ABSTRACT
The song of the white-crowned sparrow consists of an initial whistle followed by a more individual complex trill. The whistle is highly stereotyped, but the trill represents a locality dialect which is learned by the bird. There are two main types of phase-specific learning that have been studied. These are imprinting and avian song learning. Both types of learning share three important characteristics: the existence of rather distinct sensitive phases when the learning will occur; a comparatively high degree of durability and stability over time; and a degree of selectivity about the kinds of stimuli which are most effective in determining durable preferences. The young of certain precocial birds would, on emerging from the egg, learn to approach and follow the nearest moving object. Any theoretical account of the learning process that underlies song acquisition must take into account a number of salient facts.
