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McElreath, R., Luttbeg, B., Fogarty, S. P., Brodin, T., & Sih, A. (2007). Evolution of animal personalities. Nature, 450(7167), E5.
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Wolf, M., van Doorn, G. S., Leimar, O., & Weissing, F. J. (2007). Wolf et al. reply. Nature, 450(7167), E5–E6.
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Hausberger, M., Gautier, E., Muller, C., & Jego, P. (2007). Lower learning abilities in stereotypic horses. Appl. Anim. Behav. Sci., 107(3-4), 299–306.
Abstract: The question of whether motor stereotypies may be associated with learning disorders is a highly debated issue both in humans and animals, but evidence is still scarce. The aim of the present study was to investigate the relation between the occurrence of stereotypic behaviours in horses where stereotypies are well described and learning abilities measurable. Seventy horses were observed in their box at two periods (August and November) and were then submitted to an instrumental task (opening a chest by raising the lid using the nose). Fifty-one of them had shown stereotypic behaviours at both periods. It appeared that more stereotypic horses (36/51) were unsuccessful than non-stereotypic horses (3/19) in the learning task. When successful, they required a longer time in order to perform the task (368 s on average against 220 for the non-stereotypic horses). No difference was found according to the type of stereotypy performed. This is to our knowledge the first time that a relation is found between stereotypy and learning in an animal species. The additional finding that stereotypic horses spent less time lying down and sleeping suggests a possible role of attentional processes. This finding has important implications for the horse industry.
Keywords: Stereotypies; Learning ability; Horses
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Austin, N. P., & Rogers, L. J. (2007). Asymmetry of flight and escape turning responses in horses. Laterality, 12(5), 464–474.
Abstract: We investigated whether horses display greater reactivity to a novel stimulus presented in the left compared to the right monocular visual field, and whether a population bias exists for escape turning when the same stimulus was presented binocularly. Domestic horses (N=30) were tested on three occasions by a person opening an umbrella five metres away and then approaching. The distance each horse moved away before stopping was measured. Distance was greatest for approach on the left side, indicating right hemisphere control of flight behaviour, and thus followed the same pattern found previously in other species. When order of monocular presentation was considered, an asymmetry was detected. Horses tested initially on the left side exhibited greater reactivity for left approach, whereas horses tested on the right side first displayed no side difference in reactivity. Perhaps left hemisphere inhibition of flight response allowed horses to learn that the stimulus posed no threat and this information was transferred to the right hemisphere. No population bias existed for the direction of escape turning, but horses that turned to the right when approached from the front were found to exhibit longer flight distances than those that turned to the left.
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Ceacero, F., Landete-Castillejos, T., Garcia, A. J., Estevez, J. A., & Gallego, L. (2007). Kinship Discrimination and Effects on Social Rank and Aggressiveness Levels in Iberian Red Deer Hinds. Ethology, 113(12), 1133–1140.
Abstract: Abstract Kin recognition is a widespread phenomenon that allows individuals to benefit by enhancing their inclusive fitness, and one of its most common forms is reducing aggressiveness towards relatives. We carried out an experiment with Iberian red deer hinds (Cervus elaphus hispanicus) in order to examine kin biases in dominance behaviour and its consequences on social rank. Three enclosed groups (n = 36, 23 and 21, respectively) were monitored during two lactation seasons and social rank hierarchies were assessed by analysing aggressive interactions matrices with Matman 1.1 software. Aggressive interactions between related hinds was significantly smaller than expected (chi2 = 5.02, df = 1, p = 0.025), not only between mother and daughter but also in second and third kinship degrees. Although rates of aggressiveness were similar to data published relating free-ranging C. e. scoticus, aggressive interactions with relatives were significantly smaller (chi2 = 39.0, df = 1, p < 0.001). This reduction of aggressiveness between related hinds was not the result of these hinds having a lower social rank: social rank was only related to age and weight, but not to kinship degree, calf sex or calving date. The decrease of aggressiveness towards first-, second- and third-degree relatives shows a complex kin recognition system in deer. Possible nepotistic roles in lactation include preventing milk thefts by non-kin and disturbing feeding of unrelated hinds.
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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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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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Valderrabano-Ibarra, C., Brumon, I., & Drummond, H. (2007). Development of a linear dominance hierarchy in nestling birds. Anim. Behav., 74(6), 1705–1714.
Abstract: Theoreticians propose that trained winning and losing are important processes in creating linear animal dominance hierarchies, and experiments have shown that both processes can occur in animals, but their actual roles in creating natural hierarchies are unknown. We described agonism in 18 broods of three blue-footed boobies, Sula nebouxii, a species for which trained winning and losing have been demonstrated, to infer how these processes generate and maintain a natural hierarchy. Ranks in the linear hierarchy that emerged in every brood were initially assigned by asymmetries in age, size and maturity, which led to differences between broodmates in levels of expressed and received aggression and, consequently, to differences in the training of their aggressiveness and submissiveness. Later, ranks appeared to be maintained by the chicks' acquired aggressive and submissive tendencies combined with ongoing effects of persisting differences in size and maturity. Our results suggest that trained winning and trained losing are important in the construction of booby hierarchies but that these two axes of learning are largely independent. Increase in submissiveness occurs over a period of about 10-20 days, and the level of submissiveness reached varies with the amount of aggression received. After training, submissiveness is apparently maintained by a lower level of aggression and increasing use of threats. Threats become increasingly effective as chicks age, but are never as effective as attacks.
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Hübener, E. (2007). Pferdgerechte Hilfen und der Zeitgeber dafür (Vol. 1/2007). D-86938 Schondorf: Wu Wei Verlag.
Abstract: Harmonie zwischen Mensch und Pferd und Verständnis des Reiters für körperliche Beschaffenheit und Verhaltensweise des Pferdes fordern wahre Hippologen seit Jahrhunderten. Dauernde intensive Aufmerksamkeit ermöglicht dem Pferd, kaum sichtbare Signale des Leittiers oder des Reiters (!) wahrzunehmen und blitzschnell zu befolgen. Wir müssen mit dem Pferd also nicht umgehen, als sei es unwillig oder taub.
Wenn der Reiter in perfekter Balance sitzt, möchte sein Schenkel während des Vorsetzens des gleichseitigen Pferde-Hinterbeins “selbsttätig” an den wegschwingenden Pferderumpf fallen. Dies ist der einzige Moment, in dem das Pferd eine vorwärtstreibende, seitwärtstreibende oder verhaltende Einwirkung des Reiters unmittelbar befolgen kann. Video-Aufnahmen bestätigen, was wir bereits vor über hundert Jahren wußten, was dann in unserer “Sportorganisation” aber irgendwie in Vergessenheit geriet. Natürlich dürfen wir den Schenkel nicht ständig ans Pferd fallen lassen, weil das Pferd das dann nicht mehr als Signal wertet. Wie die Schenkeleinwirkung 'an-' und 'abstellbar' ist, wird erläutert. Für das reiterliche Niveau hierzulande ist von entscheidender Bedeutung, daß junge Reiter an der Basis mit dem “selbsttätigen Schenkel” vertraut gemacht werden, sobald sie halbwegs sattelfest geworden sind. Jugendliche erlernen ihn spielend und verlieren ihn nie mehr, Erwachsene haben es da mangels ausreichender Beweglichkeit ihres Beckenringes wesentlich schwerer. Angesichts des höchst unzureichenden Angebotes guten Reitunterrichts könnte ein Lehr-Video zu diesem Thema überaus nützlich sein. Sponsoren dafür werden hier gesucht! Für Reiter, die den Balancesitz beherrschen und somit fühlen, wie ihre Schenkel an den wegschwingenden Pferderumpf fallen, ist Reiten fortan im Wesentlichen Selbstdisziplin. Daß wir wichtigste Elemente der Reitkunst verlieren können, wenn wir uns nicht mehr wissenschaftlich mit ihrem Inhalt auseinandersetzen, ist für den Autor Anlaß, sich in diesem Aufsatz erneut für interdisziplinäre universitäre Forschung zur Reitlehre und für die Unterstützung solcher Projekte durch die Spitzenorganisation einzusetzen. |
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Hübener, E. (2007). Horse-Appropriate Aids And Their Timer.
Abstract: Harmony between man and horse, and the rider`s understanding of the function of a horse`s body and mind – these are things that knowledgeable horsemen have demanded for centuries. Constant, focussed attention enables the horse to understand barely visible signals from its herd leader or its rider (!) and to act upon them instantly. Thus it is not necessary to treat a horse as if it were either unwilling or deaf.
When the rider sits in perfect balance, his leg tends to fall “self-actively” against the horse`s trunk as it swings away when the horse`s hind leg on the same side moves forwards. This is the only moment in which a horse is able to immediately follow the signal from the rider to move forwards, sideways, or to hold back. Video footage proves what we already knew more than a hundred years ago, but which our sports organisations have somehow managed to forget. Of course we should not let our leg fall against the horse all the time, because then the horse will not register this as a signal. It is explained how to “switch on” and “switch off” the leg signals. For the equestrian standards in this country, it is essential that young riders are familiarized with the “self-active” leg, as soon as they are halfway firm in the saddle. Youngsters learn this easily and never forget it again; it is far more difficult for adults, as the pelvic ring is no longer so flexible. As there is a definite lack of good riding lessons, an instructive video on this subject would be extremely useful. Sponsors are urgently required! For riders who have mastered the balanced seat and can feel how their leg falls against the horse`s trunk as it swings away, riding becomes primarily a matter of self discipline. If we do not examine these matters scientifically, we are in danger of loosing the most important elements of the equestrian art. With this thought in mind, the author uses this essay to argue once again for interdisciplinary research of equitation at universities, and for the support of these projects by high ranking organisations. |