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	Author	Van Doorn G.S.; Hengeveld G.M.; Weissing F.J.
	Title	The Evolution of Social Dominance I: Two-player Models			Type	Journal Article
	Year	2003	Publication	Behavior	Abbreviated Journal	Behavior
	Volume	140	Issue	10	Pages	1305-1332
	Keywords
	Abstract	A difference in dominance rank is an often-used cue to resolve conflicts between two animals without escalated fights. At the group level, adherence to a dominance convention efficiently reduces the costs associated with conflicts, but from an individual's point of view, it is difficult to explain why a low ranking individual should accept its subordinate status. This is especially true if, as suggested by several authors, dominance not necessarily reflects differences in fighting ability but rather results from arbitrary historical asymmetries. According to this idea, rank differentiation emerges from behavioural strategies, referred to as winner and loser effects, in which winners of previous conflicts are more likely to win the current conflict, whereas the losers of previous conflicts are less likely to do so. In order to investigate whether dominance, based on such winner and loser effects, can be evolutionarily stable, we analyse a game theoretical model. The model focuses on an extreme case in which there are no differences in fighting ability between individuals at all. The only asymmetries that may arise between individuals are generated by the outcome of previous conflicts. By means of numerical analysis, we find alternative evolutionarily stable strategies, which all utilize these asymmetries for conventional conflict resolution. One class of these strategies is based on winner and loser effects, thus generating evolutionarily stable dominance relations even in the absence of differences in resource holding potential.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN		ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number	Equine Behaviour @ team @			Serial	5105
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	Author	Van Doorn G.S.; Hengeveld G.M.; Weissing F.J.
	Title	The Evolution of Social Dominance II: Multi-Player Models			Type	Journal Article
	Year	2003	Publication	Behavior	Abbreviated Journal	Behavior
	Volume	140	Issue	10	Pages	1333-1358
	Keywords
	Abstract	The social hierarchies observed in natural systems often show a high degree of transitivity. Transitive hierarchies do not only require rank differentiation within pairs of individuals but also a higher level ordering of relations within the group. Several authors have suggested that the formation of linear hierarchies at the group level is an emergent property of individual behavioural rules, referred to as winner and loser effects. Winner and loser effects occur if winners of previous conflicts are more likely to escalate the current conflict, whereas the losers of previous conflicts are less likely to do so. According to this idea, an individual's position in a hierarchy may not necessarily reflect its fighting ability, but may rather result from arbitrary historical asymmetries, in particular the history of victories and defeats. However, if this is the case, it is difficult to explain from an evolutionary perspective why a low ranking individual should accept its subordinate status. Here we present a game theoretical model to investigate whether winner and loser effects giving rise to transitive hierarchies can evolve and under which conditions they are evolutionarily stable. The main version of the model focuses on an extreme case in which there are no intrinsic differences in fighting ability between individuals. The only asymmetries that may arise between individuals are generated by the outcome of previous conflicts. We show that, at evolutionary equilibrium, these asymmetries can be utilized for conventional conflict resolution. Several evolutionarily stable strategies are based on winner and loser effects and these strategies give rise to transitive hierarchies.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN		ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number	Equine Behaviour @ team @			Serial	5106
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	Author	Bartoš, L.; Bartošová, J.; Pluhácek, J.; Šindelárová, J.
	Title	Promiscuous behaviour disrupts pregnancy block in domestic horse mares			Type	Journal Article
	Year	2011	Publication		Abbreviated Journal	Behavioral Ecology and Sociobiology
	Volume	65	Issue	8	Pages	1567-1572
	Keywords	Foetal loss; Domestic horse; Bruce effect; Sexual behaviour
	Abstract	Based on questionnaires from horse breeders, we found that bringing a pregnant mare which had been mated away from home into a vicinity of a familiar male who was not the father of her foetus increased probability of pregnancy disruption. These mares aborted in 31% of cases, while none of those mated within the home stable aborted. Repeated sexual activity either by a stallion or dominant gelding from the normal home group was observed shortly after the mare came from away-mating. Pregnant mares isolated from home males by a fence were even seen soliciting them over the fence. We speculate that, once returned to the home “herd”, and introduced to familiar males, mares were more likely to terminate their pregnancy to save energy and avoid likely future infanticidal loss of their progeny by dominant male(s) of the home social group. This is a newly discovered phenomenon where a mare manipulates the male’s paternity assessment by promiscuous mating. It may explain a common increased incidence of foetal loss in domestic horses occurring in nearly 40% of pregnancies. We conclude that the common practice of transporting the mare for mating and then bringing her back to an environment with males, stallions or geldings, which did not sire the foetus, is the main cause of high percentages of pregnancy disruption in domestic horses.
	Address
	Corporate Author				Thesis
	Publisher	Springer-Verlag	Place of Publication		Editor
	Language	English	Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0340-5443	ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number	Equine Behaviour @ team @			Serial	5834
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	Author	Asa, C.S.
	Title	Male reproductive success in free-ranging feral horses			Type	Journal Article
	Year	1999	Publication		Abbreviated Journal	Behavioral Ecology and Sociobiology
	Volume	47	Issue	1-2	Pages	89-93
	Keywords	Key words Reproductive success; Alternative mating strategies; Mating systems; Paternity
	Abstract	In the social organization of feral horses, adult males compete to monopolize groups or bands of females, sometimes called harems. Alternative male strategies are to remain alone or with other bachelors or, less commonly, to accept subordinate status within a harem. The hypothesis that dominant harem stallion status confers a reproductive advantage was tested in free-ranging feral horses. The presence of foals in harems headed by vasectomized (VSX) versus intact stallions was used to assess the ability of these stallions to control reproduction in their harems. Of harems headed by VSX stallions, 17 and 33% contained foals during years 2 and 3 post-treatment, respectively. In contrast, 86 and 80% of harems headed by non-VSX stallions contained foals in those years. Acquisition of pregnant mares appeared more likely than sneak copulations by bachelor stallions to account for foals in harems with a single stallion. However, most foals were born into harems that included a subordinate stallion, an occurrence that was undoubtedly exacerbated by the extended breeding season resulting from the sterility of the harem stallion. Thus, in comparing alternative reproductive tactics, bachelors appeared less successful than subordinate stallions within a harem. However, the highest reproductive success was achieved by the harem stallion, further demonstrating that alternative tactics are not equally profitable.
	Address
	Corporate Author				Thesis
	Publisher	Springer-Verlag	Place of Publication		Editor
	Language	English	Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0340-5443	ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number	Equine Behaviour @ team @			Serial	5786
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	Author	Lloyd, P.H.; Rasa, O.A.E.
	Title	Status, reproductive success and fitness in Cape mountain zebra (Equus zebra zebra)			Type	Journal Article
	Year	1989	Publication		Abbreviated Journal	Behavioral Ecology and Sociobiology
	Volume	25	Issue	6	Pages	411-420
	Keywords
	Abstract	Demographic data relating to herd size and stability are given for a population of Cape mountain zebra (Equus zebra zebra) under longterm observation. Temporal dispersion patterns of male and female offspring differed and were independent of the mother's status. Dispersion in females appeared to be related to physiological state, and dispersion in both sexes was related to age rather than changes in parental behaviour. Reproductive success of dominant and subordinate mares was equal and independent of age and social and reproductive variables. Fitness of dominant mares, however, was significantly higher than that of subordinates, the latter having a higher foal mortality, part of which could be attributable to dominants' aggression. The fitness of all males born was 1.6:1 compared with all females. Dominant mares produced significantly more daughters than sons. This trend was not found for subordinates. Mother's status was positively correlated with dominant status in her female offspring but not related to the subsequent status of her sons. Daughters had a more than twice as great a chance of breeding than sons. For maximum fitness gains, therefore, dominant mares should produce more daughters, since a high proportion of these would also have high status and fitness. This tendency is reflected in the sex ratio skewed towards females found for dominant mares.
	Address
	Corporate Author				Thesis
	Publisher	Springer-Verlag	Place of Publication		Editor
	Language	English	Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0340-5443	ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number	Equine Behaviour @ team @			Serial	5787
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	Author	Rossdale Pd,
	Title	Perinatal behaviour int the thoroughbred horse			Type	Book Chapter
	Year	1968	Publication		Abbreviated Journal	In: Fox,M.W. (ed.): Abnormal behavior in Animals.
	Volume	Chapt. 15	Issue		Pages
	Keywords
	Abstract
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN		ISBN		Medium
	Area		Expedition		Conference
	Notes	from Professor Hans Klingels Equine Reference List			Approved	no
	Call Number				Serial	1517
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	Author	Rappolt, G. A.; John, J.; Thompson, N. S.
	Title	Canine responses to familiar and unfamiliar humans			Type	Journal Article
	Year	1979	Publication	Aggressive Behavior	Abbreviated Journal	Aggressive Behavior
	Volume	5	Issue	2	Pages	155-161
	Keywords
	Abstract	Dogs were observed during controlled approaches by their owners and by strangers. Significant differences between the dogs' responses to their owners and their responses to strangers were found. These results supported the popular belief that dogs respond differently to different persons, and not merely to different situations in which persons are usually encountered.
	Address	Departments of Biology and Psychology, Clark University, Worcester, Massachusetts DOI – 10.1002/1098-2337(1979)5 – 2<155 – - AID-AB2480050206>3.0.CO;2-D
	Corporate Author				Thesis
	Publisher		Place of Publication	Copyright © 1979 Wiley-Liss, Inc., A Wiley Company	Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN		ISBN		Medium
	Area		Expedition		Conference
	Notes				Approved	no
	Call Number	Equine Behaviour @ team @			Serial	4978
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	Author	McGreevy, P.D.; Harman, A.; McLean, A.; Hawson, L.
	Title	Over-flexing the horse's neck: A modern equestrian obsession?			Type	Journal Article
	Year	2010	Publication	Journal of Veterinary Behavior: Clinical Applications and Research	Abbreviated Journal	Journal of Veterinary Behavior: Clinical Applications and Research
	Volume	5	Issue	4	Pages	180-186
	Keywords
	Abstract	We used an opportunistic review of photographs of different adult and juvenile horses walking, trotting, and cantering (n = 828) to compare the angle of the nasal plane relative to vertical in feral and domestic horses at liberty (n = 450) with ridden horses advertised in a popular Australian horse magazine (n = 378). We assumed that horses in advertisements were shown at, what was perceived by the vendors to be, their best. Of the ridden horses, 68% had their nasal plane behind the vertical. The mean angle of the unridden horses at walk, trot, and canter (30.7 ± 11.5; 27.3 ± 12.0; 25.5 ± 11.0) was significantly greater than those of the ridden horses (1.4 ± 14.1; ?5.1 ± ?11.1; 3.1 ± 15.4, P < 0.001). Surprisingly, unridden domestic horses showed greater angles than feral horses or domestic horses at liberty. We compared adult and juvenile horses in all 3 gaits and found no significant difference. Taken together, these findings demonstrate that the longitudinal neck flexion of the degree desirable by popular opinion in ridden horses is not a common feature of unridden horses moving naturally. Moreover, they suggest that advertised horses in our series are generally being ridden at odds with their natural carriage and contrary to the international rules of dressage (as published by the International Equestrian Federation). These findings are discussed against the backdrop of the established doctrine, which states that carrying a rider necessitates changes in longitudinal flexion, and in the context of the current debate around hyperflexion.
	Address
	Corporate Author				Thesis
	Publisher	Elsevier	Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1558-7878	ISBN		Medium
	Area		Expedition		Conference
	Notes	doi: 10.1016/j.jveb.2010.03.004			Approved	no
	Call Number	Equine Behaviour @ team @			Serial	6501
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	Author	Quick, J.S.; Warren-Smith, A.K.
	Title	Preliminary investigations of horses' (<em>Equus caballus</em>) responses to different bridles during foundation training			Type	Journal Article
	Year		Publication	Journal of Veterinary Behavior: Clinical Applications and Research	Abbreviated Journal	Journal of Veterinary Behavior: Clinical Applications and Research
	Volume	4	Issue	4	Pages	169-176
	Keywords
	Abstract	Throughout equitation history, bitted bridles have been the primary method of controlling the ridden horse. In response to health and behavioral concerns arising from the use of bitted bridles, bitless bridles offer new methods of steering and control. However, the effectiveness of bitless bridles on horses had not been previously examined scientifically. Therefore, the current study measured behavioral and cardiac responses of horses undergoing foundation training (bridling, long reining, and riding) wearing either a bitted or a bitless bridle.The horses wearing the bitted bridle exhibited more chewing, opening of the mouth, pawing the ground, and tail swishing than those in the bitless bridle. The horses wearing the bitless bridle exhibited more head lowering during long reining compared to those in the bitted bridle. The frequency of chewing, opening the mouth, and head raising decreased as training progressed. The number of steps taken after the application of the halt stimulus was greatest for the horses in the bitted bridle during long reining compared with those in the bitless bridle. During long reining, the heart rate and heart rate variability of the horses were higher for those in a bitted bridle compared with those in a bitless bridle.The results of this study suggest that horses wearing bitless bridles performed at least as well as, if not better than, those in bitted bridles. If the use of bitted bridles does cause discomfort to horses, as suggested by some, then the use of bitless bridles could be beneficial and certainly warrants further investigation.
	Address
	Corporate Author				Thesis
	Publisher	Elsevier	Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1558-7878	ISBN		Medium
	Area		Expedition		Conference
	Notes	doi: 10.1016/j.jveb.2008.12.001			Approved	no
	Call Number	Equine Behaviour @ team @			Serial	5974
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	Author	Gakahu Cg,
	Title	Strategies of feeding behavior in the Common zebra, Equus burchelli (Gray) in Amboseli National Park, Kenya (Abstract)			Type	Journal Article
	Year	1979	Publication		Abbreviated Journal	Symposium on the Ecology and Behavior of wild and feral Equids, Laramie
	Volume		Issue		Pages	158
	Keywords
	Abstract
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN		ISBN		Medium
	Area		Expedition		Conference
	Notes	from Professor Hans Klingels Equine Reference List			Approved	no
	Call Number				Serial	1100
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