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Shultz, S. (2012). Are equid brains social? Exploring the evolution of equid social structure and social intelligence. In K. Krueger (Ed.), Proceedings of the 2. International Equine Science Meeting (Vol. in press). Wald: Xenophon Publishing.
Abstract: The living equids display a variety of different forms of social organisation; plains (Equus quagga) and mountain zebra (Equus zebra) associate in small, closed harems, whereas the asses and Grevy’s zebra (Equus grevyi) are found in looser, more ephemeral associations. Feral domestic horses appear to be somewhat intermediate: although stallions generally maintain harems, there is some movement of individuals between groups. This talk will use several statistical approached to explore evolutionary explanations for these differences. Firstly, we will explore the relationship between brain architecture and social organisation both among the equids and across all Perissodactyls. Equids have larger relative neocortices than other Perissodactyls; within the equids, species typically found in more stable groups have larger neocortices than equids in more unstable ephemeral groups. The strong relationship between group stability and brain size and architecture mirrors that found in other mammals, including primates. Thus, living in stable social groups consistently appears to impose cognitive demands across species. In order to understand the historical trajectory resulting in the relatively large, social brains found in some species, we then reconstruct the evolutionary pathway of social living in the equids. Finally, we discuss how we can use network theory to measure social structure and how these differences may impose different cognitive demands on individuals.
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Palme, R., Touma, C., Arias, N., Dominchin, M. F., & Lepschy, M. (2012). Steroid extraction: Get the best out of faecal samples. Vet. Med. Austria, 100, 238–246.
Abstract: Faecal steroid hormone metabolites are becoming increasingly popular as parameters for reproductive functions and stress. Theextraction of the steroids from the faecal matrix represents the initial step before quantification can be performed. The steroid metabolites present in the faecal matrix are of varying polarity and composition, so selection of a proper extraction procedure is essential. There have been some studies to address this complex but often neglected point. Radiolabelled
steroids (e.g. cortisol or progesterone) have frequently been added to faecal samples to estimate the efficiency of the extraction procedures used. However, native, unmetabolized steroids are normally not present in the faeces and therefore the results are artificial and do not accurately reflect the actual recoveries of the substances of interest. In this respect, recovery experiments based on faecal samples from radiometabolism studies are more informative. In these samples, the metabolite content accurately reflects the mixture of metabolites present in the given species. As a result, it is possible to evaluate different extraction methods for use with faecal samples. We present studies on sheep, horses, pigs, hares and dogs that utilized samples containing naturally metabolized, 14C-labelled steroids.
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Owen, H., Hall, C., Hallam, S., & Smith, E. (2012). The use of GPS to measure feeding behaviour and activity patterns in the horse (Equus caballus). In K. Krueger (Ed.), Proceedings of the 2. International Equine Science Meeting (Vol. in press). Wald: Xenophon Publishing.
Abstract: The global positioning system (GPS) has been used to record activity and monitor habitat use in many animal species. In the horse (Equus caballus) the monitoring of activity and feeding patterns has been used to assess the impact of environmental factors on behaviour and welfare. In free-ranging animals GPS can provide such information but the accuracy and reliability of these devices has yet to be confirmed. The aim of this study was: 1) to compare the results of visual observation with GPS recordings of the horse’s head and neck position (head up (HU) and down (HD)) used to quantify time spent grazing; 2) to test the use of GPS collars to monitor activity patterns where distance, speed and location paths were recorded. In both studies two animals were fitted with Lotek GPS 3300S collars (with integrated GPS data logger and removable battery pack) round the top of the neck. In study 1 two horses were fitted with collars and turned loose into a 20x40m sand arena for 45 minutes. Feed balls and hay were provided (in nets and on the ground) to encourage movement and feeding behaviour for comparison using the two methods (observation from digital video recordings and GPS). HD was recorded by the GPS collars for a significantly longer time (interpreted as feeding/grazing time) than that recorded by observation (p=0.004). However when the visual observation was split into HU, HD and also head in mid-way position (HMW), where the nose of the horse was level or just above the chest, then no difference between the collar (HU and HD) and visual observation for (HU and HD+HMW) was found. It is likely that when in HMW the GPS collar may not be sufficiently angled to trigger the sensor to record HU or the collar may move on the neck. Conclusions relating to time spent feeding should be treated with caution. In study 2, the collars were fitted to two ponies with access to 2.02 hectares of lowland grazing. Activity (distance travelled and speed) and location was recorded for 2 days. The total distance travelled by the ponies in 24 hours (2.84km) and their average speed (4.04m/minute) was calculated and showed no significant difference between day and night. The total area was split into four equal segments and there was no significant difference in the time the ponies spent in each area although they were found to move at slower speeds and stand for longer in some areas. Movement paths could be identified by inputting the GPS collar data into ArcGIS and viewed on Google Maps. There was a high level of comparability observed between the two ponies confirming behavioural synchronicity. As in other species, the use of GPS collars to monitor the movement and location of horses/ponies was found to be effective, but data relating to head position did not provide a reliable means of recording the time spent feeding.
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Wickert, M. (2012). Die Bedeutung des Leerkauens bei Pferden aus Sicht der Physiologie und der Ethologie. Doctoral thesis, , .
Abstract: Der Umgang mit Pferden erfreut sich immer größerer Beliebtheit. Aufgrund des Verhaltens können Rückschlüsse auf die Befindlichkeiten der Tiere gezogen werden
(TSCHANZ et al. 1997a). Je mehr wir über das Verhalten der Tiere wissen, desto besser können wir in der Haltung, Ausbildung und Nutzung der Pferde dazu beitragen, die Lebensbedingungen zu verbessern und den Ansprüchen der Pferde gerechter zu werden.
Bei der Ausbildung von Pferden kommen u.a. aus Amerika neue Einflüsse auf Ausbildungsmethoden zu uns. Es wird dabei immer wieder ein „Kauen“ der Pferde während des Trainings beschrieben, doch gibt es keine wissenschaftlichen ntersuchungen darüber.
Eine Kaubewegung des Pferdes außerhalb der Futteraufnahme wird als „Leerkauen“
definiert. Es ist eine „horizontale Bewegung“ des Unterkiefers gegen den Oberkiefer zu beobachten, vergleichbar mit der Mahlbewegung (Abbildung 1). Häufig ist während des Leerkauens eine Anspannung des oberflächlichen Kaumuskels vom unteren Unterkieferrand aus in Richtung Jochbogen/Crista facialis zu erkennen.
Eine Sonderform des Leerkauens stellt die sogenannte Unterlegenheitsgebärde (UG)
dar (ZEEB 1959b). Es handelt es sich um eine „vertikale Bewegung“ der Unter- und
Oberkiefer voneinander weg und aufeinander zu (Abbildung 2). Ihre Funktion ist die
Beschwichtigung. Unter dem Begriff Leerkauen wird in dieser Dissertation immer die
horizontale Mahlbewegung verstanden.
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Sueur, C., Deneubourg, J. - L., & Petit, O. (2012). From Social Network (Centralized vs. Decentralized) to Collective Decision-Making (Unshared vs. Shared Consensus). PLoS ONE, 7(2), e32566 EP -.
Abstract: <p>Relationships we have with our friends, family, or colleagues influence our personal decisions, as well as decisions we make together with others. As in human beings, despotism and egalitarian societies seem to also exist in animals. While studies have shown that social networks constrain many phenomena from amoebae to primates, we still do not know how consensus emerges from the properties of social networks in many biological systems. We created artificial social networks that represent the continuum from centralized to decentralized organization and used an agent-based model to make predictions about the patterns of consensus and collective movements we observed according to the social network. These theoretical results showed that different social networks and especially contrasted ones – star network vs. equal network – led to totally different patterns. Our model showed that, by moving from a centralized network to a decentralized one, the central individual seemed to lose its leadership in the collective movement's decisions. We, therefore, showed a link between the type of social network and the resulting consensus. By comparing our theoretical data with data on five groups of primates, we confirmed that this relationship between social network and consensus also appears to exist in animal societies.</p>
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Klingel, H.. (2012). Social Organisation and Social Behaviour of the Equids. In K. Krueger (Ed.), Proceedings of the 2. International Equine Science Meeting (Vol. in press). Wald: Xenophon Publishing.
Abstract: In contrast to the great similarity in behaviour and ecology of the 6 extant Equid species, 2 distinct types of social organisation have evolved, and both are adapted to life in semi-arid to arid regions where environmental conditions force them to migrate seasonally or opportunistically.
The ranges of the various species overlap: Mountain Zebra Equus zebra and Plains Zebra E. quagga in South Africa and Namibia, Plains Zebra and Grevy's Zebra E. grevyi in Kenya and Ethiopia, Grevy's Zebra and African Wild Ass E. africanus in Ethiopia, Asiatic Wild Ass E. hemionus and Przewalski Horse E. przewalski in Mongolia and China. Although, in the overlap zones, individuals of the different species are using the same resources like water and grazing next to each other, they rarely make closer contacts.
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In the type 1 species, Horse, Plains Zebra and Mountain Zebra, the adults live in non-territorial, stable, one-male families and as single bachelors and in bachelor groups. Family stallions have the exclusive mating rights with the mares in their harems. These consist of up to 6 unrelated mares plus their offspring, totalling up to 20 members.
Mares stay in their harem until death. Stallions' tenure is from age 5-6 years, i.e. when they succeed in controlling a harem, for close to life time, but are replaced when dead or incapacitated. Harems are stable even in the absence of a stallion, indicating voluntary membership. Adolescent mares leave their parental families to become members of another harem.
In Plains Zebra the adolescent mares are abducted, during an oestrus, by suitors who fight the defending family stallion/father. Successful stallions are bachelors who start a family, or family stallions enlarging their harem. Young stallions leave their parental families voluntarily at age 2-3 years and join bachelor stallion groups from where the family stallions are recruited.
An individualised dominance hierarchy excists with the stallion in the alpha position. It is based on individual knowledge and recognition of the members.
In the type 2 species Grevy's Zebra, African Wild Ass and Asiatic Wild Ass adult stallions monopolise territories in which they have the exclusive mating rights. Stallions are tolerant of any conspecifics entering their territory. Bachelor stallions behave subordinately – or fight for the possession of the territory which is a prerequisite for reproduction.
Mares join up to form anonymous and unstable groups or herds. The only stable unit is of a mare and her offspring. In Grevy's Zebra mares with foal join preferentially conspecifics of the same soial status, as do mares without foal.
Matings take place inside the territory. There is no lasting relationship of the mare with a particular stallion, and the mare may be mated by any stallion whose territory she is visiting.
Territories measure up to 10 or more square kilometres, and tenure is for several years.
Grevy Zebra territorial owners leave their territories for a few hours to visit a water hole, or for months when grazing and water conditions are below requirements, and re-occupy it upon return, unchallenged.
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Klingel, H.. (2012). Soziale Organisation und Sozialverhalten der Equiden. In K. Krueger (Ed.), Proceedings of the 2. International Equine Science Meeting (Vol. in press). Wald: Xenophon Publishing.
Abstract: Verhalten und Ökologie der 6 rezenten Equiden sind in vieler Hinsicht identisch, jedoch in der Sozialen Organisation haben 2 deutliche verschiedene Formen evoluiert, die beide an das Leben in den semi-ariden und ariden Lebensräumen angepasst sind, wo sie zu säsonalen oder opportunistischen Wanderungen gezwungen sind.
Die Verbreitungsgebiete der verschiedenen Arten überlappen, in Südafrika und Namibia von Bergzebra Equus zebra und Steppenzebra E. quagga, in Kenya und Äthiopien von Steppenzebra und Grevy-Zebra E. grevyi, in Äthipien und Somalia von Grevy-Zebra und Afrikanischem Wildesel E. africanus, in China und der Mongolei Asiatischer Wildesel E. hemionus und Przewalski-Pferd E. przewalskii. Obwohl die Vertreter der verschiedenen Arten in den Überschneidungsgebieten die gleichen Ressourcen wie Wasser und Weide nutzen, nehmen sie kaum Kontakt zueinander auf.
Die Vertreter von Typ 1, Steppenzebra Equus quagga, Bergzebra E..zebra, Pferd E przewalskii, leben in nicht-territorialen , dauerhaften 1- Hengst- Familien, in Hengstgruppen und als Einzelgänger.. Die Familienhengste haben die alleinigen Paarungsrechte mit den Stuten in ihrem Harem. Dieser besteht aus bis zu ca. 6 nicht-verwandten Stuten nebst ihren Nachkommen und kann bis 20 Mitglieder haben.
Stuten bleiben bis zu ihrem Tod im Harem..Hengste können mit 5-6 Jahren einen Harem erobern oder gründen, können gleichfalls bis zum Tod die Familie begleiten, werden aber meist vorher von einem anderen Hengst ersetzt. Harems sind auch ohne Hengst stabil, ein Hinweis, dass die Stuten freiwilling im Harem sind und bleiben.. Junge Stuten verlassen ihre elterliche Familie und schliessen sich einem anderen Harem an..Beim Steppenzebra werden die Jungstuten während eines Östrus (Rosse) von Bewerbern entführt, gegen den Widerstand des Familenhengstes = Vaters. Bewerber sind Junggesellen, die so eine Familie gründen, und Familienhengste, die so ihren Harem vergrössern. Junghengste verlassen mit 2-3Jahren ihre elterliche Familie und schliessen sich Jungesellengruppen an, aus denen sich die Familenhengste rekrutieren.
In der Gruppe besteht eine Rangordnung mit dem Henst in der alpha-Position. Sie beruht aud individuellem Kennen und Erkennen der Mitglieder.
Bei Typ 2, Grevy-Zebra, Afrikanischer und Asiatischer Wildesel, monopolisieren Hengste über Jahre Territorien von 10 und mehr km2 , in denen sie die alleinigen Paarungsrechte haben. Territoriale Hengste tolerieren Artgenossen, auch erwachsene Hengste, soweit diese sich unterlegen verhalten. Oder sie stellen sich zum Kampf um den Besitz des Territoriums, eine Vorbedingung für die Fortpflanzung. Stuten im Östrus können von mehreren Hengsten begattet werden, wenn sie sich in deren Territorien aufhalten bzw diese durchwandern.
Stuten und Fohlen und nicht-territoriale Hengste schliessen sich zu anonymen instabilen Gruppen oder Herden zusammen. Feste dauerhafte Bindungen bestehen nur zwischen Stute und Fohlen. Hengste verlassen ihr Territorium für Stunden, Tage, im Extrem auch Monate, um zu Wasserstellen oder Weidegründen zu ziehen, sind aber bei Rückkehr wieder unangefochtene Besitzer.
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Hartmann, E., Søndergaard, E., & Keeling, L. J. (2012). Identifying potential risk situations for humans when removing horses from groups. Appl. Anim. Behav. Sci., 136(1), 37–43.
Abstract: Removing a horse from its social group may be considered risky, both for the handler and the horse, because other horses can interfere in the catching process. The main aim of this study was to identify where and when these risk situations occur while removing a horse from its group. A potential risk situation was defined by the closeness of loose horses in the group or by any physical contact with them. Whether the number of horses following would be influenced by the social rank of the horse being led out, and whether more horses would follow to the gate when a larger proportion of the group was removed compared to when a single horse was taken out were also investigated. Thirty-two mares (1–2 years) were kept in groups of four. All horses were taken out of their home paddock twice alone (64 tests) and twice with a companion (32 tests). One handler (or two handlers when two horses were removed) was asked to approach (phase 1) and catch the target horse (phase 2), walk it to the centre of the paddock and remain stationary at a post for 30 s (phase 3), walk to the paddock entrance (phase 4) and through the gate (phase 5). The number of horses following, and the number of loose horses in proximity (<2 m, 2–5 m) to the target horse and handler was estimated, and horse–horse and horse–human interactions were recorded continuously for the five scoring phases. Significantly more loose horses were within 2 m of a single target horse during the phases approach (mean ± SD: 1.5 ± 0.8), catch (1.6 ± 0.9) and post (1.7 ± 0.7) than during walk (1.0 ± 0.5) and gate (1.1 ± 0.6). Rank did not influence the number of horses following to the gate (high rank: 2.4 ± 0.7; lower rank: 2.0 ± 1.0; P = 0.396) and interactions between horses were rare. A greater proportion of the loose horses followed when two horses (0.9 ± 0.2) were removed compared to when a single horse (0.7 ± 0.3) was taken out (P = 0.011). In conclusion, maintaining a distance to other horses in the group by reducing the time being relatively stationary, so giving loose horses fewer chances to approach, is likely to contribute to improved handler's safety. Removing a small proportion of the group may also decrease the probability of the other horses following.
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Schneider, G., & Krueger, K. (2012). Third-party interventions keep social partners from exchanging affiliative interactions with others. Anim. Behav., 83(2), 377–387.
Abstract: Third-party interventions are defined as the interruption of dyadic interactions by third animals through direct physical contact, interposing or threats. Previous studies focused on the analysis of interventions against agonistic encounters. However, there have been no evaluations of interventions against affiliative behaviours, particularly in relation to the intervening animal�s social relationships and its social and spatial position. Horses, Equus caballus, are an interesting model species, as interventions against affiliative interactions occur more frequently than against agonistic interactions. In this study, 64 feral horses displayed 67 interventions in affiliative interactions and eight interventions in agonistic interactions within the observation period. We analysed the interventions in affiliative encounters, and found that it was mainly higher-ranking females that intervened in the affiliative interactions of group mates in the stable horse harems. The intervening animals took an active part in affiliative and agonistic encounters within the group, but did not occupy particular social roles or spatial positions. They intervened in affiliative interactions in which group mates with which they had social bonds interacted with other members of the group. They targeted the nonbonded animal and approached the one with which they were socially bonded. We suggest some species use third-party interventions in affiliative interactions to prevent competition for preferred social interaction partners from escalating into more costly agonistic encounters.
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Chittka, L., & Dyer, A. (2012). Cognition: Your face looks familiar. Nature, 481(7380), 154–155.
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