ABSTRACT
The newly hatched young of a number of precocial bird species rapidly form a social preference for a conspicuous object to which they are exposed. In the natural situation the preference is formed for the mother; but in the laboratory the young animals can develop a preference for a wide range of inanimate mother surrogates. In domestic chicks, Gallus gallus domesticus, this process involves the development of at least two different perceptual mechanisms. The first of these mechanisms is involved in learning about stimuli to which the animals are exposed, a process known as filial imprinting. The mechanisms underlying this learning process are compared with those of conventional associative learning paradigms. The second perceptual mechanism involves a predisposition to approach stimuli resembling conspecifics. The predisposition emerges in dark-reared chicks given some non-specific experience during a sensitive period, and is expressed as a relatively general preference for stimuli with a head and neck region. During the development of fililal preferences the two perceptual mechanisms appear to interact at the behavioral level; the predisposition does not constrain the range of stimuli for imprinting. In the natural situation, the animal’s response may be biased by the predisposition, and through the learning process it then comes to prefer individuals.
