Development of species identification in ducklings: IV. Change in species-specific perception caused by auditory deprivation.

Abstract

The change in species-specific perception that underlies the aurally deprived ducklings'' lack of preference or discrimination in the mallard [Anas platyrhynchos] vs. chicken call test. Among other acoustic differences, the mallard and chicken maternal calls differ in repetion rate (3.7 and 2.3 notes/s, respectively). The dimension of repetition rate was uppermost in the perceptual hierarchy underlying the auditory aspect of species identification in Peking ducklings. The relatively narrow species-typical repetition-rate preferences of normal Peking ducklings (about 4-6 notes/s) is lacking in the aurally deprived ducklings, and they respond to lower rates than usual (2.3 notes/s). This broadening of the range of responsiveness on a perceptual dimension (repetition rate) that is basic to species identification accounts for the devocal ducklings'' lack of discrimination in the mallard vs. chicken call test.