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Templeton, J. J. (1998). Learning from others' mistakes: a paradox revisited. Anim. Behav., 55(1), 79–85.
Abstract: Some researchers have reported the paradoxical finding of enhanced social learning when naive observers learn from unskilled rather than skilled demonstrators, particularly in discrimination tasks. In two experiments with starlings,Sturnus vulgaris, I considered whether this enhanced learning is because the observer (1) sees incorrect responses only, (2) sees both correct and incorrect responses or (3) sees an increase in the proportion of correct responses over trials. In experiment 1, individual starlings observed a demonstrator bird perform multiple simultaneous discrimination tasks. In one group, the demonstrator always picked the correct stimulus; in another group, the demonstrator always picked the incorrect stimulus; in a third group, the demonstrator consistently picked the correct stimulus 50% of the time. Those subjects that observed only incorrect choices performed significantly better than the other two groups, but none of the birds achieved the 90% correct performance criterion. Experiment 2 involved a single discrimination task; thus, a fourth group was added to control for individual learning. Again, subjects that observed only incorrect responses learned the discrimination significantly more quickly than the other three groups. Subjects that observed the demonstrator make both correct and incorrect responses were equally likely to select the same (correct) or opposite (incorrect) stimulus when the demonstrator picked the correct stimulus. When the demonstrator picked the incorrect stimulus, however, these subjects were significantly more likely to pick the opposite (correct) stimulus. These findings suggest that when learning a discrimination problem, observing a foraging companion's lack of success is more informative than observing its success.
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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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Templeton, J. J., & Giraldeau, L. - A. (1995). Public information cues affect the scrounging decisions of starlings.49(6), 1617–1626.
Abstract: The foraging decisions that individuals make within groups should depend on the information available to them. An aviary experiment was conducted to examine whether a starling's, Sturnus vulgaris, decisions either to approach and feed from (scrounge) or to avoid the patches exploited by a partner bird are influenced by the information the partner provides. Both the type of information a subject could recognize and the point at which this information became available during the partner's exploitation of a patch were manipulaed. Information concerning the quality of a patch was available in the form of a concealed colour cue and from the behaviour of the partner bird. The foraging environment was manipulated such that colour cues were either present or absent, and provided either correct or incorrect information concerning the presence of food. When cues corresponded with past foraging experience, test subjects responded selectively and profitably to the patch exploitations of the partner; they scrounged from a higher proportion of profitable patches than control birds, which lacked the ability to recognize colour cues. Test subjects also arrived more quickly at profitable patches that the partner bird discovered than did control birds; and consequently, were able to obtain more food at each food patch scrounged. Finally, test subjects avoided scrounging when the partner discovered empty patches and thus saved foraging time. Responding selectively to public information, therefore, allows an individual to compete more effectively for resources within a foraging group.
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