Development of species identification in ducklings: VIII. Embryonic versus postnatal critical period for the maintenance of species-typical perception.
It was previously demonstrated that the domestic mallard duck embryo must be exposed to its embryonic contact-contentment call at a repetition rate of four notes per second in order for the neonate to manifest the species-typical preference for the species maternal call at its normal rate (3.7 notes/sec) after hatching. The present study examined whether the exposure to the contact call must occur in the late embryonic period in order to be effective. It was found that exposure for as little as 5 min/hr for 24 hr was sufficient for normal perceptual development and that such stimulation could occur either before or after hatching, provided that a 48-hr "consolidation" period intervened between the end of stimulation and testing.
Within a western tradition of music education research there is an expectation that a research project will have focussed aims, regardless of the research paradigm from which it emanates. This paper discusses the dilemma of a researcher when confronted with a disparity between her carefully formulated research aims and the needs of the communities within which her research project was implemented. These issues are discussed in relation to the initial stages of a research project which is investigating the music, movement and language characteristics, cross-cultural transmission and effects of the media on the musical play of Aboriginal and non-Aboriginal children in two small towns in central Australia.