Silk, J., Cheney, D., & Seyfarth, R. (2013). A practical guide to the study of social relationships. Evol. Anthropol., 22(5), 213–225.
Abstract: Behavioral ecologists have devoted considerable effort to identifying the sources of variation in individual reproductive success. Much of this work has focused on the characteristics of individuals, such as their sex and rank. However, many animals live in stable social groups and the fitness of individuals depends at least in part on the outcome of their interactions with other group members. For example, in many primate species, high dominance rank enhances access to resources and reproductive success. The ability to acquire and maintain high rank often depends on the availability and effectiveness of coalitionary support. Allies may be cultivated and coalitions may be reinforced by affiliative interactions such as grooming, food sharing, and tolerance. These findings suggest that if we want to understand the selective pressures that shape the social behavior of primates, it will be profitable to broaden our focus from the characteristics of individuals to the properties of the relationships that they form with others. The goal of this paper is to discuss a set of methods that can be used to quantify the properties of social relationships.
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Lilienfeld, S. O., Gershon, J., Duke, M., Marino, L., & de Waal, F. B. (1999). A preliminary investigation of the construct of psychopathic personality (psychopathy) in chimpanzees (Pan troglodytes). J Comp Psychol, 113(4), 365–375.
Abstract: Although the construct of psychopathy has received considerable attention in humans, its relevance to other animals is largely unknown. We developed a measure of psychopathy for use in chimpanzees (Pan troglodytes), the Chimpanzee Psychopathy Measure (CPM), and asked 6 raters to complete this index on 34 chimpanzees. The CPM (a) demonstrated satisfactory interrater reliability and internal consistency; (b) exhibited marginally significant sex differences (males > females); (c) correlated positively with measures of extraversion, agreeableness, and observational ratings of agonism, sexual activity, daring behaviors, teasing, silent bluff displays, and temper tantrums, and negatively with observational ratings of generosity; and (d) demonstrated incremental validity above and beyond a measure of dominance. Although further validation of the CPM is needed, these findings suggest that the psychopathy construct may be relevant to chimpanzees.
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Groesel, M., Zsoldos, R. R., Kotschwar, A., Gfoehler, M., & Peham, C. (2010). A preliminary model study of the equine back including activity of longissimus dorsi muscle. Equine Veterinary Journal, 42, 401–406.
Abstract: Reasons for performing study: Identifying the underlying problem of equine back pain and diseases of the spine are significant problems in veterinary orthopaedics. A study to validate a preliminary biomechanical model of the equine back based on CT images including longissimus dorsi (LD) muscle is therefore important. Objectives: Validation of the back model by comparing the shortening of LD muscles in the model with integrated EMG (IEMG) at stance during induced lateral flexion of the spine. Methods:Longissimus dorsi muscle activity at stance has been used for validation. EMG electrodes were placed laterally at the level of T12, T16 and L3. Reflective markers have been attached on top of the spinous processes T5, T12, T16, L1 and the sacral bone (OS1, OS2) for motion tracking analysis. A virtual model of the equine's back (T1–S5) was built with inclusion of a simplified LD muscle by 2 separate contours left and right of the spine, starting at tuber coxae laterally and attaching to the spinous process T5 medially. Shortening of LD during induced lateral flexion caused by the kinematic data (input) was compared to the 3 EMG signals (T12, T16 and L3) on the active side via correlation. Results: Pearson correlation coefficient between IEMG and shortening length of LD in the model was (mean ± s.d.) 0.95 ± 0.07 for the left side and 0.91 ± 0.07 for the right side of LD. Conclusions: Activity of the LD muscles is mainly responsible for stabilisation of the vertebral column with isometric muscle contraction against dynamic forces in walk and trot. This validation requires muscle shortening in the back, like induced lateral flexion at stance. The length of the shortening muscle model and the IEMG show a linear relationship. These findings will help to model the LD for forward simulations, e.g. from force to motion.
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Houpt, K., Marrow, M., & Seeliger, M. (2000). A preliminary study of the effect of music on equine behavior. Journal of Equine Veterinary Science, 20(11), 691–737.
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Houpt, K., Marrow, M., & Seeliger, M. (2000). A preliminary study of the effect of music on equine behavior. Journal of Equine Veterinary Science, 20(11), 691–737.
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Fureix, C., Pagès, M., Bon, R., Lassalle, J. - M., Kuntz, P., & Gonzalez, G. (2009). A preliminary study of the effects of handling type on horses' emotional reactivity and the human-horse relationship. Behav. Process., 82(2), 202–210.
Abstract: Handling is a crucial component of the human-horse relationship. Here, we report data from an experiment conducted to assess and compare the effect of two training methods. Two groups of six Welsh mares were trained during four sessions of 50 min, one handled with traditional exercises (halter leading, grooming/brushing, lifting feet, lunging and pseudo-saddling (using only girth and saddle pad) and the second group with natural horsemanship exercises (desensitization, yielding to body pressure, lunging and free-lunging). Emotional reactivity (ER) and the human-horse relationship (HHR) were assessed both prior to and following handling. A social isolation test, a neophobia test and a bridge test were used to assess ER. HHR was assessed through test of spontaneous approach to, and forced approach by, an unknown human. Horses' ER decreased after both types of handling as indicated by decreases in the occurrence of whinnying during stressful situations. Head movement (jerk/shake) was the most sensitive variable to handling type. In the spontaneous approach tests, horses in the traditional handling group showed higher latencies to approach a motionless person after handling than did the natural horsemanship group. Our study suggests that natural horsemanship exercises could be more efficient than traditional exercises for improving horses' HHR.
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Sappington, B. K. F., McCall, C. A., Coleman, D. A., Kuhlers, D. L., & Lishak, R. S. (1997). A preliminary study of the relationship between discrimination reversal learning and performance tasks in yearling and 2-year-old horses. Appl. Anim. Behav. Sci., 53(3), 157–166.
Abstract: A study was conducted to determine the relationship between discrimination reversal learning and performance tasks in horses. Ten yearling and seven 2-year-old mares and geldings of Arabian (n = 4), Quarter Horse (n = 9), and Thoroughbred (n = 4) breeding were given a two-choice discrimination task in which either a black or a white bucket contained a food reward for ten trials per day during 19 test days. The spatial position of the buckets was varied on a random schedule. The rewarded bucket color was reversed each time a subject met criterion of eight correct choices per day for 2 consecutive days. Discrimination reversal testing was followed by 6 days of performance tasks: three crossing a wooden bridge and three jumping an obstacle to reach food and conspecifics, within a maximum allotted time of 15 min day-1. Total reversals attained by the horses were low (x = 1.5 +/- 0.9). All subjects did attain at least one reversal, and six had two or more reversals. No differences (P > .05) were detected between ages or sexes, nor among breeds in discrimination reversal learning or performance test measurements. However, there was a trend towards a breed difference (P <= 0.09) in the mean number of correct responses to the first reversal criterion. Correlations between reversal learning results and performance task results were extremely low, indicating that the discrimination reversal learning test was not useful for predicting success at these performance tasks. Results from the two performance tasks also showed little correlation (r = 0.04, P < 0.91), indicating that horses might not use the same approach when solving the problem of crossing these two obstacles. The overall poor performance of the horses on the discrimination reversal task suggests horses may have difficulty reversing previously learned tasks.
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Argue, C. K., & Clayton, H. M. (1993). A preliminary study of transitions between the walk and trot in dressage horses. Acta Anat (Basel), 146(2-3), 179–182.
Abstract: The object of this study was to determine the limb support sequence during the transitions from walk to trot and from trot to walk in dressage horses under saddle and to test the null hypothesis that the limb support sequence during the transitions is not related to the level of training. Sixteen dressage horses training at novice to FEI Grand Prix level were videotaped performing an average of 9 transitions each from walk to trot and from trot to walk. The 30-Hz videotapes were viewed in slow motion, and based on the limb support sequence the transitions were categorized into two types. In type 1 transitions there were no intermediate steps between the walk and trot sequences. Type 2 transitions were characterized by intermediate steps, including a single support phase. The Kendall rank-order correlation coefficient showed that a higher level of training was positively associated with an increased percentage of type 1 transitions for both walk-to-trot transitions (p < or = 0.05) and trot-to-walk transitions (p < or = 0.01). No significant preference for initiating or completing the trot on the left or right diagonal was found using the binomial test for individual horses and the Wilcoxon signed-ranks test for the group.
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McBride, S. D., Hemmings, A., & Robinson, K. (2004). A preliminary study on the effect of massage to reduce stress in the horse. Journal of Equine Veterinary Science, 24(2), 76–81.
Abstract: The use of massage (as a potential form of acupressure) has long been documented as a human relaxation aid. However, little scientific research has been carried out into its potential use as a form of stress reduction in the horse. This preliminary study investigated the effect of massage at six different sites (thoracic trapezius [withers], mid-brachiocephalicus, cervical ventral serrate and cervical trapezius [mid-neck], proximal gluteal fascia and proximal superficial gluteal [croup], proximal and mid-semitendinosus [second thigh], lateral triceps, proximal extensor carpi radialis and proximal common digital extensor [forearm], proximal brachiocephalicus, proximal splenius and ear [poll and ears) on stress-related behavioral and physiological (heart rate [HR]) measures in the horse. Ten riding school ponies/horses were massaged at each of the six sites (three preferred and three nonpreferred sites of allogrooming (mutual grooming between conspecifics) and changes in HR and behavior were recorded. The results indicated that during massage, all sites except the forearm resulted in a significant reduction in HR (P < .05) with massage at the withers, mid-neck, and croup having the greatest effect (preferred sites of allogrooming). Massage at preferred sites of allogrooming also elicited significantly more (P < .05) positive behavioral responses compared with the three nonpreferred sites. The practical implications of this study are discussed.
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Pinchbeck, G. L., Clegg, P. D., Proudman, C. J., Morgan, K. L., & French, N. P. (2004). A prospective cohort study to investigate risk factors for horse falls in UK hurdle and steeplechase racing. Equine Vet J, 36(7), 595–601.
Abstract: REASONS FOR PERFORMING STUDY: Equine fatalities during racing continue to be a major welfare concern and falls at fences are responsible for a proportion of all equine fatalities recorded on racecourses. OBJECTIVES: To identify and quantify risk factors for horse falls in National Hunt (NH) racing and to report the frequency of falling and falling-associated fatalities. METHODS: A prospective cohort study was conducted on 2879 horse starts in hurdle and steeplechase races on 6 UK racecourses. Any horse that suffered a fall at a steeplechase or hurdle fence during the race was defined as a case. Data were obtained by interview and observations in the parade ring and from commercial databases. Multivariable logistic regression models, allowing for clustering at the level of the track, were used to identify the relationship between variables and the risk of falling. RESULTS: There were 124 falling cases (32 in hurdling and 92 in steeplechasing) identified. The injury risk of fallers was 8.9% and fatality risk 6.5%. Duration of journey to the racecourse, behaviour in the parade ring and weather at the time of the race were associated with falling in both hurdle and steeplechase racing. Age, amount of rainfall and going were also associated with falling in steeplechase racing. CONCLUSIONS: Falls at fences are significant contributors to equine fatalities during NH racing. Potentially modifiable risk factors identified were the condition of track surfaces and journey time to the racecourse. POTENTIAL RELEVANCE: It is hoped that information from this study may be used in future interventions to improve horse and jockey safety in racing. The study has also identified areas requiring further research, such as equine behaviour and its effect on racing performance, and the effect of light conditions on jumping ability.
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