Examination of the role of auditory stimulation in the imprinting process of a role-nesting species indicated that the Wood duck hen begins to vocalize in the nest 20-36 hr. prior to the exodus of her young. Rate and intensity of her call increase as time of exodus approaches. Ducklings instantaneously begin their departure from the nest when the hen calls from outside (below). The lond period of exposure to the call of the hen prior to exodus allows the ducklings to become aurally imprinted while they are still in the nest. Thus, it becomes unnecessary to account for the ducklings' response by postulating an "innate perceptual mechanism." (PsycINFO Database Record (c) 2006 APA, all rights reserved)