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Johnson, D. D. P., Stopka, P., & Knights, S. (2003). Sociology: The puzzle of human cooperation. Nature, 421(6926), 911–2; discussion 912.
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Feh, C. (1999). Alliances and reproductive success in Camargue stallions. Anim. Behav., 57(3), 705–713.
Abstract: A study of a herd of Camargue horsesEquus caballus, showed that while the majority of high-ranking stallions held single-male harems, some sons of low-ranking mares, being low ranking themselves, formed alliances that could last a lifetime. The two stallions were each other's closest associate and preferential grooming partner. Alliances were based on coalitions in which either both partners confronted an intruder synchronously or the dominant of the pair tended the female(s) while the subordinate simultaneously displayed towards the rival. Alliance partners were of similar age but were not more closely related to each other than to other stallions in the herd. Long-term paternity data revealed that subordinates sired close to a quarter of the foals born into the alliance group, and significantly more foals than low-ranking stallions in the herd adopting a `sneak'-mating strategy. The dominant appeared to benefit from the presence of his subordinate partner. Fights occurred all year round, and the subordinate stallion of each alliance pair fought outside competitors more than twice as often as the dominant. Forming short-term alliances before defending mares on their own may enhance long-term reproductive success for both partners. Other benefits to both partners include higher survivorship of their foals and increased access to proven reproductive mares. These results suggest that the relationship between alliance partners is based on mutualism, but several conditions for reciprocity seem to be fulfilled: the benefit to the dominant (assistance in fights), and the benefit to the subordinate (access to reproduction), are both costly to the other partner and delayed in time.
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Moons, C., Heleski, C. R., Leece, C. M., & Zanella, A. J. (2002). Conflicting Results in the Association Between Plasma and Salivary Cortisol Levels in Foals.
Abstract: Introduction
Glucocorticoids are present in many biological fluids as a free fraction or bound to Corticoid
Binding Globulins (CBG) (Matteri et al, 2000). There are conflicting claims regarding the validity of
saliva as a biological fluid to measure cortisol in horses (Lebelt et al, 1996; McGreevy and Pell, 1998;
van der Kolk et al, 2001). Measuring changes in salivary cortisol levels in normal horses and horses
with Cushing`s disease van der Kolk and collaborators (2001) demonstrated the validity of saliva to
assess adrenal function. Puzzling results were reported by McGreevy and Pell (1998) who suggested
that plasma and salivary cortisol concentrations in horses showing oral stereotypies were correlated
but this association was non-existent in control animals. Investigating the responses of foals to
branding and foot-trimming Zanella et al (unpublished results) were unable to identify a relationship
between plasma and salivary cortisol levels in foals. In several species, levels of cortisol in plasma and
saliva are tightly correlated (Fenske, 1996). Cortisol found in blood consists of a fraction bound to
corticoid binding globulin (CBG) and a free, unbound fraction. Free cortisol represents the
biologically active fraction of this steroid hormone. Salivary cortisol reflects the unbound fraction
found in plasma or serum and it passes readily through the parotid membrane (Riad-Fahmy, 1983;
Horning Walker et al,1977). Unbound steroids transfer rapidly between plasma and saliva
(Walker,1989; Scott et al 1990). Saliva flow-rate does not appear to influence saliva cortisol levels in
different species (Hubert and de Jong-Meyer, 1989; Walker 1989, Scott et a, 1990). In horses, Lebelt
et al (1996) reported that salivary and plasma total cortisol in stallions were correlated. We
hypothesized that changes in salivary cortisol in foals would show a pattern that is correlated to that of
plasma free and plasma total cortisol concentrations in foals. In addition, we anticipated that the lack
of good sampling techniques provides an explanation for the failure in determining the association
between salivary and plasma cortisol in foals.
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McGreevy, P. D. Development and Resolution of Behavioural Problems with the. In Havemeier Workshop.
Abstract: The ideals of equestrian technique combine art and science. Therefore students of equitation
encounter measurable variables such as rhythm, tempo and impulsion alongside more ethereal ones
such as outline and harmony. This mixture accounts for many of the idiosyncrasies of equestrianism
including the subjective scoring of performance in dressage tests, the elusiveness of perfection even at
an elite level of competition and the difficulty of expressing equestrian technique in empirical terms
(Roberts, 1992).
This chapter will describe and offer examples of the unwelcome behavioural responses horses
produce under saddle. Two broad sections are then proposed to allow the reader to consider
unwelcome behavioural responses caused directly by humans as distinct from those attributable more
to the horse than the rider. Ultimately the responsibility for problems in the ridden horse lies with
humans since we have undertaken the domestication and exploitation of equids. Therefore it is
accepted that the dichotomy is not absolute. The chapter closes with a
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Feh, C. (2005). Relationships and Communication in Socially Natural Horse Herds. In D. S. Mills, & S. M. McDonnell (Eds.), The domestic horse : the origins, development, and management of its behaviour. Cambridge: Cambridge University Press 2005.
Abstract: Horses are quite unique. In most mammals, sexes segregate and maintain bonds only during the breeding season (Clutton-Brock, 1989). Some canids, a few rodents and primate species such as gorillas, hamadryas baboons and red howler monkeys are the exception, where the same males stay with the same females all year round and over many breeding seasons. Typically, both sexes disperse at puberty in these species. In horses, it was clearly shown that the causes for female dispersal were incest avoidance and not intra-specific competition (Monard, 1996). As a rule, this is confirmed for mammal species where tenure length by males exceeds the age at first reproduction in females (Clutton-Brock, 1989). When horses are allowed to choose their mating partner freely, the inbreeding coefficient of the offspring is lower than expected should they mate randomly (Duncan et al, 1984).
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Klingel, H. (). Das Verhalten der Pferde (Equidae). Handb. o. Zool., 8(10), 1–68.
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Zeeb, K. (1959). Das Verhalten des Pferdes bei der Auseinandersetzung mit dem Menschen. Z. Säugetierkunde, 7, 139–193.
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Wilson, D. S., & Dugatkin, L. A. (1996). A reply to Lombardi & Hurlbert. Anim. Behav., 52(2), 423–425.
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R. A. Hopkins. CALIFORNIA WILDLIFE HABITAT RELATIONSHIPS SYSTEM (Vol. M174).
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Nicol, C. J. (2000). Equine Stereotypies. In: Houpt K.A. (Ed.),. In Recent Advances in Companion Animal Behavior Problems. International Veterinary Information Service.
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