Abstract: Social animals face a dilemma. To reap the benefits of group living, they have to stay together. However, individuals differ in their preferences as to where to go and what to do next. If all individuals follow their own preferences, group coherence is undermined, resulting in an outcome that is unfavourable for everyone. Neglecting one's own preferences and following a leader is one way to resolve this coordination problem. But what attributes make an individual a 'leader'? A modelling study by Johnstone and Manica1 illuminates this question.

Abstract: In animals, behavioural properties such as aggressive propensity are often consistent over a life span, and they may form part of a behavioural syndrome. We studied how aggressive propensity influences dominance, contest behaviour and growth in the cooperatively breeding cichlid fish Neolamprologus pulcher. We tested whether intrinsic aggressive propensity (1) influences dominance in paired contests, (2) causes different aggression levels in contests with partners matched for aggressive propensity compared to unmatched partners, and how it (3) affects growth rate in groups that were either matched or unmatched for aggressive propensity. Intrinsic aggressive propensity was first scored with a mirror test and classified as high, medium or low. Thereafter we tested fish with either high or low aggressive propensity with partners matched for size and either matched or unmatched for aggressive type in a paired contest for a shelter. We scored dominance, aggression and submission. As predicted, (1) dominance was more clearly established in unmatched than in matched contests and (2) individuals with high aggressive propensity launched more attacks overall than fish with low intrinsic aggressiveness, suggesting a higher propensity to escalate independently of winning or losing the paired contest. However, contrary to expectation, (3) individuals with low aggressiveness grew faster than aggressive ones in unmatched groups, whereas the opposite occurred in matched groups. This suggests that individuals with low aggressive propensity may benefit from conflict evasion, which might allow them to gain dominance in the future owing to larger body size.

Abstract: Inappropriate behavior during common handling procedures with horses is often subject to aversive treatment. The present study replicated and extended previous findings using differential reinforcement to shape appropriate equine handling behavior. In Study 1, a multiple baseline across subjects design was used with four horses to determine first the effects of shaping target-touch responses and then successive approximations of full truck loading under continuous and intermittent schedules of reinforcement. Full loading responses were shaped and maintained in all four horses and occurrences of inappropriate behaviors reduced to zero. Generalization of the loading response was also observed to both a novel trainer and trailer. In Study 2, a changing criterion design was used to increase the duration of feet handling with one horse. The horse's responding reached the terminal duration criterion of 1 min and showed consistent generalization and one-week maintenance. Overall, the results of both studies support the use of applied equine training systems based on positive reinforcement for increasing appropriate behavior during common handling procedures.

Abstract: The purpose of this study is to find convincing arguments, how horses should be ridden correctly, especially concerning the best head and neck position. Currently in the riding world, the opinions differ: The traditional way is to ride a horse with its nose in front of the vertical, while a new method claims that pulling the nose behind the vertical with an extreme flexion of the poll implies “gymnastic movements”. This article is focussed on the welfare and comfort of the horse in different head-neck positions, expressed by behaviours which document discomfort. As a first step, the behaviour of standing horses was observed while their heads and necks were put into seven postulated or frequently assumed positions. In the hyperflexed position the horses displayed most discomfort (with 49,7% of all reactions, like open mouths, head tossing, tail movements and other signs of resentment). The second strongest reactions of discomfort were shown in the highly raised position of the head (34,9%). The moderately rounded neck position as in traditional dressage lessons was not without signs of discomfort either, but less than the other two positions (11,2%). The high position and the extended position did not cause discomfort at all (0,17% and 0,23% respectively). In a second step, horses moving in all gaits under a rider were observed at competitions without the riders´ knowledge. The total number of observations was divided into two categories (each containing 30 horses) on the basis of the common rules of the FN: ridden with the horse’s nose in front of the vertical and ridden with the horse’s nose behind the vertical. The proportion of horses showing discomfort with the nose behind the vertical was clearly much higher (89,3%) compared to those ridden with the nose in front of the vertical (10,7%). Thus, the horses in the first category displayed signs of discomfort 8 times more frequent than those in the second group. In addition, scans carried out at tournaments showed that 92.8% of the horses were ridden with the nose behind the vertical. A clear result of this study is that the reality of riding differs widely from the rules. These results also show that riding in the hyperflexed position causes a great deal of discomfort for the horses and therefore should be abolished.
Die aktuellen Diskussionen in der Reiterwelt, welche Art und Weise des Reitens, besonders welche Kopf-Hals-Stellung zu erstreben ist, werfen die Frage auf, ob und wie die Pferde selbst ihr Befinden zum Ausdruck bringen. Über die Empfindungen der Pferde in verschiedenen Kopfhaltungen ist bisher sehr wenig bekannt. Deswegen wurde zunächst an stehenden Pferden das Ausdrucksverhalten beobachtet. Missfallensäußerungen häuften sich (mit 49,7% aller gezeigten Verhaltensauffälligkeiten wie Sperren, Rückwärtsgehen und Kopfschlagen) in der aufgerollten, hyperflektierten Stellung des Halses. An zweiter Stelle folgten Unmutsäußerungen in der absolut aufgerichteten Haltung (34,9%). Auch die beigezäumte Haltung wurde nicht ohne Unmutsbekundungen hingenommen, hier war deren Anzahl aber wesentlich geringer (11,2%). Die hohe Kopfstellung (0,17%) und die Dehnungshaltung (0,23%) bereiteten den Tieren kaum Unbehagen. Auch das Ausdrucksverhalten der Pferde unter dem Reiter wurde untersucht. Hierfür wurden, unter Berücksichtigung der schriftlich fixierten Regeln für das Turnierwesen der FN, je 30 Pferde in zwei Kategorien beobachtet: mit der Stirnlinie vor der Senkrechten und Pferde mit der Stirnlinie hinter der Senkrechten. Die Beobachtungen wurden unbemerkt von den Reitern auf den Abreiteplätzen von Turnieren durchgeführt. Die Anzahl an Verhaltensauffälligkeiten der Pferde mit der Stirnlinie hinter der Senkrechten war deutlich (89,3 %) erhöht im Gegensatz zu der anderen Gruppe (10,7 %). Die Pferde mit der Stirnlinie hinter der Senkrechten zeigten 8 Mal mehr Unmutsäußerungen als die mit der Stirnlinie vor der Senkrechten. Entgegen den Regeln der FN zeigten die durchgeführten Scans, dass unmittelbar vor den Prüfungen auf Turnieren 92,8% der Pferde mit der Stirnnasen-Linie hinter der Senkrechten geritten wurden. Ein Befund dieser Studie ist die Feststellung, dass die Praxis deutlich von den Regeln abweicht. Das Reiten mit der Stirnlinie hinter der Senkrechten ist nach diesen Befunden abzulehnen, da die Pferde deutliches Unwohlsein in dieser Haltung signalisieren.

Abstract: Understanding cooperation between unrelated individuals remains a central problem in animal behaviour; evolutionary mechanisms are debated, and the importance of reciprocity has been questioned. Biological market theory makes specific predictions about the occurrence of reciprocity in social groups; applied to the social grooming of mammals, it predicts reciprocity in the absence of other benefits for which grooming can be exchanged. Considerable effort has been made to test this grooming trade model in nonhuman primates; such studies show mixed results, but may be confounded by kin effects. We examined patterns of reciprocity within and across bouts, and tested predictions of the grooming trade model, among wild male chimpanzees, Pan troglodytes: a system with negligible kin effects. In accord with the model's expectations, we found that some grooming was directed by lower- to higher-ranked individuals, and that, on average, higher-ranked individuals groomed more reciprocally. We found no support, however, for a prediction that more reciprocity should occur between individuals close in rank. For most dyads, reciprocity of effort occurred through unbalanced participation in grooming bouts, but reciprocity varied considerably between dyads and only a small proportion showed strongly reciprocal grooming. Despite this, each male had at least one reciprocal grooming relationship. In bouts where both individuals groomed, effort was matched through mutual grooming, not alternating roles. Our results provide mixed support for the current grooming trade, biological market model, and suggest that it needs to incorporate risks of currency inflation and cheating for species where reciprocity can be achieved through repeated dyadic interactions.