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Wolff, A., Hausberger, M., & Le Scolan, N. (1997). Experimental tests to assess emotionality in horses. Behav. Process., 40(3), 209–221.
Abstract: Different tests were used to assess different aspects of the emotionality of 1-3 year-old horses: arena test; a [`]novel object' test; and a handling test. In reaction to the test situations no important differences were observed according to age or sex in the behaviour patterns, but clear individual differences were observed within these classes. The arena test seemed to reveal the degree of gregariousness of the animals whereas the results in the two other tests were correlated and seemed to reflect an inherent degree of fearfulness in the horse. Indices were developed that enabled to rank the animals, by taking into account all behaviour patterns shown. Such individual characteristics might have some genetic basis: half-siblings tended to behave the same way in most cases.
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Slabbert, J. M., & Rasa, O. A. E. (1997). Observational learning of an acquired maternal behaviour pattern by working dog pups: an alternative training method? Appl. Anim. Behav. Sci., 53(4), 309–316.
Abstract: German shepherd pups from untrained bitches and bitches trained in the location of narcotics were either separated from their mothers at 6 weeks (standard raised) or at 3 months of age (extended maternal care). Pups with extended maternal care which were allowed to observe their trained mothers locating and retrieving a sachet of odour-producing narcotic between the ages of 6 and 12 weeks performed the same task significantly better than non-exposed pups when tested at the age of 6 months, without further reinforcement during the interim period. This difference in performance was independent of the duration of maternal care or maternal origin of the pups and was attributed to differences in early experience acquired through observational learning.
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Sterck, E., Watts, D., & van Schaik, C. (1997). The evolution of female social relationships in nonhuman primates. Behav. Ecol. Sociobiol., 41(5), 291–309.
Abstract: Considerable interspeci®c variation in female social relationships occurs in gregarious primates, particularly with regard to agonism and cooperation between females and to the quality of female relationships with males. This variation exists alongside variation in female philopatry and dispersal. Socioecological theories have tried to explain variation in female-female social relationships from an evolutionary perspective focused on ecological factors, notably predation and food distribution. According to the current ``ecological model'', predation risk forces females of most diurnal primate species to live in groups; the strength of the contest component of competition for resources within and between groups then largely determines social relationships between females. Social elationships among gregarious females are here characterized as DispersalEgalitarian, Resident-Nepotistic, Resident-Nepotistic-Tolerant, or Resident-Egalitarian. This ecological model has successfully explained i€erences in the occurrence of formal submission signals, decided dominance relation ships, coalitions and female philopatry. Group size and female rank generally a€ect female reproduction success as the model predicts, and studies of closely related species in di€erent ecological circumstances underscore the importance of the model. Some cases, however, can only be explained when we extend the model to incorporate the e€ects of infanticide risk and habitat saturation. We review evidence in support of the ecological model and test the power of alternative models that invoke between-group competition, forced female philopatry, demographic female recruitment, male interventions into female aggression, and male harassment.
Not one of these models can replace the ecological model, which already encompasses the between-group competition. Currently the best model, which explains
several phenomena that the ecological model does not, is a ``socioecological model'' based on the combined importance of ecological factors, habitat saturation and infanticide avoidance. We note some points of similarity and divergence with other mammalian taxa; these remain to be explored in detail.
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Huber, R., van Staaden, M. J., Kaufman, L. S., & Liem, K. F. (1997). Microhabitat Use, Trophic Patterns, and the Evolution of Brain Structure in African Cichlids. Brain Behav Evol, 50(3), 167–182.
Abstract: The species assemblages of cichlids in the three largest African Great Lakes are among the richest concentrations of vertebrate species on earth. The faunas are broadly similar in terms of trophic diversity, species richness, rates of endemism, and taxonomic composition, yet they are historically independent of each other. Hence, they offer a true and unique evolutionary experiment to test hypotheses concerning the mutual dependencies of ecology and brain morphology. We examined the brains of 189 species of cichlids from the three large lakes: Victoria, Tanganyika, and Malawi. A first paper demonstrated that patterns of evolutionary change in cichlid brain morphology are similar across taxonomic boundaries as well as across the three lakes [van Staaden et al., 1995 ZACS 98: 165–178]. Here we report a close relationship between the relative sizes of various brain structures and variables related to the utilization of habitat and prey. Causality is difficult to assign in this context, nonetheless, prey size and agility, turbidity levels, depth, and substrate complexity are all highly predictive of variation in brain structure. Areas associated with primary sensory functions such as vision and taste relate significantly to differences in feeding habits. Turbidity and depth are closely associated with differences in eye size, and large eyes are associated with species that pick plankton from the water column. Piscivorous taxa and others that utilize motile prey are characterized by a well developed optic tectum and a large cerebellum compared to species that prey on molluscs or plants. Structures relating to taste are well developed in species feeding on benthos over muddy or sandy substrates. The data militated against the existence of compensatory changes in brain structure. Thus enhanced development of a particular function is generally not accompanied by a parallel reduction of structures related to other modalities. Although genetic and environmental influences during ontogeny of the brain cannot be isolated, this study provides a rich source of hypotheses concerning the way the nervous system functions under various environmental conditions and how it has responded to natural selection.
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Schultz, W., Dayan, P., & Montague, P. R. (1997). A Neural Substrate of Prediction and Reward. Science, 275(5306), 1593–1599.
Abstract: The capacity to predict future events permits a creature to detect, model, and manipulate the causal structure of its interactions with its environment. Behavioral experiments suggest that learning is driven by changes in the expectations about future salient events such as rewards and punishments. Physiological work has recently complemented these studies by identifying dopaminergic neurons in the primate whose fluctuating output apparently signals changes or errors in the predictions of future salient and rewarding events. Taken together, these findings can be understood through quantitative theories of adaptive optimizing control.
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Palme, R., & Moestl, E. (1997). Measurement of cortisol metabolites in faeces of sheep as a parameter of cortisol concentration in blood. J. Mammal. Biol., 62, 192–197.
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Krebs, J. R., & Davies, N. B. (1997). Behavioural ecology : an evolutionary approach. Cambridge, Mass.: Blackwell Science.
Abstract: ntended for graduate and upper level undergraduate courses in behavioural ecology where students are already familiar with the basic ideas, this book continues to define the subject. A completely new set of contributions has been brought together once more to take account of the many exciting new developments in the field. Each chapter presents a balanced view of the subject, integrating a clear exposition of the theory with a critical discussion of how predictions have been tested by experiments and comparative studies. In addition, the book points to unreconciled issues and possible future developments. Edited by two of the most highly regarded experts in the field, this new volume contains contributions from an international authorship and continues the tradition of clarity and accessibility established by the three previous editions.
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Giraldeau, L. - A. (1997). The ecology of information use. In J. R. Krebs, & N. B. Davies (Eds.), Behavioural ecology : an evolutionary approach. Cambridge, Mass.: Blackwell Science.
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Whiten A., & Byrne, R. W. (Eds.). (1997). Machiavellian Intelligence II – Extensions and Evaluations. Cambridge: Cambridge University Press.
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Beaugrand, J. P. (1997). Relative importance of initial individual differences, victory and defeat experiences, and assessment accuracy during hierarchy formation: A simulation study (Vol. 41). Elsevier.
Abstract: This simulation study explores some conditions leading to transitivity within dominance orders. Combinations of three parameters were varied to study their consequences upon hierarchy formation and upon the degree of linearity of resultant structures. The factors studied were (i) the importance of initial Resource Holding Potentials (RHPs) , (ii) changes brought in RHPs by successive victories and defeats, and (iii) accuracy of RHP assessment made by opponents. Results show that initial differences in RHP always lead to perfectly transitive chains whose rank order reflects the importance of initial differences. Even when simulated animals make important errors while assessing each other during round robin tournaments, emerging dominance structures are perfectly linear and ranks obtained in the structure are highly correlated with initial values in RHPs. Moreover, accumulated experiences of victory and/or defeat alone always lead to perfectly linear hierarchies. Their combination with initial individual differences in RHP led to the same conclusion. Even when assessment was far from being perfect, not only perfect chains were formed but initial values in RHPs significantly influenced rank order when the contribution of victory and defeat to RHP was relatively unimportant. The higher the importance of victory and defeat to RHP as compared to that of initial RHP values, the lower was the correlation between initial RHP values and the ranks order reached by individuals in the resultant hierarchies. In general also, the lower the variation within initial RHPs, the lower was the correlation between initial RHPs and ranks in the hierarchy. At a given level of initial RHP dispersion, increasing the contribution of victory and defeat to RHP diminished the correlation between initial RHP values and obtained ranks. In addition, inaccurate assessment reduced the overall correlation, especially when dispersion of initial RHP values was low and the contribution of victory and defeat was high. These results shed some light on the controversy about the respective roles of initial individual attributes and that of patterns of resolution in the formation of animal hierarchies. We present the emergence of social order within closed systems as those simulated here as a case of self-organization.
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