Simulated maternal care facilitates the formation of filial imprinting in domestic chicks

The potential effects of maternal care-related stimuli on imprinting in domestic chicks were examined. In the first phase, one group of chicks received a simulated brooding experience with a primary imprinting object during two training sessions, whereas chicks in another group received exposure to the object without being brooded. In subsequent testing, the brooded chicks showed a robust preference for the primary imprinting object, whereas the non-brooded chicks showed a weaker preference for the object. In the second phase, one group of chicks was exposed to a secondary imprinting object associated with a feeding opportunity, whereas another group received exposure to the object in the absence of such an experience. In subsequent testing, the fed chicks showed a strong preference for the secondary imprinting object, whereas the non-fed chicks showed no preference. These results suggest that stimuli experienced through usual maternal care may be an important factor in filial imprinting.