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Bergmann, H. H., Klaus, S., Muller, F., & Wiesner, J. (1975). [Individuality and type specificity in the songs of a population of hazel grouse (Bonasa bonasia bonasia L., Tetraoninae, Phasianidae)]. Behaviour, 55(1-2), 94–114.
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Reimers, M., Schwarzenberger, F., & Preuschoft, S. (2007). Rehabilitation of research chimpanzees: stress and coping after long-term isolation. Horm Behav, 51(3), 428–435.
Abstract: We report on the permanent retirement of chimpanzees from biomedical research and on resocialization after long-term social isolation. Our aim was to investigate to what extent behavioral and endocrine measures of stress in deprived laboratory chimpanzees can be improved by a more species-typical social life style. Personality in terms of novelty responses, social dominance after resocialization and hormonal stress susceptibility were affected by the onset of maternal separation of infant chimpanzees and duration of deprivation. Chimpanzees, who were separated from their mothers at a younger age and kept in isolation for more years appeared to be more timid personalities, less socially active, less dominant and more susceptible to stress, as compared to chimpanzees with a less severe deprivation history. However, permanent retirement from biomedical research in combination with therapeutic resocialization maximizing chimpanzees' situation control resulted in reduced fecal cortisol metabolite levels. Our results indicate that chimpanzees can recover from severe social deprivation, and may experience resocialization as less stressful than solitary housing.
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Hodgson, D., Howe, S., Jeffcott, L., Reid, S., Mellor, D., & Higgins, A. (2005). Effect of prolonged use of altrenogest on behaviour in mares (Vol. 169).
Abstract: Erratum in:
Vet J. 2005 May;169(3):321.
Corrected and republished in:
Vet J. 2005 May;169(3):322-5.
Oral administration of altrenogest for oestrus suppression in competition horses is believed to be widespread in some equestrian disciplines, and can be administered continuously for several months during a competition season. To examine whether altrenogest has any anabolic or other potential performance enhancing properties that may give a horse an unfair advantage, we examined the effect of oral altrenogest (0.044 mg/kg), given daily for a period of eight weeks, on social hierarchy, activity budget, body-mass and body condition score of 12 sedentary mares. We concluded that prolonged oral administration of altrenogest at recommended dose rates to sedentary mares resulted in no effect on dominance hierarchies, body mass or condition score.
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Moses, S. N., Villate, C., & Ryan, J. D. (2006). An investigation of learning strategy supporting transitive inference performance in humans compared to other species. Neuropsychologia, 44(8), 1370–1387.
Abstract: Generalizations about neural function are often drawn from non-human animal models to human cognition, however, the assumption of cross-species conservation may sometimes be invalid. Humans may use different strategies mediated by alternative structures, or similar structures may operate differently within the context of the human brain. The transitive inference problem, considered a hallmark of logical reasoning, can be solved by non-human species via associative learning rather than logic. We tested whether humans use similar strategies to other species for transitive inference. Results are crucial for evaluating the validity of widely accepted assumptions of similar neural substrates underlying performance in humans and other animals. Here we show that successful transitive inference in humans is unrelated to use of associative learning strategies and is associated with ability to report the hierarchical relationship among stimuli. Our work stipulates that cross-species generalizations must be interpreted cautiously, since performance on the same task may be mediated by different strategies and/or neural systems.
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Cameron, E. Z. (2004). Facultative adjustment of mammalian sex ratios in support of the Trivers-Willard hypothesis: evidence for a mechanism. Proc Biol Sci, 271(1549), 1723–1728.
Abstract: Evolutionary theory predicts that mothers of different condition should adjust the birth sex ratio of their offspring in relation to future reproductive benefits. Published studies addressing variation in mammalian sex ratios have produced surprisingly contradictory results. Explaining the source of such variation has been a challenge for sex-ratio theory, not least because no mechanism for sex-ratio adjustment is known. I conducted a meta-analysis of previous mammalian sex-ratio studies to determine if there are any overall patterns in sex-ratio variation. The contradictory nature of previous results was confirmed. However, studies that investigated indices of condition around conception show almost unanimous support for the prediction that mothers in good condition bias their litters towards sons. Recent research on the role of glucose in reproductive functioning have shown that excess glucose favours the development of male blastocysts, providing a potential mechanism for sex-ratio variation in relation to maternal condition around conception. Furthermore, many of the conflicting results from studies on sex-ratio adjustment would be explained if glucose levels in utero during early cell division contributed to the determination of offspring sex ratios.
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Huebener, E. (2005). Der Natur abgelauschte Erkenntnisse: Der Weg zum Balancesitz und zum Begreifen des Timers für Signale an das Pferd;. Tierärztl. Umschau, 2, 90–99.
Abstract: Zusammenfassung
Mit dem Beitrag “Die Bewegungen von Pferderumpf und -rücken aus der Sicht des Reiters” (TU 59, 327-334, 2004) wurde um universitäre Forschung zur Ermittlung gemessener Werte für diese Begleiter der Fortbewegung geworben.
Die Entdeckung des Ranges der Rumpf-Rücken-Bewegungen für pferdgerechtes und kultiviertes, feinfühliges Reiten ist mit der Entwicklung des Balancesitzes und der Technik des vom Pferd Zeitvorgaben Empfangens und ihm Signale Sendens (Reiter sagen: des Fühlens und Einwirkens) eng verbunden. Ihre Geschichte läßt sich über viereinhalb Jahrhunderte verfolgen. Ein kurzer Abriß wird hier nachgeliefert.
Er mündet erneut in ein Plädoyer für interdisziplinäres universitäres Forschen, weil auch bei Sitz und Hilfengebung, weiteren Grundlagen des Reitens – im Interesse effektiveren Unterrichts an der Basis unseres “Sports” – dringender Klärungsbedarf besteht.
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Huebener, E. (2006). The Rider's Impacts and Their Timers – Example: Rider's Aids for Transitions Between Different Gaits. Tierärztl. Umschau, 10, 515–532.
Abstract: The scientific investigation of the basics of the inherited riding teachings assists in conserving its values. Riding instructors should be able to teach not only “how” but also “why”.
The classic European riding teachings that have developed across the centuries are based on perceptions that have their roots in natural phenomena. They are being mirrored, for instance, in the aids to stimulate the change from one gait to the next.
The movements of the horse's trunk and back provide timers for horse-friendly, sensitive aids that create attentive, diligent and happily cooperating horses.
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Huebener, E. (2006). Einwirkungen des Reiters nach Zeitgeber ? Beispiel: Hilfen für Übergänge von einer Gangart in eine andere;. Tierärztl. Umschau, 10, 515–532.
Abstract: Zusammenfassung
Wissenschaftliches Erfassen von Grundlagen der ererbten Reitlehre hilft, deren Werte zu bewahren. Und Reiten Lehrende dürfen nicht nur das “Wie”, sie sollten auch das “Weshalb” vermitteln können.
Die Grundlagen der in Jahrhunderten entstandenen klassischen europäischen Reitlehre beruhen auf der Natur abgelauschten Erkenntnissen. Sie spiegeln sich u. a. in den Hilfen für Übergänge aus einer Gangart in eine andere.
Die Bewegungen von Pferderumpf und -rücken liefern den Zeitgeber für jene pferdgerechte, feinfühlige Hilfengebung, die aufmerksam, fleißig und freudig mitarbeitende Pferde schafft.
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Hemelrijk, C. K., & Wantia, J. (2005). Individual variation by self-organisation. Neurosci Biobehav Rev, 29(1), 125–136.
Abstract: In this paper, we show that differences in dominance and spatial centrality of individuals in a group may arise through self-organisation. Our instrument is a model, called DomWorld, that represents two traits that are often found in animals, namely grouping and competing. In this model individual differences grow under the following conditions: (1) when the intensity of aggression increases and grouping becomes denser, (2) when the degree of sexual dimorphism in fighting power increases. In this case the differences among females compared to males grow too, (3) when, upon encountering another individual, the tendency to attack is 'obligate' and not conditional, namely 'sensitive to risks'. Results resemble phenomena described for societies of primates, mice, birds and pigs.
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Acuna, B. D., Sanes, J. N., & Donoghue, J. P. (2002). Cognitive mechanisms of transitive inference. Exp Brain Res, 146(1), 1–10.
Abstract: We examined how the brain organizes interrelated facts during learning and how the facts are subsequently manipulated in a transitive inference (TI) paradigm (e.g., if A<B and B<C, then A<C). This task determined features such as learned facts and behavioral goals, but the learned facts could be organized in any of several ways. For example, if one learns a list by operating on paired items, the pairs may be stored individually as separate facts and reaction time (RT) should decrease with learning. Alternatively, the pairs may be stored as a single, unified list, which may yield a different RT pattern. We characterized RT patterns that occurred as participants learned, by trial and error, the predetermined order of 11 shapes. The task goal was to choose the shape occurring closer to the end of the list, and feedback about correctness was provided during this phase. RT increased even as its variance decreased during learning, suggesting that the learnt knowledge became progressively unified into a single representation, requiring more time to manipulate as participants acquired relational knowledge. After learning, non-adjacent (NA) list items were presented to examine how participants reasoned in a TI task. The task goal also required choosing from each presented pair the item occurring closer to the list end, but without feedback. Participants could solve the TI problems by applying formal logic to the previously learnt pairs of adjacent items; alternatively, they could manipulate a single, unified representation of the list. Shorter RT occurred for NA pairs having more intervening items, supporting the hypothesis that humans employ unified mental representations during TI. The response pattern does not support mental logic solutions of applying inference rules sequentially, which would predict longer RT with more intervening items. We conclude that the brain organizes information in such a way that reflects the relations among the items, even if the facts were learned in an arbitrary order, and that this representation is subsequently used to make inferences.
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