Beaugrand, J. P. (1997). Relative importance of initial individual differences, victory and defeat experiences, and assessment accuracy during hierarchy formation: A simulation study (Vol. 41). Elsevier.
Abstract: This simulation study explores some conditions leading to transitivity within dominance orders. Combinations of three parameters were varied to study their consequences upon hierarchy formation and upon the degree of linearity of resultant structures. The factors studied were (i) the importance of initial Resource Holding Potentials (RHPs) , (ii) changes brought in RHPs by successive victories and defeats, and (iii) accuracy of RHP assessment made by opponents. Results show that initial differences in RHP always lead to perfectly transitive chains whose rank order reflects the importance of initial differences. Even when simulated animals make important errors while assessing each other during round robin tournaments, emerging dominance structures are perfectly linear and ranks obtained in the structure are highly correlated with initial values in RHPs. Moreover, accumulated experiences of victory and/or defeat alone always lead to perfectly linear hierarchies. Their combination with initial individual differences in RHP led to the same conclusion. Even when assessment was far from being perfect, not only perfect chains were formed but initial values in RHPs significantly influenced rank order when the contribution of victory and defeat to RHP was relatively unimportant. The higher the importance of victory and defeat to RHP as compared to that of initial RHP values, the lower was the correlation between initial RHP values and the ranks order reached by individuals in the resultant hierarchies. In general also, the lower the variation within initial RHPs, the lower was the correlation between initial RHPs and ranks in the hierarchy. At a given level of initial RHP dispersion, increasing the contribution of victory and defeat to RHP diminished the correlation between initial RHP values and obtained ranks. In addition, inaccurate assessment reduced the overall correlation, especially when dispersion of initial RHP values was low and the contribution of victory and defeat was high. These results shed some light on the controversy about the respective roles of initial individual attributes and that of patterns of resolution in the formation of animal hierarchies. We present the emergence of social order within closed systems as those simulated here as a case of self-organization.
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Beaver Bv,. (1981). Maternal behavior in mares. Vet Med Small Anim Clin, 76, 315–317.
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Beaver Bv,. (1982). Aggressive bhavior associated with naturally elevated serum Testosterone in mares. Appl Anim Ethol, 8, 425–428.
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Beaver, B. V. (1986). Aggressive behavior problems. Vet Clin North Am Equine Pract, 2(3), 635–644.
Abstract: Accurate diagnosis of the cause of aggression in horses is essential to determining the appropriate course of action. The affective forms of aggression include fear-induced, pain-induced, intermale, dominance, protective, maternal, learned, and redirected aggressions. Non-affective aggression includes play and sex-related forms. Irritable aggression and hypertestosteronism in mares are medical problems, whereas genetic factors, brain dysfunction, and self-mutilation are also concerns.
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Beaver, B. V. (1981). Problems & values associated with dominance. Vet Med Small Anim Clin, 76(8), 1129–1131.
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Beck, B. B. (1980). Animal tool behaviour: The use and manufacture of tools by animals. New York: Garland.
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Beck, B. B. (1982). Chimpocentrism: Bias in cognitive ethology. Journal of Human Evolution, 11(1), 3–17.
Abstract: Herring gulls drop hard-shelled mollusks and hermit crab-inhabited molluskan prey in order to break the shells and gain access to the edible interior. A field study of predatory shell dropping on Cape Cod, Massachusetts, U.S.A. showed that the gulls usually drop the same shell repeatedly, orient directly to dropping sites that are invisible from the point at which the mollusks are captured, drop preferentially on hard surfaces, adjust dropping heights to suit the area and elasticity of the substrate, orient directly into the wind while dropping, sever the large defensive cheliped of hermit crabs before consumption, and rinse prey that is difficult to swallow. Proficiency in prey dropping is acquired through dropping objects in play, trial-and-error learning, and perhaps, observation learning.
Observable attributes of predatory shell-dropping support inferences that the gulls are capable of extended concentration, purposefulness, mental representation of spatially and temporally displaced environmental features, cognitive mapping, cognitive modeling, selectivity, and strategy formation. Identical cognitive processes have been inferred to underlie the most sophisticated forms of chimpanzee tool-use.
Advanced cognitive capacities are not restricted to chimpanzees and other pongids, and are not associated uniquely with tool use. The chimpocentric bias should be abandoned, and reconstructions of the evolution of intelligence should be modified accordingly.
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Becker C,. (1983). Grevy's zebra of Smburu Keya: Mother-infant behavior. Master's thesis, , .
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Becker, C. D., & Ginsberg, J. R. (1990). Mother-infant behaviour of wild Grevy's zebra: adaptations for survival in semidesert East Africa. Anim. Behav., 40(6), 1111–1118.
Abstract: Mother-infant interactions and patterns of foal behaviour in the Grevy's zebra, Equus grevyi, differe from those reported for other equids. Grevy's zebra foals exhibit longer intervals between suckling bouts, do not drink water until they are 3 months old, and reach independence from the mare sooner than other equids. Furthermore, Grevy's zebra foals advance their acquisition of adult feeding behaviour. A 6-week-old Grevy's zebra foal spends as much time feeding as a 5-month-old wild horse foal. From the time their foals are born until the foals reach an age of 3 months, females form small groups (three females and their foals). These groups are never found further than 2·0 km from surface water and are usually associated with a territorial male. Unlike other equids, the foals of which always follow their mares, when female Grevy's zebra go to drink, they leave their foals in “kindergartens”, which are guarded by a single adult animal, usually a territorial male. It is proposed that many of these differences in behaviour and rates of juvenile development are the result of adaptation to an arid environment. Water requirements during early lactation appear to influence strongly the social behaviour of the Grevy's zebra and should also be a strong influence on the mother-infant behaviour of other arid-living ungulates.
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Becker-Birck, M., Biau, S., Aurich, C., Möstl, E., Ille, N., & Aurich, J. (2012). Heart rate and heart rate variability in the horse and its rider: different responses to training and a public equestrian performance. In K. Krueger (Ed.), Proceedings of the 2. International Equine Science Meeting (Vol. in press). Wald: Xenophon Publishing.
Abstract: While detailed information exists on the cardiovascular response of horses to racing or endurance, much less is known about cardiovascular function of the rider in equestrian sports. Combined analysis of the horse-rider-team has not been investigated so far. In this study, we have analyzed changes in heart rate and heart variability (HRV) variables SDRR (standard deviation of beat-to-beat interval) and RMSSD (root mean square of successive beat-to-beat intervals) both in well-trained horses (n=9) and their highly experienced riders (n=7) during the airs above the ground (sauteurs en liberté of the Cadre noir de Saumur) at a public performance and at an identical, but non-public training session, both lasting for exactly 7 min. Heart rate in the horses and riders increased during the airs above the ground, both in training and in the public performance (p<0.001 over time). In the horses, this increase did not differ between training and public performance (training: from 35±6 in the stable to 97±17 beats/min during riding, performance: from 43±13 to 103±13 beats/min, respectively). In contrast, in the riders, the increase in heart rate was significantly more pronounced (p<0.01) during the public performance (basal value 91±10, maximum 150±15 beats/min) than during training (basal value 94±10, maximum 118±12 beats/min). With regard to HRV in horses, overall SDRR did not change significantly over time and did not differ significantly between training and performance. RMSSD decreased during both training and performance to the same extent, indicating a decrease in parasympathetic (vagal) tone. In the riders, both HRV variables decreased significantly during riding (p<0.001) and for SDRR the decrease was more pronounced (p<0.05) during an equestrian performance compared to a training session. During the performance SDRR decreased from a basal value of 5.0±1.5 to a minimum of 3.2±0.6 msec while respective values for the training session were 5.3±1.1 and 2.3±1.1 msec. Both a public performance and an identical training session of the airs above the ground in the ridden horse caused an increase in heart rate and a decrease in HRV variables. While increases in heart rate are mainly caused by physical activity, decreases in HRV also indicate a stress response. The cardiovascular response in the horses did not differ between a training session and a public performance but clear differences could be demonstrated in the riders. During a public performance, the increase in heart rate and decrease in SDRR were more pronounced than during a similar training session. In conclusion, the presence of an audience thus causes more pronounced sympathoadrenal activity in experienced riders than the same equestrian tasks ridden without spectators present. In contrast, the presence of an audience was without effect on sympathoadrenal activity in experienced horses. KW -
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