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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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Judge, P. G., & De Waa, l F. B. M. (1997). Rhesus monkey behaviour under diverse population densities: coping with long-term crowding. Anim. Behav., 54(3), 643–662.
Abstract: A popular view is that high population density promotes behavioural pathology, particularly increased aggression. In contrast, according to a coping model, some primates have behavioural mechanisms (e.g. formal displays, reconciliation and grooming) that regulate social tensions and control the negative consequences of crowding. Seven captive rhesus monkey groups, Macaca mulattawere observed over a wide range of population densities where high-density groups were over 2000 times more crowded than low-density free-ranging groups. As density increased, male rhesus monkeys increased grooming and huddling but did not increase rates of aggression. Females increased all categories of behaviour examined (heavy aggression, mild aggression, formal bared-teeth displays, grooming and huddling), but the increases were not distributed uniformly to all classes of partners. Females increased only grooming, huddling and appeasement displays to males, increased only aggression and huddling with kin and increased all categories of behaviour to non-kin adult females. There were no differences in the percentage of aggressive conflicts reconciled across density conditions. Increased density had different effects on particular relationships. Relationships between females and males were characterized by a coping pattern in which animals modified their behaviour in ways that may decrease aggression under crowded conditions. Female relationships with kin and non-kin were characterized by increases in both aggression and friendly interactions as density increased. The different patterns of response to higher density may reflect different strategies depending on the strength and stability of relationships and the potential consequences if certain relationships are disrupted.1997The Association for the Study of Animal Behaviour
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Pennisi, E. (1997). Schizophrenia clues from monkeys (Vol. 277).
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Anderson JR, & Gallup GG. (1997). Self-recognition in Saguinus? A critical essay. Anim. Behav., 54, 1563.
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Bergstrom, C. T., & Lachmann, M. (1997). Signalling among relatives. I. Is costly signalling too costly? Proc. Natl. Acad. Sci. U.S.A., 352(1353), 609–617.
Abstract: ahavi's handicap principle,originally proposed as an explanation for sexual selection ofelaborate male traits, suggests that a sufficient cost to dishonest signals can outweigh the rewards of deception and allow individuals to communicate honestly. Maynard Smith (1991) and Johnstone and Grafen (1992) introduce the Sir Philip Sidney game in order to extend the handicap principle to interactions among related individuals, and to demonstrate that stable costly signalling systems can exist among relatives.
In this paper we demonstrate that despite the benefits associated with honest information transfer, the costs incurred in a stable costly signalling system may leave all participants worse off than they would be in a system with no signalling at all. In both the discrete and continuous forms of the Sir Philip Sidney game, there exist conditions under which costly signalling among relatives, while stable, is so costly that it is disadvantageous compared with no signalling at all. We determine the factors which dictate signal cost and signal benefit in a generalized version of this game, and explain how signal cost can exceed signal value. Such results raise concerns about theevolutionary pathways which could have led to the existence of signalling equilibria in nature. The paper stresses the importance of comparing signalling equilibria with other possible strategies, beforedrawing conclusions regarding the optimality of signalling.
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Russell, C. L., Bard, K. A., & Adamson, L. B. (1997). Social referencing by young chimpanzees (Pan troglodytes). J. Comp. Psychol., 111(2), 185–191.
Abstract: Social referencing is the seeking of information from another individual and the use of that information to evaluate a situation. It is a well-documented ability in human infants but has not been studied experimentally in nonhuman primates. Seventeen young nursery-reared chimpanzees (14 to 41 months old) were observed in a standard social referencing paradigm in which they received happy and fear messages concerning novel objects from a familiar human caregiver. Each chimpanzee looked referentially at their caregiver, and the emotional messages that they received differentially influenced their gaze behavior and avoidance of the novel objects. It is concluded that chimpanzees can acquire information about their complex social and physical environments through social referencing and can use emotional information to alter their own behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)
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Le Scolan, N., Hausberger, M., & Wolff, A. (1997). Stability over situations in temperamental traits of horses as revealed by experimental and scoring approaches. Behav. Process., 41(3), 257–266.
Abstract: Individual behavioural reactions of adult horses in a variety of experimental tests were compared with ratings by riding teachers. The tests were made in a non working situation, with the animals being released in an arena, a box (arena test, new object test, learning tests) or handled (new object/handling situation). The traits rated by teachers were fearfulness, nervousness, gregariousness and learning abilities at work (ridden or handled). Despite a great homogeneity in the reactions exhibited by the horses in the different situations, large individual differences were present. Correlations appeared between the reactivity in the arena test and the score of gregariousness, between the reactivity in the novel object test and the rating of nervousness when ridden, between the results in the handling test and the rating of general fearfulness and between the ability to memorise an instrumental task and the score of general learning ability. Such results strengthen the idea that there are underlying behavioural dispositions that are stable across situations and that the experimental tests may be good predictors of the temperament in untrained animals.
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Bateson, M., & Kacelnik, A. (1997). Starlings' preferences for predictable and unpredictable delays to food. Anim. Behav., 53(6), 1129–1142.
Abstract: Risk-sensitive foraging theory is based on the premise that unpredictable runs of good or bad luck can cause a variable food source to differ in fitness value from a fixed food source yielding the same average rate of gain but no unpredictability. Thus, risk-sensitive predictions are dependent on the food intake from variable sources being not only variable but also unpredictable or `risky' in outcome. This study tested whether unpredictability is a component of the value that foraging starlings,Sturnus vulgarisattribute to food sources that are variable in the delay to obtain food. Two groups of birds chose between a fixed and a variable delay option; the variable option was unpredictable in the risky group and predictable in the risk-free group in the overall rate of intake it yielded. In both groups the fixed option was adjusted by titration to quantify the magnitude of preference for predictable and unpredictable variance. On negative energy budgets both groups were significantly risk-prone, with the risky group being significantly more risk-prone than the risk-free group. Switching the birds to positive budgets by doubling the size of each food reward had no significant effect on preference, and similar trends to those found with negative budgets were observed. These results are not readily explained by risk-sensitive foraging theory, but may be explained by the algorithm used by the birds to attribute value to average expected rewards.
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Gibson, K. T., Burbidge, H. M., & Anderson, B. H. (1997). Tendonitis of the branches of insertion of the superficial digital flexor tendon in horses. Aust Vet J, 75(4), 253–256.
Abstract: OBJECTIVE: To describe clinical findings, ultrasonographic features and outcome of injury to the branches of insertion of the superficial digital flexor (SDF) tendon in horses. DESIGN: Retrospective study of 14 cases. PROCEDURE: Fourteen Thoroughbred horses with tendonitis affecting the branches of insertion of the SDF tendon were examined for lameness, location and amount of swelling, and the presence of other musculoskeletal abnormalities. The flexor tendons were assessed by ultrasonographic examination, and recommendations were made for management of the cases. Outcome was assessed by re-examination of some horses, direct communication with the owner or trainer, and examination of race records. RESULTS: The lateral SDF branch was affected in 10 horses; the medial branch in three, and both branches in one horse. Two horses had concurrent injuries to the SDF tendon in the metacarpal region of the contralateral limb. Ultrasonographic findings included swelling of the affected SDF branch, peritendinous fluid accumulation, disruption of normal fibre alignment on sagittal scan, and variable loss of echogenicity. As healing occurred, there was return of normal echogenicity, but normal fibre alignment did not return completely and apparent adhesions formed between the affected SDF branch and adjacent structures. Seven of 10 horses which returned to their previous use were able to compete without further tendon injury. Recurrence of injury occurred in one case, and another two horses developed tendonitis in the metacarpal region. One horse was retired from racing but was able to compete at dressage without recurrence of injury. Two horses were retired for breeding without returning to training, and one horse was sold and lost to follow up but did not race. CONCLUSION: The prognosis is fair for return to previous use following injury to the branches of insertion of the SDF tendon in athletic horses.
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Owren, M. J., Seyfarth, R. M., & Cheney, D. L. (1997). The acoustic features of vowel-like grunt calls in chacma baboons (Papio cyncephalus ursinus): implications for production processes and functions. J Acoust Soc Am, 101(5 Pt 1), 2951–2963.
Abstract: The acoustic features of 216 baboon grunts were investigated through analysis of field-recorded calls produced by identified females in known contexts. Analyses addressed two distinct questions: whether the acoustic features of these tonal sounds could be characterized using a source-filter approach and whether the acoustic features of grunts varied by individual caller and social context. Converging evidence indicated that grunts were produced through a combination of periodic laryngeal vibration and a stable vocal tract filter. Their acoustic properties closely resembled those of prototypical human vowel sounds. In general, variation in the acoustic features of the grunts was more strongly related to caller identity than to the social contexts of calling. However, two acoustic parameters, second formant frequency and overall spectral tilt, did vary consistently depending on whether the caller was interacting with an infant or participating in a group move. Nonetheless, in accordance with the general view that identity cueing is a compelling function in animal communication, it can be concluded that much of the observed variability in grunt acoustics is likely to be related to this aspect of signaling. Further, cues related to vocal tract filtering appear particularly likely to play an important role in identifying individual calling animals.
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