but that insectivores lie on a separate grade to the left of these two orders. Among the insectivores, there appears to be a distinction between the 'advanced' genera (which show a relationship between group size and neocortex size) and the 'basal' genera (which do not).
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Bourjade, M., Moulinot, M., Henry, S., & Richard-Yris, M. - A. H. M. (2008). Could Adults be Used to Improve Social Skills of Young Horses, Equus caballus? Ethology, 50(4), 408–417.
Abstract: We investigated the effects of the introduction of foreign adults on the behavior of young horses. First, we observed the behavior of 1- and 2-year-old domestic horses housed in same-age and same-sex groups (a standard housing system, but different from a natural situation). Then, two same-sex adults were introduced into each experimental group. Observations made before, during and after an introduction indicated that young horses reared in homogeneous groups of young had different behaviors compared to other domestic horses reared under more socially natural conditions. After the introduction of adults, young horses expressed new behaviors, preferential social associations emerged, positive social behavior increased and agonistic interactions decreased. These results have important implications both for understanding the influence that adults may have on the behavior of young horses, and in terms of husbandry, indicating the importance of keeping young horses with adults, although further studies are still necessary. © 2008 Wiley Periodicals, Inc. Dev Psychobiol 50: 408-417, 2008.
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Bourjade, M., Thierry, B., Maumy, M., & Petit, O. (2009). Decision-making in Przewalski horses (Equus ferus przewalskii) is driven by the ecological contexts of collective movements. Ethology, 115(4), 321–330.
Abstract: We addressed decision-making processes in the collective movements of
two groups of Przewalski horses (Equus ferus przewalskii) living in a semi free-ranging population. We investigated whether different patterns of group movement are related to certain ecological contexts (habitat use and group activity) and analysed the possible decision-making processes involved. We found two distinct patterns; ‘single-bout’ and ‘multiplebout’ movements occurred in both study groups. The movements were defined by the occurrence of collective stops between bouts and differed by their duration, distance covered and ecological context. For both movements, we found that a preliminary period involving several horses occurred before departure. In single-bout movements, all group members rapidly joined the first moving horse, independently of the preliminary period. In multiple-bout movements, however, the joining process was longer; in particular when the number of decision-makers and their pre-departure behaviour before departure increased. Multiplebout movements were more often used by horses to switch habitats and activities. This observation demonstrates that the horses need more time to resolve motivational conflicts before these departures. We conclude that decision-making in Przewalski horses is based on a shared consensus process driven by ecological determinants. |
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Hinz, K., Sennet, S., Maros, K., & Krueger, K. (2015). Waiting behaviour in front of a computerized feeding system in an active stable – Effects on heart rate, heart rate variability and sensory laterality in horses. In Current research in applied ethology [Aktuelle Arbeiten zur artgemäßen Tierhaltung. Darmstadt: KTBL-Schrift 510.
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Fraser, N. O., Schino, G., & Aureli, F. F. (2008). Components of Relationship Quality in Chimpanzees. Ethology, 114(9), 834–843.
Abstract: A novel approach to studying social relationships in captive adult chimpanzees (Pan troglodytes) was taken by using principal components analysis (PCA) to extract three key components of relationship quality from nine behavioural variables. Based on the loadings of the behavioural variables, the components appeared to match previously hypothesized critical aspects of social relationships and were therefore labelled Value, Compatibility and Security. The effects of kinship, sex combination, age difference and time spent together on each of the relationship quality components were analysed. As expected, kin were found to have more valuable, compatible and secure relationships than non-kin. Female2013female dyads were found to be more compatible than male2013male or mixed-sex dyads, whereas the latter were found to be most secure. Partners of a similar age were found to have more secure and more valuable relationships than those with a larger age gap. Individuals that were together in the group for longer were more valuable and more compatible, but their relationships were found to be less secure than individuals that were together in the group for a shorter time. Although some of the results may be unexpected based on chimpanzee socio-ecology, they fit well overall with the history and social dynamics of the study group. The methods used confer a significant advantage in producing quantitative composite measures of each component of relationship quality, obtained in an objective manner. These findings therefore promote the use of such measures in future studies requiring an assessment of the qualities of dyadic social relationships.
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