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Behrens, T. E. J., Hunt, L. T., Woolrich, M. W., & Rushworth, M. F. S. (2008). Associative learning of social value. Nature, 456(7219), 245–249.
Abstract: Our decisions are guided by information learnt from our environment. This information may come via personal experiences of reward, but also from the behaviour of social partners1, 2. Social learning is widely held to be distinct from other forms of learning in its mechanism and neural implementation; it is often assumed to compete with simpler mechanisms, such as reward-based associative learning, to drive behaviour3. Recently, neural signals have been observed during social exchange reminiscent of signals seen in studies of associative learning4. Here we demonstrate that social information may be acquired using the same associative processes assumed to underlie reward-based learning. We find that key computational variables for learning in the social and reward domains are processed in a similar fashion, but in parallel neural processing streams. Two neighbouring divisions of the anterior cingulate cortex were central to learning about social and reward-based information, and for determining the extent to which each source of information guides behaviour. When making a decision, however, the information learnt using these parallel streams was combined within ventromedial prefrontal cortex. These findings suggest that human social valuation can be realized by means of the same associative processes previously established for learning other, simpler, features of the environment.
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Hoffmann, & G. (2008). Bewegungsaktivität und Stressbelastung bei Pferden in Auslaufhaltungssystemen mit verschiedenen Bewegungsangeboten.
Abstract: Pferdehaltungssysteme mit angrenzenden Ausläufen gelten als eine sehr tiergerechte
Haltungsform, da sie den Tieren eine gewisse Bewegungsmöglichkeit
bieten. Ziel der vorliegenden Untersuchung war es, zu erfassen, ob der angrenzende
Auslauf selbst einen ausreichenden Anreiz zur Bewegung darstellt und wie sich verschiedene
Bewegungs- und Platzangebote auf die Bewegungsaktivität von Pferden
in einer Gruppen-Auslaufhaltung auswirken. Zudem wurde ermittelt, welche Auswirkung
die Bewegungsform bzw. –intensität auf das Wohlbefinden der Tiere hat.
Der Großteil der in Deutschland gehaltenen Pferde verbringt die meiste Zeit des
Tages im Stall, obwohl mittlerweile bekannt ist, dass Pferde unter natürlichen
Haltungsbedingungen 12 bis 16 Stunden des Tages in Bewegung verbringen. Der
Optimierung der Stallhaltungssysteme gilt daher ein besonderes Interesse.
Zu diesem Zweck wurden von September 2004 bis Oktober 2005 Versuche mit 24
Warmblutstuten im Alter von 1½ bis 3½ Jahren in Einzel- und Gruppen-
Auslaufhaltungssystemen durchgeführt. Jeweils sechs Pferde bildeten eine Versuchsgruppe.
In jeder Gruppe fanden fünf Varianten von einer ca. dreiwöchigen
Dauer statt. Die Gruppenhaltung wurde dabei durch drei unterschiedliche Zusatzbewegungsangebote
(2 Std. Weide / Tag, 2 Std. unbegrünte Koppel / Tag, 1 Std. Freilauf-
Führanlage / Tag) ergänzt. In der Einzel-Auslaufhaltung (Box mit 45 m²-großem
angrenzenden Auslauf) und in einer Versuchsvariante der Gruppenhaltung bekamen
die Pferde hingegen keine zusätzliche Bewegung außerhalb des Stallhaltungssystems
angeboten. Das Gruppenhaltungssystem selbst war durch die räumliche
Trennung der Funktionsbereiche (Liegen, Fressen, Trinken, Bewegen) gekennzeichnet
und der angrenzende Auslauf war 270 m² groß. In einer zusätzlichen Versuchsphase
fand in der Gruppenhaltung eine Erweiterung des permanent zugänglichen
Auslaufs auf insg. 540 m² statt.
Die Bewegungsaktivität wurde mit Pedometern erfasst, die an jeweils einem Hinterbein
der Pferde befestigt wurden und ergänzend fand eine Analyse von Videoaufzeichnungen
statt. Zur Beurteilung der Stressbelastung fanden Messungen der Herz192
Zusammenfassung
frequenzvariabilität (Parameter HF und SD2) und der fäkalen Cortisolmetabolitenkonzentration
statt.
Die Auswertung des Bewegungsverhaltens ergab, dass eine zusätzliche zweistündige
freie Bewegung der Pferdegruppe auf einer Weide zu einer deutlichen
Steigerung der durchschnittlichen Bewegungsaktivität (149,6 Min. / Tag) führt,
ebenso wie eine einstündige Bewegung in einer Führanlage (173,0 Min. / Tag). Eine
unbegrünte Koppel regte die Pferde der Gruppenhaltung hingegen nicht zu vermehrter
Bewegung an (131,6 Min. / Tag), sondern bewirkte z. T. sogar eine Abnahme
der Bewegungsaktivität. In der Gruppen-Auslaufhaltung ohne zusätzliches Bewegungsangebot
war die Bewegungsaktivität ebenfalls gering (125,8 Min / Tag) und
während der Einzel-Auslaufhaltung ohne Zusatzbewegung zeigten die Pferde die
geringste Bewegungsaktivität (102,3 Min. / Tag).
Bei der alleinigen Analyse der Bewegungszeit im Stallhaltungssystem war kein signifikanter
Einfluss der zusätzlichen Bewegung außerhalb des Stallsystems auf die
übrige Fortbewegung feststellbar.
Auch eine Vergrößerung des an den Stall angrenzenden Auslaufs im Gruppenhaltungssystem
hatte keinen steigernden Einfluss auf das Bewegungsverhalten der
Pferde.
Die Stressbelastung der Pferde war in den Varianten der Gruppenhaltung mit zweistündigem
Weidegang (SD2: 82,9 ms; Cortisolmetaboliten: 29,0 nmol / kg Kot) sowie
der einstündigen Bewegung in einer Freilauf-Führanlage (SD2: 99,2 ms; Cortisolmetaboliten:
27,7 nmol / kg Kot) am geringsten. Die Untersuchungen zeigten eine
Stresszunahme in der Gruppenhaltung mit zweistündigem Auslauf auf einer unbegrünten
Koppel ohne Futterangebot (SD2: 101,3 ms; Cortisolmetaboliten:
39,6 nmol / kg Kot) sowie in der Variante der Gruppenhaltung ohne zusätzliches Bewegungsangebot
(SD2: 113,3 ms; Cortisolmetaboliten: 38,4 nmol / kg Kot). Dem
Mittelwert der Gruppe nach zu folgern hatten die Pferde während der Einzelhaltung
ohne Zusatzbewegung eine sehr große Stressbelastung (SD2: 123,8 ms; Cortisolmetaboliten:
37,5 nmol / kg Kot). Ein Vergleich der Gruppen- und Einzelhaltung hinsichtlich
der Herzfrequenzvariabilität hat jedoch gezeigt, dass insg. 70 % der Pferde
während der Haltung in einer Gruppe weniger Stress empfinden. Es gab aber auch
Zusammenfassung 193
Pferde (30 %), die in der Einzelhaltung eine abnehmende Stressbelastung zeigten,
wobei hier der Einfluss der Rangordnung eine entscheidende Rolle zu spielen
scheint.
Durch die Auswertung mehrerer Messparameter (sowohl für Stress- als auch für Bewegungsverhalten)
werden gleichgerichtete Tendenzen bei den Versuchsvarianten
deutlich, allerdings ist eine eindeutige Gewichtung der Parameter nicht möglich.
Somit ist die methodische Vorgehensweise dieser Untersuchung sehr positiv und als
notwendig anzusehen, da die Messdaten auch immer gewissen Schwankungen
durch externe Einflüsse unterliegen.
Allgemein ist festzuhalten, dass Auslaufhaltungssysteme zwar eine gewisse
Anregung zur Bewegung bieten, aber mit maximal vier Stunden (insg. 62 – 248 Min.)
Bewegung pro Tag war der tägliche Anteil an Bewegung sehr viel geringer als
beispielsweise bei Pferden in freier Wildbahn oder ganzjähriger Weidehaltung. Somit
deckt ein Auslaufhaltungssystem trotz getrennter Funktionsbereiche und eines
großen Auslaufs nicht den Bewegungsbedarf der Pferde, wenn keine zusätzlichen
Bewegungsanreize und –möglichkeiten angeboten werden.
Eine zusätzliche Bewegung von Pferden ist nicht nur zur Gesunderhaltung des
Bewegungsapparates und der Körperfunktionen notwendig, sondern auch um das
Wohlbefinden und die Ausgeglichenheit der Pferde zu steigern.
[Horse husbandry systems with close-by discharge are considered to be a very livestock-
friendly housing form, as they offer a certain movement opportunity for the
animals. The aim of the present study was to examine how different movement and
space offerings affect the movement activities of horses in a group horse husbandry
with close-by discharge, and whether the discharge provides itself an adequate
incentive for movement. The impact that the form or rather intensity of movement has
on the wellbeing of the animals was also established.
Most of the horses held in Germany spend most of the day in the stable, although it is
meanwhile known that horses under natural housing conditions are 12 to 16 hours of
the day in motion. Therefore the improvement of stable housing systems applies a
special interest.
For this purpose, 24 warmblood mares, aged from 1½ to 3½ years, were studied in
single and group discharge husbandry systems from September 2004 until October
2005. Six horses formed an experimental group. In every group five variants of approximately
three weeks were proceeded. Thereby the group husbandry was supplemented
with three different additional movement opportunities (2 h pasture / day,
2 h non-grassy pasture land / day, 1 h free range horse walker / day). In the single
discharge husbandry (single box with 45 sq. m-large close-by discharge) and in one
experimental variant of the group husbandry got the horses, however, offered no additional
movement outside the husbandry system. The group husbandry system itself
was marked by the spatial division of the functional areas (lying, eating, drinking,
moving) and the close-by discharge measured 270 sq. m. In an additional phase of
the study, and expansion of the permanently accessible close-by discharge to
540 sq. m was found.
The movement activity was documented with pedometers attached respectively to
one hind leg of the horse and a supplementary analysis of video documentation. To
evaluate the stress exposure measurements of heart frequency variability (parameters
HF and SD2) and of the faecal cortisol metabolite concentration were performed.
Summary 195
The interpretation of the movement behaviour showed that additional two hours of
free movement on a pasture led to a significant increase in the average movement
activity (149.6 min / day), as well as one hour movement in a horsewalker did
(173.0 min / day). The non-grassy pasture land, however, didn’t inspire the horses of
the group husbandry to increased movement (131.6 min / day), but sometimes even
caused a decrease in movement activity. In the group discharge husbandry without
additional movement opportunities the movement activity was also low
(125.8 min / day), and during the single discharge husbandry without additional
movement the horses showed the least movement activity (102.3 min / day).
In analysing only the movement time in the stable system was no significant impact
of the additional movement outside the housing system to the rest of locomotion
ascertainable.
As well an expansion of the close-by stable discharge in the group husbandry system
had no increasing influence on the movement behaviour of the horses.
The stress exposure of the horses was least in the variations of group husbandry
with two hours on a pasture (SD2: 82.9 ms; cortisol metabolites: 29.0 nmol / kg faeces)
as well as one hour of movement in a free range horse walker (SD2: 99.2 ms;
cortisol metabolites: 27.7 nmol / kg faeces). The studies showed a rise in stress in
group husbandry with two hours of movement on a non-grassy pasture land without
feeding opportunity (SD2: 101.3 ms; cortisol metabolites: 39.6 nmol / kg faeces) as
well as in the variation of the group husbandry without additional movement offerings
(SD2: 113.3 ms; cortisol metabolites: 38.4 nmol / kg faeces). Judging from the mean
of the group the horses had a very high stress exposure in the variation of the single
husbandry without additional movement offerings (SD2: 123.8 ms; cortisol metabolites:
37.5 nmol / kg faeces). But a comparison of the group and single husbandry in
terms of the heart frequency variability showed that alltogether 70 % of the horses
experienced less stress if hold in a group. However, some horses (30 %) showed
reducing stress in the single husbandry, whereas here the influence of social hierarchy
seems to play a decisive role.
196 Summary
In consequence of the examination of several measuring parameters (both for stressand
for movement behaviour) parallel aligned tendencies become apparent in the
experimental variants, however, is a unique weighting of the parameters not possible.
Thus, the methodological approach of this study is to be regarde as very positive and
necessary, since the data always vary with some fluctuations by external influences.
In general it can be established that discharge husbandry systems offer some incentive
for the horse to move, but with a maximum of four hours (overall 62 – 248 min) of
movement per day, the daily proportion of movement was much less than, for example,
in the case of wild horses or year-round pasture keeping. Thus, if no additional
movement incentives and possibilities are offered, the discharge husbandry system
doesn’t cover the movement needs of the horse despite separate functional areas
and a large outside discharge.
Additional movement is not only necessary to keep the musculoskeletal system and
bodily functions of the horse healthy, but also to ensure the horse’s well being and
mental balance.]
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Cameron, E. Z., Linklater, W. L., Stafford, K. J., & Minot, E. O. (2008). Maternal investment results in better foal condition through increased play behaviour in horses. Anim. Behav., 76(5), 1511–1518.
Abstract: Play behaviour is widespread in mammals, but benefits to play have been difficult to demonstrate. Physical training is one of the many proposed hypotheses, suggesting that males and females should play differently, that increased maternal investment should lead to increases in play, and that increases in play should result in physical advantages. In a population of feral horses, Equus caballus, males and females did not differ in their play behaviour except that males initiated more of their play bouts than females. Maternal condition influenced play behaviour only in males, with sons of mothers in good condition playing more. However, when we controlled for maternal effects by comparing a son and a daughter of the same mother, daughters played more when their mother was in poor condition and sons played more when their mother was in good condition. Mothers of foals that played more lost more condition. Therefore, the difference in play behaviour could not be explained by offspring sex or maternal condition alone, but play behaviour mirrored variation in maternal investment. In addition, those individuals that played more survived better and had better body condition as yearlings despite weaning earlier. Since increased activity has been linked to enhanced musculoskeletal development in domestic horses, we suggest that play provides a link between increased maternal investment, increased body condition and future reproductive success in feral horses, and probably in other species.
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De Cremer, D., & van Dijk, E. (2008). Leader--Follower Effects in Resource Dilemmas: The Roles of Leadership Selection and Social Responsibility. Group Processes Intergroup Relations, 11(3), 355–369.
Abstract: Previous research on the allocation of scarce resources shows that when people are assigned labels of leader or follower in their group, leaders allocate more of the scarce resources to themselves than followers do. In three laboratory studies, we examine the idea that how people are selected for the leader role (i.e. election or appointment) determines whether leaders take more or equal shares (relative to followers) from a common resource. In a first experiment, we show that participants were more accepting of norm violating behavior by an appointed versus elected leader. In a second experiment, we show that when participants were assigned to a leader or follower role, allocations of appointed leaders differed significantly from those of elected leaders and followers, whereas there was no difference between the two latter conditions. Moreover, elected leaders were shown to feel more social responsibility than both appointed leaders and followers. In a final experiment, we show that when participants were primed with the concept of social responsibility (relative to a neutral condition) no difference in allocations between appointed and elected leaders emerged.
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Powell, D. (2008). Female–female competition or male mate choice? Patterns of courtship and breeding behavior among feral horses (Equus caballus) on Assateague Island. J. Ethol., 26(1), 137-144.
Abstract: Previous research on the Assateague horses found that high-ranking females had more surviving offspring than low-ranking females. Variance in reproductive success may be the result of a variety of proximate processes that affect sexual behavior such as mate choice and mate competition. A study was done to determine whether patterns of courtship, social, and sexual behavior could be identified that would suggest mate choice and/or mate competition. Behavioral data were collected from approximately 40 sexually mature mares living in harem bands. Stallions showed more interest in the eliminations of dominant mares than subordinate mares. Males also engaged in significantly more high-intensity (e.g., mounts and copulations) sexual behavior with dominant mares than subordinate mares, and there was a trend for males to engage in more low-intensity (e.g., flehmen and ano-genital sniffing) sexual behavior with dominant mares than subordinate mares. There was no effect of mare rank on spatial relationships with the stallion; however, dominant mares did attempt to restrict reproductive access to the stallion by harassing and disrupting copulations. Higher foaling rates among dominant mares on Assateague Island could therefore be the result of rank-related mate choice by stallions and direct female competition for mating opportunities.
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Romero, T., & Aureli, F. (2008). Reciprocity of support in coatis (Nasua nasua). Journal of Comparative Psychology, 122(1), 19–25.
Abstract: Primate sociality has received much attention and its complexity has been viewed as a driving force for the evolution of cognitive abilities. Improved analytic techniques have allowed primate researchers to reveal intricate social networks based on the exchange of cooperative acts and services. Although nonprimates are known to show similar behavior (e.g., cooperative hunting, food sharing, coalitions) there seems a consensus that social life is less complex than in primates. Here the authors present the first group-level analysis of reciprocity of social interactions in a social carnivore, the ring-tailed coati (<xh:i xmlns:search=“http://marklogic.com/appservices/search” xmlns=“http://apa.org/pimain” xmlns:xsi=“http://www.w3.org/2001/XMLSchema-instance” xmlns:xh=“http://www.w3.org/1999/xhtml”>Nasua nasua</xh:i>). The authors found that support in aggressive conflicts is a common feature in coatis and that this behavior is reciprocally exchanged in a manner seemingly as complex as in primates. Given that reciprocity correlations persisted after controlling for the effect of spatial association and subunit membership, some level of scorekeeping may be involved. Further studies will be needed to confirm our findings and understand the mechanisms underlying such reciprocity, but our results contribute to the body of work that has begun to challenge primate supremacy in social complexity and cognition. (PsycINFO Database Record (c) 2012 APA, all rights reserved)
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O'Grady, S. E. (2008). Basic farriery for the performance horse. Vet Clin North Am Equine Pract, 24(1), 203–218.
Abstract: Proper farriery promotes a healthy functional foot and biomechanical efficiency and prevents lameness. Because the equine veterinarian is responsible for the soundness of the horse, a working knowledge of farriery becomes essential. A thorough knowledge of traditional horseshoeing enables the veterinarian to interact with the farrier at the farrier's level; this ultimately enhances and promotes quality hoof care. This article focuses on fundamental farriery and recognizing subtle changes in hoof conformation that can be used to preserve the integrity of the hoof capsule, along with the structures enclosed within, and thus prevent lameness in the performance horse.
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McGrogan, C., Hutchison, M. D., & King, J. E. (2008). Dimensions of horse personality based on owner and trainer supplied personality traits. Appl. Anim. Behav. Sci., 113(1), 206–214.
Abstract: Ratings on 36 personality descriptive adjectives were made on 100 companion horses by owners, trainers, and stable managers. The descriptors had been previously provided by a subset of 30 raters based on their own experience with horses. Principal components analysis revealed three statistically significant factors accounting for 59% of the variance. The first was a large, complex factor resembling the human Agreeableness factor. This factor contained four clusters of items reflecting obedience, kindness, sociality, and non-aggressiveness. The second factor resembled human Extraversion, although it also contained items reflecting intellect and curiosity. The third factor reflected Neuroticism or Emotionality. Factors similar to Agreeableness, Extraversion, and Emotionality are frequently observed in other taxa. The diverse composition of the Agreeableness factor indicating covariation among obedience, kindness, sociality, and non-aggressiveness may be a result of the intense artificial selection for all four components during the 6000 years of horse domestication.
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Sullivan, K. A., Hill, A. E., & Haussler, K. K. (2008). The effects of chiropractic, massage and phenylbutazone on spinal mechanical nociceptive thresholds in horses without clinical signs. Equine Vet J, 40(1), 14–20.
Abstract: REASON FOR PERFORMING STUDY: Common methods used to treat back problems in horses need to be assessed objectively. OBJECTIVES: To measure spinal mechanical nociceptive thresholds (MNTs) and evaluate the effects of chiropractic, massage and phenylbutazone, compared with active and inactive control groups. METHODS: Baseline MNTs at 7 sites within the thoracolumbar and sacral regions were measured in 38 healthy mature horses exhibiting no clinical signs of lumbar pain. Horses were assigned to one of 3 treatment groups: instrument-assisted chiropractic treatment, therapeutic massage and phenylbutazone; or 2 control groups: ridden exercise (active control) or routine paddock turnout with no ridden exercise (inactive control). MNT measurements were repeated at 1, 3 and 7 days post treatment. The percentage change from baseline MNT values was calculated within groups. RESULTS: On Day 7, the median MNT had increased by 27, 12 and 8% in the chiropractic, massage and phenylbutazone groups, respectively. MNT changes of <1% were seen within the active and inactive control groups. CONCLUSIONS: Chiropractic treatment and massage therapy increased spinal MNTs within horses not exhibiting signs of lumbar pain. POTENTIAL RELEVANCE: Pressure algometry provides an objective tool to evaluate the effects of commonly used, but currently unproven treatment modalities on spinal MNTs. Future studies need to evaluate combined treatment effects and longer-term MNT changes in horses with documented back pain.
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Christensen, J. W., Malmkvist, J., Nielsen, B. L., & Keeling, L. J. (2008). Effects of a calm companion on fear reactions in naive test horses. Equine Vet J, 40(1), 46–50.
Abstract: REASON FOR PERFORMING STUDY: In fear-eliciting situations, horses tend to show flight reactions that can be dangerous for both horse and man. Finding appropriate methods for reducing fearfulness in horses has important practical implications. OBJECTIVES: To investigate whether the presence of a calm companion horse influences fear reactions in naive subject horses. HYPOTHESES: The presence of a habituated (calm) companion horse in a fear-eliciting situation can reduce fear reactions in naive subject horses, compared to subject horses with a nonhabituated companion (control). METHODS: Minimally handled (n = 36), 2-year-old stallions were used, 18 as subjects and 18 as companions. Companion horses (n = 9) were habituated to an otherwise frightening, standardised test stimulus (calm companions), whereas the rest (n = 9) of the companion horses remained nonhabituated (control companions). During the test, unique pairs of companion and subject horses were exposed to the test stimulus while heart rate and behavioural responses were registered. Subsequently, subject horses were exposed to the stimulus on their own (post test). RESULTS: Subject horses, paired with a calm companion horse, showed less fear-related behaviour and lower heart rate responses compared to subject horses with control companions. Results from the post test suggest that the difference between treatment groups remained in the subsequent absence of companion horses. CONCLUSIONS AND POTENTIAL RELEVANCE: It appears possible to reduce fear reactions in young, naive horses by allowing them to interact with a calm companion horse in fear-eliciting situations.
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