INDUCTION AND DEVELOPMENT OF A FILIAL PREDISPOSITION IN THE CHICK

Filial preferences in young domestic chicks, Gallus gallus domesticus, are influenced by at least two systems: one involved in learning abou t stimuli to which the animals are exposed, and the other a predisposi tion to approach stimuli resembling conspecifics. The predisposition i s manifest in dark-reared chicks as an emerging preference for a rotat ing, stuffed jungle fowl over a rotating red box. In previous studies, 24 h-old visually naive chicks were placed in running wheels for 2 h. Throughout this time the chicks were in darkness. A significant prefe rence for the stuffed fowl was found 24 h, but not 2 h later. In the p resent study it was shown that the predisposition becomes manifest at 10 h (Experiment 1a) and 5 h (Experiment 1b) after either placement in running wheels, or after the chicks had been trained by exposure to a rotating red box. In Experiment 2 it was shown that placement in runn ing wheels was not necessary for the predisposition to emerge. However , handling the birds was sufficient for the induction of a significant preference, expressed 5 h later. Exposure to a maternal call for 2 h (Experiment 3) was also sufficient to induce the development of the vi sual predisposition 24 h later. These results show that a visual predi sposition to approach certain stimuli becomes manifest in dark-reared chicks between 2 and 5 h after the experience of handling, and that ex posure to a maternal call is also sufficient to induce this predisposi tion.