Reproductive behaviour of female white-crowned sparrows: effect of dialects and synthetic hybrid songs

• Published in: Animal behaviour Vol. 35; no. 6; pp. 1766 - 1774
• Main Authors: Baker, Myron Charles, Spitler-Nabors, Kimberly J., Thompson, Andrew D., Cunningham, Michael A.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 1987
• Subjects: Zonotrichia leucophrys nuttalli
• ISSN: 0003-3472; 1095-8282
• DOI: 10.1016/S0003-3472(87)80069-6

Previous laboratory studies showed that female white-crowned sparrows, Zonotrichia leucophrys nuttalli, performed more copulation solicitation displays when stimulated with male songs characteristic of their own local area than when stimulated by songs from other geographical locations. This female bioassay of male song was used in the present study to identify the relative contributions of different song components to the discrimination made by female subjects. In experiment 1, females responded with more solicitation displays when stimulated by a song dialect that was characteristic of their natal experience or of their breeding experience than when stimulated by a song dialect that was characteristic of a neighbouring population. In experiments 2 and 3, ‘hybrid’ songs were created which were synthesized from the two stimuli used in experiment 1. The females responded differentially to several of the hybrid songs. Replacing syllables of the ‘local’ dialect control song with those of a neighbouring population which sang a different dialect indicated two general kinds of results: (1) it was necessary to replace about half of the local song with alien song components to obtain a significant reduction in female display; (2) some regions of the song were more important than others in controlling female sexual response. The results have implications for the functional descriptions of song ‘dialects’ and for the more general proposition that different kinds of information are encoded in different parts of the songs of songbirds.