Social Interactions in Discrimination Learning With Special Reference To Feeding Behavior in Birds

Abstract

A full understanding of the ontogeny of species-specific food preference requires a knowledge of the effects of social interactions on discrimination learning. In this study, learning rates and processes were compared in paired and single birds. The term empathic behaviour has been proposed to cover all forms of motor mimicry. Processes involved may include conditioning, social facilitation, local enhancement or visual imitation, though these distinctions are not fundamental. There is evidence supporting the operation of all these in avian behaviour, except the last. Greenfinches (Chloris chloris) were trained to feed from one of two patterns and to avoid the other, with whole and aspirin-filled sunflower seeds serving as positive and negative reinforcement. Single birds learned the discrimination rapidly, as did birds which had been allowed to observe a previously trained bird performing. Birds which were being trained in the presence of an untrained partner, however, required much longer. When birds of this last group were permitted to observe the training sequence of their untrained partners, their performances, which had previously been correct, repeatedly fluctuated to a random or nondiscriminatory level. The partners, in turn, then also began to fluctuate between random and non-random levels. Behavioral data preclude the operation of local enhancement or social facilitation. Thus, the results are interpreted to mean that, under the conditions that prevailed, a feeding response can be established more readily than an avoidance response, apparently as the result of conditioning (the unconditioned stimulus being the sight of another bird feeding). The suggestion is made that birds which show this type of learning pattern in nature will prove to be conservative in their feeding habits when compared with opportunistic species whose learned avoidance responses should be more stable.