Horses Equus Caballus Research Articles

Potential ecological effects of the free-roaming horses Equus caballus (Perissodactyla: Equidae) on wild mammals: a review of current knowledge

Introduction: The horse (Equus caballus) is an adaptable large herbivore distributed in a wide range of terrestrial biomes that negatively affects ecosystems around the world. Most research on horse–ecosystems interactions have been focused on plants and soils, whereas horse effects on vertebrate species are poorly understanded. Objective: We aimed to synthesize, at a global scale, the effects of free-roaming horses on wild mammals. Methods: We conducted a systematic literature review that included these words; "feral horses + competition ", "feral horses + interactions", "feral horses + impacts", "feral horses + effects", based on the “Web of Science” internet search engine. Results: We located 366 articles in our search, but only 14 peer-reviewed documents described the effects of horses on local wild mammals. Most studies were published in the last decade (64%), and were located in United States (64%). Additional information showed most studies used correlational approaches while experimental approaches were used less. The effect of horses on mammal taxonomic groups varied significantly, suggesting changes on habitat structure mostly affects vertebrate species such as small rodents. Nevertheless, large ungulates exhibited interference competition derived from presence of free-roaming horses. Conclusion: This review identified patterns and gaps in our current knowledge about the effect of horse presence on wild mammals, and can help to readdress further research. Therefore, we recommend careful monitoring of horses and their potential effects on wildlife by using species proxies such as ungulates and rodents to determine if the presence of horses in protected areas affects conservation objectives

The skull on the hill. Anthropological and osteological investigation of contemporary horse skull ritual practices in central Mongolia (Arkhangai province)

Among the five kinds of animals Mongolian herders breed (i.e. horses Equus caballus Linnaeus, 1758, camels Camelus bactrianus Linnaeus, 1758, cattle Bos taurus Linnaeus, 1758, Bos grunniens Linnaeus, 1766, and their hybrids, sheep Ovis aries Linnaeus, 1758, and goats Capra hircus Linnaeus, 1758), the horse holds a particular status, perceivable in the slaughtering techniques used and the way its skull is treated after death. Leaving horse skulls in high places (i.e. trees, mountains, and ovoos − stone cairns erected in homage to the master spirits of a place) is a common, though poorly understood, practice. This article studies the modalities of these horse skull repositories within an interdisciplinary approach, combining social anthropology and osteology. The study of the choice of place for the skulls and their associated objects highlights the differentiation processes among the horses as individuals, in relation to their lifetime status. This relation between human and horses unfolds into the landscape, which is invested with numerous ovoo cairns and horse skulls; a reminder that these spaces are shared between humans, horses and invisible entities. In the absence of private land ownership on the Mongolian steppe and in the interest of a balanced coexistence with all the inhabitants of this shared land, we show that the horse skull repositories subtly combine honour to individual horses, respect to the master spirits of the land, and discrete appropriation of territory by herders.

Investigating anhedonia in a non-conventional species: Do some riding horses Equus caballus display symptoms of depression?

Investigating depression-like conditions in animals is methodologically challenging, but potentially important for welfare. Some riding horses display ‘withdrawn’ states of inactivity and low responsiveness that resemble the reduced engagement with the environment shown by certain depressed patients. To assess whether these animals are experiencing a depression-like state, we investigated anhedonia – the loss of pleasure, a key symptom of human depression – in 20 withdrawn and non-withdrawn horses from the same stable. The time horses spent being withdrawn appeared unrelated to age or sex, but correlated with time devoted to stereotypic behaviour, a possible marker of lifetime stress. Comparison with data collected 5 years earlier also revealed that horses scored as withdrawn then remained significantly likely to display the behaviour. We measured sucrose intake, a classic measure of anhedonia never previously applied to horses. Flavoured sugar blocks, novel to these subjects, were mounted in each stall and weighed 3, 8, 24 and 30h after provision. We predicted that if affected by depression-like states, the most withdrawn horses would consume the least sucrose. This prediction was met (F1,18=4.65, two tailed p=0.04). This pattern could, however, potentially reflect general appetite levels and/or food neophobia. To control for these confounds, hay consumption was measured over 5 days, as were subjects’ latencies to eat a meal scented with a novel odour. Although low hay consumption and long latencies to eat scented food did predict low sucrose consumption, statistically controlling for these confounds did not eliminate the relationship between being withdrawn and consuming less sucrose (although reducing it to a strong trend): F1,15=4.28, two-tailed p=0.056. These data thus suggest long-lasting depression-like states in certain riding horses, which correlate with stereotypic behaviour and are characterised by anhedonia and bouts of ‘withdrawn’ unresponsiveness.

Exploring aggression regulation in managed groups of horses Equus caballus

Horses are highly social animals that have evolved to live in social groups. However, in modern husbandry systems, single housing prevails where horses experience social isolation, a challenge-to-welfare factor. One major reason for this single housing is the owners’ concerns that horses may injure each other during aggressive encounters. However, in natural conditions, serious injuries due to aggressive encounters are rare. What could therefore explain the claimed risks of group living for domestic horses? Basing our questioning on the current knowledge of the social life of horses in natural conditions, we review different practices that may lead to higher levels of aggression in horses and propose practical solutions.Observations of natural and feral horses mostly indicate a predominance of low frequencies and mild forms of aggression, based on subtle communication signals and ritualized displays and made possible by group stability (i.e. stable composition), dominance hierarchy and learning of appropriate social skills by young horses. Obviously, adults play a major role here in canalizing undesirable behaviours, and social experience during development, associated with a diversity of social partners, seems to be a prerequisite for the young horse to become socially skilled.Given the natural propensity of horses to have a regulation of aggression in groups, the tendency to display more aggression in groups of domestic horses under some management practices seems clearly related to the conditions offered. We therefore review the managing practices that could trigger aggressiveness in horses. Non social practices (space, resource availability) and social practices (group size, stability of membership, composition and opportunities for social experiences during development) in groups of domestic horses are discussed here.Finally, we propose simple practical solutions leading to more peaceful interactions in groups of domestic horses, based on the knowledge of horses’ natural social life which therefore should be enhanced (e.g. ensuring roughage availability, favouring group stability, introducing socially experienced adults in groups of young horses, etc.). The state of the art indicates that many questions still need to be answered. Given the importance of the associated welfare issues and the consequences on the use of horses, further research is required, which could benefit horses… and humans.

Comparative analysis of walking gaits in South American camelids

Although several studies on the locomotion of Old World camels, mainly the dromedary Camelus dromedarius, exist, detailed data on their relatives, the New World camelids are very scarce. Camelids are distinguished from most mammals by their pacing gaits, a pace-like walk and running pace. We conducted detailed video analyses of undisturbed walking in the alpaca Lama pacos and llama Lama glama and compared these with observations of the dromedary and domestic warmblood horses Equus caballus. The average walking speed, stride length and stride frequency (mean±sd) were 0.97±0.15 m s−1, 0.94±0.08 m and 1.03±0.08 s−1 for alpacas and 1.13±0.12 m s−1, 1.18±0.08 m and 0.95±0.05 s−1 for llamas, respectively. The mean support phase (mean±sd) was 0.67±0.11, 0.72±0.10 and 1.11±0.14 s for llama, horse and dromedary, respectively, corresponding to 58.9±3.8, 61.7±3.2 and 66.0±1.2%, respectively. We found remarkable differences between New and Old World camelids. Contrary to the dromedary, alpacas and llamas in our study did not perform a symmetrical running pace. The lateral time lag was shortest in the llama, decreasing with increasing speed from 15 to 5% with an average of 10%.

Genetic characterization of six microsatellites in colombian horses Equus caballus (Equidae) and its use for parentage testing

In terms of commercial and cultural implications Co-lombian equines are very valuable; however their genetic potential is unknown. As a result, programs regarding selection and improvement have been limited. In order to contribute to the genetic potential, the variability of 264 horses Criollo Colombiano, Paso Fino Colombiano y Trocha Pura Colombiana breeds was evaluated. The allelic characterization was made with six molecular markers, micro satellite sort (ASB17, AHT4, AHT5, HTG4, HMS3 y HMS6) for further population studies. The analysis of the six microsatellites indicated high allelic polymorphism for the ASB17 with 18 alleles, the less variable was the HTG4 with seven alleles. The allele’s standard was 9.83. Besides, the allelic frequency showed that the populatio-ns are represented by few alleles. The gene diversity He0.7773 and Ho 0.765 was calculated to determine the genetic variability of the population. It indicated a large variability and high gene diversity in equines from the de-partment of Cundinamarca with an endogamy coefficient of FIS 0.0011. In the paternity test, the AHT4 and HMS3 demonstrated that they are the most informative ones; which is due to their high exclusion probability. Neverthe-less, the accumulated probability validity of 0.9543 with the six markers was low. It is recommended to change the AHT4 and HMS6 markers for more informative ones and also to increase the number of markers.