Beerda, B., Schilder, M. B. H., Janssen, N. S. C. R. M., & Mol, J. A. (1996). The Use of Saliva Cortisol, Urinary Cortisol, and Catecholamine Measurements for a Noninvasive Assessment of Stress Responses in Dogs. Horm. Behav., 30(3), 272–279.
Abstract: A problem in assessing animal welfare is that collecting data in itself may be stressful to the animals. Therefore, noninvasive methods for collecting data have to be devised and tested. A first step in investigating saliva cortisol, urinary cortisol, and urinary catecholamine as noninvasive indicators of canine well-being is the validation of these hormonal measures as alternatives for those in plasma. Using a model of insulin (0.2 U/kg)-induced hypoglycemia, we report on stress-induced responses in saliva cortisol, urinary cortisol, and urinary catacholamines relative to cortisol and catecholamine responses in plasma. Hypoglycemia in six dogs induced significant (P< 0.05) increases in plasma cortisol and adrenaline but not noradrenaline. Saliva cortisol responses expressed as net area under the response curve correlated significantly with plasma cortisol responses (r> 0.92). Saliva cortisol levels measured 7 to 12% of plasma cortisol concentrations. Cortisol/creatinine ratios in urine were significantly higher when voided after insulin administeration, compared to when voided after saline treatment. Insulin-induced increments in cortisol/creatinine ratios were nonsignificant when urine samples were assayed after dichloromethane extraction. Although urinary adrenaline/creatinine (A/C) ratios were significantly correlated with maximum plasma adrenaline values after insulin administration, A/C ratios did not differ significantly between insulin and saline treatment. The present experiment provides strong support for using saliva sampling and urine collection as noninvasive methods to establish stress-induced cortisol responses. For measuring acute plasma adrenaline responses, measuring A/C ratios may not be a valid alternative.
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Dugatkin, L. A. (1996). Tit for Tat, by-product mutualism and predator inspection: a reply to Connor. Anim. Behav., 51(2), 455–457.
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Zentall TR, Sutton JE, & Sherburne LM. (1996). True imitative learning in pigeons. Psychol. Sci., 7, 343.
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Zentall, T. R., Sutton, J. E., & Sherburne, L. M. (1996). True imitative learning in pigeons. Psychol Sci, 7.
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Zentall, T. R., Sherburne, L. M., Roper, K. L., & Kraemer, P. J. (1996). Value transfer in a simultaneous discrimination appears to result from within-event pavlovian conditioning. J Exp Psychol Anim Behav Process, 22(1), 68–75.
Abstract: When pigeons acquire a simple simultaneous discrimination, some of the value acquired by the S+ transfers to the S-. The mechanism underlying this transfer of value was examined in three experiments. In Experiment 1, pigeons trained on two simultaneous discriminations (A + B- and C +/- D-) showed a preference for B over D. This preference was reduced, however, following the devaluation of A. In Experiment 2, when after the same original training, value was given to D, the pigeons' preference for C did not significantly increase. In Experiment 3, when both discriminations involved partial reinforcement (S +/-), A + C- training resulted in a preference for B over D, whereas B + D- training resulted in a preference for A over C. Thus, simultaneous discrimination training appears to result in bidirectional within-event conditioning involving the S+ and S-.
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Templeton, J. J., & Giraldeau, L. - A. (1996). Vicarious sampling: the use of personal and public information by starlings foraging in a simple patchy environment. Behav. Ecol. Sociobiol., 38(2), 105–114.
Abstract: Group foragers may be able to assess patch quality more efficiently by paying attention to the sampling activities of conspecifics foraging in the same patch. In a previous field experiment, we showed that starlings foraging on patches of hidden food could use the successful foraging activities of others to help them assess patch quality. In order to determine whether a starling could also use another individual's lack of foraging success to assess and depart from empty patches more quickly, we carried out two experimental studies which compared the behaviour of captive starlings sampling artificial patches both when alone and when in pairs. Solitary starlings were first trained to assess patch quality in our experimental two-patch system, and were then tested on an empty patch both alone and with two types of partner bird. One partner sampled very few holes and thus provided a low amount of public information; the other sampled numerous holes and thus provided a high amount of public information. In experiment 1, we found no evidence of vicarious sampling. Subjects sampled a similar number of empty holes when alone as when with the low and high information partners; thus they continued to rely on their own personal information to make their patch departure decisions. In experiment 2, we modified the experimental patches, increasing the ease with which a bird could watch another's sampling activities, and increasing the difficulty of acquiring accurate personal sampling information. This time, subjects apparently did use public information, sampling fewer empty holes before departure when with the high-information partner than when with the low-information partner, and sampling fewer holes when with the low-information partner than when alone. We suggest that the degree to which personal and public information are used is likely to depend both on a forager's ability to remember where it has already sampled and on the type of environment in which foraging takes place.
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Povinelli, D. J., & Eddy T. J. (1996). What Young Chimpanzees Know about Seeing. Chicago: University of Chicago Press.
Abstract: Synopsis
Does a young chimpanzee's gaze subjectively link it to the outside world? Is seeing “about” something to this species? This volume reports the results of fifteen studies conducted with chimpanzees and preschool children. The findings provide little evidence that young chimpanzees understand seeing as a mental event. Even though young chimps spontaneously attend to and follow the visual gaze of others, they simultaneously appear oblivious to the attentional significance of that gaze. This interpretation is consistent with three different possibilities: chimpanzees may experience a delay in psychological development; alternatively, they may possess a different theory of attention, connected subjectively through other behavioral indicators; or the subjective understanding of visual perception may only be present in humans.
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Boyd, R., & Richerson, P. J. (1996). Why Culture is Common, but Cultural Evolution is Rare. Proc Br Acad, 88, 73–93.
Abstract: If culture is defined as variation acquired and maintained by social learning, then culture is common in nature. However, cumulative cultural evolution resulting in behaviors that no individual could invent on their own is limited to humans, song birds, and perhaps chimpanzees. Circumstantial evidence suggests that cumulative cultural evolution requires the capacity for observational learning. Here, we analyze two models the evolution of psychological capacities that allow cumulative cultural evolution. Both models suggest that the conditions which allow the evolution of such capacities when rare are much more stringent than the conditions which allow the maintenance of the capacities when common. This result follows from the fact that the assumed benefit of the capacities, cumulative cultural adaptation, cannot occur when the capacities are rare. These results suggest why such capacities may be rare in nature.
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Puppe, B. (1996). [Social dominance and rank relationships in domestic pigs: a critical review]. Berl Munch Tierarztl Wochenschr, 109(11-12), 457–464.
Abstract: Viewing dominance as an attribute of repeated agonistic interactions between two individuals, the present paper reviews theoretical approaches towards concepts of dominance, methods of measurement, and basic principles and problems connected with social dominance in domestic pigs. Domestic pigs are able to establish social organization structures during all stages of their ontogeny. According to definition, dominance relationships occur when a consistent asymmetry of the result of dyadic agonistic interactions can be assessed. This must not necessarily be connected immediately with a better availability of resources, or a high stability of existing dominance relationships, or a functional definition of dominance. When sociometric characteristics are calculated, it seems to be appropriate to use them for different levels of a biological system (individual, individual pair, group). Investigations of social behaviour and dominance in farm animals should take into account that mechanisms of social behaviour in confined environments are often carried out in parts only. Connections of the dominance concept with other concepts of behavioural regulation should be theoretically considered and further investigated by experimental studies.
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Kraak, S. B. M. (1996). `Copying mate choice': Which phenomena deserve this term? Behav. Process., 36(1), 99–102.
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