Development of Species Identification in Birds: An Inquiry into the Prenatal Determinants of Perception

This pioneering behavioral study confronts the question of how young ducklings and chicks come to identify their own species during the course of prenatal and postnatal development. In a series of laboratory experiments conducted over seven years, Gilbert Gottlieb has devoted himself both to an intensive investigation of the key elements necessary to evoke a sensory discrimination response in various species of ducklings and in chicks, working backward through embryology to the prenatal environment, and to an original interpretation of the macroscopic aspects of the development of species perception. The laboratory experiments in this book indicate that the maternal call of the parent is an essential compnent of the perceptal complex that directs a young bird's behavior to a hen of its own species. "The fascinating thing about this species-specific auditory perception," writes Gottlieb, "is that the hatchlings are capable of making without the benefit of prior exposure to the maternal call, and in this sense, the response is an instinctive one. Even more fascinating is the fact that embryos are capable of responding selectively to the maternal call of their own species five days before hatching." The author goes on to analyze the factors that contribute to the embryo's and the hatchling's ability to make this selective response. This is the first time that the embryonic roots of species-species perception have been analyzed in any animal, and the results indicate that normally occuring embryonic and postnatal sensory stimulation play an essential role in bringing the young bird's instinctive perceptual capabilities to perfection. Gottlieb's careful study is a fundamental contribution to the investigation of the ontogeny of instinctive behavior and to the developmental conception of behavioral studies.