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Birch, H. G. (1945). The relation of previous experience to insightful problem-solving. J Comp Psychol, 38, 367–383.
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Biro, D., Inoue-Nakamura, N., Tonooka, R., Yamakoshi, G., Sousa, C., & Matsuzawa, T. (2003). Cultural innovation and transmission of tool use in wild chimpanzees: evidence from field experiments. Anim. Cogn., 6(4), 213–223.
Abstract: Chimpanzees (Pan troglodytes) are the most proficient and versatile users of tools in the wild. How such skills become integrated into the behavioural repertoire of wild chimpanzee communities is investigated here by drawing together evidence from three complementary approaches in a group of oil-palm nut- ( Elaeis guineensis) cracking chimpanzees at Bossou, Guinea. First, extensive surveys of communities adjacent to Bossou have shown that population-specific details of tool use, such as the selection of species of nuts as targets for cracking, cannot be explained purely on the basis of ecological differences. Second, a 16-year longitudinal record tracing the development of nut-cracking in individual chimpanzees has highlighted the importance of a critical period for learning (3-5 years of age), while the similar learning contexts experienced by siblings have been found to result in near-perfect (13 out of 14 dyads) inter-sibling correspondence in laterality. Third, novel data from field experiments involving the introduction of unfamiliar species of nuts to the Bossou group illuminates key aspects of both cultural innovation and transmission. We show that responses of individuals toward the novel items differ markedly with age, with juveniles being the most likely to explore. Furthermore, subjects are highly specific in their selection of conspecifics as models for observation, attending to the nut-cracking activities of individuals in the same age group or older, but not younger than themselves. Together with the phenomenon of inter-community migration, these results demonstrate a mechanism for the emergence of culture in wild chimpanzees.
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Blaisdell, A. P., & Cook, R. G. (2005). Integration of spatial maps in pigeons. Anim. Cogn., 8(1), 7–16.
Abstract: The integration of spatial maps in pigeons was investigated using a spatial analog to sensory preconditioning. The pigeons were tested in an open-field arena in which they had to locate hidden food among a 4x4 grid of gravel-filled cups. In phase 1, the pigeons were exposed to a consistent spatial relationship (vector) between landmark L (a red L-shaped block of wood), landmark T (a blue T-shaped block of wood) and the hidden food goal. In phase 2, the pigeons were then exposed to landmark T with a different spatial vector to the hidden food goal. Following phase 2, pigeons were tested with trials on which they were presented with only landmark L to examine the potential integration of the phase 1 and 2 vectors via their shared common elements. When these test trials were preceded by phase 1 and phase 2 reminder trials, pigeons searched for the goal most often at a location consistent with their integration of the L-->T phase 1 and T-->phase 2 goal vectors. This result indicates that integration of spatial vectors acquired during phases 1 and 2 allowed the pigeons to compute a novel L-->goal vector. This suggests that spatial maps may be enlarged by successively integrating additional spatial information through the linkage of common elements.
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Bobbert, M. F., Alvarez, C. B. G., van Weeren, P. R., Roepstorff, L., & Weishaupt, M. A. (2007). Validation of vertical ground reaction forces on individual limbs calculated from kinematics of horse locomotion. J Exp Biol, 210(Pt 11), 1885–1896.
Abstract: The purpose of this study was to determine whether individual limb forces could be calculated accurately from kinematics of trotting and walking horses. We collected kinematic data and measured vertical ground reaction forces on the individual limbs of seven Warmblood dressage horses, trotting at 3.4 m s(-1) and walking at 1.6 m s(-1) on a treadmill. First, using a segmental model, we calculated from kinematics the total ground reaction force vector and its moment arm relative to each of the hoofs. Second, for phases in which the body was supported by only two limbs, we calculated the individual reaction forces on these limbs. Third, we assumed that the distal limbs operated as linear springs, and determined their force-length relationships using calculated individual limb forces at trot. Finally, we calculated individual limb force-time histories from distal limb lengths. A good correspondence was obtained between calculated and measured individual limb forces. At trot, the average peak vertical reaction force on the forelimb was calculated to be 11.5+/-0.9 N kg(-1) and measured to be 11.7+/-0.9 N kg(-1), and for the hindlimb these values were 9.8+/-0.7 N kg(-1) and 10.0+/-0.6 N kg(-1), respectively. At walk, the average peak vertical reaction force on the forelimb was calculated to be 6.9+/-0.5 N kg(-1) and measured to be 7.1+/-0.3 N kg(-1), and for the hindlimb these values were 4.8+/-0.5 N kg(-1) and 4.7+/-0.3 N kg(-1), respectively. It was concluded that the proposed method of calculating individual limb reaction forces is sufficiently accurate to detect changes in loading reported in the literature for mild to moderate lameness at trot.
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Boden, L. A., Anderson, G. A., Charles, J. A., Morgan, K. L., Morton, J. M., Parkin, T. D. H., et al. (2006). Risk of fatality and causes of death of Thoroughbred horses associated with racing in Victoria, Australia: 1989-2004. Equine Vet J, 38(4), 312–318.
Abstract: REASONS FOR PERFORMING STUDY: Determining the risk of fatality of Thoroughbred horses while racing is essential to assess the impact of intervention measures designed to minimise such fatalities. OBJECTIVES: To measure the risk of racehorse fatality in jump and flat starts on racecourses in Victoria, Australia, over a 15 year period and to determine proportional mortality rates for specific causes of death. METHODS: All fatalities of Thoroughbred horses that occurred during or within 24 h of a race were identified from a database. The risk of a start resulting in a racehorse fatality in all races and within flat and jump races, proportional mortality rates, population attributable risk, population attributable fraction and risk ratios were calculated along with 95% confidence intervals. Poisson regression was also performed to estimate risk ratios. RESULTS: There were 514 fatalities over the 15 year period; 316 in flat races and 198 in jump races. The risk of fatality was 0.44 per 1000 flat starts and 8.3 per 1000 jump starts (18.9 x greater). The risk of fatality on city tracks was 1.1 per 1000 starts whereas on country tracks it was 0.57 per 1000 starts. Of the 316 fatalities in flat races, 73.4% were due to limb injury, 2.5% to cranial or vertebral injury and 19.0% were sudden deaths. Of the 198 fatalities in jump races, 68.7% were due to limb injury, 16.2% to cranial or vertebral injury and 3.5% were sudden deaths. The risk of fatality in flat starts increased between 1989 and 2004 but the risk in jump starts remained unchanged over the 15 year period. CONCLUSIONS: The risk of fatality in flat starts was lower in Victoria than North America and the UK but the risk in jump starts was greater. Catastrophic limb injury was the major reason for racehorse fatality in Victoria but there was a larger percentage of sudden deaths than has been reported overseas. The risk of fatality in jump starts remained constant over the study period despite jump racing reviews that recommended changes to hurdle and steeple races to improve safety. POTENTIAL RELEVANCE: This study provides important benchmarks for the racing industry to monitor racetrack fatalities and evaluate intervention strategies.
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Bonabeau, E., Theraulaz, G., & Deneubourg, J. - L. (1999). Dominance orders in animal societies: the selforganization. Bull Math Biol, 61(4). Retrieved April 28, 2024, from http://dx.doi.org/10.1006/bulm.1999.0108
Abstract: In previous papers (Theraulaz et al. 1995, Bonabeau et al. 1996) we suggested, following Hogeweg and Hesper (1983, 1985), that the formation of dominance orders in animal societies could result from a selforganizing process involving a double reinforcement mechanism: winners reinforce their probability of winning and losers reinforce their probability of losing. This assumption, and subsequent models, were based on empirical data on primitively eusocial wasps (Polistes dominulus). By...
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Borgatti, S. P., Everett, M.G., Freeman, L.C. (2002). Ucinet for Windows: Software for Social Network Analysis.
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Bottoms, G. D., Roesel, O. F., Rausch, F. D., & Akins, E. L. (1972). Circadian variation in plasma cortisol and corticosterone in pigs and mares. Am J Vet Res, 33(4), 785–790.
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Boysen, S. T., Bernston, G. G., Hannan, M. B., & Cacioppo, J. T. (1996). Quantity-based interference and symbolic representations in chimpanzees (Pan troglodytes). J Exp Psychol Anim Behav Process, 22(1), 76–86.
Abstract: Five chimpanzees with training in counting and numerical skills selected between 2 arrays of different amounts of candy or 2 Arabic numerals. A reversed reinforcement contingency was in effect, in which the selected array was removed and the subject received the nonselected candies (or the number of candies represented by the nonselected Arabic numeral). Animals were unable to maximize reward by selecting the smaller array when candies were used as array elements. When Arabic numerals were substituted for the candy arrays, all animals showed an immediate shift to a more optimal response strategy of selecting the smaller numeral, thereby receiving the larger reward. Results suggest that a response disposition to the high-incentive candy stimuli introduced a powerful interference effect on performance, which was effectively overridden by the use of symbolic representations.
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Boysen, S. T., & Berntson, G. G. (1995). Responses to quantity: perceptual versus cognitive mechanisms in chimpanzees (Pan troglodytes). J Exp Psychol Anim Behav Process, 21(1), 82–86.
Abstract: Two chimpanzees were trained to select among 2 different amounts of candy (1-6 items). The task was designed so that selection of either array by the active (selector) chimpanzee resulted in that array being given to the passive (observer) animal, with the remaining (nonselected) array going to the selector. Neither animal was able to select consistently the smaller array, which would reap the larger reward. Rather, both animals preferentially selected the larger array, thereby receiving the smaller number of reinforcers. When Arabic numerals were substituted for the food arrays, however, the selector animal evidenced more optimal performance, immediately selecting the smaller numeral and thus receiving the larger reward. These findings suggest that a basic predisposition to respond to the perceptual-motivational features of incentive stimuli can interfere with task performance and that this interference can be overridden when abstract symbols serve as choice stimuli.
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