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Hampson, B. A., Morton, J. M., Mills, P. C., Trotter, M. G., Lamb, D. W., & Pollitt, C. C. (2010). Monitoring distances travelled by horses using GPS tracking collars. Aust. Vet. J., 88(5), 176–181.
Abstract: Objective The aims of this work were to (1) develop a low-cost equine movement tracking collar based on readily available components, (2) conduct preliminary studies assessing the effects of both paddock size and internal fence design on the movements of domestic horses, with and without foals at foot, and (3) describe distances moved by mares and their foals. Additional monitoring of free-ranging feral horses was conducted to allow preliminary comparisons with the movement of confined domestic horses. Procedures A lightweight global positioning system (GPS) data logger modified from a personal/vehicle tracker and mounted on a collar was used to monitor the movement of domestic horses in a range of paddock sizes and internal fence designs for 6.5-day periods. Results In the paddocks used (0.8-16 ha), groups of domestic horses exhibited a logarithmic response in mean daily distance travelled as a function of increasing paddock size, tending asymptotically towards approximately 7.5 km/day. The distance moved by newborn foals was similar to their dams, with total distance travelled also dependent on paddock size. Without altering available paddock area, paddock design, with the exception of a spiral design, did not significantly affect mean daily distance travelled. Feral horses (17.9 km/day) travelled substantially greater mean daily distances than domestic horses (7.2 km/day in 16-ha paddock), even when allowing for larger paddock size. Conclusions Horses kept in stables or small yards and paddocks are quite sedentary in comparison with their feral relatives. For a given paddock area, most designs did not significantly affect mean daily distance travelled.
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Tricomi, E., Rangel, A., Camerer, C. F., & O/'Doherty, J. P. (2010). Neural evidence for inequality-averse social preferences. Nature, 463(7284), 1089–1091.
Abstract: A popular hypothesis in the social sciences is that humans have social preferences to reduce inequality in outcome distributions because it has a negative impact on their experienced reward1, 2, 3. Although there is a large body of behavioural and anthropological evidence consistent with the predictions of these theories1, 4, 5, 6, there is no direct neural evidence for the existence of inequality-averse preferences. Such evidence would be especially useful because some behaviours that are consistent with a dislike for unequal outcomes could also be explained by concerns for social image7 or reciprocity8, 9, which do not require a direct aversion towards inequality. Here we use functional MRI to test directly for the existence of inequality-averse social preferences in the human brain. Inequality was created by recruiting pairs of subjects and giving one of them a large monetary endowment. While both subjects evaluated further monetary transfers from the experimenter to themselves and to the other participant, we measured neural responses in the ventral striatum and ventromedial prefrontal cortex, two areas that have been shown to be involved in the valuation of monetary and primary rewards in both social and non-social contexts10, 11, 12, 13, 14. Consistent with inequality-averse models of social preferences, we find that activity in these areas was more responsive to transfers to others than to self in the ‘high-pay’ subject, whereas the activity of the ‘low-pay’ subject showed the opposite pattern. These results provide direct evidence for the validity of this class of models, and also show that the brain’s reward circuitry is sensitive to both advantageous and disadvantageous inequality.
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Llusia, D., Márquez, R., & Beltrán, J. F. (2010). Non-Selective and Time-Dependent Behavioural Responses of Common Toads (Bufo bufo) to Predator Acoustic Cues. Ethology, 116(12), 1146–1154.
Abstract: Abstract Acoustic predator recognition has rarely been studied in anurans, in spite of the fact that hearing is widespread in these animals and that it has been demonstrated to play an important role in both arthropods and other vertebrates. Using field playback experiments, we tested the hypothesis that adult common toads (Bufo bufo) are capable of recognizing natural vocalizations of a common predator, the Eurasian otter (Lutra lutra), and show antipredator responses. We found that toads exposed to both natural (two types of otter sounds) and synthetic stimuli [white noise (WN) and otter sound-based amplitude modulated WN] increased time allocated to locomotion and escape behaviour. These responses were correlated with time elapsed from sunset to the onset of testing and were independent from the type of acoustic signal, toad features and other environmental factors monitored. We conclude that B. bufo has not developed a selective recognition of predator vocalizations, suggesting that low-frequency or seismic sounds associated with predator movements may provide anurans with better cues about an approaching risk. We propose that the time-dependent response to acoustic stimuli of common toads represents a case of threat-sensitivity and demonstrates that it can occur even when the response to the threat is not predator specific.
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Lachapelle, S., & Healey, J. (2010). On Hans, Zou and the others: wonder animals and the question of animal intelligence in early twentieth-century France. Studies in History and Philosophy of Science Part C: Studies in History and Philosophy of Biological and Biomedical Sciences, 41(1), 12–20.
Abstract: During the second half of the nineteenth century, the advent of widespread pet ownership was accompanied by claims of heightened animal abilities. Psychical researchers investigated many of these claims, including animal telepathy and ghostly apparitions. By the beginning of the twentieth century, news of horses and dogs with the ability to read and calculate fascinated the French public and scientists alike. Amidst questions about the justification of animal cruelty in laboratory experiments, wonder animals came to represent some extraordinary possibilities associated with their kind. Psychologists speculated on the feats of wonder animals. They considered the possibility that these animals shared consciousness and intelligence with humans, and that--if confirmed--their alleged amazing abilities could lead to a new understanding of cognition for all animals. This article focuses on the few years during which claims of wonder animals occupied a significant place in French psychology and psychical research. It argues that as explanations involving deception or unconscious cues gained increased acceptance, the interest in wonder animals soon led to a backlash in comparative psychology that had repercussions for all animals, particularly those used in experimentation, in that it contributed to the decline of research addressing cognitive abilities in non-human species.
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McGreevy, P. D., Harman, A., McLean, A., & Hawson, L. (2010). Over-flexing the horse's neck: A modern equestrian obsession? Journal of Veterinary Behavior: Clinical Applications and Research, 5(4), 180–186.
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.
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Sankey, C., Richard-Yris, M. - A., Leroy, H., Henry, S., & Hausberger, M. (2010). Positive interactions lead to lasting positive memories in horses, Equus caballus. Anim. Behav., 79(4), 869–875.
Abstract: Social relationships are important in social species. These relationships, based on repeated interactions, define each partner's expectations during the following encounters. The creation of a relationship implies high social cognitive abilities which require that each partner is able to associate the positive or negative content of an interaction with a specific partner and to recall this association. In this study, we tested the effects of repeated interactions on the memory kept by 23 young horses about humans, after 6 and 8 months of separation. The association of a reward with a learning task in an interactional context induced positive reactions towards humans during training. It also increased contact and interest, not only just after training, but also several months later, despite no further interaction with humans. In addition, this ‘positive memory’ of humans extended to novel persons. Overall, positive reinforcement enhanced learning and memorization of the task itself. These findings suggest remarkable social cognitive abilities that can be transposed from intraspecific to interspecific social contexts.
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Cozzi, A., Sighieri, C., Gazzano, A., Nicol, C. J., & Baragli, P. (2010). Post-conflict friendly reunion in a permanent group of horses (Equus caballus). Behav. Process., 85(2), 185–190.
Abstract: Gregarious animals living in permanent social groups experience intra-group competition. Conflicts over resources can escalate into costly aggression and, in some conditions, non-dispersive forms of conflict resolution may be favoured. Post-conflict friendly reunions, hence reconciliation, have been described in a variety of species. The aim of this study was to explore, for the first time, the occurrence of reconciliation in a group of domestic horses (Equus caballus) and learn more about strategies used to maintain group cohesion. The behaviour of seven horses living as permanent group in an enclosure for at least 2 years was observed by video for 108 h from June to August 2007. We used a Post-Conflict/Matched Control method to assess the existence of reconciliation and third-party affiliation. Behaviours recorded Post-Conflict, or during Matched Control periods, were classified as affiliative based on previous descriptions of visual communication patterns in horses. The proportion of attracted pairs over total post-conflict situations was significantly greater than the proportion of dispersed pairs, both during dyadic interactions (p < 0.001) and during triadic interactions (p = 0.002). The results of the present study show that both dyadic reconciliation and third-party post-conflict affiliative interactions form important social mechanisms for managing post-conflict situations in horses.
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R Development Core Team. (2010). R: A Language and Environment for Statistical Computing [Computer software]. http://www.R-project.org. Available from http://www.R-project.org
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Sankey, C., Richard-Yris, M. - A., Henry, S., Fureix, C., Nassur, F., & Hausberger, M. (2010). Reinforcement as a mediator of the perception of humans by horses (Equus caballus). Anim. Cogn., 13(5), 753-764.
Abstract: A central question in the interspecific human/animal relationship is how domestic animals perceive humans as a significant element of their environment. In this study, we tested the hypothesis that the use of positive or negative reinforcement in horse training may have consequences on the animals’ perception of humans, as a positive, negative or neutral element. Two groups of ponies were trained to walk backwards in response to a vocal order using either positive or negative reinforcement. Heart rate monitors and behavioural observations were used to assess the animals’ perception of humans on the short (just after training) and long (5 months later) terms. The results showed that the type of reinforcement had a major effect on the subsequent animals’ perception of familiar and unfamiliar humans. Negative reinforcement was rapidly associated with an increased emotional state, as revealed by heart rate measurements and behavioural observations (head movements and ears laid back position). Its use led the ponies to seek less contact with humans. On the contrary, ponies trained with positive reinforcement showed an increased interest in humans and sought contact after training. This is especially remarkable as it was reached in a maximum of 5 sessions of 1 to 3 min (i.e. 5 to 15 min) and had lasting effects (visible after 5 months). Even learning was positively influenced by positive reinforcement. Overall, horses seem capable of associating humans to particular experiences and display extended long-term memory abilities.
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Von PEINEN, K., Wiestner, T., Von RECHENBERG, B., & Weishaupt, M. A. (2010). Relationship between saddle pressure measurements and clinical signs of saddle soreness at the withers. Equine Veterinary Journal, 42, 650–653.
Abstract: Reasons for performing the study: Similar to human decubitus ulcers, local high pressure points from ill-fitting saddles induce perfusion disturbances of different degrees resulting in tissue hypoxia and alteration in sweat production. Objective: To relate the different clinical manifestations of saddle sores to the magnitude of saddle pressures at the location of the withers. Methods: Sixteen horses with dry spots after exercise (Group A) and 7 cases presented with acute clinical signs of saddle pressure in the withers area (Group B) were compared with a control group of 16 sound horses with well fitting saddles (Group C). All horses underwent a saddle pressure measurement at walk, trot and canter. Mean and maximal pressures in the area of interest were compared between groups within each gait. Results: Mean pressures differed significantly between groups in all 3 gaits. Maximal pressure differed between groups at trot; at walk and canter, however, the only significant difference was between Group C and Groups A and B, respectively, (P>0.05). Mean and maximal pressures at walk in Group A were 15.3 and 30.6 kPa, in Group B 24.0 and 38.9 kPa and in Group C 7.8 and 13.4 kPa, respectively; at trot in Group A 18.1 and 43.4 kPa, in Group B 29.7 and 53.3 kPa and in Group C 9.8 and 21.0 kPa, respectively; and at canter in Group A 21.4 and 48.9 kPa, in Group B 28.6 and 56.0 kPa and in Group C 10.9 and 24.7 kPa, respectively. Conclusion: The study shows that there is a distinguishable difference between the 3 groups regarding the mean pressure value, in all gaits.
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