"Imprinting" in nature.
Much laboratory research is based on the assumption that the learning of parental characteristics by young nidifugous birds is rooted on visual factors. Naturalistic observations of ground- and hole-nesting duck species, augmented by sound amplification equipment, indicate that hatchlings are exposed to the call of their mother for a relatively long period before they are exposed to the sight of her.
D000818:Animals; D001717:Birds; D004372:Ducks; D007858:Learning
BIRDS; LEARNING