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McFarland, R., & Majolo, B. (2011). Reconciliation and the Costs of Aggression in Wild Barbary Macaques (Macaca sylvanus): A Test of the Integrated Hypothesis. Ethology, , no-no.
Abstract: The ‘integrated hypothesis’ predicts that reconciliation (the post-conflict friendly interaction between former opponents observed in various group-living species) functions to reduce anxiety and the risk of aggression from the former opponent or a bystander in the aftermath of a conflict. It also predicts that relationship quality between opponents affects the occurrence of reconciliation and modulates the anxious response of the opponents after a conflict. Because of the asymmetric nature of aggressive interactions, the cost of aggression is likely to differ between the victim and the aggressor. The aim of this study was to test the predictions of the ‘integrated hypothesis’ independently for the victim and the aggressor of a conflict. We collected data on two wild groups of Barbary macaques. This study represents, to our knowledge, the first systematic test of the integrated hypothesis on wild, non-provisioned animals. Victims of aggression were at a greater risk of receiving aggression from the former opponent or a bystander after a conflict and showed elevated anxiety. We found no such costs for the aggressor. Reconciliation reduced anxiety in the victim but did not reduce their risk of receiving aggression. Finally, relationship quality affected the occurrence of reconciliation but did not modulate post-conflict anxiety. The results of our study show that the costs of aggression are asymmetrically distributed between the victim and the aggressor. Such differences are likely to lead to different social tactics used by the victim and the aggressor in the aftermath of a conflict.
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Ramsden, S., Richardson, F. M., Josse, G., Thomas, M. S. C., Ellis, C., Shakeshaft, C., et al. (2011). Verbal and non-verbal intelligence changes in the teenage brain. Nature, advance online publication.
Abstract: Intelligence quotient (IQ) is a standardized measure of human intellectual capacity that takes into account a wide range of cognitive skills1. IQ is generally considered to be stable across the lifespan, with scores at one time point used to predict educational achievement and employment prospects in later years1. Neuroimaging allows us to test whether unexpected longitudinal fluctuations in measured IQ are related to brain development. Here we show that verbal and non-verbal IQ can rise or fall in the teenage years, with these changes in performance validated by their close correlation with changes in local brain structure. A combination of structural and functional imaging showed that verbal IQ changed with grey matter in a region that was activated by speech, whereas non-verbal IQ changed with grey matter in a region that was activated by finger movements. By using longitudinal assessments of the same individuals, we obviated the many sources of variation in brain structure that confound cross-sectional studies. This allowed us to dissociate neural markers for the two types of IQ and to show that general verbal and non-verbal abilities are closely linked to the sensorimotor skills involved in learning. More generally, our results emphasize the possibility that an individual’s intellectual capacity relative to their peers can decrease or increase in the teenage years. This would be encouraging to those whose intellectual potential may improve, and would be a warning that early achievers may not maintain their potential.
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Pays, O., Sirot, E., & Fritz, H. (2011). Collective Vigilance in the Greater Kudu: Towards a Better Understanding of Synchronization Patterns. Ethology, , no-no.
Abstract: Collective detection of predators is one of the main advantages of living in groups in prey species. However, the mechanisms linking individual and collective vigilance remain largely unknown. Here, we investigated individual and collective vigilance in a natural population of greater kudu (Tragelaphus strepsiceros), a gregarious ruminant living under high predation risk. Controlling for environmental, individual and group factors, we show that the proportion of time during which at least one individual was vigilant increased with group size, whereas individual investment in vigilance decreased. We also show that individuals tended to synchronize both vigilance and feeding activities. More generally, and whatever the considered group size, we demonstrate how the independent scanning assumption underestimated both the proportion of time during which no individual was vigilant and the proportion of time during which all individuals were simultaneously vigilant, but overestimated the proportion of time during which one vigilant individual only was present. Our results thus contrast with the point of view that the alternative to independent vigilance is coordinated vigilance and plead for a better description of the processes whereby reciprocal influences between individuals shape collective patterns of vigilance.
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Krueger K., F. K., Byrne R. (2011). The use of sensory laterality for indicating emotional and cognitive reactions on environmental stimuli in animals [Die sensorische Lateralität als Indikator für emotionale und kognitive Reaktionen auf Umweltreize beim Tier]. In M. Erhard, U. Pollmann, B. Puppe, K. Reiter, & S. Waiblinger (Eds.), Current research in applied ethology [Aktuelle Arbeiten zur artgemäßen Tierhaltung (pp. 13–23). Darmstadt: KTBL.
Abstract: Summary
Many animals are lateralized when using sensory organs such as the eyes, ears or nostrils. Sensory laterality is not, as previously believed, caused by adjustment to motor laterality, but rather by one sided information processing in the particular brain hemi-spheres. While the right hemisphere predominantly analyses emotional information, the left hemisphere governs controlled rational, cognitive decisions. Since the brain hemi-spheres are largely connected with contralateral sensory organs, it is possible to infer how the information may be being interpreted by the side of preferred eye, ear or nostril used. The left eye usually dominates in emotional situations, i.e. fear or positive ex-citement, and the right eye in rational situations. Moreover, laterality increases when animals are stressed, e.g. when animals are confronted with anthropogenic or natural factors they can not handle, such as unsuitable housing or training conditions or un-avoidable predation pressure and social competition. A strong or increasing laterality could therefore potentially indicate welfare issues. Zusammenfassung Viele Tiere zeigen eine eindeutige sensorische Lateralität, sprich sie benutzen bevor-zugt ein Auge, ein Ohr, oder eine Nüster zur Aufnahme von Sinneseindrücken. Dies korreliert in den meisten Fällen nicht mit der motorischen Lateralität, sondern wird viel mehr durch die einseitige Verarbeitung von Informationen in den jeweiligen Gehirnhe-misphären bedingt. So werden emotionale Reaktionen von der rechten, reaktiven Ge-hirnhemisphäre und rationale Reaktionen von der linken, kognitiven Gehirnhemisphäre gesteuert. Da die Gehirnhälften zum Großen Teil mit den kontrolateralen Sinnesorga-nen verbunden sind lässt die Seite mit welcher Sinneseindrücke aufgenommen werden Schlüsse auf deren Informationsgehalt zu. So zeigen Tiere bei linksseitiger Aufnahme von Sinneseindrücken vermehrt reaktive, emotionalen Reaktionen, wie etwa bei Angst oder freudige Erregung, und bei rechtsseitig aufgenommene Sinneseindrücke eher rationales, gesteuertes Verhalten. Zudem verstärkt sich die sensorische Lateralität wenn Tiere Stress erfahren, sprich wenn sie wiederholt mit Situationen anthropogenen oder natürlichen Ursprungs konfrontiert werden denen sie nicht gewachsen sind, wie etwa bei unpassenden Haltungs- und Trainingsbedingungen, oder bei unausweichli-chem Raubtierdruck und sozialer Konkurrenz. Eine stark ausgeprägte, zunehmende sensorische Lateralität kann daher auf ein beeinträchtigtes Wohlergehen der Tiere hinweisen. |
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Noy, L., Dekel, E., & Alon, U. (2011). The mirror game as a paradigm for studying the dynamics of two people improvising motion together. Proceedings of the National Academy of Sciences, .
Abstract: Joint improvisation is the creative action of two or more people without a script or designated leader. Examples include improvisational theater and music, and day-to-day activities such as conversations. In joint improvisation, novel action is created, emerging from the interaction between people. Although central to creative processes and social interaction, joint improvisation remains largely unexplored due to the lack of experimental paradigms. Here we introduce a paradigm based on a theater practice called the mirror game. We measured the hand motions of two people mirroring each other at high temporal and spatial resolution. We focused on expert actors and musicians skilled in joint improvisation. We found that players can jointly create novel complex motion without a designated leader, synchronized to less than 40 ms. In contrast, we found that designating one player as leader deteriorated performance: The follower showed 2–3 Hz oscillation around the leader's smooth trajectory, decreasing synchrony and reducing the range of velocities reached. A mathematical model suggests a mechanism for these observations based on mutual agreement on future motion in mirrored reactive–predictive controllers. This is a step toward understanding the human ability to create novelty by improvising together.
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Romero L. M. (2011). Using the reactive scope model to understand why stress physiology predicts survival during starvation in Galápagos marine iguanas. Gen Comp Endocrinol, .
Abstract: Even though the term “stress” is widely used, a precise definition is notoriously difficult. Notwithstanding this difficulty, stress continues to be an important concept in biology because it attempts to describe how animals cope with environmental change under emergency conditions. Without a precise definition, however, it becomes nearly impossible to make testable a priori predictions about how physiological and hormonal systems will respond to emergency conditions and what the ultimate impact on the animal will be. The reactive scope model is a recent attempt to formulate testable predictions. This model provides a physiological basis to explain why corticosterone negative feedback, but not baseline corticosterone concentrations, corticosterone responses to acute stress, or the interrenal capacity to secrete corticosterone, is correlated with survival during famine conditions in Galápagos marine iguanas. Reactive scope thus provides a foundation for interpreting and predicting physiological stress responses.
Keywords: Reactive scope; Allostasis; Glucocorticoids; Stress; Survival
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Steidele, N. (2011). Beobachtungen einer Przewalski-Junggesellenherde im Jahresverlauf unter besonderer Berücksichtigung von Ruheverhalten und Rangordnung.
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Krueger, K.. (2011). Soziales Lernen der Pferde. In Göttinger Pferdetage '11: Zucht, Haltung und Ernährung von Sportpferden (51). Warendorf: FN Verlag.
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Krueger, K. (2011). Die Relevanz von sozialem Lernen beim Pferd für Tierhaltung und Tierschutz. In DVG 12. Internationale Fachtagung zu Fragen von Verhaltenskunde, Tierhaltung und Tierschutz. (pp. 220–221). Gießen: DVG.
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Schnerr, C. U. (2011). Feldstudie zur Epidemiologie und Bekämpfung von Strongyliden in Pferdebeständen im Raum Baden- Württemberg. Ph.D. thesis, , .
Abstract: In der Zeit von April 2005 bis März 2006 wurden bei 105 Pferden monatlich
koprologische Untersuchungen durchgeführt. Die Pferde waren zu zwei Drittel Jungtiere (≤ 4 Jahre) und ein Drittel > 4 Jahre. Die zur Verfügung stehenden vier Betriebe befanden sich alle im Raum Baden-Württemberg. Die Kotproben wurden mit Hilfe der Flotation auf Magen-Darmnematoden untersucht und anschließend einer quantitativen Eizahlbestimmung nach Mc Master unterzogen. Ab einem Eigehalt von 250 Eiern pro Gramm Kot (EpG) wurden die Pferde entsprechend der Gruppenzugehörigkeit entweder mit Pyrantel oder Ivermectin behandelt. Es wurden bei 73 Pferden ausschließlich Strongylideneier nachgewiesen; bei vier Pferden waren in der Flotation zusätzlich Eier von Parascaris equorum zu finden. Bei 28 (26,7%) der untersuchten Pferde wurden in keiner der 12 untersuchten Proben Eier von Magen-Darmnematoden nachgewiesen. Insgesamt mussten 57 (54,3%) der Pferde über den gesamten Untersuchungszeitraum hinweg nicht behandelt werden. 48 (45,7%) Pferde mussten mindestens einmal anthelminthisch behandelt werden. Kein Pferd musste häufiger als dreimal behandelt werden. In den Monaten August bis November war der Anteil an positiven Proben der Jungtiere signifikant höher als bei den Pferden > 4 Jahre. Innerhalb der Jungtiergruppe nahm die Höhe der Strongyliden-Eiausscheidung mit zunehmendem Alter signifikant ab. Ebenso nahm die Anzahl der positiven Proben im Laufe des Untersuchungszeitraums signifikant ab. Die beiden zur Entwurmung eingesetzten Substanzen (Pyrantel und Ivermectin) waren voll wirksam. In 98,8% der untersuchten Proben war ein Rückgang der Ei-Ausscheidung noch vier Wochen nach der Behandlung auf 0 EpG nachweisbar, d. h. es gab keinerlei Anzeichen für das Vorliegen von Resistenzen gegen die eingesetzten Substanzen. Die vorliegenden Untersuchungen sind ein weiterer Beweis dafür, dass mit Hilfe der selektiven anthelminthischen Behandlung die Anzahl der Entwurmungen – insbesondere auch bei Jungtieren – deutlich gesenkt werden kann. Die Eiausscheidung und damit die Weidekontamination werden mit Hilfe dieses Verfahrens deutlich reduziert. [Between April 2005 and March 2006 monthly koprological examinations where carried out on 105 horses. Two third of the horses were young animals (≤ 4 years) and a third were > 4 years old. The four farms on hand were all located in the Baden- Württemberg area. Faecal samples were examined for gastro-intestinal nematodes by means of flotation and subsequently subjected to an egg-quantity counting according to Mc Master. Starting from an egg content of 250 eggs per gram faeces (EpG), the horses were treated with either Pyrantel or Ivermectin according to their group affiliation. In 73 horses solely Strongyle eggs were detected; the flotation of four horses additionaly showed eggs of Parascaris equorum. In 28 (26,7%) of the examined horses none of the 12 examined samples showed eggs of gastro-intestinal nematodes. Overall 57 (54,3%) horses didn´t need any treatment during the total examination cycle. 48 (45,7%) of the horses needed at least one anthelminthic treatment. None of the horses needed to be treated more than three times. From August to November the rate of positive samples within the group of young animals was significantly higher than in the horses > 4 years. Whithin the group of young animals the level of Strongyle egg excretions dropped significantly with advancing age. Likewise, the number of positive samples also dropped significantly in the course of the examination cycle. Both substances (Pyrantel and Ivermectin) applied for deworming were fully effective. Even a further 4 weeks after treatment the examined sample showed a drop of egg excretion to 0 EpG in 98,8% of the samples, in other words there were no signs of prevailing resistance appearances towards the applied substance. The present studies are further proof that the number of dewormings-especially in young animals can be distinctly reduced by means of selective anthelminthic treatments. Egg excretion and therewith pasture land contamination can be clearly reduced by means of this procedure.] |