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Moses, S. N., Villate, C., & Ryan, J. D. (2006). An investigation of learning strategy supporting transitive inference performance in humans compared to other species. Neuropsychologia, 44(8), 1370–1387.
Abstract: Generalizations about neural function are often drawn from non-human animal models to human cognition, however, the assumption of cross-species conservation may sometimes be invalid. Humans may use different strategies mediated by alternative structures, or similar structures may operate differently within the context of the human brain. The transitive inference problem, considered a hallmark of logical reasoning, can be solved by non-human species via associative learning rather than logic. We tested whether humans use similar strategies to other species for transitive inference. Results are crucial for evaluating the validity of widely accepted assumptions of similar neural substrates underlying performance in humans and other animals. Here we show that successful transitive inference in humans is unrelated to use of associative learning strategies and is associated with ability to report the hierarchical relationship among stimuli. Our work stipulates that cross-species generalizations must be interpreted cautiously, since performance on the same task may be mediated by different strategies and/or neural systems.
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Henry, S., Richard-Yris, M. - A., & Hausberger, M. (2006). Influence of various early human-foal interferences on subsequent human-foal relationship. Dev Psychobiol, 48(8), 712–718.
Abstract: Whereas the way animals perceive human contact has been particularly examined in pet animals, a small amount of investigations has been done in domestic ungulates. It was nevertheless assumed that, as pet animals, non-aggressive forms of tactile contact were as well rewarding or positive for these species, even though the features of intraspecific relationships in pet animals and domestic ungulates may be to some extent different.We test here the hypothesis that horses may not consider physical handling by humans as a positive event. When comparing different early human-foal interactions, we found that early exposure to a motionless human enhanced slightly foals reactions to humans whereas forced stroking or handling in early life did not improve later human-foal relation. Foals that were assisted during their first suckling (e.g., brought to the dam's teat) even tended to avoid human approach at 2 weeks, and physical contact at 1 month of age.We argue that interspecies differences may exist in how tactile stimulation is perceived. It may be important for the establishment of a bond that a young animal is active in the process and able, through its behavioral responses, to help define what is positive for it. This way of investigation may have important general implications in how we consider the development of social relations, both within and between species.
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Polley, L. (1986). Strongylid parasites of horses: experimental ecology of the free-living stages on the Canadian prairie. Am J Vet Res, 47(8), 1686–1693.
Abstract: Each month for a 1-year period (October through September), equine fecal masses containing eggs of strongylid nematodes were placed outdoors on small grass plots in Saskatchewan, Canada. Thereafter, feces and grass from the plots were sampled after intervals of 1 week or longer, and the strongylid eggs and larvae recovered were counted. These observations were made over a 2-year period. Development of eggs to infective larvae occurred in all experiments, except those established in October, December, and January. Infective larvae from experiments set up in April through September survived that winter. During the summer, there was a gradual build up of infective larvae in the fecal masses, which reached a peak in August and September and then decreased into the winter. These results are discussed in the context of the control of strongylid parasites of horses on the Canadian prairie and in other areas of the world with a similar climate and similar horse management practices.
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Mallavarapu, S., Stoinski, T. S., Bloomsmith, M. A., & Maple, T. L. (2006). Postconflict behavior in captive western lowland gorillas (Gorilla gorilla gorilla). Am. J. Primatol., 68(8), 789–801.
Abstract: Postconflict (PC) behaviors, including reconciliation and consolation, have been observed in many primate and several nonprimate species. Using the PC-matched control (MC) method, PC behavior was examined in two groups (n=13) of captive western lowland gorillas, a species for which no conflict resolution data have been published. Analyses of 223 conflicts showed significantly more affiliation between former opponents after a conflict when compared to control periods, indicating reconciliation. Results also showed significantly more affiliation between the victim and a third-party after a conflict, indicating consolation. Both solicited and unsolicited consolation were observed. The majority of the affiliative interactions observed for both reconciliation and consolation were social proximity, which suggests that unlike most nonhuman primates, proximity, rather than physical contact, may be the main mechanism for resolving conflicts in western lowland gorillas. PC behavior was not uniform throughout the groups, but rather varied according to dyad type.
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Licka, T., Kapaun, M., & Peham, C. (2004). Influence of rider on lameness in trotting horses. Equine Vet J, 36(8), 734–736.
Abstract: REASONS FOR PERFORMING STUDY: Equine lameness is commonly evaluated when the horse is being ridden, but the influence of the rider on the lameness has not been documented. OBJECTIVE: To document the effect of 2 riders of different training levels on the vertical movement of the head and croup. METHODS: Twenty mature horses were ridden at trot by an experienced dressage rider and a novice rider, as well as trotted in hand. Kinematic measurements of markers placed on the horse's head and sacral bone were carried out. The asymmetries of the vertical head and sacral bone motion were calculated as lameness parameters and compared with paired t tests. RESULTS: Trotting in hand, 17 horses showed forelimb lameness (1-4/10) and 13 hindlimb lameness (1-2/10). Intra-individually, 11 horses showed significant differences in forelimb lameness and 4 horses showed significant differences in hindlimb lameness when ridden. Over all horses, hindlimb lameness increased significantly under the dressage rider compared to unridden horses. CONCLUSIONS: The presence of a rider can alter the degree of lameness; however, its influence cannot be predicted for an individual horse. POTENTIAL RELEVANCE: In order to evaluate mild lameness, horses should be evaluated at trot both under saddle and in hand. If lameness is exacerbated, a second rider may be helpful; the level of training of the rider should be taken into consideration.
Keywords: Animals; Biomechanics; Body Weight; Exercise Test/veterinary; Female; Forelimb/physiopathology; Gait/*physiology; Head Movements/*physiology; Hindlimb/physiopathology; Horse Diseases/diagnosis/*physiopathology; Horses; Humans; Lameness, Animal/diagnosis/*physiopathology; Male; Stress, Mechanical; Weight-Bearing/physiology
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Hinrichs, K., Watson, E. D., & Kenney, R. M. (1990). Granulosa cell tumor in a mare with a functional contralateral ovary. J Am Vet Med Assoc, 197(8), 1037–1038.
Abstract: A functional corpus luteum was found in the ovary contralateral to the ovary with a granulosa cell tumor in a 24-year-old Standardbred mare. The mare was ovariectomized because she was to be used as a jump mare for collection of semen from stallions. The blood concentration of progesterone was 2.2 ng/ml, and the luteal tissue progesterone concentration was 6.3 micrograms/mg. Atrophy of the contralateral ovary is one of the major signs used in diagnosis of granulosa cell tumor; however, our findings indicate that the ovary contralateral to a granulosa cell tumor is not invariably nonfunctional.
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Cassiat, G., Pourcelot, P., Tavernier, L., Geiger, D., Denoix, J. M., & Degueurce, D. (2004). Influence of individual competition level on back kinematics of horses jumping a vertical fence. Equine Vet J, 36(8), 748–753.
Abstract: REASONS FOR PERFORMING STUDY: The costs and investments required for the purchase and training of showjumpers justify the need to find selection means for jumping horses. Use of objective kinematic criteria correlated to jumping ability could be helpful for this assessment. OBJECTIVES: To compare back kinematics between 2 groups of horses of different competition levels (Group 1, competing at high level; Group 2 competing at low level) while free jumping over a 1 m vertical fence. METHODS: Three-dimensional recordings were performed using 2 panning cameras. Kinematic parameters of the withers and tuber sacrale (vertical displacement, vertical and horizontal velocities), backline inclination and flexion-extension motion of the 3 main dorsal segments (thoracic, thoracolumbar and lumbosacral) were analysed. RESULTS: Group 2 horses had a lower displacement of their withers and tuber sacrale from the end of the last approach stride until the first departure stride (P<0.05). As a result, they increased the flexion of their thoracolumbar and lumbosacral junctions during the hindlimb swing phase before take-off (P<0.05). However, withers and tuber sacrale velocities were slightly modified. Group 1 horses pitched their backline less forward during the forelimb stance phase before take-off and straightened it more after landing (P<0.05), probably indicating a more efficient strutting action of their forelimbs. CONCLUSIONS AND POTENTIAL RELEVANCE: Because significant differences in back motion were found between good and poor jumpers when jumping a 1 m high fence, criteria based on certain back kinematics can be developed that may help in the selection of talented showjumpers.
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Grosenick, L., Clement, T. S., & Fernald, R. D. (2007). Fish can infer social rank by observation alone. Nature, 445(7126), 429–432.
Abstract: Transitive inference (TI) involves using known relationships to deduce unknown ones (for example, using A > B and B > C to infer A > C), and is thus essential to logical reasoning. First described as a developmental milestone in children, TI has since been reported in nonhuman primates, rats and birds. Still, how animals acquire and represent transitive relationships and why such abilities might have evolved remain open problems. Here we show that male fish (Astatotilapia burtoni) can successfully make inferences on a hierarchy implied by pairwise fights between rival males. These fish learned the implied hierarchy vicariously (as 'bystanders'), by watching fights between rivals arranged around them in separate tank units. Our findings show that fish use TI when trained on socially relevant stimuli, and that they can make such inferences by using indirect information alone. Further, these bystanders seem to have both spatial and featural representations related to rival abilities, which they can use to make correct inferences depending on what kind of information is available to them. Beyond extending TI to fish and experimentally demonstrating indirect TI learning in animals, these results indicate that a universal mechanism underlying TI is unlikely. Rather, animals probably use multiple domain-specific representations adapted to different social and ecological pressures that they encounter during the course of their natural lives.
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Arnold, K., & Zuberbuhler, K. (2006). Language evolution: semantic combinations in primate calls. Nature, 441(7091), 303.
Abstract: Syntax sets human language apart from other natural communication systems, although its evolutionary origins are obscure. Here we show that free-ranging putty-nosed monkeys combine two vocalizations into different call sequences that are linked to specific external events, such as the presence of a predator and the imminent movement of the group. Our findings indicate that non-human primates can combine calls into higher-order sequences that have a particular meaning.
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Flack, J. C., Girvan, M., de Waal, F. B. M., & Krakauer, D. C. (2006). Policing stabilizes construction of social niches in primates. Nature, 439(7075), 426–429.
Abstract: All organisms interact with their environment, and in doing so shape it, modifying resource availability. Termed niche construction, this process has been studied primarily at the ecological level with an emphasis on the consequences of construction across generations. We focus on the behavioural process of construction within a single generation, identifying the role a robustness mechanism--conflict management--has in promoting interactions that build social resource networks or social niches. Using 'knockout' experiments on a large, captive group of pigtailed macaques (Macaca nemestrina), we show that a policing function, performed infrequently by a small subset of individuals, significantly contributes to maintaining stable resource networks in the face of chronic perturbations that arise through conflict. When policing is absent, social niches destabilize, with group members building smaller, less diverse, and less integrated grooming, play, proximity and contact-sitting networks. Instability is quantified in terms of reduced mean degree, increased clustering, reduced reach, and increased assortativity. Policing not only controls conflict, we find it significantly influences the structure of networks that constitute essential social resources in gregarious primate societies. The structure of such networks plays a critical role in infant survivorship, emergence and spread of cooperative behaviour, social learning and cultural traditions.
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